| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Wed, 24 May 2017 10:15:38 +0200 |
| Subject: [PATCH 27/32] 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(-) |
| |
| --- a/arch/arm/kernel/patch.c |
| +++ b/arch/arm/kernel/patch.c |
| @@ -124,5 +124,5 @@ void __kprobes patch_text(void *addr, un |
| .insn = insn, |
| }; |
| |
| - stop_machine(patch_text_stop_machine, &patch, NULL); |
| + stop_machine_cpuslocked(patch_text_stop_machine, &patch, NULL); |
| } |
| --- a/arch/arm/probes/kprobes/core.c |
| +++ b/arch/arm/probes/kprobes/core.c |
| @@ -182,7 +182,8 @@ void __kprobes kprobes_remove_breakpoint |
| .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) |
