diff options
| author | Brian Gerst <brgerst@gmail.com> | 2016-08-13 12:38:18 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-08-24 12:27:41 +0200 |
| commit | 7b32aeadbc95d4a41402c1c0da6aa3ab51af4c10 (patch) | |
| tree | 8ae68aec049bfffe5fdcd725836bd31c61538fda | |
| parent | 163630191ecb0dd9e4146d3c910045aba1cfeec1 (diff) | |
sched/x86: Add 'struct inactive_task_frame' to better document the sleeping task stack frame
Add 'struct inactive_task_frame', which defines the layout of the stack for
a sleeping process. For now, the only defined field is the BP register
(frame pointer).
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1471106302-10159-4-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/include/asm/stacktrace.h | 4 | ||||
| -rw-r--r-- | arch/x86/include/asm/switch_to.h | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/kgdb.c | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 3 |
4 files changed, 11 insertions, 4 deletions
diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h index 0944218af9e2..7646fb2772f8 100644 --- a/arch/x86/include/asm/stacktrace.h +++ b/arch/x86/include/asm/stacktrace.h @@ -8,6 +8,7 @@ #include <linux/uaccess.h> #include <linux/ptrace.h> +#include <asm/switch_to.h> extern int kstack_depth_to_print; @@ -70,8 +71,7 @@ stack_frame(struct task_struct *task, struct pt_regs *regs) return bp; } - /* bp is the last reg pushed by switch_to */ - return *(unsigned long *)task->thread.sp; + return ((struct inactive_task_frame *)task->thread.sp)->bp; } #else static inline unsigned long diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index 14e4b20f0aaf..ec689c62c01f 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -30,6 +30,11 @@ static inline void prepare_switch_to(struct task_struct *prev, #endif } +/* data that is pointed to by thread.sp */ +struct inactive_task_frame { + unsigned long bp; +}; + #ifdef CONFIG_X86_32 #ifdef CONFIG_CC_STACKPROTECTOR diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index 5e3f294ce264..8e36f249646e 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -50,6 +50,7 @@ #include <asm/apicdef.h> #include <asm/apic.h> #include <asm/nmi.h> +#include <asm/switch_to.h> struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = { @@ -166,7 +167,7 @@ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) gdb_regs[GDB_DX] = 0; gdb_regs[GDB_SI] = 0; gdb_regs[GDB_DI] = 0; - gdb_regs[GDB_BP] = *(unsigned long *)p->thread.sp; + gdb_regs[GDB_BP] = ((struct inactive_task_frame *)p->thread.sp)->bp; #ifdef CONFIG_X86_32 gdb_regs[GDB_DS] = __KERNEL_DS; gdb_regs[GDB_ES] = __KERNEL_DS; diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 62c0b0ea2ce4..0115a4a4db96 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -32,6 +32,7 @@ #include <asm/tlbflush.h> #include <asm/mce.h> #include <asm/vm86.h> +#include <asm/switch_to.h> /* * per-CPU TSS segments. Threads are completely 'soft' on Linux, @@ -556,7 +557,7 @@ unsigned long get_wchan(struct task_struct *p) if (sp < bottom || sp > top) return 0; - fp = READ_ONCE_NOCHECK(*(unsigned long *)sp); + fp = READ_ONCE_NOCHECK(((struct inactive_task_frame *)sp)->bp); do { if (fp < bottom || fp > top) return 0; |