sched: Add wrapper for get_wchan() to keep task blocked

Having a stable wchan means the process must be blocked and for it to
stay that way while performing stack unwinding.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm]
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org
This commit is contained in:
Kees Cook
2021-09-29 15:02:14 -07:00
committed by Peter Zijlstra
parent bc9bbb8173
commit 42a20f86dc
50 changed files with 80 additions and 112 deletions

View File

@@ -663,7 +663,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
return 0;
}
unsigned long get_wchan(struct task_struct *task)
unsigned long __get_wchan(struct task_struct *task)
{
unsigned long pc, fp, bias = 0;
struct thread_info *tp;
@@ -671,9 +671,6 @@ unsigned long get_wchan(struct task_struct *task)
unsigned long ret = 0;
int count = 0;
if (!task || task == current || task_is_running(task))
goto out;
tp = task_thread_info(task);
bias = STACK_BIAS;
fp = task_thread_info(task)->ksp + bias;