From 42a20f86dc19f9282d974df0ba4d226c865ab9dd Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 29 Sep 2021 15:02:14 -0700 Subject: 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 Signed-off-by: Kees Cook Signed-off-by: Peter Zijlstra (Intel) Acked-by: Geert Uytterhoeven Acked-by: Russell King (Oracle) [arm] Tested-by: Mark Rutland [arm64] Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org --- arch/nios2/include/asm/processor.h | 2 +- arch/nios2/kernel/process.c | 5 +---- 2 files changed, 2 insertions(+), 5 deletions(-) (limited to 'arch/nios2') diff --git a/arch/nios2/include/asm/processor.h b/arch/nios2/include/asm/processor.h index 94bcb86f679f..b8125dfbcad2 100644 --- a/arch/nios2/include/asm/processor.h +++ b/arch/nios2/include/asm/processor.h @@ -69,7 +69,7 @@ static inline void release_thread(struct task_struct *dead_task) { } -extern unsigned long get_wchan(struct task_struct *p); +extern unsigned long __get_wchan(struct task_struct *p); #define task_pt_regs(p) \ ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1) diff --git a/arch/nios2/kernel/process.c b/arch/nios2/kernel/process.c index 9ff37ba2bb60..f8ea522a1588 100644 --- a/arch/nios2/kernel/process.c +++ b/arch/nios2/kernel/process.c @@ -217,15 +217,12 @@ void dump(struct pt_regs *fp) pr_emerg("\n\n"); } -unsigned long get_wchan(struct task_struct *p) +unsigned long __get_wchan(struct task_struct *p) { unsigned long fp, pc; unsigned long stack_page; int count = 0; - if (!p || p == current || task_is_running(p)) - return 0; - stack_page = (unsigned long)p; fp = ((struct switch_stack *)p->thread.ksp)->fp; /* ;dgt2 */ do { -- cgit