From d9e05cc5a53246e074dc2b84956252e4bbe392cd Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Tue, 10 Mar 2015 11:05:59 -0700 Subject: [PATCH] x86/asm/entry: Unify and fix initial thread_struct::sp0 values x86_32 and x86_64 need slightly different thread_struct::sp0 values, and x86_32's was incorrect for init. This never mattered -- the init thread never runs user code, so we never used thread_struct::sp0 for anything. Fix it and mostly unify them. Signed-off-by: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1b810c1d2e797e27bb4a7708c426101161edd1f6.1426009661.git.luto@amacapital.net Signed-off-by: Ingo Molnar --- arch/x86/include/asm/processor.h | 7 +++++-- arch/x86/kernel/process.c | 2 +- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 88d9aa745898..fc6d8d0d8d53 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -811,6 +811,9 @@ static inline void spin_lock_prefetch(const void *x) prefetchw(x); } +#define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack) - \ + TOP_OF_KERNEL_STACK_PADDING) + #ifdef CONFIG_X86_32 /* * User space process size: 3GB (default). @@ -821,7 +824,7 @@ static inline void spin_lock_prefetch(const void *x) #define STACK_TOP_MAX STACK_TOP #define INIT_THREAD { \ - .sp0 = sizeof(init_stack) + (long)&init_stack, \ + .sp0 = TOP_OF_INIT_STACK, \ .vm86_info = NULL, \ .sysenter_cs = __KERNEL_CS, \ .io_bitmap_ptr = NULL, \ @@ -883,7 +886,7 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk); #define STACK_TOP_MAX TASK_SIZE_MAX #define INIT_THREAD { \ - .sp0 = (unsigned long)&init_stack + sizeof(init_stack) \ + .sp0 = TOP_OF_INIT_STACK \ } /* diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index f4c0af7fc3a0..12b1cf606ddf 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -39,7 +39,7 @@ */ __visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = { .x86_tss = { - .sp0 = (unsigned long)&init_stack + sizeof(init_stack), + .sp0 = TOP_OF_INIT_STACK, #ifdef CONFIG_X86_32 .ss0 = __KERNEL_DS, .ss1 = __KERNEL_CS, -- 2.20.1