From: Yang Shi <yang....@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....@linaro.org>
Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
Reviewed-by: Arnd Bergmann <a...@arndb.de>
Signed-off-by: Russell King <rmk+ker...@armlinux.org.uk>
Signed-off-by: Sasha Levin <sas...@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);
 }
-- 
2.19.1

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