kexec: split kexec_load syscall from kexec core code
authorDave Young <dyoung@redhat.com>
Wed, 9 Sep 2015 22:38:55 +0000 (15:38 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 10 Sep 2015 20:29:01 +0000 (13:29 -0700)
There are two kexec load syscalls, kexec_load another and kexec_file_load.
 kexec_file_load has been splited as kernel/kexec_file.c.  In this patch I
split kexec_load syscall code to kernel/kexec.c.

And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.

The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled.  But kexec-tools use
kexec_load syscall can bypass the checking.

Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel.  KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.

Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig.  Also updated general kernel code with to
kexec_load syscall.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
32 files changed:
arch/Kconfig
arch/arm/Kconfig
arch/ia64/Kconfig
arch/m68k/Kconfig
arch/mips/Kconfig
arch/powerpc/Kconfig
arch/s390/Kconfig
arch/sh/Kconfig
arch/tile/Kconfig
arch/x86/Kconfig
arch/x86/boot/header.S
arch/x86/include/asm/kdebug.h
arch/x86/kernel/Makefile
arch/x86/kernel/kvmclock.c
arch/x86/kernel/reboot.c
arch/x86/kernel/setup.c
arch/x86/kernel/vmlinux.lds.S
arch/x86/kvm/vmx.c
arch/x86/platform/efi/efi.c
arch/x86/platform/uv/uv_nmi.c
drivers/firmware/efi/Kconfig
drivers/pci/pci-driver.c
include/linux/kexec.h
init/initramfs.c
kernel/Makefile
kernel/events/core.c
kernel/kexec.c
kernel/kexec_core.c [new file with mode: 0644]
kernel/ksysfs.c
kernel/printk/printk.c
kernel/reboot.c
kernel/sysctl.c

index 8f35649305804c913efe1501e486ddb465e12810..4e949e58b1928363232abac3a69a25413e90652e 100644 (file)
@@ -2,6 +2,9 @@
 # General architecture dependent options
 #
 
+config KEXEC_CORE
+       bool
+
 config OPROFILE
        tristate "OProfile system profiling"
        depends on PROFILING
index 0d1b717e1eca6754672294777f9d7f17b9f08364..72ad724c67ae94cd6682ec15f3834966dd7028c0 100644 (file)
@@ -2020,6 +2020,7 @@ config KEXEC
        bool "Kexec system call (EXPERIMENTAL)"
        depends on (!SMP || PM_SLEEP_SMP)
        depends on !CPU_V7M
+       select KEXEC_CORE
        help
          kexec is a system call that implements the ability to shutdown your
          current kernel, and to start another kernel.  It is like a reboot
index 42a91a7aa2b08fa3a9ba4f1de06e07fdb47bfa9d..eb0249e3798112615fd5774d6f30229aa6241e53 100644 (file)
@@ -518,6 +518,7 @@ source "drivers/sn/Kconfig"
 config KEXEC
        bool "kexec system call"
        depends on !IA64_HP_SIM && (!SMP || HOTPLUG_CPU)
+       select KEXEC_CORE
        help
          kexec is a system call that implements the ability to shutdown your
          current kernel, and to start another kernel.  It is like a reboot
index 2dd8f63bfbbb7850e7e797eb108f708eb1fc6d54..498b567f007b0a80d1905dc21e8fb503101b3724 100644 (file)
@@ -95,6 +95,7 @@ config MMU_SUN3
 config KEXEC
        bool "kexec system call"
        depends on M68KCLASSIC
+       select KEXEC_CORE
        help
          kexec is a system call that implements the ability to shutdown your
          current kernel, and to start another kernel.  It is like a reboot
index 752acca8de1fa9f6f73aaf1d218840c04cd1abc7..e3aa5b0b4ef17771fbd2afa1557f29ee6a7a2b3d 100644 (file)
@@ -2597,6 +2597,7 @@ source "kernel/Kconfig.preempt"
 
 config KEXEC
        bool "Kexec system call"
+       select KEXEC_CORE
        help
          kexec is a system call that implements the ability to shutdown your
          current kernel, and to start another kernel.  It is like a reboot
index b447918b9e2c8bd289372d5bcf69d0f3bb1f2aad..9a7057ec21541a09af3cedc4e49350852cba1791 100644 (file)
@@ -420,6 +420,7 @@ config PPC64_SUPPORTS_MEMORY_FAILURE
 config KEXEC
        bool "kexec system call"
        depends on (PPC_BOOK3S || FSL_BOOKE || (44x && !SMP))
+       select KEXEC_CORE
        help
          kexec is a system call that implements the ability to shutdown your
          current kernel, and to start another kernel.  It is like a reboot
index 4827870f7a6d8c00925b7d052ed68efda20f364e..1d57000b1b24ad6c6946f67ea821385e436391b6 100644 (file)
@@ -48,6 +48,7 @@ config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 
 config KEXEC
        def_bool y
+       select KEXEC_CORE
 
 config AUDIT_ARCH
        def_bool y
index 50057fed819ddf3c07a8e16841c65d63cbaa5168..d514df7e04dd4c866597bd0772bfdc6a7dc000f9 100644 (file)
@@ -602,6 +602,7 @@ source kernel/Kconfig.hz
 config KEXEC
        bool "kexec system call (EXPERIMENTAL)"
        depends on SUPERH32 && MMU
+       select KEXEC_CORE
        help
          kexec is a system call that implements the ability to shutdown your
          current kernel, and to start another kernel.  It is like a reboot
index 2ba12d7617234417c4bec81988ae64f688e34704..106c21bd7f449d947094db5fdefce8a9a6e1b142 100644 (file)
@@ -205,6 +205,7 @@ source "kernel/Kconfig.hz"
 
 config KEXEC
        bool "kexec system call"
+       select KEXEC_CORE
        ---help---
          kexec is a system call that implements the ability to shutdown your
          current kernel, and to start another kernel.  It is like a reboot
index cc0d73eac047920f6845767123554df9c8deee7f..7aef2d52daa0d8ea8b55a683a11eb2c2e204eaef 100644 (file)
@@ -1754,6 +1754,7 @@ source kernel/Kconfig.hz
 
 config KEXEC
        bool "kexec system call"
+       select KEXEC_CORE
        ---help---
          kexec is a system call that implements the ability to shutdown your
          current kernel, and to start another kernel.  It is like a reboot
@@ -1770,8 +1771,8 @@ config KEXEC
 
 config KEXEC_FILE
        bool "kexec file based system call"
+       select KEXEC_CORE
        select BUILD_BIN2C
-       depends on KEXEC
        depends on X86_64
        depends on CRYPTO=y
        depends on CRYPTO_SHA256=y
index 16ef02596db2daf1fa8eadd9c17fd994ec3c21b3..2d6b309c8e9a12ac67ddf9d9cb429cb1fe8a7eae 100644 (file)
@@ -414,7 +414,7 @@ xloadflags:
 # define XLF23 0
 #endif
 
-#if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC)
+#if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC_CORE)
 # define XLF4 XLF_EFI_KEXEC
 #else
 # define XLF4 0
index 32ce71375b212cd0fc8fa5d847d09c1d7aa5bc6b..b130d59406fb12ab3a75d5a2a8631b202be50ab3 100644 (file)
@@ -29,7 +29,7 @@ extern void show_trace(struct task_struct *t, struct pt_regs *regs,
 extern void __show_regs(struct pt_regs *regs, int all);
 extern unsigned long oops_begin(void);
 extern void oops_end(unsigned long, struct pt_regs *, int signr);
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 extern int in_crash_kexec;
 #else
 /* no crash dump is ever in progress if no crash kernel can be kexec'd */
index 9ffdf25e5b86843e94e29b3361a86f34349341c9..b1b78ffe01d060a38c93c3c7486393702edd4ffc 100644 (file)
@@ -71,8 +71,8 @@ obj-$(CONFIG_LIVEPATCH)               += livepatch.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
 obj-$(CONFIG_FTRACE_SYSCALLS)  += ftrace.o
 obj-$(CONFIG_X86_TSC)          += trace_clock.o
-obj-$(CONFIG_KEXEC)            += machine_kexec_$(BITS).o
-obj-$(CONFIG_KEXEC)            += relocate_kernel_$(BITS).o crash.o
+obj-$(CONFIG_KEXEC_CORE)       += machine_kexec_$(BITS).o
+obj-$(CONFIG_KEXEC_CORE)       += relocate_kernel_$(BITS).o crash.o
 obj-$(CONFIG_KEXEC_FILE)       += kexec-bzimage64.o
 obj-$(CONFIG_CRASH_DUMP)       += crash_dump_$(BITS).o
 obj-y                          += kprobes/
index 49487b4880616a225427c99d8eb7c498da36bae3..2c7aafa7070274420a909f4f804e964d2ddc473d 100644 (file)
@@ -200,7 +200,7 @@ static void kvm_setup_secondary_clock(void)
  * kind of shutdown from our side, we unregister the clock by writting anything
  * that does not have the 'enable' bit set in the msr
  */
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 static void kvm_crash_shutdown(struct pt_regs *regs)
 {
        native_write_msr(msr_kvm_system_time, 0, 0);
@@ -259,7 +259,7 @@ void __init kvmclock_init(void)
        x86_platform.save_sched_clock_state = kvm_save_sched_clock_state;
        x86_platform.restore_sched_clock_state = kvm_restore_sched_clock_state;
        machine_ops.shutdown  = kvm_shutdown;
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        machine_ops.crash_shutdown  = kvm_crash_shutdown;
 #endif
        kvm_get_preset_lpj();
index 86db4bcd7ce52bcb74a5bf42efcd8e7152488cf1..02693dd9a0790b804a515294714d59ed68688ba8 100644 (file)
@@ -673,7 +673,7 @@ struct machine_ops machine_ops = {
        .emergency_restart = native_machine_emergency_restart,
        .restart = native_machine_restart,
        .halt = native_machine_halt,
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        .crash_shutdown = native_machine_crash_shutdown,
 #endif
 };
@@ -703,7 +703,7 @@ void machine_halt(void)
        machine_ops.halt();
 }
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 void machine_crash_shutdown(struct pt_regs *regs)
 {
        machine_ops.crash_shutdown(regs);
index baadbf90a7c59f4aafc6faa8abb0409344fa5244..fdb7f2a2d3286013a7ea41d392e48596c90fc672 100644 (file)
@@ -478,7 +478,7 @@ static void __init memblock_x86_reserve_range_setup_data(void)
  * --------- Crashkernel reservation ------------------------------
  */
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 
 /*
  * Keep the crash kernel below this limit.  On 32 bits earlier kernels
index 00bf300fd8468db0e5bcd2fd9e32fc4f80e48adb..74e4bf11f562e0354c227518421e2375ec16fafa 100644 (file)
@@ -364,7 +364,7 @@ INIT_PER_CPU(irq_stack_union);
 
 #endif /* CONFIG_X86_32 */
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 #include <asm/kexec.h>
 
 . = ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE,
index 148ea20160222fa70a30ddb8c54a97f1cbcc8e32..d01986832afc28ed225b2f414ccb2742e528169c 100644 (file)
@@ -1264,7 +1264,7 @@ static void vmcs_load(struct vmcs *vmcs)
                       vmcs, phys_addr);
 }
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 /*
  * This bitmap is used to indicate whether the vmclear
  * operation is enabled on all cpus. All disabled by
@@ -1302,7 +1302,7 @@ static void crash_vmclear_local_loaded_vmcss(void)
 #else
 static inline void crash_enable_local_vmclear(int cpu) { }
 static inline void crash_disable_local_vmclear(int cpu) { }
-#endif /* CONFIG_KEXEC */
+#endif /* CONFIG_KEXEC_CORE */
 
 static void __loaded_vmcs_clear(void *arg)
 {
@@ -10411,7 +10411,7 @@ static int __init vmx_init(void)
        if (r)
                return r;
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        rcu_assign_pointer(crash_vmclear_loaded_vmcss,
                           crash_vmclear_local_loaded_vmcss);
 #endif
@@ -10421,7 +10421,7 @@ static int __init vmx_init(void)
 
 static void __exit vmx_exit(void)
 {
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        RCU_INIT_POINTER(crash_vmclear_loaded_vmcss, NULL);
        synchronize_rcu();
 #endif
index e4308fe6afe81e4d8be5a42a6cc682174761fe1f..1db84c0758b732b3465fcc896ef98862dabe0f16 100644 (file)
@@ -650,7 +650,7 @@ static void __init get_systab_virt_addr(efi_memory_desc_t *md)
 
 static void __init save_runtime_map(void)
 {
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        efi_memory_desc_t *md;
        void *tmp, *p, *q = NULL;
        int count = 0;
@@ -748,7 +748,7 @@ static void * __init efi_map_regions(int *count, int *pg_shift)
 
 static void __init kexec_enter_virtual_mode(void)
 {
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        efi_memory_desc_t *md;
        void *p;
 
index 020c101c255fec8386ba36c13c82ac8ddaf715b3..5c9f63fa6abf24ed575005d7ffb0c3118a728505 100644 (file)
@@ -492,7 +492,7 @@ static void uv_nmi_touch_watchdogs(void)
        touch_nmi_watchdog();
 }
 
-#if defined(CONFIG_KEXEC)
+#if defined(CONFIG_KEXEC_CORE)
 static atomic_t uv_nmi_kexec_failed;
 static void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs)
 {
@@ -519,13 +519,13 @@ static void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs)
        uv_nmi_sync_exit(0);
 }
 
-#else /* !CONFIG_KEXEC */
+#else /* !CONFIG_KEXEC_CORE */
 static inline void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs)
 {
        if (master)
                pr_err("UV: NMI kdump: KEXEC not supported in this kernel\n");
 }
-#endif /* !CONFIG_KEXEC */
+#endif /* !CONFIG_KEXEC_CORE */
 
 #ifdef CONFIG_KGDB
 #ifdef CONFIG_KGDB_KDB
index 54071c1483400d41e214c0f83512ca1f4600814a..84533e02fbf8ba292cddf960fde5881e1898821c 100644 (file)
@@ -43,7 +43,7 @@ config EFI_VARS_PSTORE_DEFAULT_DISABLE
 
 config EFI_RUNTIME_MAP
        bool "Export efi runtime maps to sysfs"
-       depends on X86 && EFI && KEXEC
+       depends on X86 && EFI && KEXEC_CORE
        default y
        help
          Export efi runtime memory maps to /sys/firmware/efi/runtime-map.
index 52a880ca1768362ec41399e8df11c3504a28a107..dd652f2ae03db964ed539c5d369092173ab9ab33 100644 (file)
@@ -467,7 +467,7 @@ static void pci_device_shutdown(struct device *dev)
        pci_msi_shutdown(pci_dev);
        pci_msix_shutdown(pci_dev);
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        /*
         * If this is a kexec reboot, turn off Bus Master bit on the
         * device to tell it to not continue to do DMA. Don't touch
index ab150ade0d1879d02e3a29a19f5139eca78d592a..d140b1e9faa71791264d6439bd8429810fff3ddd 100644 (file)
@@ -16,7 +16,7 @@
 
 #include <uapi/linux/kexec.h>
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 #include <linux/list.h>
 #include <linux/linkage.h>
 #include <linux/compat.h>
@@ -329,13 +329,13 @@ int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr,
 int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
                                        unsigned int relsec);
 
-#else /* !CONFIG_KEXEC */
+#else /* !CONFIG_KEXEC_CORE */
 struct pt_regs;
 struct task_struct;
 static inline void crash_kexec(struct pt_regs *regs) { }
 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
 #define kexec_in_progress false
-#endif /* CONFIG_KEXEC */
+#endif /* CONFIG_KEXEC_CORE */
 
 #endif /* !defined(__ASSEBMLY__) */
 
index ad1bd7787bbb0c3298e2f9790b0edd5322227639..b32ad7d97ac94f52a0c50acd2a904e8a0c2f888d 100644 (file)
@@ -526,14 +526,14 @@ extern unsigned long __initramfs_size;
 
 static void __init free_initrd(void)
 {
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
        unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
 #endif
        if (do_retain_initrd)
                goto skip;
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        /*
         * If the initrd region is overlapped with crashkernel reserved region,
         * free only memory that is not part of crashkernel region.
index 1b4890af5a659c616bae04757a21e6aeaecebe60..d4988410b410a6ae802b5d796b99e73d80393dc1 100644 (file)
@@ -49,6 +49,7 @@ obj-$(CONFIG_MODULES) += module.o
 obj-$(CONFIG_MODULE_SIG) += module_signing.o
 obj-$(CONFIG_KALLSYMS) += kallsyms.o
 obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
+obj-$(CONFIG_KEXEC_CORE) += kexec_core.o
 obj-$(CONFIG_KEXEC) += kexec.o
 obj-$(CONFIG_KEXEC_FILE) += kexec_file.o
 obj-$(CONFIG_BACKTRACE_SELF_TEST) += backtracetest.o
index e8183895691c61f021e9dc9a7e0aab5f6cc709fc..f548f69c4299dd1ee44bfdc1f84d79d655d0d6d7 100644 (file)
@@ -9094,7 +9094,7 @@ static void perf_event_init_cpu(int cpu)
        mutex_unlock(&swhash->hlist_mutex);
 }
 
-#if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC
+#if defined CONFIG_HOTPLUG_CPU || defined CONFIG_KEXEC_CORE
 static void __perf_event_exit_context(void *__info)
 {
        struct remove_event re = { .detach_group = true };
index 2d73ecfa550581ae86d7851d29dfe0d8dd44b313..4c5edc357923a1b6198c9f8122b90b73b9a5e38f 100644 (file)
 /*
- * kexec.c - kexec system call
+ * kexec.c - kexec_load system call
  * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
  *
  * This source code is licensed under the GNU General Public License,
  * Version 2.  See the file COPYING for more details.
  */
 
-#define pr_fmt(fmt)    "kexec: " fmt
-
 #include <linux/capability.h>
 #include <linux/mm.h>
 #include <linux/file.h>
-#include <linux/slab.h>
-#include <linux/fs.h>
 #include <linux/kexec.h>
 #include <linux/mutex.h>
 #include <linux/list.h>
-#include <linux/highmem.h>
 #include <linux/syscalls.h>
-#include <linux/reboot.h>
-#include <linux/ioport.h>
-#include <linux/hardirq.h>
-#include <linux/elf.h>
-#include <linux/elfcore.h>
-#include <linux/utsname.h>
-#include <linux/numa.h>
-#include <linux/suspend.h>
-#include <linux/device.h>
-#include <linux/freezer.h>
 #include <linux/vmalloc.h>
-#include <linux/pm.h>
-#include <linux/cpu.h>
-#include <linux/console.h>
-#include <linux/swap.h>
-#include <linux/syscore_ops.h>
-#include <linux/compiler.h>
-#include <linux/hugetlb.h>
-
-#include <asm/page.h>
-#include <asm/uaccess.h>
-#include <asm/io.h>
-#include <asm/sections.h>
+#include <linux/slab.h>
 
-#include <crypto/hash.h>
-#include <crypto/sha.h>
 #include "kexec_internal.h"
 
-DEFINE_MUTEX(kexec_mutex);
-
-/* Per cpu memory for storing cpu states in case of system crash. */
-note_buf_t __percpu *crash_notes;
-
-/* vmcoreinfo stuff */
-static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
-u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
-size_t vmcoreinfo_size;
-size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
-
-/* Flag to indicate we are going to kexec a new kernel */
-bool kexec_in_progress = false;
-
-
-/* Location of the reserved area for the crash kernel */
-struct resource crashk_res = {
-       .name  = "Crash kernel",
-       .start = 0,
-       .end   = 0,
-       .flags = IORESOURCE_BUSY | IORESOURCE_MEM
-};
-struct resource crashk_low_res = {
-       .name  = "Crash kernel",
-       .start = 0,
-       .end   = 0,
-       .flags = IORESOURCE_BUSY | IORESOURCE_MEM
-};
-
-int kexec_should_crash(struct task_struct *p)
-{
-       /*
-        * If crash_kexec_post_notifiers is enabled, don't run
-        * crash_kexec() here yet, which must be run after panic
-        * notifiers in panic().
-        */
-       if (crash_kexec_post_notifiers)
-               return 0;
-       /*
-        * There are 4 panic() calls in do_exit() path, each of which
-        * corresponds to each of these 4 conditions.
-        */
-       if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops)
-               return 1;
-       return 0;
-}
-
-/*
- * When kexec transitions to the new kernel there is a one-to-one
- * mapping between physical and virtual addresses.  On processors
- * where you can disable the MMU this is trivial, and easy.  For
- * others it is still a simple predictable page table to setup.
- *
- * In that environment kexec copies the new kernel to its final
- * resting place.  This means I can only support memory whose
- * physical address can fit in an unsigned long.  In particular
- * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled.
- * If the assembly stub has more restrictive requirements
- * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be
- * defined more restrictively in <asm/kexec.h>.
- *
- * The code for the transition from the current kernel to the
- * the new kernel is placed in the control_code_buffer, whose size
- * is given by KEXEC_CONTROL_PAGE_SIZE.  In the best case only a single
- * page of memory is necessary, but some architectures require more.
- * Because this memory must be identity mapped in the transition from
- * virtual to physical addresses it must live in the range
- * 0 - TASK_SIZE, as only the user space mappings are arbitrarily
- * modifiable.
- *
- * The assembly stub in the control code buffer is passed a linked list
- * of descriptor pages detailing the source pages of the new kernel,
- * and the destination addresses of those source pages.  As this data
- * structure is not used in the context of the current OS, it must
- * be self-contained.
- *
- * The code has been made to work with highmem pages and will use a
- * destination page in its final resting place (if it happens
- * to allocate it).  The end product of this is that most of the
- * physical address space, and most of RAM can be used.
- *
- * Future directions include:
- *  - allocating a page table with the control code buffer identity
- *    mapped, to simplify machine_kexec and make kexec_on_panic more
- *    reliable.
- */
-
-/*
- * KIMAGE_NO_DEST is an impossible destination address..., for
- * allocating pages whose destination address we do not care about.
- */
-#define KIMAGE_NO_DEST (-1UL)
-
-static struct page *kimage_alloc_page(struct kimage *image,
-                                      gfp_t gfp_mask,
-                                      unsigned long dest);
-
 static int copy_user_segment_list(struct kimage *image,
                                  unsigned long nr_segments,
                                  struct kexec_segment __user *segments)
@@ -160,123 +35,6 @@ static int copy_user_segment_list(struct kimage *image,
        return ret;
 }
 
-int sanity_check_segment_list(struct kimage *image)
-{
-       int result, i;
-       unsigned long nr_segments = image->nr_segments;
-
-       /*
-        * Verify we have good destination addresses.  The caller is
-        * responsible for making certain we don't attempt to load
-        * the new image into invalid or reserved areas of RAM.  This
-        * just verifies it is an address we can use.
-        *
-        * Since the kernel does everything in page size chunks ensure
-        * the destination addresses are page aligned.  Too many
-        * special cases crop of when we don't do this.  The most
-        * insidious is getting overlapping destination addresses
-        * simply because addresses are changed to page size
-        * granularity.
-        */
-       result = -EADDRNOTAVAIL;
-       for (i = 0; i < nr_segments; i++) {
-               unsigned long mstart, mend;
-
-               mstart = image->segment[i].mem;
-               mend   = mstart + image->segment[i].memsz;
-               if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK))
-                       return result;
-               if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)
-                       return result;
-       }
-
-       /* Verify our destination addresses do not overlap.
-        * If we alloed overlapping destination addresses
-        * through very weird things can happen with no
-        * easy explanation as one segment stops on another.
-        */
-       result = -EINVAL;
-       for (i = 0; i < nr_segments; i++) {
-               unsigned long mstart, mend;
-               unsigned long j;
-
-               mstart = image->segment[i].mem;
-               mend   = mstart + image->segment[i].memsz;
-               for (j = 0; j < i; j++) {
-                       unsigned long pstart, pend;
-                       pstart = image->segment[j].mem;
-                       pend   = pstart + image->segment[j].memsz;
-                       /* Do the segments overlap ? */
-                       if ((mend > pstart) && (mstart < pend))
-                               return result;
-               }
-       }
-
-       /* Ensure our buffer sizes are strictly less than
-        * our memory sizes.  This should always be the case,
-        * and it is easier to check up front than to be surprised
-        * later on.
-        */
-       result = -EINVAL;
-       for (i = 0; i < nr_segments; i++) {
-               if (image->segment[i].bufsz > image->segment[i].memsz)
-                       return result;
-       }
-
-       /*
-        * Verify we have good destination addresses.  Normally
-        * the caller is responsible for making certain we don't
-        * attempt to load the new image into invalid or reserved
-        * areas of RAM.  But crash kernels are preloaded into a
-        * reserved area of ram.  We must ensure the addresses
-        * are in the reserved area otherwise preloading the
-        * kernel could corrupt things.
-        */
-
-       if (image->type == KEXEC_TYPE_CRASH) {
-               result = -EADDRNOTAVAIL;
-               for (i = 0; i < nr_segments; i++) {
-                       unsigned long mstart, mend;
-
-                       mstart = image->segment[i].mem;
-                       mend = mstart + image->segment[i].memsz - 1;
-                       /* Ensure we are within the crash kernel limits */
-                       if ((mstart < crashk_res.start) ||
-                           (mend > crashk_res.end))
-                               return result;
-               }
-       }
-
-       return 0;
-}
-
-struct kimage *do_kimage_alloc_init(void)
-{
-       struct kimage *image;
-
-       /* Allocate a controlling structure */
-       image = kzalloc(sizeof(*image), GFP_KERNEL);
-       if (!image)
-               return NULL;
-
-       image->head = 0;
-       image->entry = &image->head;
-       image->last_entry = &image->head;
-       image->control_page = ~0; /* By default this does not apply */
-       image->type = KEXEC_TYPE_DEFAULT;
-
-       /* Initialize the list of control pages */
-       INIT_LIST_HEAD(&image->control_pages);
-
-       /* Initialize the list of destination pages */
-       INIT_LIST_HEAD(&image->dest_pages);
-
-       /* Initialize the list of unusable pages */
-       INIT_LIST_HEAD(&image->unusable_pages);
-
-       return image;
-}
-
 static int kimage_alloc_init(struct kimage **rimage, unsigned long entry,
                             unsigned long nr_segments,
                             struct kexec_segment __user *segments,
@@ -343,597 +101,6 @@ out_free_image:
        return ret;
 }
 
-int kimage_is_destination_range(struct kimage *image,
-                                       unsigned long start,
-                                       unsigned long end)
-{
-       unsigned long i;
-
-       for (i = 0; i < image->nr_segments; i++) {
-               unsigned long mstart, mend;
-
-               mstart = image->segment[i].mem;
-               mend = mstart + image->segment[i].memsz;
-               if ((end > mstart) && (start < mend))
-                       return 1;
-       }
-
-       return 0;
-}
-
-static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
-{
-       struct page *pages;
-
-       pages = alloc_pages(gfp_mask, order);
-       if (pages) {
-               unsigned int count, i;
-               pages->mapping = NULL;
-               set_page_private(pages, order);
-               count = 1 << order;
-               for (i = 0; i < count; i++)
-                       SetPageReserved(pages + i);
-       }
-
-       return pages;
-}
-
-static void kimage_free_pages(struct page *page)
-{
-       unsigned int order, count, i;
-
-       order = page_private(page);
-       count = 1 << order;
-       for (i = 0; i < count; i++)
-               ClearPageReserved(page + i);
-       __free_pages(page, order);
-}
-
-void kimage_free_page_list(struct list_head *list)
-{
-       struct list_head *pos, *next;
-
-       list_for_each_safe(pos, next, list) {
-               struct page *page;
-
-               page = list_entry(pos, struct page, lru);
-               list_del(&page->lru);
-               kimage_free_pages(page);
-       }
-}
-
-static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
-                                                       unsigned int order)
-{
-       /* Control pages are special, they are the intermediaries
-        * that are needed while we copy the rest of the pages
-        * to their final resting place.  As such they must
-        * not conflict with either the destination addresses
-        * or memory the kernel is already using.
-        *
-        * The only case where we really need more than one of
-        * these are for architectures where we cannot disable
-        * the MMU and must instead generate an identity mapped
-        * page table for all of the memory.
-        *
-        * At worst this runs in O(N) of the image size.
-        */
-       struct list_head extra_pages;
-       struct page *pages;
-       unsigned int count;
-
-       count = 1 << order;
-       INIT_LIST_HEAD(&extra_pages);
-
-       /* Loop while I can allocate a page and the page allocated
-        * is a destination page.
-        */
-       do {
-               unsigned long pfn, epfn, addr, eaddr;
-
-               pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order);
-               if (!pages)
-                       break;
-               pfn   = page_to_pfn(pages);
-               epfn  = pfn + count;
-               addr  = pfn << PAGE_SHIFT;
-               eaddr = epfn << PAGE_SHIFT;
-               if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) ||
-                             kimage_is_destination_range(image, addr, eaddr)) {
-                       list_add(&pages->lru, &extra_pages);
-                       pages = NULL;
-               }
-       } while (!pages);
-
-       if (pages) {
-               /* Remember the allocated page... */
-               list_add(&pages->lru, &image->control_pages);
-
-               /* Because the page is already in it's destination
-                * location we will never allocate another page at
-                * that address.  Therefore kimage_alloc_pages
-                * will not return it (again) and we don't need
-                * to give it an entry in image->segment[].
-                */
-       }
-       /* Deal with the destination pages I have inadvertently allocated.
-        *
-        * Ideally I would convert multi-page allocations into single
-        * page allocations, and add everything to image->dest_pages.
-        *
-        * For now it is simpler to just free the pages.
-        */
-       kimage_free_page_list(&extra_pages);
-
-       return pages;
-}
-
-static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
-                                                     unsigned int order)
-{
-       /* Control pages are special, they are the intermediaries
-        * that are needed while we copy the rest of the pages
-        * to their final resting place.  As such they must
-        * not conflict with either the destination addresses
-        * or memory the kernel is already using.
-        *
-        * Control pages are also the only pags we must allocate
-        * when loading a crash kernel.  All of the other pages
-        * are specified by the segments and we just memcpy
-        * into them directly.
-        *
-        * The only case where we really need more than one of
-        * these are for architectures where we cannot disable
-        * the MMU and must instead generate an identity mapped
-        * page table for all of the memory.
-        *
-        * Given the low demand this implements a very simple
-        * allocator that finds the first hole of the appropriate
-        * size in the reserved memory region, and allocates all
-        * of the memory up to and including the hole.
-        */
-       unsigned long hole_start, hole_end, size;
-       struct page *pages;
-
-       pages = NULL;
-       size = (1 << order) << PAGE_SHIFT;
-       hole_start = (image->control_page + (size - 1)) & ~(size - 1);
-       hole_end   = hole_start + size - 1;
-       while (hole_end <= crashk_res.end) {
-               unsigned long i;
-
-               if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)
-                       break;
-               /* See if I overlap any of the segments */
-               for (i = 0; i < image->nr_segments; i++) {
-                       unsigned long mstart, mend;
-
-                       mstart = image->segment[i].mem;
-                       mend   = mstart + image->segment[i].memsz - 1;
-                       if ((hole_end >= mstart) && (hole_start <= mend)) {
-                               /* Advance the hole to the end of the segment */
-                               hole_start = (mend + (size - 1)) & ~(size - 1);
-                               hole_end   = hole_start + size - 1;
-                               break;
-                       }
-               }
-               /* If I don't overlap any segments I have found my hole! */
-               if (i == image->nr_segments) {
-                       pages = pfn_to_page(hole_start >> PAGE_SHIFT);
-                       break;
-               }
-       }
-       if (pages)
-               image->control_page = hole_end;
-
-       return pages;
-}
-
-
-struct page *kimage_alloc_control_pages(struct kimage *image,
-                                        unsigned int order)
-{
-       struct page *pages = NULL;
-
-       switch (image->type) {
-       case KEXEC_TYPE_DEFAULT:
-               pages = kimage_alloc_normal_control_pages(image, order);
-               break;
-       case KEXEC_TYPE_CRASH:
-               pages = kimage_alloc_crash_control_pages(image, order);
-               break;
-       }
-
-       return pages;
-}
-
-static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
-{
-       if (*image->entry != 0)
-               image->entry++;
-
-       if (image->entry == image->last_entry) {
-               kimage_entry_t *ind_page;
-               struct page *page;
-
-               page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
-               if (!page)
-                       return -ENOMEM;
-
-               ind_page = page_address(page);
-               *image->entry = virt_to_phys(ind_page) | IND_INDIRECTION;
-               image->entry = ind_page;
-               image->last_entry = ind_page +
-                                     ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
-       }
-       *image->entry = entry;
-       image->entry++;
-       *image->entry = 0;
-
-       return 0;
-}
-
-static int kimage_set_destination(struct kimage *image,
-                                  unsigned long destination)
-{
-       int result;
-
-       destination &= PAGE_MASK;
-       result = kimage_add_entry(image, destination | IND_DESTINATION);
-
-       return result;
-}
-
-
-static int kimage_add_page(struct kimage *image, unsigned long page)
-{
-       int result;
-
-       page &= PAGE_MASK;
-       result = kimage_add_entry(image, page | IND_SOURCE);
-
-       return result;
-}
-
-
-static void kimage_free_extra_pages(struct kimage *image)
-{
-       /* Walk through and free any extra destination pages I may have */
-       kimage_free_page_list(&image->dest_pages);
-
-       /* Walk through and free any unusable pages I have cached */
-       kimage_free_page_list(&image->unusable_pages);
-
-}
-void kimage_terminate(struct kimage *image)
-{
-       if (*image->entry != 0)
-               image->entry++;
-
-       *image->entry = IND_DONE;
-}
-
-#define for_each_kimage_entry(image, ptr, entry) \
-       for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \
-               ptr = (entry & IND_INDIRECTION) ? \
-                       phys_to_virt((entry & PAGE_MASK)) : ptr + 1)
-
-static void kimage_free_entry(kimage_entry_t entry)
-{
-       struct page *page;
-
-       page = pfn_to_page(entry >> PAGE_SHIFT);
-       kimage_free_pages(page);
-}
-
-void kimage_free(struct kimage *image)
-{
-       kimage_entry_t *ptr, entry;
-       kimage_entry_t ind = 0;
-
-       if (!image)
-               return;
-
-       kimage_free_extra_pages(image);
-       for_each_kimage_entry(image, ptr, entry) {
-               if (entry & IND_INDIRECTION) {
-                       /* Free the previous indirection page */
-                       if (ind & IND_INDIRECTION)
-                               kimage_free_entry(ind);
-                       /* Save this indirection page until we are
-                        * done with it.
-                        */
-                       ind = entry;
-               } else if (entry & IND_SOURCE)
-                       kimage_free_entry(entry);
-       }
-       /* Free the final indirection page */
-       if (ind & IND_INDIRECTION)
-               kimage_free_entry(ind);
-
-       /* Handle any machine specific cleanup */
-       machine_kexec_cleanup(image);
-
-       /* Free the kexec control pages... */
-       kimage_free_page_list(&image->control_pages);
-
-       /*
-        * Free up any temporary buffers allocated. This might hit if
-        * error occurred much later after buffer allocation.
-        */
-       if (image->file_mode)
-               kimage_file_post_load_cleanup(image);
-
-       kfree(image);
-}
-
-static kimage_entry_t *kimage_dst_used(struct kimage *image,
-                                       unsigned long page)
-{
-       kimage_entry_t *ptr, entry;
-       unsigned long destination = 0;
-
-       for_each_kimage_entry(image, ptr, entry) {
-               if (entry & IND_DESTINATION)
-                       destination = entry & PAGE_MASK;
-               else if (entry & IND_SOURCE) {
-                       if (page == destination)
-                               return ptr;
-                       destination += PAGE_SIZE;
-               }
-       }
-
-       return NULL;
-}
-
-static struct page *kimage_alloc_page(struct kimage *image,
-                                       gfp_t gfp_mask,
-                                       unsigned long destination)
-{
-       /*
-        * Here we implement safeguards to ensure that a source page
-        * is not copied to its destination page before the data on
-        * the destination page is no longer useful.
-        *
-        * To do this we maintain the invariant that a source page is
-        * either its own destination page, or it is not a
-        * destination page at all.
-        *
-        * That is slightly stronger than required, but the proof
-        * that no problems will not occur is trivial, and the
-        * implementation is simply to verify.
-        *
-        * When allocating all pages normally this algorithm will run
-        * in O(N) time, but in the worst case it will run in O(N^2)
-        * time.   If the runtime is a problem the data structures can
-        * be fixed.
-        */
-       struct page *page;
-       unsigned long addr;
-
-       /*
-        * Walk through the list of destination pages, and see if I
-        * have a match.
-        */
-       list_for_each_entry(page, &image->dest_pages, lru) {
-               addr = page_to_pfn(page) << PAGE_SHIFT;
-               if (addr == destination) {
-                       list_del(&page->lru);
-                       return page;
-               }
-       }
-       page = NULL;
-       while (1) {
-               kimage_entry_t *old;
-
-               /* Allocate a page, if we run out of memory give up */
-               page = kimage_alloc_pages(gfp_mask, 0);
-               if (!page)
-                       return NULL;
-               /* If the page cannot be used file it away */
-               if (page_to_pfn(page) >
-                               (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
-                       list_add(&page->lru, &image->unusable_pages);
-                       continue;
-               }
-               addr = page_to_pfn(page) << PAGE_SHIFT;
-
-               /* If it is the destination page we want use it */
-               if (addr == destination)
-                       break;
-
-               /* If the page is not a destination page use it */
-               if (!kimage_is_destination_range(image, addr,
-                                                 addr + PAGE_SIZE))
-                       break;
-
-               /*
-                * I know that the page is someones destination page.
-                * See if there is already a source page for this
-                * destination page.  And if so swap the source pages.
-                */
-               old = kimage_dst_used(image, addr);
-               if (old) {
-                       /* If so move it */
-                       unsigned long old_addr;
-                       struct page *old_page;
-
-                       old_addr = *old & PAGE_MASK;
-                       old_page = pfn_to_page(old_addr >> PAGE_SHIFT);
-                       copy_highpage(page, old_page);
-                       *old = addr | (*old & ~PAGE_MASK);
-
-                       /* The old page I have found cannot be a
-                        * destination page, so return it if it's
-                        * gfp_flags honor the ones passed in.
-                        */
-                       if (!(gfp_mask & __GFP_HIGHMEM) &&
-                           PageHighMem(old_page)) {
-                               kimage_free_pages(old_page);
-                               continue;
-                       }
-                       addr = old_addr;
-                       page = old_page;
-                       break;
-               } else {
-                       /* Place the page on the destination list I
-                        * will use it later.
-                        */
-                       list_add(&page->lru, &image->dest_pages);
-               }
-       }
-
-       return page;
-}
-
-static int kimage_load_normal_segment(struct kimage *image,
-                                        struct kexec_segment *segment)
-{
-       unsigned long maddr;
-       size_t ubytes, mbytes;
-       int result;
-       unsigned char __user *buf = NULL;
-       unsigned char *kbuf = NULL;
-
-       result = 0;
-       if (image->file_mode)
-               kbuf = segment->kbuf;
-       else
-               buf = segment->buf;
-       ubytes = segment->bufsz;
-       mbytes = segment->memsz;
-       maddr = segment->mem;
-
-       result = kimage_set_destination(image, maddr);
-       if (result < 0)
-               goto out;
-
-       while (mbytes) {
-               struct page *page;
-               char *ptr;
-               size_t uchunk, mchunk;
-
-               page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
-               if (!page) {
-                       result  = -ENOMEM;
-                       goto out;
-               }
-               result = kimage_add_page(image, page_to_pfn(page)
-                                                               << PAGE_SHIFT);
-               if (result < 0)
-                       goto out;
-
-               ptr = kmap(page);
-               /* Start with a clear page */
-               clear_page(ptr);
-               ptr += maddr & ~PAGE_MASK;
-               mchunk = min_t(size_t, mbytes,
-                               PAGE_SIZE - (maddr & ~PAGE_MASK));
-               uchunk = min(ubytes, mchunk);
-
-               /* For file based kexec, source pages are in kernel memory */
-               if (image->file_mode)
-                       memcpy(ptr, kbuf, uchunk);
-               else
-                       result = copy_from_user(ptr, buf, uchunk);
-               kunmap(page);
-               if (result) {
-                       result = -EFAULT;
-                       goto out;
-               }
-               ubytes -= uchunk;
-               maddr  += mchunk;
-               if (image->file_mode)
-                       kbuf += mchunk;
-               else
-                       buf += mchunk;
-               mbytes -= mchunk;
-       }
-out:
-       return result;
-}
-
-static int kimage_load_crash_segment(struct kimage *image,
-                                       struct kexec_segment *segment)
-{
-       /* For crash dumps kernels we simply copy the data from
-        * user space to it's destination.
-        * We do things a page at a time for the sake of kmap.
-        */
-       unsigned long maddr;
-       size_t ubytes, mbytes;
-       int result;
-       unsigned char __user *buf = NULL;
-       unsigned char *kbuf = NULL;
-
-       result = 0;
-       if (image->file_mode)
-               kbuf = segment->kbuf;
-       else
-               buf = segment->buf;
-       ubytes = segment->bufsz;
-       mbytes = segment->memsz;
-       maddr = segment->mem;
-       while (mbytes) {
-               struct page *page;
-               char *ptr;
-               size_t uchunk, mchunk;
-
-               page = pfn_to_page(maddr >> PAGE_SHIFT);
-               if (!page) {
-                       result  = -ENOMEM;
-                       goto out;
-               }
-               ptr = kmap(page);
-               ptr += maddr & ~PAGE_MASK;
-               mchunk = min_t(size_t, mbytes,
-                               PAGE_SIZE - (maddr & ~PAGE_MASK));
-               uchunk = min(ubytes, mchunk);
-               if (mchunk > uchunk) {
-                       /* Zero the trailing part of the page */
-                       memset(ptr + uchunk, 0, mchunk - uchunk);
-               }
-
-               /* For file based kexec, source pages are in kernel memory */
-               if (image->file_mode)
-                       memcpy(ptr, kbuf, uchunk);
-               else
-                       result = copy_from_user(ptr, buf, uchunk);
-               kexec_flush_icache_page(page);
-               kunmap(page);
-               if (result) {
-                       result = -EFAULT;
-                       goto out;
-               }
-               ubytes -= uchunk;
-               maddr  += mchunk;
-               if (image->file_mode)
-                       kbuf += mchunk;
-               else
-                       buf += mchunk;
-               mbytes -= mchunk;
-       }
-out:
-       return result;
-}
-
-int kimage_load_segment(struct kimage *image,
-                               struct kexec_segment *segment)
-{
-       int result = -ENOMEM;
-
-       switch (image->type) {
-       case KEXEC_TYPE_DEFAULT:
-               result = kimage_load_normal_segment(image, segment);
-               break;
-       case KEXEC_TYPE_CRASH:
-               result = kimage_load_crash_segment(image, segment);
-               break;
-       }
-
-       return result;
-}
-
 /*
  * Exec Kernel system call: for obvious reasons only root may call it.
  *
@@ -954,9 +121,6 @@ int kimage_load_segment(struct kimage *image,
  * kexec does not sync, or unmount filesystems so if you need
  * that to happen you need to do that yourself.
  */
-struct kimage *kexec_image;
-struct kimage *kexec_crash_image;
-int kexec_load_disabled;
 
 SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
                struct kexec_segment __user *, segments, unsigned long, flags)
@@ -1051,18 +215,6 @@ out:
        return result;
 }
 
-/*
- * Add and remove page tables for crashkernel memory
- *
- * Provide an empty default implementation here -- architecture
- * code may override this
- */
-void __weak crash_map_reserved_pages(void)
-{}
-
-void __weak crash_unmap_reserved_pages(void)
-{}
-
 #ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
                       compat_ulong_t, nr_segments,
@@ -1101,646 +253,3 @@ COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
        return sys_kexec_load(entry, nr_segments, ksegments, flags);
 }
 #endif
-
-void crash_kexec(struct pt_regs *regs)
-{
-       /* Take the kexec_mutex here to prevent sys_kexec_load
-        * running on one cpu from replacing the crash kernel
-        * we are using after a panic on a different cpu.
-        *
-        * If the crash kernel was not located in a fixed area
-        * of memory the xchg(&kexec_crash_image) would be
-        * sufficient.  But since I reuse the memory...
-        */
-       if (mutex_trylock(&kexec_mutex)) {
-               if (kexec_crash_image) {
-                       struct pt_regs fixed_regs;
-
-                       crash_setup_regs(&fixed_regs, regs);
-                       crash_save_vmcoreinfo();
-                       machine_crash_shutdown(&fixed_regs);
-                       machine_kexec(kexec_crash_image);
-               }
-               mutex_unlock(&kexec_mutex);
-       }
-}
-
-size_t crash_get_memory_size(void)
-{
-       size_t size = 0;
-       mutex_lock(&kexec_mutex);
-       if (crashk_res.end != crashk_res.start)
-               size = resource_size(&crashk_res);
-       mutex_unlock(&kexec_mutex);
-       return size;
-}
-
-void __weak crash_free_reserved_phys_range(unsigned long begin,
-                                          unsigned long end)
-{
-       unsigned long addr;
-
-       for (addr = begin; addr < end; addr += PAGE_SIZE)
-               free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
-}
-
-int crash_shrink_memory(unsigned long new_size)
-{
-       int ret = 0;
-       unsigned long start, end;
-       unsigned long old_size;
-       struct resource *ram_res;
-
-       mutex_lock(&kexec_mutex);
-
-       if (kexec_crash_image) {
-               ret = -ENOENT;
-               goto unlock;
-       }
-       start = crashk_res.start;
-       end = crashk_res.end;
-       old_size = (end == 0) ? 0 : end - start + 1;
-       if (new_size >= old_size) {
-               ret = (new_size == old_size) ? 0 : -EINVAL;
-               goto unlock;
-       }
-
-       ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
-       if (!ram_res) {
-               ret = -ENOMEM;
-               goto unlock;
-       }
-
-       start = roundup(start, KEXEC_CRASH_MEM_ALIGN);
-       end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN);
-
-       crash_map_reserved_pages();
-       crash_free_reserved_phys_range(end, crashk_res.end);
-
-       if ((start == end) && (crashk_res.parent != NULL))
-               release_resource(&crashk_res);
-
-       ram_res->start = end;
-       ram_res->end = crashk_res.end;
-       ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
-       ram_res->name = "System RAM";
-
-       crashk_res.end = end - 1;
-
-       insert_resource(&iomem_resource, ram_res);
-       crash_unmap_reserved_pages();
-
-unlock:
-       mutex_unlock(&kexec_mutex);
-       return ret;
-}
-
-static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
-                           size_t data_len)
-{
-       struct elf_note note;
-
-       note.n_namesz = strlen(name) + 1;
-       note.n_descsz = data_len;
-       note.n_type   = type;
-       memcpy(buf, &note, sizeof(note));
-       buf += (sizeof(note) + 3)/4;
-       memcpy(buf, name, note.n_namesz);
-       buf += (note.n_namesz + 3)/4;
-       memcpy(buf, data, note.n_descsz);
-       buf += (note.n_descsz + 3)/4;
-
-       return buf;
-}
-
-static void final_note(u32 *buf)
-{
-       struct elf_note note;
-
-       note.n_namesz = 0;
-       note.n_descsz = 0;
-       note.n_type   = 0;
-       memcpy(buf, &note, sizeof(note));
-}
-
-void crash_save_cpu(struct pt_regs *regs, int cpu)
-{
-       struct elf_prstatus prstatus;
-       u32 *buf;
-
-       if ((cpu < 0) || (cpu >= nr_cpu_ids))
-               return;
-
-       /* Using ELF notes here is opportunistic.
-        * I need a well defined structure format
-        * for the data I pass, and I need tags
-        * on the data to indicate what information I have
-        * squirrelled away.  ELF notes happen to provide
-        * all of that, so there is no need to invent something new.
-        */
-       buf = (u32 *)per_cpu_ptr(crash_notes, cpu);
-       if (!buf)
-               return;
-       memset(&prstatus, 0, sizeof(prstatus));
-       prstatus.pr_pid = current->pid;
-       elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
-       buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
-                             &prstatus, sizeof(prstatus));
-       final_note(buf);
-}
-
-static int __init crash_notes_memory_init(void)
-{
-       /* Allocate memory for saving cpu registers. */
-       crash_notes = alloc_percpu(note_buf_t);
-       if (!crash_notes) {
-               pr_warn("Kexec: Memory allocation for saving cpu register states failed\n");
-               return -ENOMEM;
-       }
-       return 0;
-}
-subsys_initcall(crash_notes_memory_init);
-
-
-/*
- * parsing the "crashkernel" commandline
- *
- * this code is intended to be called from architecture specific code
- */
-
-
-/*
- * This function parses command lines in the format
- *
- *   crashkernel=ramsize-range:size[,...][@offset]
- *
- * The function returns 0 on success and -EINVAL on failure.
- */
-static int __init parse_crashkernel_mem(char *cmdline,
-                                       unsigned long long system_ram,
-                                       unsigned long long *crash_size,
-                                       unsigned long long *crash_base)
-{
-       char *cur = cmdline, *tmp;
-
-       /* for each entry of the comma-separated list */
-       do {
-               unsigned long long start, end = ULLONG_MAX, size;
-
-               /* get the start of the range */
-               start = memparse(cur, &tmp);
-               if (cur == tmp) {
-                       pr_warn("crashkernel: Memory value expected\n");
-                       return -EINVAL;
-               }
-               cur = tmp;
-               if (*cur != '-') {
-                       pr_warn("crashkernel: '-' expected\n");
-                       return -EINVAL;
-               }
-               cur++;
-
-               /* if no ':' is here, than we read the end */
-               if (*cur != ':') {
-                       end = memparse(cur, &tmp);
-                       if (cur == tmp) {
-                               pr_warn("crashkernel: Memory value expected\n");
-                               return -EINVAL;
-                       }
-                       cur = tmp;
-                       if (end <= start) {
-                               pr_warn("crashkernel: end <= start\n");
-                               return -EINVAL;
-                       }
-               }
-
-               if (*cur != ':') {
-                       pr_warn("crashkernel: ':' expected\n");
-                       return -EINVAL;
-               }
-               cur++;
-
-               size = memparse(cur, &tmp);
-               if (cur == tmp) {
-                       pr_warn("Memory value expected\n");
-                       return -EINVAL;
-               }
-               cur = tmp;
-               if (size >= system_ram) {
-                       pr_warn("crashkernel: invalid size\n");
-                       return -EINVAL;
-               }
-
-               /* match ? */
-               if (system_ram >= start && system_ram < end) {
-                       *crash_size = size;
-                       break;
-               }
-       } while (*cur++ == ',');
-
-       if (*crash_size > 0) {
-               while (*cur && *cur != ' ' && *cur != '@')
-                       cur++;
-               if (*cur == '@') {
-                       cur++;
-                       *crash_base = memparse(cur, &tmp);
-                       if (cur == tmp) {
-                               pr_warn("Memory value expected after '@'\n");
-                               return -EINVAL;
-                       }
-               }
-       }
-
-       return 0;
-}
-
-/*
- * That function parses "simple" (old) crashkernel command lines like
- *
- *     crashkernel=size[@offset]
- *
- * It returns 0 on success and -EINVAL on failure.
- */
-static int __init parse_crashkernel_simple(char *cmdline,
-                                          unsigned long long *crash_size,
-                                          unsigned long long *crash_base)
-{
-       char *cur = cmdline;
-
-       *crash_size = memparse(cmdline, &cur);
-       if (cmdline == cur) {
-               pr_warn("crashkernel: memory value expected\n");
-               return -EINVAL;
-       }
-
-       if (*cur == '@')
-               *crash_base = memparse(cur+1, &cur);
-       else if (*cur != ' ' && *cur != '\0') {
-               pr_warn("crashkernel: unrecognized char\n");
-               return -EINVAL;
-       }
-
-       return 0;
-}
-
-#define SUFFIX_HIGH 0
-#define SUFFIX_LOW  1
-#define SUFFIX_NULL 2
-static __initdata char *suffix_tbl[] = {
-       [SUFFIX_HIGH] = ",high",
-       [SUFFIX_LOW]  = ",low",
-       [SUFFIX_NULL] = NULL,
-};
-
-/*
- * That function parses "suffix"  crashkernel command lines like
- *
- *     crashkernel=size,[high|low]
- *
- * It returns 0 on success and -EINVAL on failure.
- */
-static int __init parse_crashkernel_suffix(char *cmdline,
-                                          unsigned long long   *crash_size,
-                                          const char *suffix)
-{
-       char *cur = cmdline;
-
-       *crash_size = memparse(cmdline, &cur);
-       if (cmdline == cur) {
-               pr_warn("crashkernel: memory value expected\n");
-               return -EINVAL;
-       }
-
-       /* check with suffix */
-       if (strncmp(cur, suffix, strlen(suffix))) {
-               pr_warn("crashkernel: unrecognized char\n");
-               return -EINVAL;
-       }
-       cur += strlen(suffix);
-       if (*cur != ' ' && *cur != '\0') {
-               pr_warn("crashkernel: unrecognized char\n");
-               return -EINVAL;
-       }
-
-       return 0;
-}
-
-static __init char *get_last_crashkernel(char *cmdline,
-                            const char *name,
-                            const char *suffix)
-{
-       char *p = cmdline, *ck_cmdline = NULL;
-
-       /* find crashkernel and use the last one if there are more */
-       p = strstr(p, name);
-       while (p) {
-               char *end_p = strchr(p, ' ');
-               char *q;
-
-               if (!end_p)
-                       end_p = p + strlen(p);
-
-               if (!suffix) {
-                       int i;
-
-                       /* skip the one with any known suffix */
-                       for (i = 0; suffix_tbl[i]; i++) {
-                               q = end_p - strlen(suffix_tbl[i]);
-                               if (!strncmp(q, suffix_tbl[i],
-                                            strlen(suffix_tbl[i])))
-                                       goto next;
-                       }
-                       ck_cmdline = p;
-               } else {
-                       q = end_p - strlen(suffix);
-                       if (!strncmp(q, suffix, strlen(suffix)))
-                               ck_cmdline = p;
-               }
-next:
-               p = strstr(p+1, name);
-       }
-
-       if (!ck_cmdline)
-               return NULL;
-
-       return ck_cmdline;
-}
-
-static int __init __parse_crashkernel(char *cmdline,
-                            unsigned long long system_ram,
-                            unsigned long long *crash_size,
-                            unsigned long long *crash_base,
-                            const char *name,
-                            const char *suffix)
-{
-       char    *first_colon, *first_space;
-       char    *ck_cmdline;
-
-       BUG_ON(!crash_size || !crash_base);
-       *crash_size = 0;
-       *crash_base = 0;
-
-       ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
-
-       if (!ck_cmdline)
-               return -EINVAL;
-
-       ck_cmdline += strlen(name);
-
-       if (suffix)
-               return parse_crashkernel_suffix(ck_cmdline, crash_size,
-                               suffix);
-       /*
-        * if the commandline contains a ':', then that's the extended
-        * syntax -- if not, it must be the classic syntax
-        */
-       first_colon = strchr(ck_cmdline, ':');
-       first_space = strchr(ck_cmdline, ' ');
-       if (first_colon && (!first_space || first_colon < first_space))
-               return parse_crashkernel_mem(ck_cmdline, system_ram,
-                               crash_size, crash_base);
-
-       return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
-}
-
-/*
- * That function is the entry point for command line parsing and should be
- * called from the arch-specific code.
- */
-int __init parse_crashkernel(char *cmdline,
-                            unsigned long long system_ram,
-                            unsigned long long *crash_size,
-                            unsigned long long *crash_base)
-{
-       return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
-                                       "crashkernel=", NULL);
-}
-
-int __init parse_crashkernel_high(char *cmdline,
-                            unsigned long long system_ram,
-                            unsigned long long *crash_size,
-                            unsigned long long *crash_base)
-{
-       return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
-                               "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
-}
-
-int __init parse_crashkernel_low(char *cmdline,
-                            unsigned long long system_ram,
-                            unsigned long long *crash_size,
-                            unsigned long long *crash_base)
-{
-       return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
-                               "crashkernel=", suffix_tbl[SUFFIX_LOW]);
-}
-
-static void update_vmcoreinfo_note(void)
-{
-       u32 *buf = vmcoreinfo_note;
-
-       if (!vmcoreinfo_size)
-               return;
-       buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
-                             vmcoreinfo_size);
-       final_note(buf);
-}
-
-void crash_save_vmcoreinfo(void)
-{
-       vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds());
-       update_vmcoreinfo_note();
-}
-
-void vmcoreinfo_append_str(const char *fmt, ...)
-{
-       va_list args;
-       char buf[0x50];
-       size_t r;
-
-       va_start(args, fmt);
-       r = vscnprintf(buf, sizeof(buf), fmt, args);
-       va_end(args);
-
-       r = min(r, vmcoreinfo_max_size - vmcoreinfo_size);
-
-       memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
-
-       vmcoreinfo_size += r;
-}
-
-/*
- * provide an empty default implementation here -- architecture
- * code may override this
- */
-void __weak arch_crash_save_vmcoreinfo(void)
-{}
-
-unsigned long __weak paddr_vmcoreinfo_note(void)
-{
-       return __pa((unsigned long)(char *)&vmcoreinfo_note);
-}
-
-static int __init crash_save_vmcoreinfo_init(void)
-{
-       VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
-       VMCOREINFO_PAGESIZE(PAGE_SIZE);
-
-       VMCOREINFO_SYMBOL(init_uts_ns);
-       VMCOREINFO_SYMBOL(node_online_map);
-#ifdef CONFIG_MMU
-       VMCOREINFO_SYMBOL(swapper_pg_dir);
-#endif
-       VMCOREINFO_SYMBOL(_stext);
-       VMCOREINFO_SYMBOL(vmap_area_list);
-
-#ifndef CONFIG_NEED_MULTIPLE_NODES
-       VMCOREINFO_SYMBOL(mem_map);
-       VMCOREINFO_SYMBOL(contig_page_data);
-#endif
-#ifdef CONFIG_SPARSEMEM
-       VMCOREINFO_SYMBOL(mem_section);
-       VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
-       VMCOREINFO_STRUCT_SIZE(mem_section);
-       VMCOREINFO_OFFSET(mem_section, section_mem_map);
-#endif
-       VMCOREINFO_STRUCT_SIZE(page);
-       VMCOREINFO_STRUCT_SIZE(pglist_data);
-       VMCOREINFO_STRUCT_SIZE(zone);
-       VMCOREINFO_STRUCT_SIZE(free_area);
-       VMCOREINFO_STRUCT_SIZE(list_head);
-       VMCOREINFO_SIZE(nodemask_t);
-       VMCOREINFO_OFFSET(page, flags);
-       VMCOREINFO_OFFSET(page, _count);
-       VMCOREINFO_OFFSET(page, mapping);
-       VMCOREINFO_OFFSET(page, lru);
-       VMCOREINFO_OFFSET(page, _mapcount);
-       VMCOREINFO_OFFSET(page, private);
-       VMCOREINFO_OFFSET(pglist_data, node_zones);
-       VMCOREINFO_OFFSET(pglist_data, nr_zones);
-#ifdef CONFIG_FLAT_NODE_MEM_MAP
-       VMCOREINFO_OFFSET(pglist_data, node_mem_map);
-#endif
-       VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
-       VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
-       VMCOREINFO_OFFSET(pglist_data, node_id);
-       VMCOREINFO_OFFSET(zone, free_area);
-       VMCOREINFO_OFFSET(zone, vm_stat);
-       VMCOREINFO_OFFSET(zone, spanned_pages);
-       VMCOREINFO_OFFSET(free_area, free_list);
-       VMCOREINFO_OFFSET(list_head, next);
-       VMCOREINFO_OFFSET(list_head, prev);
-       VMCOREINFO_OFFSET(vmap_area, va_start);
-       VMCOREINFO_OFFSET(vmap_area, list);
-       VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
-       log_buf_kexec_setup();
-       VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
-       VMCOREINFO_NUMBER(NR_FREE_PAGES);
-       VMCOREINFO_NUMBER(PG_lru);
-       VMCOREINFO_NUMBER(PG_private);
-       VMCOREINFO_NUMBER(PG_swapcache);
-       VMCOREINFO_NUMBER(PG_slab);
-#ifdef CONFIG_MEMORY_FAILURE
-       VMCOREINFO_NUMBER(PG_hwpoison);
-#endif
-       VMCOREINFO_NUMBER(PG_head_mask);
-       VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
-#ifdef CONFIG_HUGETLBFS
-       VMCOREINFO_SYMBOL(free_huge_page);
-#endif
-
-       arch_crash_save_vmcoreinfo();
-       update_vmcoreinfo_note();
-
-       return 0;
-}
-
-subsys_initcall(crash_save_vmcoreinfo_init);
-
-/*
- * Move into place and start executing a preloaded standalone
- * executable.  If nothing was preloaded return an error.
- */
-int kernel_kexec(void)
-{
-       int error = 0;
-
-       if (!mutex_trylock(&kexec_mutex))
-               return -EBUSY;
-       if (!kexec_image) {
-               error = -EINVAL;
-               goto Unlock;
-       }
-
-#ifdef CONFIG_KEXEC_JUMP
-       if (kexec_image->preserve_context) {
-               lock_system_sleep();
-               pm_prepare_console();
-               error = freeze_processes();
-               if (error) {
-                       error = -EBUSY;
-                       goto Restore_console;
-               }
-               suspend_console();
-               error = dpm_suspend_start(PMSG_FREEZE);
-               if (error)
-                       goto Resume_console;
-               /* At this point, dpm_suspend_start() has been called,
-                * but *not* dpm_suspend_end(). We *must* call
-                * dpm_suspend_end() now.  Otherwise, drivers for
-                * some devices (e.g. interrupt controllers) become
-                * desynchronized with the actual state of the
-                * hardware at resume time, and evil weirdness ensues.
-                */
-               error = dpm_suspend_end(PMSG_FREEZE);
-               if (error)
-                       goto Resume_devices;
-               error = disable_nonboot_cpus();
-               if (error)
-                       goto Enable_cpus;
-               local_irq_disable();
-               error = syscore_suspend();
-               if (error)
-                       goto Enable_irqs;
-       } else
-#endif
-       {
-               kexec_in_progress = true;
-               kernel_restart_prepare(NULL);
-               migrate_to_reboot_cpu();
-
-               /*
-                * migrate_to_reboot_cpu() disables CPU hotplug assuming that
-                * no further code needs to use CPU hotplug (which is true in
-                * the reboot case). However, the kexec path depends on using
-                * CPU hotplug again; so re-enable it here.
-                */
-               cpu_hotplug_enable();
-               pr_emerg("Starting new kernel\n");
-               machine_shutdown();
-       }
-
-       machine_kexec(kexec_image);
-
-#ifdef CONFIG_KEXEC_JUMP
-       if (kexec_image->preserve_context) {
-               syscore_resume();
- Enable_irqs:
-               local_irq_enable();
- Enable_cpus:
-               enable_nonboot_cpus();
-               dpm_resume_start(PMSG_RESTORE);
- Resume_devices:
-               dpm_resume_end(PMSG_RESTORE);
- Resume_console:
-               resume_console();
-               thaw_processes();
- Restore_console:
-               pm_restore_console();
-               unlock_system_sleep();
-       }
-#endif
-
- Unlock:
-       mutex_unlock(&kexec_mutex);
-       return error;
-}
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
new file mode 100644 (file)
index 0000000..9aa25c0
--- /dev/null
@@ -0,0 +1,1511 @@
+/*
+ * kexec.c - kexec system call core code.
+ * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#define pr_fmt(fmt)    "kexec: " fmt
+
+#include <linux/capability.h>
+#include <linux/mm.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/kexec.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/highmem.h>
+#include <linux/syscalls.h>
+#include <linux/reboot.h>
+#include <linux/ioport.h>
+#include <linux/hardirq.h>
+#include <linux/elf.h>
+#include <linux/elfcore.h>
+#include <linux/utsname.h>
+#include <linux/numa.h>
+#include <linux/suspend.h>
+#include <linux/device.h>
+#include <linux/freezer.h>
+#include <linux/pm.h>
+#include <linux/cpu.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/console.h>
+#include <linux/vmalloc.h>
+#include <linux/swap.h>
+#include <linux/syscore_ops.h>
+#include <linux/compiler.h>
+#include <linux/hugetlb.h>
+
+#include <asm/page.h>
+#include <asm/sections.h>
+
+#include <crypto/hash.h>
+#include <crypto/sha.h>
+#include "kexec_internal.h"
+
+DEFINE_MUTEX(kexec_mutex);
+
+/* Per cpu memory for storing cpu states in case of system crash. */
+note_buf_t __percpu *crash_notes;
+
+/* vmcoreinfo stuff */
+static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES];
+u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
+size_t vmcoreinfo_size;
+size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
+
+/* Flag to indicate we are going to kexec a new kernel */
+bool kexec_in_progress = false;
+
+
+/* Location of the reserved area for the crash kernel */
+struct resource crashk_res = {
+       .name  = "Crash kernel",
+       .start = 0,
+       .end   = 0,
+       .flags = IORESOURCE_BUSY | IORESOURCE_MEM
+};
+struct resource crashk_low_res = {
+       .name  = "Crash kernel",
+       .start = 0,
+       .end   = 0,
+       .flags = IORESOURCE_BUSY | IORESOURCE_MEM
+};
+
+int kexec_should_crash(struct task_struct *p)
+{
+       /*
+        * If crash_kexec_post_notifiers is enabled, don't run
+        * crash_kexec() here yet, which must be run after panic
+        * notifiers in panic().
+        */
+       if (crash_kexec_post_notifiers)
+               return 0;
+       /*
+        * There are 4 panic() calls in do_exit() path, each of which
+        * corresponds to each of these 4 conditions.
+        */
+       if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops)
+               return 1;
+       return 0;
+}
+
+/*
+ * When kexec transitions to the new kernel there is a one-to-one
+ * mapping between physical and virtual addresses.  On processors
+ * where you can disable the MMU this is trivial, and easy.  For
+ * others it is still a simple predictable page table to setup.
+ *
+ * In that environment kexec copies the new kernel to its final
+ * resting place.  This means I can only support memory whose
+ * physical address can fit in an unsigned long.  In particular
+ * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled.
+ * If the assembly stub has more restrictive requirements
+ * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be
+ * defined more restrictively in <asm/kexec.h>.
+ *
+ * The code for the transition from the current kernel to the
+ * the new kernel is placed in the control_code_buffer, whose size
+ * is given by KEXEC_CONTROL_PAGE_SIZE.  In the best case only a single
+ * page of memory is necessary, but some architectures require more.
+ * Because this memory must be identity mapped in the transition from
+ * virtual to physical addresses it must live in the range
+ * 0 - TASK_SIZE, as only the user space mappings are arbitrarily
+ * modifiable.
+ *
+ * The assembly stub in the control code buffer is passed a linked list
+ * of descriptor pages detailing the source pages of the new kernel,
+ * and the destination addresses of those source pages.  As this data
+ * structure is not used in the context of the current OS, it must
+ * be self-contained.
+ *
+ * The code has been made to work with highmem pages and will use a
+ * destination page in its final resting place (if it happens
+ * to allocate it).  The end product of this is that most of the
+ * physical address space, and most of RAM can be used.
+ *
+ * Future directions include:
+ *  - allocating a page table with the control code buffer identity
+ *    mapped, to simplify machine_kexec and make kexec_on_panic more
+ *    reliable.
+ */
+
+/*
+ * KIMAGE_NO_DEST is an impossible destination address..., for
+ * allocating pages whose destination address we do not care about.
+ */
+#define KIMAGE_NO_DEST (-1UL)
+
+static struct page *kimage_alloc_page(struct kimage *image,
+                                      gfp_t gfp_mask,
+                                      unsigned long dest);
+
+int sanity_check_segment_list(struct kimage *image)
+{
+       int result, i;
+       unsigned long nr_segments = image->nr_segments;
+
+       /*
+        * Verify we have good destination addresses.  The caller is
+        * responsible for making certain we don't attempt to load
+        * the new image into invalid or reserved areas of RAM.  This
+        * just verifies it is an address we can use.
+        *
+        * Since the kernel does everything in page size chunks ensure
+        * the destination addresses are page aligned.  Too many
+        * special cases crop of when we don't do this.  The most
+        * insidious is getting overlapping destination addresses
+        * simply because addresses are changed to page size
+        * granularity.
+        */
+       result = -EADDRNOTAVAIL;
+       for (i = 0; i < nr_segments; i++) {
+               unsigned long mstart, mend;
+
+               mstart = image->segment[i].mem;
+               mend   = mstart + image->segment[i].memsz;
+               if ((mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK))
+                       return result;
+               if (mend >= KEXEC_DESTINATION_MEMORY_LIMIT)
+                       return result;
+       }
+
+       /* Verify our destination addresses do not overlap.
+        * If we alloed overlapping destination addresses
+        * through very weird things can happen with no
+        * easy explanation as one segment stops on another.
+        */
+       result = -EINVAL;
+       for (i = 0; i < nr_segments; i++) {
+               unsigned long mstart, mend;
+               unsigned long j;
+
+               mstart = image->segment[i].mem;
+               mend   = mstart + image->segment[i].memsz;
+               for (j = 0; j < i; j++) {
+                       unsigned long pstart, pend;
+
+                       pstart = image->segment[j].mem;
+                       pend   = pstart + image->segment[j].memsz;
+                       /* Do the segments overlap ? */
+                       if ((mend > pstart) && (mstart < pend))
+                               return result;
+               }
+       }
+
+       /* Ensure our buffer sizes are strictly less than
+        * our memory sizes.  This should always be the case,
+        * and it is easier to check up front than to be surprised
+        * later on.
+        */
+       result = -EINVAL;
+       for (i = 0; i < nr_segments; i++) {
+               if (image->segment[i].bufsz > image->segment[i].memsz)
+                       return result;
+       }
+
+       /*
+        * Verify we have good destination addresses.  Normally
+        * the caller is responsible for making certain we don't
+        * attempt to load the new image into invalid or reserved
+        * areas of RAM.  But crash kernels are preloaded into a
+        * reserved area of ram.  We must ensure the addresses
+        * are in the reserved area otherwise preloading the
+        * kernel could corrupt things.
+        */
+
+       if (image->type == KEXEC_TYPE_CRASH) {
+               result = -EADDRNOTAVAIL;
+               for (i = 0; i < nr_segments; i++) {
+                       unsigned long mstart, mend;
+
+                       mstart = image->segment[i].mem;
+                       mend = mstart + image->segment[i].memsz - 1;
+                       /* Ensure we are within the crash kernel limits */
+                       if ((mstart < crashk_res.start) ||
+                           (mend > crashk_res.end))
+                               return result;
+               }
+       }
+
+       return 0;
+}
+
+struct kimage *do_kimage_alloc_init(void)
+{
+       struct kimage *image;
+
+       /* Allocate a controlling structure */
+       image = kzalloc(sizeof(*image), GFP_KERNEL);
+       if (!image)
+               return NULL;
+
+       image->head = 0;
+       image->entry = &image->head;
+       image->last_entry = &image->head;
+       image->control_page = ~0; /* By default this does not apply */
+       image->type = KEXEC_TYPE_DEFAULT;
+
+       /* Initialize the list of control pages */
+       INIT_LIST_HEAD(&image->control_pages);
+
+       /* Initialize the list of destination pages */
+       INIT_LIST_HEAD(&image->dest_pages);
+
+       /* Initialize the list of unusable pages */
+       INIT_LIST_HEAD(&image->unusable_pages);
+
+       return image;
+}
+
+int kimage_is_destination_range(struct kimage *image,
+                                       unsigned long start,
+                                       unsigned long end)
+{
+       unsigned long i;
+
+       for (i = 0; i < image->nr_segments; i++) {
+               unsigned long mstart, mend;
+
+               mstart = image->segment[i].mem;
+               mend = mstart + image->segment[i].memsz;
+               if ((end > mstart) && (start < mend))
+                       return 1;
+       }
+
+       return 0;
+}
+
+static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
+{
+       struct page *pages;
+
+       pages = alloc_pages(gfp_mask, order);
+       if (pages) {
+               unsigned int count, i;
+
+               pages->mapping = NULL;
+               set_page_private(pages, order);
+               count = 1 << order;
+               for (i = 0; i < count; i++)
+                       SetPageReserved(pages + i);
+       }
+
+       return pages;
+}
+
+static void kimage_free_pages(struct page *page)
+{
+       unsigned int order, count, i;
+
+       order = page_private(page);
+       count = 1 << order;
+       for (i = 0; i < count; i++)
+               ClearPageReserved(page + i);
+       __free_pages(page, order);
+}
+
+void kimage_free_page_list(struct list_head *list)
+{
+       struct list_head *pos, *next;
+
+       list_for_each_safe(pos, next, list) {
+               struct page *page;
+
+               page = list_entry(pos, struct page, lru);
+               list_del(&page->lru);
+               kimage_free_pages(page);
+       }
+}
+
+static struct page *kimage_alloc_normal_control_pages(struct kimage *image,
+                                                       unsigned int order)
+{
+       /* Control pages are special, they are the intermediaries
+        * that are needed while we copy the rest of the pages
+        * to their final resting place.  As such they must
+        * not conflict with either the destination addresses
+        * or memory the kernel is already using.
+        *
+        * The only case where we really need more than one of
+        * these are for architectures where we cannot disable
+        * the MMU and must instead generate an identity mapped
+        * page table for all of the memory.
+        *
+        * At worst this runs in O(N) of the image size.
+        */
+       struct list_head extra_pages;
+       struct page *pages;
+       unsigned int count;
+
+       count = 1 << order;
+       INIT_LIST_HEAD(&extra_pages);
+
+       /* Loop while I can allocate a page and the page allocated
+        * is a destination page.
+        */
+       do {
+               unsigned long pfn, epfn, addr, eaddr;
+
+               pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order);
+               if (!pages)
+                       break;
+               pfn   = page_to_pfn(pages);
+               epfn  = pfn + count;
+               addr  = pfn << PAGE_SHIFT;
+               eaddr = epfn << PAGE_SHIFT;
+               if ((epfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) ||
+                             kimage_is_destination_range(image, addr, eaddr)) {
+                       list_add(&pages->lru, &extra_pages);
+                       pages = NULL;
+               }
+       } while (!pages);
+
+       if (pages) {
+               /* Remember the allocated page... */
+               list_add(&pages->lru, &image->control_pages);
+
+               /* Because the page is already in it's destination
+                * location we will never allocate another page at
+                * that address.  Therefore kimage_alloc_pages
+                * will not return it (again) and we don't need
+                * to give it an entry in image->segment[].
+                */
+       }
+       /* Deal with the destination pages I have inadvertently allocated.
+        *
+        * Ideally I would convert multi-page allocations into single
+        * page allocations, and add everything to image->dest_pages.
+        *
+        * For now it is simpler to just free the pages.
+        */
+       kimage_free_page_list(&extra_pages);
+
+       return pages;
+}
+
+static struct page *kimage_alloc_crash_control_pages(struct kimage *image,
+                                                     unsigned int order)
+{
+       /* Control pages are special, they are the intermediaries
+        * that are needed while we copy the rest of the pages
+        * to their final resting place.  As such they must
+        * not conflict with either the destination addresses
+        * or memory the kernel is already using.
+        *
+        * Control pages are also the only pags we must allocate
+        * when loading a crash kernel.  All of the other pages
+        * are specified by the segments and we just memcpy
+        * into them directly.
+        *
+        * The only case where we really need more than one of
+        * these are for architectures where we cannot disable
+        * the MMU and must instead generate an identity mapped
+        * page table for all of the memory.
+        *
+        * Given the low demand this implements a very simple
+        * allocator that finds the first hole of the appropriate
+        * size in the reserved memory region, and allocates all
+        * of the memory up to and including the hole.
+        */
+       unsigned long hole_start, hole_end, size;
+       struct page *pages;
+
+       pages = NULL;
+       size = (1 << order) << PAGE_SHIFT;
+       hole_start = (image->control_page + (size - 1)) & ~(size - 1);
+       hole_end   = hole_start + size - 1;
+       while (hole_end <= crashk_res.end) {
+               unsigned long i;
+
+               if (hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT)
+                       break;
+               /* See if I overlap any of the segments */
+               for (i = 0; i < image->nr_segments; i++) {
+                       unsigned long mstart, mend;
+
+                       mstart = image->segment[i].mem;
+                       mend   = mstart + image->segment[i].memsz - 1;
+                       if ((hole_end >= mstart) && (hole_start <= mend)) {
+                               /* Advance the hole to the end of the segment */
+                               hole_start = (mend + (size - 1)) & ~(size - 1);
+                               hole_end   = hole_start + size - 1;
+                               break;
+                       }
+               }
+               /* If I don't overlap any segments I have found my hole! */
+               if (i == image->nr_segments) {
+                       pages = pfn_to_page(hole_start >> PAGE_SHIFT);
+                       break;
+               }
+       }
+       if (pages)
+               image->control_page = hole_end;
+
+       return pages;
+}
+
+
+struct page *kimage_alloc_control_pages(struct kimage *image,
+                                        unsigned int order)
+{
+       struct page *pages = NULL;
+
+       switch (image->type) {
+       case KEXEC_TYPE_DEFAULT:
+               pages = kimage_alloc_normal_control_pages(image, order);
+               break;
+       case KEXEC_TYPE_CRASH:
+               pages = kimage_alloc_crash_control_pages(image, order);
+               break;
+       }
+
+       return pages;
+}
+
+static int kimage_add_entry(struct kimage *image, kimage_entry_t entry)
+{
+       if (*image->entry != 0)
+               image->entry++;
+
+       if (image->entry == image->last_entry) {
+               kimage_entry_t *ind_page;
+               struct page *page;
+
+               page = kimage_alloc_page(image, GFP_KERNEL, KIMAGE_NO_DEST);
+               if (!page)
+                       return -ENOMEM;
+
+               ind_page = page_address(page);
+               *image->entry = virt_to_phys(ind_page) | IND_INDIRECTION;
+               image->entry = ind_page;
+               image->last_entry = ind_page +
+                                     ((PAGE_SIZE/sizeof(kimage_entry_t)) - 1);
+       }
+       *image->entry = entry;
+       image->entry++;
+       *image->entry = 0;
+
+       return 0;
+}
+
+static int kimage_set_destination(struct kimage *image,
+                                  unsigned long destination)
+{
+       int result;
+
+       destination &= PAGE_MASK;
+       result = kimage_add_entry(image, destination | IND_DESTINATION);
+
+       return result;
+}
+
+
+static int kimage_add_page(struct kimage *image, unsigned long page)
+{
+       int result;
+
+       page &= PAGE_MASK;
+       result = kimage_add_entry(image, page | IND_SOURCE);
+
+       return result;
+}
+
+
+static void kimage_free_extra_pages(struct kimage *image)
+{
+       /* Walk through and free any extra destination pages I may have */
+       kimage_free_page_list(&image->dest_pages);
+
+       /* Walk through and free any unusable pages I have cached */
+       kimage_free_page_list(&image->unusable_pages);
+
+}
+void kimage_terminate(struct kimage *image)
+{
+       if (*image->entry != 0)
+               image->entry++;
+
+       *image->entry = IND_DONE;
+}
+
+#define for_each_kimage_entry(image, ptr, entry) \
+       for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE); \
+               ptr = (entry & IND_INDIRECTION) ? \
+                       phys_to_virt((entry & PAGE_MASK)) : ptr + 1)
+
+static void kimage_free_entry(kimage_entry_t entry)
+{
+       struct page *page;
+
+       page = pfn_to_page(entry >> PAGE_SHIFT);
+       kimage_free_pages(page);
+}
+
+void kimage_free(struct kimage *image)
+{
+       kimage_entry_t *ptr, entry;
+       kimage_entry_t ind = 0;
+
+       if (!image)
+               return;
+
+       kimage_free_extra_pages(image);
+       for_each_kimage_entry(image, ptr, entry) {
+               if (entry & IND_INDIRECTION) {
+                       /* Free the previous indirection page */
+                       if (ind & IND_INDIRECTION)
+                               kimage_free_entry(ind);
+                       /* Save this indirection page until we are
+                        * done with it.
+                        */
+                       ind = entry;
+               } else if (entry & IND_SOURCE)
+                       kimage_free_entry(entry);
+       }
+       /* Free the final indirection page */
+       if (ind & IND_INDIRECTION)
+               kimage_free_entry(ind);
+
+       /* Handle any machine specific cleanup */
+       machine_kexec_cleanup(image);
+
+       /* Free the kexec control pages... */
+       kimage_free_page_list(&image->control_pages);
+
+       /*
+        * Free up any temporary buffers allocated. This might hit if
+        * error occurred much later after buffer allocation.
+        */
+       if (image->file_mode)
+               kimage_file_post_load_cleanup(image);
+
+       kfree(image);
+}
+
+static kimage_entry_t *kimage_dst_used(struct kimage *image,
+                                       unsigned long page)
+{
+       kimage_entry_t *ptr, entry;
+       unsigned long destination = 0;
+
+       for_each_kimage_entry(image, ptr, entry) {
+               if (entry & IND_DESTINATION)
+                       destination = entry & PAGE_MASK;
+               else if (entry & IND_SOURCE) {
+                       if (page == destination)
+                               return ptr;
+                       destination += PAGE_SIZE;
+               }
+       }
+
+       return NULL;
+}
+
+static struct page *kimage_alloc_page(struct kimage *image,
+                                       gfp_t gfp_mask,
+                                       unsigned long destination)
+{
+       /*
+        * Here we implement safeguards to ensure that a source page
+        * is not copied to its destination page before the data on
+        * the destination page is no longer useful.
+        *
+        * To do this we maintain the invariant that a source page is
+        * either its own destination page, or it is not a
+        * destination page at all.
+        *
+        * That is slightly stronger than required, but the proof
+        * that no problems will not occur is trivial, and the
+        * implementation is simply to verify.
+        *
+        * When allocating all pages normally this algorithm will run
+        * in O(N) time, but in the worst case it will run in O(N^2)
+        * time.   If the runtime is a problem the data structures can
+        * be fixed.
+        */
+       struct page *page;
+       unsigned long addr;
+
+       /*
+        * Walk through the list of destination pages, and see if I
+        * have a match.
+        */
+       list_for_each_entry(page, &image->dest_pages, lru) {
+               addr = page_to_pfn(page) << PAGE_SHIFT;
+               if (addr == destination) {
+                       list_del(&page->lru);
+                       return page;
+               }
+       }
+       page = NULL;
+       while (1) {
+               kimage_entry_t *old;
+
+               /* Allocate a page, if we run out of memory give up */
+               page = kimage_alloc_pages(gfp_mask, 0);
+               if (!page)
+                       return NULL;
+               /* If the page cannot be used file it away */
+               if (page_to_pfn(page) >
+                               (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT)) {
+                       list_add(&page->lru, &image->unusable_pages);
+                       continue;
+               }
+               addr = page_to_pfn(page) << PAGE_SHIFT;
+
+               /* If it is the destination page we want use it */
+               if (addr == destination)
+                       break;
+
+               /* If the page is not a destination page use it */
+               if (!kimage_is_destination_range(image, addr,
+                                                 addr + PAGE_SIZE))
+                       break;
+
+               /*
+                * I know that the page is someones destination page.
+                * See if there is already a source page for this
+                * destination page.  And if so swap the source pages.
+                */
+               old = kimage_dst_used(image, addr);
+               if (old) {
+                       /* If so move it */
+                       unsigned long old_addr;
+                       struct page *old_page;
+
+                       old_addr = *old & PAGE_MASK;
+                       old_page = pfn_to_page(old_addr >> PAGE_SHIFT);
+                       copy_highpage(page, old_page);
+                       *old = addr | (*old & ~PAGE_MASK);
+
+                       /* The old page I have found cannot be a
+                        * destination page, so return it if it's
+                        * gfp_flags honor the ones passed in.
+                        */
+                       if (!(gfp_mask & __GFP_HIGHMEM) &&
+                           PageHighMem(old_page)) {
+                               kimage_free_pages(old_page);
+                               continue;
+                       }
+                       addr = old_addr;
+                       page = old_page;
+                       break;
+               }
+               /* Place the page on the destination list, to be used later */
+               list_add(&page->lru, &image->dest_pages);
+       }
+
+       return page;
+}
+
+static int kimage_load_normal_segment(struct kimage *image,
+                                        struct kexec_segment *segment)
+{
+       unsigned long maddr;
+       size_t ubytes, mbytes;
+       int result;
+       unsigned char __user *buf = NULL;
+       unsigned char *kbuf = NULL;
+
+       result = 0;
+       if (image->file_mode)
+               kbuf = segment->kbuf;
+       else
+               buf = segment->buf;
+       ubytes = segment->bufsz;
+       mbytes = segment->memsz;
+       maddr = segment->mem;
+
+       result = kimage_set_destination(image, maddr);
+       if (result < 0)
+               goto out;
+
+       while (mbytes) {
+               struct page *page;
+               char *ptr;
+               size_t uchunk, mchunk;
+
+               page = kimage_alloc_page(image, GFP_HIGHUSER, maddr);
+               if (!page) {
+                       result  = -ENOMEM;
+                       goto out;
+               }
+               result = kimage_add_page(image, page_to_pfn(page)
+                                                               << PAGE_SHIFT);
+               if (result < 0)
+                       goto out;
+
+               ptr = kmap(page);
+               /* Start with a clear page */
+               clear_page(ptr);
+               ptr += maddr & ~PAGE_MASK;
+               mchunk = min_t(size_t, mbytes,
+                               PAGE_SIZE - (maddr & ~PAGE_MASK));
+               uchunk = min(ubytes, mchunk);
+
+               /* For file based kexec, source pages are in kernel memory */
+               if (image->file_mode)
+                       memcpy(ptr, kbuf, uchunk);
+               else
+                       result = copy_from_user(ptr, buf, uchunk);
+               kunmap(page);
+               if (result) {
+                       result = -EFAULT;
+                       goto out;
+               }
+               ubytes -= uchunk;
+               maddr  += mchunk;
+               if (image->file_mode)
+                       kbuf += mchunk;
+               else
+                       buf += mchunk;
+               mbytes -= mchunk;
+       }
+out:
+       return result;
+}
+
+static int kimage_load_crash_segment(struct kimage *image,
+                                       struct kexec_segment *segment)
+{
+       /* For crash dumps kernels we simply copy the data from
+        * user space to it's destination.
+        * We do things a page at a time for the sake of kmap.
+        */
+       unsigned long maddr;
+       size_t ubytes, mbytes;
+       int result;
+       unsigned char __user *buf = NULL;
+       unsigned char *kbuf = NULL;
+
+       result = 0;
+       if (image->file_mode)
+               kbuf = segment->kbuf;
+       else
+               buf = segment->buf;
+       ubytes = segment->bufsz;
+       mbytes = segment->memsz;
+       maddr = segment->mem;
+       while (mbytes) {
+               struct page *page;
+               char *ptr;
+               size_t uchunk, mchunk;
+
+               page = pfn_to_page(maddr >> PAGE_SHIFT);
+               if (!page) {
+                       result  = -ENOMEM;
+                       goto out;
+               }
+               ptr = kmap(page);
+               ptr += maddr & ~PAGE_MASK;
+               mchunk = min_t(size_t, mbytes,
+                               PAGE_SIZE - (maddr & ~PAGE_MASK));
+               uchunk = min(ubytes, mchunk);
+               if (mchunk > uchunk) {
+                       /* Zero the trailing part of the page */
+                       memset(ptr + uchunk, 0, mchunk - uchunk);
+               }
+
+               /* For file based kexec, source pages are in kernel memory */
+               if (image->file_mode)
+                       memcpy(ptr, kbuf, uchunk);
+               else
+                       result = copy_from_user(ptr, buf, uchunk);
+               kexec_flush_icache_page(page);
+               kunmap(page);
+               if (result) {
+                       result = -EFAULT;
+                       goto out;
+               }
+               ubytes -= uchunk;
+               maddr  += mchunk;
+               if (image->file_mode)
+                       kbuf += mchunk;
+               else
+                       buf += mchunk;
+               mbytes -= mchunk;
+       }
+out:
+       return result;
+}
+
+int kimage_load_segment(struct kimage *image,
+                               struct kexec_segment *segment)
+{
+       int result = -ENOMEM;
+
+       switch (image->type) {
+       case KEXEC_TYPE_DEFAULT:
+               result = kimage_load_normal_segment(image, segment);
+               break;
+       case KEXEC_TYPE_CRASH:
+               result = kimage_load_crash_segment(image, segment);
+               break;
+       }
+
+       return result;
+}
+
+struct kimage *kexec_image;
+struct kimage *kexec_crash_image;
+int kexec_load_disabled;
+
+void crash_kexec(struct pt_regs *regs)
+{
+       /* Take the kexec_mutex here to prevent sys_kexec_load
+        * running on one cpu from replacing the crash kernel
+        * we are using after a panic on a different cpu.
+        *
+        * If the crash kernel was not located in a fixed area
+        * of memory the xchg(&kexec_crash_image) would be
+        * sufficient.  But since I reuse the memory...
+        */
+       if (mutex_trylock(&kexec_mutex)) {
+               if (kexec_crash_image) {
+                       struct pt_regs fixed_regs;
+
+                       crash_setup_regs(&fixed_regs, regs);
+                       crash_save_vmcoreinfo();
+                       machine_crash_shutdown(&fixed_regs);
+                       machine_kexec(kexec_crash_image);
+               }
+               mutex_unlock(&kexec_mutex);
+       }
+}
+
+size_t crash_get_memory_size(void)
+{
+       size_t size = 0;
+
+       mutex_lock(&kexec_mutex);
+       if (crashk_res.end != crashk_res.start)
+               size = resource_size(&crashk_res);
+       mutex_unlock(&kexec_mutex);
+       return size;
+}
+
+void __weak crash_free_reserved_phys_range(unsigned long begin,
+                                          unsigned long end)
+{
+       unsigned long addr;
+
+       for (addr = begin; addr < end; addr += PAGE_SIZE)
+               free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
+}
+
+int crash_shrink_memory(unsigned long new_size)
+{
+       int ret = 0;
+       unsigned long start, end;
+       unsigned long old_size;
+       struct resource *ram_res;
+
+       mutex_lock(&kexec_mutex);
+
+       if (kexec_crash_image) {
+               ret = -ENOENT;
+               goto unlock;
+       }
+       start = crashk_res.start;
+       end = crashk_res.end;
+       old_size = (end == 0) ? 0 : end - start + 1;
+       if (new_size >= old_size) {
+               ret = (new_size == old_size) ? 0 : -EINVAL;
+               goto unlock;
+       }
+
+       ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL);
+       if (!ram_res) {
+               ret = -ENOMEM;
+               goto unlock;
+       }
+
+       start = roundup(start, KEXEC_CRASH_MEM_ALIGN);
+       end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN);
+
+       crash_map_reserved_pages();
+       crash_free_reserved_phys_range(end, crashk_res.end);
+
+       if ((start == end) && (crashk_res.parent != NULL))
+               release_resource(&crashk_res);
+
+       ram_res->start = end;
+       ram_res->end = crashk_res.end;
+       ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
+       ram_res->name = "System RAM";
+
+       crashk_res.end = end - 1;
+
+       insert_resource(&iomem_resource, ram_res);
+       crash_unmap_reserved_pages();
+
+unlock:
+       mutex_unlock(&kexec_mutex);
+       return ret;
+}
+
+static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
+                           size_t data_len)
+{
+       struct elf_note note;
+
+       note.n_namesz = strlen(name) + 1;
+       note.n_descsz = data_len;
+       note.n_type   = type;
+       memcpy(buf, &note, sizeof(note));
+       buf += (sizeof(note) + 3)/4;
+       memcpy(buf, name, note.n_namesz);
+       buf += (note.n_namesz + 3)/4;
+       memcpy(buf, data, note.n_descsz);
+       buf += (note.n_descsz + 3)/4;
+
+       return buf;
+}
+
+static void final_note(u32 *buf)
+{
+       struct elf_note note;
+
+       note.n_namesz = 0;
+       note.n_descsz = 0;
+       note.n_type   = 0;
+       memcpy(buf, &note, sizeof(note));
+}
+
+void crash_save_cpu(struct pt_regs *regs, int cpu)
+{
+       struct elf_prstatus prstatus;
+       u32 *buf;
+
+       if ((cpu < 0) || (cpu >= nr_cpu_ids))
+               return;
+
+       /* Using ELF notes here is opportunistic.
+        * I need a well defined structure format
+        * for the data I pass, and I need tags
+        * on the data to indicate what information I have
+        * squirrelled away.  ELF notes happen to provide
+        * all of that, so there is no need to invent something new.
+        */
+       buf = (u32 *)per_cpu_ptr(crash_notes, cpu);
+       if (!buf)
+               return;
+       memset(&prstatus, 0, sizeof(prstatus));
+       prstatus.pr_pid = current->pid;
+       elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
+       buf = append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
+                             &prstatus, sizeof(prstatus));
+       final_note(buf);
+}
+
+static int __init crash_notes_memory_init(void)
+{
+       /* Allocate memory for saving cpu registers. */
+       crash_notes = alloc_percpu(note_buf_t);
+       if (!crash_notes) {
+               pr_warn("Kexec: Memory allocation for saving cpu register states failed\n");
+               return -ENOMEM;
+       }
+       return 0;
+}
+subsys_initcall(crash_notes_memory_init);
+
+
+/*
+ * parsing the "crashkernel" commandline
+ *
+ * this code is intended to be called from architecture specific code
+ */
+
+
+/*
+ * This function parses command lines in the format
+ *
+ *   crashkernel=ramsize-range:size[,...][@offset]
+ *
+ * The function returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_mem(char *cmdline,
+                                       unsigned long long system_ram,
+                                       unsigned long long *crash_size,
+                                       unsigned long long *crash_base)
+{
+       char *cur = cmdline, *tmp;
+
+       /* for each entry of the comma-separated list */
+       do {
+               unsigned long long start, end = ULLONG_MAX, size;
+
+               /* get the start of the range */
+               start = memparse(cur, &tmp);
+               if (cur == tmp) {
+                       pr_warn("crashkernel: Memory value expected\n");
+                       return -EINVAL;
+               }
+               cur = tmp;
+               if (*cur != '-') {
+                       pr_warn("crashkernel: '-' expected\n");
+                       return -EINVAL;
+               }
+               cur++;
+
+               /* if no ':' is here, than we read the end */
+               if (*cur != ':') {
+                       end = memparse(cur, &tmp);
+                       if (cur == tmp) {
+                               pr_warn("crashkernel: Memory value expected\n");
+                               return -EINVAL;
+                       }
+                       cur = tmp;
+                       if (end <= start) {
+                               pr_warn("crashkernel: end <= start\n");
+                               return -EINVAL;
+                       }
+               }
+
+               if (*cur != ':') {
+                       pr_warn("crashkernel: ':' expected\n");
+                       return -EINVAL;
+               }
+               cur++;
+
+               size = memparse(cur, &tmp);
+               if (cur == tmp) {
+                       pr_warn("Memory value expected\n");
+                       return -EINVAL;
+               }
+               cur = tmp;
+               if (size >= system_ram) {
+                       pr_warn("crashkernel: invalid size\n");
+                       return -EINVAL;
+               }
+
+               /* match ? */
+               if (system_ram >= start && system_ram < end) {
+                       *crash_size = size;
+                       break;
+               }
+       } while (*cur++ == ',');
+
+       if (*crash_size > 0) {
+               while (*cur && *cur != ' ' && *cur != '@')
+                       cur++;
+               if (*cur == '@') {
+                       cur++;
+                       *crash_base = memparse(cur, &tmp);
+                       if (cur == tmp) {
+                               pr_warn("Memory value expected after '@'\n");
+                               return -EINVAL;
+                       }
+               }
+       }
+
+       return 0;
+}
+
+/*
+ * That function parses "simple" (old) crashkernel command lines like
+ *
+ *     crashkernel=size[@offset]
+ *
+ * It returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_simple(char *cmdline,
+                                          unsigned long long *crash_size,
+                                          unsigned long long *crash_base)
+{
+       char *cur = cmdline;
+
+       *crash_size = memparse(cmdline, &cur);
+       if (cmdline == cur) {
+               pr_warn("crashkernel: memory value expected\n");
+               return -EINVAL;
+       }
+
+       if (*cur == '@')
+               *crash_base = memparse(cur+1, &cur);
+       else if (*cur != ' ' && *cur != '\0') {
+               pr_warn("crashkernel: unrecognized char\n");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+#define SUFFIX_HIGH 0
+#define SUFFIX_LOW  1
+#define SUFFIX_NULL 2
+static __initdata char *suffix_tbl[] = {
+       [SUFFIX_HIGH] = ",high",
+       [SUFFIX_LOW]  = ",low",
+       [SUFFIX_NULL] = NULL,
+};
+
+/*
+ * That function parses "suffix"  crashkernel command lines like
+ *
+ *     crashkernel=size,[high|low]
+ *
+ * It returns 0 on success and -EINVAL on failure.
+ */
+static int __init parse_crashkernel_suffix(char *cmdline,
+                                          unsigned long long   *crash_size,
+                                          const char *suffix)
+{
+       char *cur = cmdline;
+
+       *crash_size = memparse(cmdline, &cur);
+       if (cmdline == cur) {
+               pr_warn("crashkernel: memory value expected\n");
+               return -EINVAL;
+       }
+
+       /* check with suffix */
+       if (strncmp(cur, suffix, strlen(suffix))) {
+               pr_warn("crashkernel: unrecognized char\n");
+               return -EINVAL;
+       }
+       cur += strlen(suffix);
+       if (*cur != ' ' && *cur != '\0') {
+               pr_warn("crashkernel: unrecognized char\n");
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static __init char *get_last_crashkernel(char *cmdline,
+                            const char *name,
+                            const char *suffix)
+{
+       char *p = cmdline, *ck_cmdline = NULL;
+
+       /* find crashkernel and use the last one if there are more */
+       p = strstr(p, name);
+       while (p) {
+               char *end_p = strchr(p, ' ');
+               char *q;
+
+               if (!end_p)
+                       end_p = p + strlen(p);
+
+               if (!suffix) {
+                       int i;
+
+                       /* skip the one with any known suffix */
+                       for (i = 0; suffix_tbl[i]; i++) {
+                               q = end_p - strlen(suffix_tbl[i]);
+                               if (!strncmp(q, suffix_tbl[i],
+                                            strlen(suffix_tbl[i])))
+                                       goto next;
+                       }
+                       ck_cmdline = p;
+               } else {
+                       q = end_p - strlen(suffix);
+                       if (!strncmp(q, suffix, strlen(suffix)))
+                               ck_cmdline = p;
+               }
+next:
+               p = strstr(p+1, name);
+       }
+
+       if (!ck_cmdline)
+               return NULL;
+
+       return ck_cmdline;
+}
+
+static int __init __parse_crashkernel(char *cmdline,
+                            unsigned long long system_ram,
+                            unsigned long long *crash_size,
+                            unsigned long long *crash_base,
+                            const char *name,
+                            const char *suffix)
+{
+       char    *first_colon, *first_space;
+       char    *ck_cmdline;
+
+       BUG_ON(!crash_size || !crash_base);
+       *crash_size = 0;
+       *crash_base = 0;
+
+       ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
+
+       if (!ck_cmdline)
+               return -EINVAL;
+
+       ck_cmdline += strlen(name);
+
+       if (suffix)
+               return parse_crashkernel_suffix(ck_cmdline, crash_size,
+                               suffix);
+       /*
+        * if the commandline contains a ':', then that's the extended
+        * syntax -- if not, it must be the classic syntax
+        */
+       first_colon = strchr(ck_cmdline, ':');
+       first_space = strchr(ck_cmdline, ' ');
+       if (first_colon && (!first_space || first_colon < first_space))
+               return parse_crashkernel_mem(ck_cmdline, system_ram,
+                               crash_size, crash_base);
+
+       return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
+}
+
+/*
+ * That function is the entry point for command line parsing and should be
+ * called from the arch-specific code.
+ */
+int __init parse_crashkernel(char *cmdline,
+                            unsigned long long system_ram,
+                            unsigned long long *crash_size,
+                            unsigned long long *crash_base)
+{
+       return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
+                                       "crashkernel=", NULL);
+}
+
+int __init parse_crashkernel_high(char *cmdline,
+                            unsigned long long system_ram,
+                            unsigned long long *crash_size,
+                            unsigned long long *crash_base)
+{
+       return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
+                               "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
+}
+
+int __init parse_crashkernel_low(char *cmdline,
+                            unsigned long long system_ram,
+                            unsigned long long *crash_size,
+                            unsigned long long *crash_base)
+{
+       return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
+                               "crashkernel=", suffix_tbl[SUFFIX_LOW]);
+}
+
+static void update_vmcoreinfo_note(void)
+{
+       u32 *buf = vmcoreinfo_note;
+
+       if (!vmcoreinfo_size)
+               return;
+       buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
+                             vmcoreinfo_size);
+       final_note(buf);
+}
+
+void crash_save_vmcoreinfo(void)
+{
+       vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds());
+       update_vmcoreinfo_note();
+}
+
+void vmcoreinfo_append_str(const char *fmt, ...)
+{
+       va_list args;
+       char buf[0x50];
+       size_t r;
+
+       va_start(args, fmt);
+       r = vscnprintf(buf, sizeof(buf), fmt, args);
+       va_end(args);
+
+       r = min(r, vmcoreinfo_max_size - vmcoreinfo_size);
+
+       memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
+
+       vmcoreinfo_size += r;
+}
+
+/*
+ * provide an empty default implementation here -- architecture
+ * code may override this
+ */
+void __weak arch_crash_save_vmcoreinfo(void)
+{}
+
+unsigned long __weak paddr_vmcoreinfo_note(void)
+{
+       return __pa((unsigned long)(char *)&vmcoreinfo_note);
+}
+
+static int __init crash_save_vmcoreinfo_init(void)
+{
+       VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
+       VMCOREINFO_PAGESIZE(PAGE_SIZE);
+
+       VMCOREINFO_SYMBOL(init_uts_ns);
+       VMCOREINFO_SYMBOL(node_online_map);
+#ifdef CONFIG_MMU
+       VMCOREINFO_SYMBOL(swapper_pg_dir);
+#endif
+       VMCOREINFO_SYMBOL(_stext);
+       VMCOREINFO_SYMBOL(vmap_area_list);
+
+#ifndef CONFIG_NEED_MULTIPLE_NODES
+       VMCOREINFO_SYMBOL(mem_map);
+       VMCOREINFO_SYMBOL(contig_page_data);
+#endif
+#ifdef CONFIG_SPARSEMEM
+       VMCOREINFO_SYMBOL(mem_section);
+       VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
+       VMCOREINFO_STRUCT_SIZE(mem_section);
+       VMCOREINFO_OFFSET(mem_section, section_mem_map);
+#endif
+       VMCOREINFO_STRUCT_SIZE(page);
+       VMCOREINFO_STRUCT_SIZE(pglist_data);
+       VMCOREINFO_STRUCT_SIZE(zone);
+       VMCOREINFO_STRUCT_SIZE(free_area);
+       VMCOREINFO_STRUCT_SIZE(list_head);
+       VMCOREINFO_SIZE(nodemask_t);
+       VMCOREINFO_OFFSET(page, flags);
+       VMCOREINFO_OFFSET(page, _count);
+       VMCOREINFO_OFFSET(page, mapping);
+       VMCOREINFO_OFFSET(page, lru);
+       VMCOREINFO_OFFSET(page, _mapcount);
+       VMCOREINFO_OFFSET(page, private);
+       VMCOREINFO_OFFSET(pglist_data, node_zones);
+       VMCOREINFO_OFFSET(pglist_data, nr_zones);
+#ifdef CONFIG_FLAT_NODE_MEM_MAP
+       VMCOREINFO_OFFSET(pglist_data, node_mem_map);
+#endif
+       VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
+       VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
+       VMCOREINFO_OFFSET(pglist_data, node_id);
+       VMCOREINFO_OFFSET(zone, free_area);
+       VMCOREINFO_OFFSET(zone, vm_stat);
+       VMCOREINFO_OFFSET(zone, spanned_pages);
+       VMCOREINFO_OFFSET(free_area, free_list);
+       VMCOREINFO_OFFSET(list_head, next);
+       VMCOREINFO_OFFSET(list_head, prev);
+       VMCOREINFO_OFFSET(vmap_area, va_start);
+       VMCOREINFO_OFFSET(vmap_area, list);
+       VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
+       log_buf_kexec_setup();
+       VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
+       VMCOREINFO_NUMBER(NR_FREE_PAGES);
+       VMCOREINFO_NUMBER(PG_lru);
+       VMCOREINFO_NUMBER(PG_private);
+       VMCOREINFO_NUMBER(PG_swapcache);
+       VMCOREINFO_NUMBER(PG_slab);
+#ifdef CONFIG_MEMORY_FAILURE
+       VMCOREINFO_NUMBER(PG_hwpoison);
+#endif
+       VMCOREINFO_NUMBER(PG_head_mask);
+       VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
+#ifdef CONFIG_HUGETLBFS
+       VMCOREINFO_SYMBOL(free_huge_page);
+#endif
+
+       arch_crash_save_vmcoreinfo();
+       update_vmcoreinfo_note();
+
+       return 0;
+}
+
+subsys_initcall(crash_save_vmcoreinfo_init);
+
+/*
+ * Move into place and start executing a preloaded standalone
+ * executable.  If nothing was preloaded return an error.
+ */
+int kernel_kexec(void)
+{
+       int error = 0;
+
+       if (!mutex_trylock(&kexec_mutex))
+               return -EBUSY;
+       if (!kexec_image) {
+               error = -EINVAL;
+               goto Unlock;
+       }
+
+#ifdef CONFIG_KEXEC_JUMP
+       if (kexec_image->preserve_context) {
+               lock_system_sleep();
+               pm_prepare_console();
+               error = freeze_processes();
+               if (error) {
+                       error = -EBUSY;
+                       goto Restore_console;
+               }
+               suspend_console();
+               error = dpm_suspend_start(PMSG_FREEZE);
+               if (error)
+                       goto Resume_console;
+               /* At this point, dpm_suspend_start() has been called,
+                * but *not* dpm_suspend_end(). We *must* call
+                * dpm_suspend_end() now.  Otherwise, drivers for
+                * some devices (e.g. interrupt controllers) become
+                * desynchronized with the actual state of the
+                * hardware at resume time, and evil weirdness ensues.
+                */
+               error = dpm_suspend_end(PMSG_FREEZE);
+               if (error)
+                       goto Resume_devices;
+               error = disable_nonboot_cpus();
+               if (error)
+                       goto Enable_cpus;
+               local_irq_disable();
+               error = syscore_suspend();
+               if (error)
+                       goto Enable_irqs;
+       } else
+#endif
+       {
+               kexec_in_progress = true;
+               kernel_restart_prepare(NULL);
+               migrate_to_reboot_cpu();
+
+               /*
+                * migrate_to_reboot_cpu() disables CPU hotplug assuming that
+                * no further code needs to use CPU hotplug (which is true in
+                * the reboot case). However, the kexec path depends on using
+                * CPU hotplug again; so re-enable it here.
+                */
+               cpu_hotplug_enable();
+               pr_emerg("Starting new kernel\n");
+               machine_shutdown();
+       }
+
+       machine_kexec(kexec_image);
+
+#ifdef CONFIG_KEXEC_JUMP
+       if (kexec_image->preserve_context) {
+               syscore_resume();
+ Enable_irqs:
+               local_irq_enable();
+ Enable_cpus:
+               enable_nonboot_cpus();
+               dpm_resume_start(PMSG_RESTORE);
+ Resume_devices:
+               dpm_resume_end(PMSG_RESTORE);
+ Resume_console:
+               resume_console();
+               thaw_processes();
+ Restore_console:
+               pm_restore_console();
+               unlock_system_sleep();
+       }
+#endif
+
+ Unlock:
+       mutex_unlock(&kexec_mutex);
+       return error;
+}
+
+/*
+ * Add and remove page tables for crashkernel memory
+ *
+ * Provide an empty default implementation here -- architecture
+ * code may override this
+ */
+void __weak crash_map_reserved_pages(void)
+{}
+
+void __weak crash_unmap_reserved_pages(void)
+{}
index 6683ccef9fffb2de28b6a4d6d01393b080811d6a..e83b264640615c47c31cce539f31014dc11b0776 100644 (file)
@@ -90,7 +90,7 @@ static ssize_t profiling_store(struct kobject *kobj,
 KERNEL_ATTR_RW(profiling);
 #endif
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 static ssize_t kexec_loaded_show(struct kobject *kobj,
                                 struct kobj_attribute *attr, char *buf)
 {
@@ -134,7 +134,7 @@ static ssize_t vmcoreinfo_show(struct kobject *kobj,
 }
 KERNEL_ATTR_RO(vmcoreinfo);
 
-#endif /* CONFIG_KEXEC */
+#endif /* CONFIG_KEXEC_CORE */
 
 /* whether file capabilities are enabled */
 static ssize_t fscaps_show(struct kobject *kobj,
@@ -196,7 +196,7 @@ static struct attribute * kernel_attrs[] = {
 #ifdef CONFIG_PROFILING
        &profiling_attr.attr,
 #endif
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        &kexec_loaded_attr.attr,
        &kexec_crash_loaded_attr.attr,
        &kexec_crash_size_attr.attr,
index cf8c24203368651af417eba7525a053e9cc8ff93..8f0324ef72ab374925badb5454aa0a79ae731c61 100644 (file)
@@ -835,7 +835,7 @@ const struct file_operations kmsg_fops = {
        .release = devkmsg_release,
 };
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
 /*
  * This appends the listed symbols to /proc/vmcore
  *
index d20c85d9f8c0d71df00a2ac7297d4ace5ed18323..bd30a973fe946b03916a1eeb873928adfe1b32b0 100644 (file)
@@ -346,7 +346,7 @@ SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
                kernel_restart(buffer);
                break;
 
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        case LINUX_REBOOT_CMD_KEXEC:
                ret = kernel_kexec();
                break;
index 19b62b522158acb6414cd7440b25e64bd16add35..715cc57cc66acbec4b9c67cbbe4768fe4a1f9b7b 100644 (file)
@@ -621,7 +621,7 @@ static struct ctl_table kern_table[] = {
                .proc_handler   = proc_dointvec,
        },
 #endif
-#ifdef CONFIG_KEXEC
+#ifdef CONFIG_KEXEC_CORE
        {
                .procname       = "kexec_load_disabled",
                .data           = &kexec_load_disabled,