Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic...

diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
index 1762b81fcdf2ec4a235423687865453a16196aed..741fe66d6eca4852894cac79d6ad2d3162486c7a 100644 (file)
--- a/Documentation/kprobes.txt
+++ b/Documentation/kprobes.txt
@@ -542,9 +542,11 @@ Kprobes does not use mutexes or allocate memory except during
 registration and unregistration.
 
 Probe handlers are run with preemption disabled.  Depending on the
-architecture, handlers may also run with interrupts disabled.  In any
-case, your handler should not yield the CPU (e.g., by attempting to
-acquire a semaphore).
+architecture and optimization state, handlers may also run with
+interrupts disabled (e.g., kretprobe handlers and optimized kprobe
+handlers run without interrupt disabled on x86/x86-64).  In any case,
+your handler should not yield the CPU (e.g., by attempting to acquire
+a semaphore).
 
 Since a return probe is implemented by replacing the return
 address with the trampoline's address, stack backtraces and calls

diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index ad19c276b10fa1b5d7f82a8f5c2169560d9ebdd0..55addc85eaa7f6706334f11cdb48207fc0f69ce5 100644 (file)
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -534,7 +534,7 @@ static int armpmu_event_init(struct perf_event *event)
        event->destroy = hw_perf_event_destroy;
 
        if (!atomic_inc_not_zero(&active_events)) {
-               if (atomic_read(&active_events) > armpmu.num_events) {
+               if (atomic_read(&active_events) > armpmu->num_events) {
                        atomic_dec(&active_events);
                        return -ENOSPC;
                }

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b431a0824a9356b92d5c9328eb1e3176ba9eb0ff..c14d8b4d2f71ce62935786a39d465133b78fd8c6 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -60,6 +60,7 @@ config X86
        select HAVE_ARCH_KMEMCHECK
        select HAVE_USER_RETURN_NOTIFIER
        select HAVE_ARCH_JUMP_LABEL
+       select HAVE_TEXT_POKE_SMP
 
 config INSTRUCTION_DECODER
        def_bool (KPROBES || PERF_EVENTS)
@@ -2126,6 +2127,10 @@ config HAVE_ATOMIC_IOMAP
        def_bool y
        depends on X86_32
 
+config HAVE_TEXT_POKE_SMP
+       bool
+       select STOP_MACHINE if SMP
+
 source "net/Kconfig"
 
 source "drivers/Kconfig"

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index cb0e6d385f6d6e5a78527a738788904a092bc180..a36bb90aef5383d68bcf4af0b0c33749d572163a 100644 (file)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -637,7 +637,8 @@ void *__kprobes text_poke_smp(void *addr, const void *opcode, size_t len)
        tpp.len = len;
        atomic_set(&stop_machine_first, 1);
        wrote_text = 0;
-       stop_machine(stop_machine_text_poke, (void *)&tpp, NULL);
+       /* Use __stop_machine() because the caller already got online_cpus. */
+       __stop_machine(stop_machine_text_poke, (void *)&tpp, NULL);
        return addr;
 }
 

diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h
index 6b524a0d02e42b14419c5ae75133360a1f4874a5..1808960c50595908935455ca90a80fc02e421ef0 100644 (file)
--- a/include/linux/stop_machine.h
+++ b/include/linux/stop_machine.h
@@ -126,8 +126,8 @@ int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus);
 
 #else   /* CONFIG_STOP_MACHINE && CONFIG_SMP */
 
-static inline int stop_machine(int (*fn)(void *), void *data,
-                              const struct cpumask *cpus)
+static inline int __stop_machine(int (*fn)(void *), void *data,
+                                const struct cpumask *cpus)
 {
        int ret;
        local_irq_disable();
@@ -136,5 +136,11 @@ static inline int stop_machine(int (*fn)(void *), void *data,
        return ret;
 }
 
+static inline int stop_machine(int (*fn)(void *), void *data,
+                              const struct cpumask *cpus)
+{
+       return __stop_machine(fn, data, cpus);
+}
+
 #endif /* CONFIG_STOP_MACHINE && CONFIG_SMP */
 #endif /* _LINUX_STOP_MACHINE */

diff --git a/kernel/test_kprobes.c b/kernel/test_kprobes.c
index 4f104515a19bcb18ca73226c745786a41d41b4ae..f8b11a283171b65849c5ed3bc0e162397f76fbea 100644 (file)
--- a/kernel/test_kprobes.c
+++ b/kernel/test_kprobes.c
@@ -115,7 +115,9 @@ static int test_kprobes(void)
        int ret;
        struct kprobe *kps[2] = {&kp, &kp2};
 
-       kp.addr = 0; /* addr should be cleard for reusing kprobe. */
+       /* addr and flags should be cleard for reusing kprobe. */
+       kp.addr = NULL;
+       kp.flags = 0;
        ret = register_kprobes(kps, 2);
        if (ret < 0) {
                printk(KERN_ERR "Kprobe smoke test failed: "
@@ -210,7 +212,9 @@ static int test_jprobes(void)
        int ret;
        struct jprobe *jps[2] = {&jp, &jp2};
 
-       jp.kp.addr = 0; /* addr should be cleard for reusing kprobe. */
+       /* addr and flags should be cleard for reusing kprobe. */
+       jp.kp.addr = NULL;
+       jp.kp.flags = 0;
        ret = register_jprobes(jps, 2);
        if (ret < 0) {
                printk(KERN_ERR "Kprobe smoke test failed: "
@@ -323,7 +327,9 @@ static int test_kretprobes(void)
        int ret;
        struct kretprobe *rps[2] = {&rp, &rp2};
 
-       rp.kp.addr = 0; /* addr should be cleard for reusing kprobe. */
+       /* addr and flags should be cleard for reusing kprobe. */
+       rp.kp.addr = NULL;
+       rp.kp.flags = 0;
        ret = register_kretprobes(rps, 2);
        if (ret < 0) {
                printk(KERN_ERR "Kprobe smoke test failed: "