| Date | Fri, 26 May 2017 01:45:38 -0700 | From | tip-bot for Thomas Gleixner <> | Subject | [tip:smp/hotplug] arm64: Prevent cpu hotplug rwsem recursion |
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Commit-ID: c23a465625e287c4deba0fdf5e8adc59cfd2a0b7 Gitweb: http://git.kernel.org/tip/c23a465625e287c4deba0fdf5e8adc59cfd2a0b7 Author: Thomas Gleixner <tglx@linutronix.de> AuthorDate: Wed, 24 May 2017 10:15:37 +0200 Committer: Thomas Gleixner <tglx@linutronix.de> CommitDate: Fri, 26 May 2017 10:10:45 +0200
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 <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20170524081549.197070135@linutronix.de
--- arch/arm64/include/asm/insn.h | 1 - arch/arm64/kernel/insn.c | 5 +++-- 2 files changed, 3 insertions(+), 3 deletions(-)
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)
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