From: Thomas Gleixner Date: Wed, 24 May 2017 08:15:37 +0000 (+0200) Subject: arm64: Prevent cpu hotplug rwsem recursion X-Git-Tag: v4.14-rc1~626^2~11 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c23a465625e287c4deba0fdf5e8adc59cfd2a0b7;p=platform%2Fkernel%2Flinux-rpi3.git arm64: Prevent cpu 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 Acked-by: Ingo Molnar Cc: Paul E. McKenney Cc: Mark Rutland Cc: Peter Zijlstra Cc: Catalin Marinas Cc: Sebastian Siewior Cc: Will Deacon Cc: Steven Rostedt Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20170524081549.197070135@linutronix.de --- diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index 29cb2ca..4214c38 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -433,7 +433,6 @@ u32 aarch64_set_branch_offset(u32 insn, s32 offset); bool aarch64_insn_hotpatch_safe(u32 old_insn, u32 new_insn); int aarch64_insn_patch_text_nosync(void *addr, u32 insn); -int aarch64_insn_patch_text_sync(void *addrs[], u32 insns[], int cnt); int aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt); s32 aarch64_insn_adrp_get_offset(u32 insn); diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index b884a92..cd87213 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -255,6 +255,7 @@ static int __kprobes aarch64_insn_patch_text_cb(void *arg) return ret; } +static int __kprobes aarch64_insn_patch_text_sync(void *addrs[], u32 insns[], int cnt) { struct aarch64_insn_patch patch = { @@ -267,8 +268,8 @@ int __kprobes aarch64_insn_patch_text_sync(void *addrs[], u32 insns[], int cnt) if (cnt <= 0) return -EINVAL; - return stop_machine(aarch64_insn_patch_text_cb, &patch, - cpu_online_mask); + return stop_machine_cpuslocked(aarch64_insn_patch_text_cb, &patch, + cpu_online_mask); } int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt)