From: Yang Shi yang.shi@linaro.org
[ Upstream commit 143c2a89e0e5fda6c6fd08d7bc1126438c19ae90 ]
When running kprobe on -rt kernel, the below bug is caught:
|BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:931 |in_atomic(): 1, irqs_disabled(): 128, pid: 14, name: migration/0 |Preemption disabled at:[<802f2b98>] cpu_stopper_thread+0xc0/0x140 |CPU: 0 PID: 14 Comm: migration/0 Tainted: G O 4.8.3-rt2 #1 |Hardware name: Freescale LS1021A |[<8025a43c>] (___might_sleep) |[<80b5b324>] (rt_spin_lock) |[<80b5c31c>] (__patch_text_real) |[<80b5c3ac>] (patch_text_stop_machine) |[<802f2920>] (multi_cpu_stop)
Since patch_text_stop_machine() is called in stop_machine() which disables IRQ, sleepable lock should be not used in this atomic context, so replace patch_lock to raw lock.
Signed-off-by: Yang Shi yang.shi@linaro.org Signed-off-by: Sebastian Andrzej Siewior bigeasy@linutronix.de Reviewed-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Russell King rmk+kernel@armlinux.org.uk Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm/kernel/patch.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm/kernel/patch.c b/arch/arm/kernel/patch.c index 69bda1a5707e..1f665acaa6a9 100644 --- a/arch/arm/kernel/patch.c +++ b/arch/arm/kernel/patch.c @@ -15,7 +15,7 @@ struct patch { unsigned int insn; };
-static DEFINE_SPINLOCK(patch_lock); +static DEFINE_RAW_SPINLOCK(patch_lock);
static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags) __acquires(&patch_lock) @@ -32,7 +32,7 @@ static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags) return addr;
if (flags) - spin_lock_irqsave(&patch_lock, *flags); + raw_spin_lock_irqsave(&patch_lock, *flags); else __acquire(&patch_lock);
@@ -47,7 +47,7 @@ static void __kprobes patch_unmap(int fixmap, unsigned long *flags) clear_fixmap(fixmap);
if (flags) - spin_unlock_irqrestore(&patch_lock, *flags); + raw_spin_unlock_irqrestore(&patch_lock, *flags); else __release(&patch_lock); }