From: Greg Kroah-Hartman Date: Thu, 7 Dec 2017 07:55:59 +0000 (+0100) Subject: 4.14-stable patches X-Git-Tag: v3.18.87~15 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ddbea21fba7c8547731e1172619dd339fc93b7ef;p=thirdparty%2Fkernel%2Fstable-queue.git 4.14-stable patches added patches: powerpc-jprobes-disable-preemption-when-triggered-through-ftrace.patch powerpc-kprobes-disable-preemption-before-invoking-probe-handler-for-optprobes.patch --- diff --git a/queue-4.14/powerpc-jprobes-disable-preemption-when-triggered-through-ftrace.patch b/queue-4.14/powerpc-jprobes-disable-preemption-when-triggered-through-ftrace.patch new file mode 100644 index 00000000000..e8edf21b846 --- /dev/null +++ b/queue-4.14/powerpc-jprobes-disable-preemption-when-triggered-through-ftrace.patch @@ -0,0 +1,93 @@ +From 6baea433bc84cd148af1c524389a8d756f67412e Mon Sep 17 00:00:00 2001 +From: "Naveen N. Rao" +Date: Fri, 22 Sep 2017 14:40:47 +0530 +Subject: powerpc/jprobes: Disable preemption when triggered through ftrace + +From: Naveen N. Rao + +commit 6baea433bc84cd148af1c524389a8d756f67412e upstream. + +KPROBES_SANITY_TEST throws the below splat when CONFIG_PREEMPT is +enabled: + + Kprobe smoke test: started + DEBUG_LOCKS_WARN_ON(val > preempt_count()) + ------------[ cut here ]------------ + WARNING: CPU: 19 PID: 1 at kernel/sched/core.c:3094 preempt_count_sub+0xcc/0x140 + Modules linked in: + CPU: 19 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc7-nnr+ #97 + task: c0000000fea80000 task.stack: c0000000feb00000 + NIP: c00000000011d3dc LR: c00000000011d3d8 CTR: c000000000a090d0 + REGS: c0000000feb03400 TRAP: 0700 Not tainted (4.13.0-rc7-nnr+) + MSR: 8000000000021033 CR: 28000282 XER: 00000000 + CFAR: c00000000015aa18 SOFTE: 0 + + NIP preempt_count_sub+0xcc/0x140 + LR preempt_count_sub+0xc8/0x140 + Call Trace: + preempt_count_sub+0xc8/0x140 (unreliable) + kprobe_handler+0x228/0x4b0 + program_check_exception+0x58/0x3b0 + program_check_common+0x16c/0x170 + --- interrupt: 0 at kprobe_target+0x8/0x20 + LR = init_test_probes+0x248/0x7d0 + kp+0x0/0x80 (unreliable) + livepatch_handler+0x38/0x74 + init_kprobes+0x1d8/0x208 + do_one_initcall+0x68/0x1d0 + kernel_init_freeable+0x298/0x374 + kernel_init+0x24/0x160 + ret_from_kernel_thread+0x5c/0x70 + Instruction dump: + 419effdc 3d22001b 39299240 81290000 2f890000 409effc8 3c82ffcb 3c62ffcb + 3884bc68 3863bc18 4803d5fd 60000000 <0fe00000> 4bffffa8 60000000 60000000 + ---[ end trace 432dd46b4ce3d29f ]--- + Kprobe smoke test: passed successfully + +The issue is that we aren't disabling preemption in +kprobe_ftrace_handler(). Disable it. + +Fixes: ead514d5fb30a0 ("powerpc/kprobes: Add support for KPROBES_ON_FTRACE") +Acked-by: Masami Hiramatsu +Signed-off-by: Naveen N. Rao +[mpe: Trim oops a little for formatting] +Signed-off-by: Michael Ellerman +Signed-off-by: Greg Kroah-Hartman + +--- + arch/powerpc/kernel/kprobes-ftrace.c | 15 +++++++++++---- + 1 file changed, 11 insertions(+), 4 deletions(-) + +--- a/arch/powerpc/kernel/kprobes-ftrace.c ++++ b/arch/powerpc/kernel/kprobes-ftrace.c +@@ -65,6 +65,7 @@ void kprobe_ftrace_handler(unsigned long + /* Disable irq for emulating a breakpoint and avoiding preempt */ + local_irq_save(flags); + hard_irq_disable(); ++ preempt_disable(); + + p = get_kprobe((kprobe_opcode_t *)nip); + if (unlikely(!p) || kprobe_disabled(p)) +@@ -86,12 +87,18 @@ void kprobe_ftrace_handler(unsigned long + kcb->kprobe_status = KPROBE_HIT_ACTIVE; + if (!p->pre_handler || !p->pre_handler(p, regs)) + __skip_singlestep(p, regs, kcb, orig_nip); +- /* +- * If pre_handler returns !0, it sets regs->nip and +- * resets current kprobe. +- */ ++ else { ++ /* ++ * If pre_handler returns !0, it sets regs->nip and ++ * resets current kprobe. In this case, we still need ++ * to restore irq, but not preemption. ++ */ ++ local_irq_restore(flags); ++ return; ++ } + } + end: ++ preempt_enable_no_resched(); + local_irq_restore(flags); + } + NOKPROBE_SYMBOL(kprobe_ftrace_handler); diff --git a/queue-4.14/powerpc-kprobes-disable-preemption-before-invoking-probe-handler-for-optprobes.patch b/queue-4.14/powerpc-kprobes-disable-preemption-before-invoking-probe-handler-for-optprobes.patch new file mode 100644 index 00000000000..b6156b9d160 --- /dev/null +++ b/queue-4.14/powerpc-kprobes-disable-preemption-before-invoking-probe-handler-for-optprobes.patch @@ -0,0 +1,62 @@ +From 8a2d71a3f2737e2448aa68de2b6052cb570d3d2a Mon Sep 17 00:00:00 2001 +From: "Naveen N. Rao" +Date: Mon, 23 Oct 2017 22:07:38 +0530 +Subject: powerpc/kprobes: Disable preemption before invoking probe handler for optprobes + +From: Naveen N. Rao + +commit 8a2d71a3f2737e2448aa68de2b6052cb570d3d2a upstream. + +Per Documentation/kprobes.txt, probe handlers need to be invoked with +preemption disabled. Update optimized_callback() to do so. Also move +get_kprobe_ctlblk() invocation post preemption disable, since it +accesses pre-cpu data. + +This was not an issue so far since optprobes wasn't selected if +CONFIG_PREEMPT was enabled. Commit a30b85df7d599f ("kprobes: Use +synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT=y") changes +this. + +Signed-off-by: Naveen N. Rao +Acked-by: Masami Hiramatsu +Signed-off-by: Michael Ellerman +Signed-off-by: Greg Kroah-Hartman + +--- + arch/powerpc/kernel/optprobes.c | 5 +++-- + 1 file changed, 3 insertions(+), 2 deletions(-) + +--- a/arch/powerpc/kernel/optprobes.c ++++ b/arch/powerpc/kernel/optprobes.c +@@ -115,7 +115,6 @@ static unsigned long can_optimize(struct + static void optimized_callback(struct optimized_kprobe *op, + struct pt_regs *regs) + { +- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + unsigned long flags; + + /* This is possible if op is under delayed unoptimizing */ +@@ -124,13 +123,14 @@ static void optimized_callback(struct op + + local_irq_save(flags); + hard_irq_disable(); ++ preempt_disable(); + + if (kprobe_running()) { + kprobes_inc_nmissed_count(&op->kp); + } else { + __this_cpu_write(current_kprobe, &op->kp); + regs->nip = (unsigned long)op->kp.addr; +- kcb->kprobe_status = KPROBE_HIT_ACTIVE; ++ get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE; + opt_pre_handler(&op->kp, regs); + __this_cpu_write(current_kprobe, NULL); + } +@@ -140,6 +140,7 @@ static void optimized_callback(struct op + * local_irq_restore() will re-enable interrupts, + * if they were hard disabled. + */ ++ preempt_enable_no_resched(); + local_irq_restore(flags); + } + NOKPROBE_SYMBOL(optimized_callback); diff --git a/queue-4.14/series b/queue-4.14/series index 8ebd237251b..a6c7b35513a 100644 --- a/queue-4.14/series +++ b/queue-4.14/series @@ -62,3 +62,5 @@ mm-x86-mm-fix-performance-regression-in-get_user_pages_fast.patch iio-adc-ti-ads1015-add-10-to-conversion-wait-time.patch iio-multiplexer-add-null-check-on-devm_kzalloc-and-devm_kmemdup-return-values.patch locking-refcounts-x86-asm-enable-config_arch_has_refcount.patch +powerpc-jprobes-disable-preemption-when-triggered-through-ftrace.patch +powerpc-kprobes-disable-preemption-before-invoking-probe-handler-for-optprobes.patch