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>
This commit is contained in:
Brian Gerst
2016-08-13 12:38:18 -04:00
committed by Ingo Molnar
parent 163630191e
commit 7b32aeadbc
4 changed files with 11 additions and 4 deletions

View File

@@ -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;