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authorKees Cook <keescook@chromium.org>2021-09-30 00:02:14 +0200
committerPeter Zijlstra <peterz@infradead.org>2021-10-15 11:25:14 +0200
commit42a20f86dc19f9282d974df0ba4d226c865ab9dd (patch)
tree548e09e31785a53f7907e0e4c28471d0e53fcbb5 /arch/um
parentx86: Fix get_wchan() to support the ORC unwinder (diff)
downloadlinux-42a20f86dc19f9282d974df0ba4d226c865ab9dd.tar.xz
linux-42a20f86dc19f9282d974df0ba4d226c865ab9dd.zip
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/um')
-rw-r--r--arch/um/include/asm/processor-generic.h2
-rw-r--r--arch/um/kernel/process.c5
2 files changed, 2 insertions, 5 deletions
diff --git a/arch/um/include/asm/processor-generic.h b/arch/um/include/asm/processor-generic.h
index b5cf0ed116d9..579692a40a55 100644
--- a/arch/um/include/asm/processor-generic.h
+++ b/arch/um/include/asm/processor-generic.h
@@ -106,6 +106,6 @@ extern struct cpuinfo_um boot_cpu_data;
#define cache_line_size() (boot_cpu_data.cache_alignment)
#define KSTK_REG(tsk, reg) get_thread_reg(reg, &tsk->thread.switch_buf)
-extern unsigned long get_wchan(struct task_struct *p);
+extern unsigned long __get_wchan(struct task_struct *p);
#endif
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 457a38db368b..82107373ac7e 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -364,14 +364,11 @@ unsigned long arch_align_stack(unsigned long sp)
}
#endif
-unsigned long get_wchan(struct task_struct *p)
+unsigned long __get_wchan(struct task_struct *p)
{
unsigned long stack_page, sp, ip;
bool seen_sched = 0;
- if ((p == NULL) || (p == current) || task_is_running(p))
- return 0;
-
stack_page = (unsigned long) task_stack_page(p);
/* Bail if the process has no kernel stack for some reason */
if (stack_page == 0)