Commit 5e3f6ba8 authored by Yang Shi's avatar Yang Shi Committed by Greg Kroah-Hartman

ARM: 8839/1: kprobe: make patch_lock a raw_spinlock_t

[ Upstream commit 143c2a89 ]

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: default avatarYang Shi <yang.shi@linaro.org>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 03e67ed3
...@@ -16,7 +16,7 @@ struct patch { ...@@ -16,7 +16,7 @@ struct patch {
unsigned int insn; 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) static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
__acquires(&patch_lock) __acquires(&patch_lock)
...@@ -33,7 +33,7 @@ static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags) ...@@ -33,7 +33,7 @@ static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
return addr; return addr;
if (flags) if (flags)
spin_lock_irqsave(&patch_lock, *flags); raw_spin_lock_irqsave(&patch_lock, *flags);
else else
__acquire(&patch_lock); __acquire(&patch_lock);
...@@ -48,7 +48,7 @@ static void __kprobes patch_unmap(int fixmap, unsigned long *flags) ...@@ -48,7 +48,7 @@ static void __kprobes patch_unmap(int fixmap, unsigned long *flags)
clear_fixmap(fixmap); clear_fixmap(fixmap);
if (flags) if (flags)
spin_unlock_irqrestore(&patch_lock, *flags); raw_spin_unlock_irqrestore(&patch_lock, *flags);
else else
__release(&patch_lock); __release(&patch_lock);
} }
......
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