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authorKees Cook <keescook@chromium.org>2021-09-29 15:02:14 -0700
committerPeter Zijlstra <peterz@infradead.org>2021-10-15 11:25:14 +0200
commit42a20f86dc19f9282d974df0ba4d226c865ab9dd (patch)
tree548e09e31785a53f7907e0e4c28471d0e53fcbb5 /arch/riscv
parentbc9bbb81730ea667c31c5b284f95ee312bab466f (diff)
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
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/include/asm/processor.h2
-rw-r--r--arch/riscv/kernel/stacktrace.c12
2 files changed, 6 insertions, 8 deletions
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 46b492c78cbb..0749924d9e55 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -66,7 +66,7 @@ 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);
static inline void wait_for_interrupt(void)
diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
index 315db3d0229b..0fcdc0233fac 100644
--- a/arch/riscv/kernel/stacktrace.c
+++ b/arch/riscv/kernel/stacktrace.c
@@ -128,16 +128,14 @@ static bool save_wchan(void *arg, unsigned long pc)
return true;
}
-unsigned long get_wchan(struct task_struct *task)
+unsigned long __get_wchan(struct task_struct *task)
{
unsigned long pc = 0;
- if (likely(task && task != current && !task_is_running(task))) {
- if (!try_get_task_stack(task))
- return 0;
- walk_stackframe(task, NULL, save_wchan, &pc);
- put_task_stack(task);
- }
+ if (!try_get_task_stack(task))
+ return 0;
+ walk_stackframe(task, NULL, save_wchan, &pc);
+ put_task_stack(task);
return pc;
}