| Date | Fri, 26 May 2017 01:46:10 -0700 | From | tip-bot for Thomas Gleixner <> | Subject | [tip:smp/hotplug] arm: Prevent hotplug rwsem recursion |
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Commit-ID: 9489cc8f370be811f7e741a772bcce88b712272d Gitweb: http://git.kernel.org/tip/9489cc8f370be811f7e741a772bcce88b712272d Author: Thomas Gleixner <tglx@linutronix.de> AuthorDate: Wed, 24 May 2017 10:15:38 +0200 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Fri, 26 May 2017 10:10:46 +0200
arm: Prevent hotplug rwsem recursion
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
--- arch/arm/kernel/patch.c | 2 +- arch/arm/probes/kprobes/core.c | 3 ++- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/arm/kernel/patch.c b/arch/arm/kernel/patch.c index 020560b..a1a3472 100644 --- a/arch/arm/kernel/patch.c +++ b/arch/arm/kernel/patch.c @@ -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); } diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c index ad1f4e6..52d1cd1 100644 --- a/arch/arm/probes/kprobes/core.c +++ b/arch/arm/probes/kprobes/core.c @@ -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)
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