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arm: Prevent hotplug rwsem recursion

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The text patching functions which are invoked from jump_label and kprobes
code are protected against cpu hotplug at the call sites.

Use stop_machine_cpuslocked() to avoid recursion on the cpu hotplug
rwsem. stop_machine_cpuslocked() contains a lockdep assertion to catch any
unprotected callers.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20170524081549.275871311@linutronix.de
This commit is contained in:
Thomas Gleixner 2017-05-24 10:15:38 +02:00
parent c23a465625
commit 9489cc8f37
2 changed files with 3 additions and 2 deletions
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2
arch/arm/kernel/patch.c
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@ -124,5 +124,5 @@ void __kprobes patch_text(void *addr, unsigned int insn)
.insn = insn,
};
stop_machine(patch_text_stop_machine, &patch, NULL);
stop_machine_cpuslocked(patch_text_stop_machine, &patch, NULL);
}

3
arch/arm/probes/kprobes/core.c
View file

@ -182,7 +182,8 @@ void __kprobes kprobes_remove_breakpoint(void *addr, unsigned int insn)
.addr = addr,
.insn = insn,
};
stop_machine(__kprobes_remove_breakpoint, &p, cpu_online_mask);
stop_machine_cpuslocked(__kprobes_remove_breakpoint, &p,
cpu_online_mask);
}
void __kprobes arch_disarm_kprobe(struct kprobe *p)