From b32f96c75d0dcbb9bf9cc7994e8022c8ce20a668 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Thu, 18 Aug 2016 10:59:03 -0500 Subject: [PATCH] x86/asm/head: Rename 'stack_start' -> 'initial_stack' The 'stack_start' variable is similar in usage to 'initial_code' and 'initial_gs': they're all stored in head_64.S and they're all updated by SMP and ACPI suspend before starting a CPU. Rename it to 'initial_stack' to be consistent with the others. Signed-off-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Byungchul Park Cc: Denys Vlasenko Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Nilay Vaish Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/87063d773a3212051b77e17b0ee427f6582a5050.1471535549.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/realmode.h | 1 + arch/x86/include/asm/smp.h | 3 --- arch/x86/kernel/acpi/sleep.c | 2 +- arch/x86/kernel/head_32.S | 8 ++++---- arch/x86/kernel/head_64.S | 11 +++++------ arch/x86/kernel/smpboot.c | 2 +- 6 files changed, 12 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h index 3327ffb38926..230e1903acf0 100644 --- a/arch/x86/include/asm/realmode.h +++ b/arch/x86/include/asm/realmode.h @@ -46,6 +46,7 @@ extern unsigned char real_mode_blob_end[]; extern unsigned long initial_code; extern unsigned long initial_gs; +extern unsigned long initial_stack; extern unsigned char real_mode_blob[]; extern unsigned char real_mode_relocs[]; diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index ebd0c164cd4e..19980b36f394 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -39,9 +39,6 @@ DECLARE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid); DECLARE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid); #endif -/* Static state in head.S used to set up a CPU */ -extern unsigned long stack_start; /* Initial stack pointer address */ - struct task_struct; struct smp_ops { diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index adb3eaf8fe2a..48587335ede8 100644 --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -99,7 +99,7 @@ int x86_acpi_suspend_lowlevel(void) saved_magic = 0x12345678; #else /* CONFIG_64BIT */ #ifdef CONFIG_SMP - stack_start = (unsigned long)temp_stack + sizeof(temp_stack); + initial_stack = (unsigned long)temp_stack + sizeof(temp_stack); early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(smp_processor_id()); initial_gs = per_cpu_offset(smp_processor_id()); diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index 6f8902b0d151..5f401262f12d 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -94,7 +94,7 @@ RESERVE_BRK(pagetables, INIT_MAP_SIZE) */ __HEAD ENTRY(startup_32) - movl pa(stack_start),%ecx + movl pa(initial_stack),%ecx /* test KEEP_SEGMENTS flag to see if the bootloader is asking us to not reload segments */ @@ -286,7 +286,7 @@ num_subarch_entries = (. - subarch_entries) / 4 * start_secondary(). */ ENTRY(start_cpu0) - movl stack_start, %ecx + movl initial_stack, %ecx movl %ecx, %esp jmp *(initial_code) ENDPROC(start_cpu0) @@ -307,7 +307,7 @@ ENTRY(startup_32_smp) movl %eax,%es movl %eax,%fs movl %eax,%gs - movl pa(stack_start),%ecx + movl pa(initial_stack),%ecx movl %eax,%ss leal -__PAGE_OFFSET(%ecx),%esp @@ -703,7 +703,7 @@ ENTRY(initial_page_table) .data .balign 4 -ENTRY(stack_start) +ENTRY(initial_stack) .long init_thread_union+THREAD_SIZE __INITRODATA diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 9f8efc9f0075..e04814215f15 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -66,7 +66,7 @@ startup_64: */ /* - * Setup stack for verify_cpu(). "-8" because stack_start is defined + * Setup stack for verify_cpu(). "-8" because initial_stack is defined * this way, see below. Our best guess is a NULL ptr for stack * termination heuristics and we don't want to break anything which * might depend on it (kgdb, ...). @@ -226,7 +226,7 @@ ENTRY(secondary_startup_64) movq %rax, %cr0 /* Setup a boot time stack */ - movq stack_start(%rip), %rsp + movq initial_stack(%rip), %rsp /* zero EFLAGS after setting rsp */ pushq $0 @@ -310,7 +310,7 @@ ENDPROC(secondary_startup_64) * start_secondary(). */ ENTRY(start_cpu0) - movq stack_start(%rip),%rsp + movq initial_stack(%rip),%rsp movq initial_code(%rip),%rax pushq $0 # fake return address to stop unwinder pushq $__KERNEL_CS # set correct cs @@ -319,15 +319,14 @@ ENTRY(start_cpu0) ENDPROC(start_cpu0) #endif - /* SMP bootup changes these two */ + /* Both SMP bootup and ACPI suspend change these variables */ __REFDATA .balign 8 GLOBAL(initial_code) .quad x86_64_start_kernel GLOBAL(initial_gs) .quad INIT_PER_CPU_VAR(irq_stack_union) - - GLOBAL(stack_start) + GLOBAL(initial_stack) .quad init_thread_union+THREAD_SIZE-8 .word 0 __FINITDATA diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 4296beb8fdd3..c85d2c636092 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -969,7 +969,7 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle) early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu); initial_code = (unsigned long)start_secondary; - stack_start = idle->thread.sp; + initial_stack = idle->thread.sp; /* * Enable the espfix hack for this CPU -- 2.20.1