Re: [PATCH 2/3] x86: Unify and fix init sp0
On Tue, Mar 10, 2015 at 11:05:59AM -0700, Andy Lutomirski wrote: > x86_32 and x86_64 need slightly different sp0 values, and x86_32's was > incorrect for init. (This never mattered -- the init thread never > runs user code, so we never used sp0 for anything.) Damn old x86 cruft - sp0 is the stack pointer for CPL0 in the TSS. Had to go dig that out. > Fix it and mostly unify them. > > Signed-off-by: Andy Lutomirski Acked-by: Borislav Petkov -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2/3] x86: Unify and fix init sp0
On Tue, Mar 10, 2015 at 11:05:59AM -0700, Andy Lutomirski wrote: x86_32 and x86_64 need slightly different sp0 values, and x86_32's was incorrect for init. (This never mattered -- the init thread never runs user code, so we never used sp0 for anything.) Damn old x86 cruft - sp0 is the stack pointer for CPL0 in the TSS. Had to go dig that out. Fix it and mostly unify them. Signed-off-by: Andy Lutomirski l...@amacapital.net Acked-by: Borislav Petkov b...@suse.de -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 2/3] x86: Unify and fix init sp0
x86_32 and x86_64 need slightly different sp0 values, and x86_32's was
incorrect for init. (This never mattered -- the init thread never
runs user code, so we never used sp0 for anything.)
Fix it and mostly unify them.
Signed-off-by: Andy Lutomirski
---
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)_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)_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)_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)_stack + sizeof(init_stack),
+ .sp0 = TOP_OF_INIT_STACK,
#ifdef CONFIG_X86_32
.ss0 = __KERNEL_DS,
.ss1 = __KERNEL_CS,
--
2.3.0
--
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH 2/3] x86: Unify and fix init sp0
x86_32 and x86_64 need slightly different sp0 values, and x86_32's was
incorrect for init. (This never mattered -- the init thread never
runs user code, so we never used sp0 for anything.)
Fix it and mostly unify them.
Signed-off-by: Andy Lutomirski l...@amacapital.net
---
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,
--
2.3.0
--
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