[patch V3 27/32] arm: Prevent hotplug rwsem recursion
From: Thomas Gleixner <hidden>
Date: 2017-05-24 08:28:40
Also in:
lkml
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 <redacted> Cc: linux-arm-kernel at lists.infradead.org Cc: Russell King <linux@armlinux.org.uk> --- 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)