| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Wed, 24 May 2017 10:15:37 +0200 |
| Subject: [PATCH 26/32] 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(-) |
| |
| --- a/arch/arm64/include/asm/insn.h |
| +++ b/arch/arm64/include/asm/insn.h |
| @@ -403,7 +403,6 @@ u32 aarch64_set_branch_offset(u32 insn, |
| 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); |
| --- a/arch/arm64/kernel/insn.c |
| +++ b/arch/arm64/kernel/insn.c |
| @@ -255,6 +255,7 @@ static int __kprobes aarch64_insn_patch_ |
| 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_sy |
| 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) |
