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From: Yang Shi <yang.shi@linaro.org>
Date: Thu, 10 Nov 2016 16:17:55 -0800
Subject: [PATCH] arm: kprobe: replace patch_lock to raw lock
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.5-rt4.tar.xz
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
INFO: lockdep is turned off.
irq event stamp: 238
hardirqs last enabled at (237): [<80b5aecc>] _raw_spin_unlock_irqrestore+0x88/0x90
hardirqs last disabled at (238): [<80b56d88>] __schedule+0xec/0x94c
softirqs last enabled at (0): [<80225584>] copy_process.part.5+0x30c/0x1994
softirqs last disabled at (0): [< (null)>] (null)
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
[<80212e7c>] (unwind_backtrace) from [<8020cd2c>] (show_stack+0x20/0x24)
[<8020cd2c>] (show_stack) from [<80689e14>] (dump_stack+0xa0/0xcc)
[<80689e14>] (dump_stack) from [<8025a43c>] (___might_sleep+0x1b8/0x2a4)
[<8025a43c>] (___might_sleep) from [<80b5b324>] (rt_spin_lock+0x34/0x74)
[<80b5b324>] (rt_spin_lock) from [<80b5c31c>] (__patch_text_real+0x70/0xe8)
[<80b5c31c>] (__patch_text_real) from [<80b5c3ac>] (patch_text_stop_machine+0x18/0x20)
[<80b5c3ac>] (patch_text_stop_machine) from [<802f2920>] (multi_cpu_stop+0xfc/0x134)
[<802f2920>] (multi_cpu_stop) from [<802f2ba0>] (cpu_stopper_thread+0xc8/0x140)
[<802f2ba0>] (cpu_stopper_thread) from [<802563a4>] (smpboot_thread_fn+0x1a4/0x354)
[<802563a4>] (smpboot_thread_fn) from [<80251d38>] (kthread+0x104/0x11c)
[<80251d38>] (kthread) from [<80207f70>] (ret_from_fork+0x14/0x24)
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>
---
arch/arm/kernel/patch.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/arch/arm/kernel/patch.c
+++ b/arch/arm/kernel/patch.c
@@ -16,7 +16,7 @@ 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)
@@ -33,7 +33,7 @@ static void __kprobes *patch_map(void *a
return addr;
if (flags)
- spin_lock_irqsave(&patch_lock, *flags);
+ raw_spin_lock_irqsave(&patch_lock, *flags);
else
__acquire(&patch_lock);
@@ -48,7 +48,7 @@ static void __kprobes patch_unmap(int fi
clear_fixmap(fixmap);
if (flags)
- spin_unlock_irqrestore(&patch_lock, *flags);
+ raw_spin_unlock_irqrestore(&patch_lock, *flags);
else
__release(&patch_lock);
}
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