uml: fix stub address calculations
authorJeff Dike <jdike@addtoit.com>
Tue, 16 Oct 2007 08:27:33 +0000 (01:27 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Tue, 16 Oct 2007 16:43:09 +0000 (09:43 -0700)
The calculation of CONFIG_STUB_CODE and CONFIG_STUB_DATA didn't take into
account anything but 3G/1G and 2G/2G, leaving the other vmsplits out in the
cold.

I'd rather not duplicate the four known host vmsplit cases for each of these
symbols.  I'd also like to calculate them based on the highest userspace
address.

The Kconfig language seems not to allow calculation of hex constants, so I
moved this to as-layout.h.  CONFIG_STUB_CODE, CONFIG_STUB_DATA, and
CONFIG_STUB_START are now gone.  In their place are STUB_CODE, STUB_DATA, and
STUB_START in as-layout.h.

i386 and x86_64 seem to differ as to whether an unadorned constant is an int
or a long, so I cast them to unsigned long so they can be printed
consistently.  However, they are also used in stub.S, where C types don't work
so well.  So, there are ASM_ versions of these constants for use in stub.S.  I
also ifdef-ed the non-asm-friendly portion of as-layout.h.

With this in place, most of the rest of this patch is changing CONFIG_STUB_*
to STUB_*, except in stub.S, where they are changed to ASM_STUB_*.

defconfig has the old symbols deleted.

I also print these addresses out in case there is any problem mapping them on
the host.

The two stub.S files had some trailing whitespace, so that is cleaned up here.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
18 files changed:
arch/um/Kconfig.i386
arch/um/Kconfig.x86_64
arch/um/defconfig
arch/um/include/as-layout.h
arch/um/include/sysdep-i386/stub.h
arch/um/include/sysdep-x86_64/stub.h
arch/um/kernel/exec.c
arch/um/kernel/skas/clone.c
arch/um/kernel/skas/mmu.c
arch/um/kernel/skas/process.c
arch/um/kernel/tlb.c
arch/um/kernel/um_arch.c
arch/um/os-Linux/skas/mem.c
arch/um/os-Linux/skas/process.c
arch/um/sys-i386/stub.S
arch/um/sys-i386/stub_segv.c
arch/um/sys-x86_64/stub.S
arch/um/sys-x86_64/stub_segv.c

index d6cffb27fff8159b255177a09ac68e1899fd0d01..9876d80d85ddccdba00e5e89cd1e54db6ab8612b 100644 (file)
@@ -65,20 +65,6 @@ config 3_LEVEL_PGTABLES
        However, this it experimental on 32-bit architectures, so if unsure say
        N (on x86-64 it's automatically enabled, instead, as it's safe there).
 
-config STUB_CODE
-       hex
-       default 0xbfffe000 if !HOST_VMSPLIT_2G
-       default 0x7fffe000 if HOST_VMSPLIT_2G
-
-config STUB_DATA
-       hex
-       default 0xbffff000 if !HOST_VMSPLIT_2G
-       default 0x7ffff000 if HOST_VMSPLIT_2G
-
-config STUB_START
-       hex
-       default STUB_CODE
-
 config ARCH_HAS_SC_SIGNALS
        bool
        default y
index f60e9e506424cf91e6b97ff61105a7dfc4b4788d..d632e9a89cc3d671ab69730cb5d0e457457e30d9 100644 (file)
@@ -17,24 +17,12 @@ config SEMAPHORE_SLEEPERS
 
 config TOP_ADDR
        hex
-       default 0x80000000
+       default 0x7fc0000000
 
 config 3_LEVEL_PGTABLES
        bool
        default y
 
-config STUB_CODE
-       hex
-       default 0x7fbfffe000
-
-config STUB_DATA
-       hex
-       default 0x7fbffff000
-
-config STUB_START
-       hex
-       default STUB_CODE
-
 config ARCH_HAS_SC_SIGNALS
        bool
        default n
index 1cbbe980f10621bfcf0d0f1d595463aa2367c354..f609edede0657fe5cebb1641a8458cb66e9cdd96 100644 (file)
@@ -59,9 +59,6 @@ CONFIG_SEMAPHORE_SLEEPERS=y
 # CONFIG_HOST_2G_2G is not set
 CONFIG_TOP_ADDR=0xc0000000
 # CONFIG_3_LEVEL_PGTABLES is not set
-CONFIG_STUB_CODE=0xbfffe000
-CONFIG_STUB_DATA=0xbffff000
-CONFIG_STUB_START=0xbfffe000
 CONFIG_ARCH_HAS_SC_SIGNALS=y
 CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA=y
 CONFIG_GENERIC_HWEIGHT=y
index 2f16a1c7d6163e3bed009045137c2df30e244405..a5cdf953e04a964569e9ea6f2912e9a9b9d6369a 100644 (file)
@@ -6,6 +6,28 @@
 #ifndef __START_H__
 #define __START_H__
 
+#include "uml-config.h"
+#include "kern_constants.h"
+
+/*
+ * Assembly doesn't want any casting, but C does, so define these
+ * without casts here, and define new symbols with casts inside the C
+ * section.
+ */
+#define ASM_STUB_CODE (UML_CONFIG_TOP_ADDR - 2 * UM_KERN_PAGE_SIZE)
+#define ASM_STUB_DATA (UML_CONFIG_TOP_ADDR - UM_KERN_PAGE_SIZE)
+#define ASM_STUB_START ASM_STUB_CODE
+
+/*
+ * This file is included by the assembly stubs, which just want the
+ * definitions above.
+ */
+#ifndef __ASSEMBLY__
+
+#define STUB_CODE ((unsigned long) ASM_STUB_CODE)
+#define STUB_DATA ((unsigned long) ASM_STUB_DATA)
+#define STUB_START ((unsigned long) ASM_STUB_START)
+
 #include "sysdep/ptrace.h"
 
 struct cpu_task {
@@ -32,3 +54,5 @@ extern int linux_main(int argc, char **argv);
 extern void (*sig_info[])(int, struct uml_pt_regs *);
 
 #endif
+
+#endif
index 19c85f330fc1602af09cb6ca9f19953bc6a0ba32..8c097b87fca7be4b3ea209feff41aa4fa2adc3d6 100644 (file)
@@ -9,6 +9,7 @@
 #include <sys/mman.h>
 #include <asm/ptrace.h>
 #include <asm/unistd.h>
+#include "as-layout.h"
 #include "stub-data.h"
 #include "kern_constants.h"
 #include "uml-config.h"
@@ -89,12 +90,12 @@ static inline void remap_stack(int fd, unsigned long offset)
 {
        __asm__ volatile ("movl %%eax,%%ebp ; movl %0,%%eax ; int $0x80 ;"
                          "movl %7, %%ebx ; movl %%eax, (%%ebx)"
-                         : : "g" (STUB_MMAP_NR), "b" (UML_CONFIG_STUB_DATA), 
-                           "c" (UM_KERN_PAGE_SIZE), 
+                         : : "g" (STUB_MMAP_NR), "b" (STUB_DATA),
+                           "c" (UM_KERN_PAGE_SIZE),
                            "d" (PROT_READ | PROT_WRITE),
-                           "S" (MAP_FIXED | MAP_SHARED), "D" (fd), 
-                           "a" (offset), 
-                           "i" (&((struct stub_data *) UML_CONFIG_STUB_DATA)->err) 
+                           "S" (MAP_FIXED | MAP_SHARED), "D" (fd),
+                           "a" (offset),
+                           "i" (&((struct stub_data *) STUB_DATA)->err)
                          : "memory");
 }
 
index 92e989f81761d64f0616fc5be6aa6da18fd2676e..655f9c2de3ac0b127a6e57729b5d5ab3de7b9540 100644 (file)
@@ -9,6 +9,7 @@
 #include <sys/mman.h>
 #include <asm/unistd.h>
 #include <sysdep/ptrace_user.h>
+#include "as-layout.h"
 #include "stub-data.h"
 #include "kern_constants.h"
 #include "uml-config.h"
@@ -94,13 +95,13 @@ static inline void remap_stack(long fd, unsigned long offset)
 {
        __asm__ volatile ("movq %4,%%r10 ; movq %5,%%r8 ; "
                          "movq %6, %%r9; " __syscall "; movq %7, %%rbx ; "
-                         "movq %%rax, (%%rbx)": 
-                         : "a" (STUB_MMAP_NR), "D" (UML_CONFIG_STUB_DATA), 
-                           "S" (UM_KERN_PAGE_SIZE), 
-                           "d" (PROT_READ | PROT_WRITE), 
-                            "g" (MAP_FIXED | MAP_SHARED), "g" (fd), 
+                         "movq %%rax, (%%rbx)":
+                         : "a" (STUB_MMAP_NR), "D" (STUB_DATA),
+                           "S" (UM_KERN_PAGE_SIZE),
+                           "d" (PROT_READ | PROT_WRITE),
+                            "g" (MAP_FIXED | MAP_SHARED), "g" (fd),
                            "g" (offset),
-                           "i" (&((struct stub_data *) UML_CONFIG_STUB_DATA)->err)
+                           "i" (&((struct stub_data *) STUB_DATA)->err)
                          : __syscall_clobber, "r10", "r8", "r9" );
 }
 
index 7c77adecd9193d899531b3ffe80e4e6497beeebf..8196450451cd6332d6b76eb97bbb3b9ffc93a17f 100644 (file)
@@ -11,6 +11,7 @@
 #include "asm/current.h"
 #include "asm/processor.h"
 #include "asm/uaccess.h"
+#include "as-layout.h"
 #include "mem_user.h"
 #include "skas.h"
 #include "os.h"
@@ -18,7 +19,7 @@
 void flush_thread(void)
 {
        void *data = NULL;
-       unsigned long end = proc_mm ? task_size : CONFIG_STUB_START;
+       unsigned long end = proc_mm ? task_size : STUB_START;
        int ret;
 
        arch_flush_thread(&current->thread.arch);
index 47b812b3bca88b965b48563de658db9ada72fd81..d119f4f7d8971ee7576e6c7db57c59bd3d4704a5 100644 (file)
@@ -4,6 +4,7 @@
 #include <sys/time.h>
 #include <asm/unistd.h>
 #include <asm/page.h>
+#include "as-layout.h"
 #include "ptrace_user.h"
 #include "skas.h"
 #include "stub-data.h"
 void __attribute__ ((__section__ (".__syscall_stub")))
 stub_clone_handler(void)
 {
-       struct stub_data *data = (struct stub_data *) UML_CONFIG_STUB_DATA;
+       struct stub_data *data = (struct stub_data *) STUB_DATA;
        long err;
 
        err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD,
-                           UML_CONFIG_STUB_DATA + UM_KERN_PAGE_SIZE / 2 -
-                           sizeof(void *));
+                           STUB_DATA + UM_KERN_PAGE_SIZE / 2 - sizeof(void *));
        if(err != 0)
                goto out;
 
index ae79888cf5200b76eab111dabf29ca2642c33d67..f859ec306cd5ded54f4239bba0519d58eb52f2e3 100644 (file)
@@ -7,6 +7,7 @@
 #include "linux/sched.h"
 #include "asm/pgalloc.h"
 #include "asm/pgtable.h"
+#include "as-layout.h"
 #include "os.h"
 #include "skas.h"
 
@@ -83,12 +84,12 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm)
                 */
                mm->pgd[USER_PTRS_PER_PGD] = __pgd(0);
 
-               ret = init_stub_pte(mm, CONFIG_STUB_CODE,
+               ret = init_stub_pte(mm, STUB_CODE,
                                    (unsigned long) &__syscall_stub_start);
                if (ret)
                        goto out_free;
 
-               ret = init_stub_pte(mm, CONFIG_STUB_DATA, stack);
+               ret = init_stub_pte(mm, STUB_DATA, stack);
                if (ret)
                        goto out_free;
 
index 0297e63f9725c1bbbcc121e412a5f07bd7f52940..fce389c2342f3d942cdae4d047edbb1f3a2bab50 100644 (file)
@@ -18,7 +18,7 @@ int new_mm(unsigned long stack)
                return fd;
 
        if (skas_needs_stub)
-               map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
+               map_stub_pages(fd, STUB_CODE, STUB_DATA, stack);
 
        return fd;
 }
index 942f20ea888aa89dde2cfd52a3dbf5826090d77b..f4a0e407eee4d66e9fb8b62db6a3e36110d2854a 100644 (file)
@@ -485,8 +485,8 @@ void __flush_tlb_one(unsigned long addr)
 static void fix_range(struct mm_struct *mm, unsigned long start_addr,
                      unsigned long end_addr, int force)
 {
-       if (!proc_mm && (end_addr > CONFIG_STUB_START))
-               end_addr = CONFIG_STUB_START;
+       if (!proc_mm && (end_addr > STUB_START))
+               end_addr = STUB_START;
 
        fix_range_common(mm, start_addr, end_addr, force);
 }
@@ -510,7 +510,7 @@ void flush_tlb_mm(struct mm_struct *mm)
        if (atomic_read(&mm->mm_users) == 0)
                return;
 
-       end = proc_mm ? task_size : CONFIG_STUB_START;
+       end = proc_mm ? task_size : STUB_START;
        fix_range(mm, 0, end, 0);
 }
 
index 1993e5e1225659f43d36e7b3953f1969cb698f23..f1c71393f57810feb8368b256f7dab7bf5111a43 100644 (file)
@@ -242,7 +242,8 @@ static unsigned long set_task_sizes_skas(unsigned long *task_size_out)
 
        if (!skas_needs_stub)
                *task_size_out = host_task_size;
-       else *task_size_out = CONFIG_STUB_START & PGDIR_MASK;
+       else
+               *task_size_out = STUB_START & PGDIR_MASK;
 
        return host_task_size;
 }
index d58d11179bb7ce1bde906e89d1b1079b9e03afe9..484e68f9f7ae7362a0e36b87505ed9048f7302f2 100644 (file)
@@ -10,6 +10,7 @@
 #include <sys/mman.h>
 #include "init.h"
 #include "kern_constants.h"
+#include "as-layout.h"
 #include "mm_id.h"
 #include "os.h"
 #include "proc_mm.h"
@@ -40,7 +41,7 @@ static unsigned long syscall_regs[MAX_REG_NR];
 static int __init init_syscall_regs(void)
 {
        get_safe_registers(syscall_regs);
-       syscall_regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
+       syscall_regs[REGS_IP_INDEX] = STUB_CODE +
                ((unsigned long) &batch_syscall_stub -
                 (unsigned long) &__syscall_stub_start);
        return 0;
@@ -93,8 +94,7 @@ static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
        ret = *((unsigned long *) mm_idp->stack);
        offset = *((unsigned long *) mm_idp->stack + 1);
        if (offset) {
-               data = (unsigned long *)(mm_idp->stack +
-                                        offset - UML_CONFIG_STUB_DATA);
+               data = (unsigned long *)(mm_idp->stack + offset - STUB_DATA);
                printk(UM_KERN_ERR "do_syscall_stub : ret = %ld, offset = %ld, "
                       "data = %p\n", ret, offset, data);
                syscall = (unsigned long *)((unsigned long)data + data[0]);
@@ -182,7 +182,7 @@ long syscall_stub_data(struct mm_id * mm_idp,
        memcpy(stack + 1, data, data_count * sizeof(long));
 
        *stub_addr = (void *)(((unsigned long)(stack + 1) &
-                              ~UM_KERN_PAGE_MASK) + UML_CONFIG_STUB_DATA);
+                              ~UM_KERN_PAGE_MASK) + STUB_DATA);
 
        return 0;
 }
index 8548f126d6287c0af594469644dd4109cce9069e..e60d6e6c5a58a913c0abbce0f0d8b78c01857afb 100644 (file)
@@ -191,22 +191,23 @@ static int userspace_tramp(void *stack)
                int fd;
                unsigned long long offset;
                fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
-               addr = mmap64((void *) UML_CONFIG_STUB_CODE, UM_KERN_PAGE_SIZE,
+               addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE,
                              PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
                if (addr == MAP_FAILED) {
-                       printk(UM_KERN_ERR "mapping mmap stub failed, "
-                              "errno = %d\n", errno);
+                       printk(UM_KERN_ERR "mapping mmap stub at 0x%lx failed, "
+                              "errno = %d\n", STUB_CODE, errno);
                        exit(1);
                }
 
                if (stack != NULL) {
                        fd = phys_mapping(to_phys(stack), &offset);
-                       addr = mmap((void *) UML_CONFIG_STUB_DATA,
+                       addr = mmap((void *) STUB_DATA,
                                    UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
                                    MAP_FIXED | MAP_SHARED, fd, offset);
                        if (addr == MAP_FAILED) {
                                printk(UM_KERN_ERR "mapping segfault stack "
-                                      "failed, errno = %d\n", errno);
+                                      "at 0x%lx failed, errno = %d\n",
+                                      STUB_DATA, errno);
                                exit(1);
                        }
                }
@@ -214,11 +215,11 @@ static int userspace_tramp(void *stack)
        if (!ptrace_faultinfo && (stack != NULL)) {
                struct sigaction sa;
 
-               unsigned long v = UML_CONFIG_STUB_CODE +
+               unsigned long v = STUB_CODE +
                                  (unsigned long) stub_segv_handler -
                                  (unsigned long) &__syscall_stub_start;
 
-               set_sigstack((void *) UML_CONFIG_STUB_DATA, UM_KERN_PAGE_SIZE);
+               set_sigstack((void *) STUB_DATA, UM_KERN_PAGE_SIZE);
                sigemptyset(&sa.sa_mask);
                sigaddset(&sa.sa_mask, SIGIO);
                sigaddset(&sa.sa_mask, SIGWINCH);
@@ -382,10 +383,10 @@ static int __init init_thread_regs(void)
 {
        get_safe_registers(thread_regs);
        /* Set parent's instruction pointer to start of clone-stub */
-       thread_regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
+       thread_regs[REGS_IP_INDEX] = STUB_CODE +
                                (unsigned long) stub_clone_handler -
                                (unsigned long) &__syscall_stub_start;
-       thread_regs[REGS_SP_INDEX] = UML_CONFIG_STUB_DATA + UM_KERN_PAGE_SIZE -
+       thread_regs[REGS_SP_INDEX] = STUB_DATA + UM_KERN_PAGE_SIZE -
                sizeof(void *);
 #ifdef __SIGNAL_FRAMESIZE
        thread_regs[REGS_SP_INDEX] -= __SIGNAL_FRAMESIZE;
@@ -443,7 +444,7 @@ int copy_context_skas0(unsigned long new_stack, int pid)
         * child's stack and check it.
         */
        wait_stub_done(pid);
-       if (child_data->err != UML_CONFIG_STUB_DATA)
+       if (child_data->err != STUB_DATA)
                panic("copy_context_skas0 - stub-child reports error %ld\n",
                      child_data->err);
 
index 6a70d9ab5c2905177429ba9b0f3ae2c1fc084fad..e730772c401b53206810ceb387aa56b9f4f06cf9 100644 (file)
@@ -1,4 +1,5 @@
 #include "uml-config.h"
+#include "as-layout.h"
 
        .globl syscall_stub
 .section .__syscall_stub, "x"
@@ -6,7 +7,7 @@
        .globl batch_syscall_stub
 batch_syscall_stub:
        /* load pointer to first operation */
-       mov     $(UML_CONFIG_STUB_DATA+8), %esp
+       mov     $(ASM_STUB_DATA+8), %esp
 
 again:
        /* load length of additional data */
@@ -14,12 +15,12 @@ again:
 
        /* if(length == 0) : end of list */
        /* write possible 0 to header */
-       mov     %eax, UML_CONFIG_STUB_DATA+4
+       mov     %eax, ASM_STUB_DATA+4
        cmpl    $0, %eax
        jz      done
 
        /* save current pointer */
-       mov     %esp, UML_CONFIG_STUB_DATA+4
+       mov     %esp, ASM_STUB_DATA+4
 
        /* skip additional data */
        add     %eax, %esp
@@ -45,7 +46,7 @@ again:
 
 done:
        /* save return value */
-       mov     %eax, UML_CONFIG_STUB_DATA
+       mov     %eax, ASM_STUB_DATA
 
        /* stop */
        int3
index 2355dc19c46c544db5627b4e6f678903a23a5a0c..b3999cb76bfd2eb004ba5f8be32fec82e38beeeb 100644 (file)
@@ -6,6 +6,7 @@
 #include <signal.h>
 #include <sys/select.h> /* The only way I can see to get sigset_t */
 #include <asm/unistd.h>
+#include "as-layout.h"
 #include "uml-config.h"
 #include "sysdep/stub.h"
 #include "sysdep/sigcontext.h"
@@ -17,8 +18,7 @@ stub_segv_handler(int sig)
        struct sigcontext *sc = (struct sigcontext *) (&sig + 1);
        int pid;
 
-       GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
-                             sc);
+       GET_FAULTINFO_FROM_SC(*((struct faultinfo *) STUB_DATA), sc);
 
        pid = stub_syscall0(__NR_getpid);
        stub_syscall2(__NR_kill, pid, SIGUSR1);
index 03c2797357842f2ad8cc4d61651c1e110d88ddb5..4afe204a6af7acea809aa768facf1c6c11c3eb51 100644 (file)
@@ -1,4 +1,5 @@
 #include "uml-config.h"
+#include "as-layout.h"
 
        .globl syscall_stub
 .section .__syscall_stub, "x"
@@ -7,18 +8,18 @@ syscall_stub:
        /* We don't have 64-bit constants, so this constructs the address
         * we need.
         */
-       movq    $(UML_CONFIG_STUB_DATA >> 32), %rbx
+       movq    $(ASM_STUB_DATA >> 32), %rbx
        salq    $32, %rbx
-       movq    $(UML_CONFIG_STUB_DATA & 0xffffffff), %rcx
+       movq    $(ASM_STUB_DATA & 0xffffffff), %rcx
        or      %rcx, %rbx
        movq    %rax, (%rbx)
        int3
 
        .globl batch_syscall_stub
 batch_syscall_stub:
-       mov     $(UML_CONFIG_STUB_DATA >> 32), %rbx
+       mov     $(ASM_STUB_DATA >> 32), %rbx
        sal     $32, %rbx
-       mov     $(UML_CONFIG_STUB_DATA & 0xffffffff), %rax
+       mov     $(ASM_STUB_DATA & 0xffffffff), %rax
        or      %rax, %rbx
        /* load pointer to first operation */
        mov     %rbx, %rsp
index 652fa34c2cd3d3f0a3f7a8074cfb4ca890e56488..3afb590f007212e2da4e90bad9c8447017b46dd4 100644 (file)
@@ -6,6 +6,7 @@
 #include <stddef.h>
 #include <signal.h>
 #include <asm/unistd.h>
+#include "as-layout.h"
 #include "uml-config.h"
 #include "sysdep/sigcontext.h"
 #include "sysdep/faultinfo.h"
@@ -33,7 +34,7 @@ stub_segv_handler(int sig)
         int pid;
 
        __asm__ __volatile__("movq %%rdx, %0" : "=g" (uc) :);
-       GET_FAULTINFO_FROM_SC(*((struct faultinfo *) UML_CONFIG_STUB_DATA),
+       GET_FAULTINFO_FROM_SC(*((struct faultinfo *) STUB_DATA),
                              &uc->uc_mcontext);
 
        pid = stub_syscall0(__NR_getpid);