Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ftrace: Revert 8ab2b7efd ftrace: Remove unnecessary disabling of irqs
  kprobes/trace: Fix kprobe selftest for gcc 4.6
  ftrace: Fix possible undefined return code
  oprofile, dcookies: Fix possible circular locking dependency
  oprofile: Fix locking dependency in sync_start()
  oprofile: Free potentially owned tasks in case of errors
  oprofile, x86: Add comments to IBS LVT offset initialization

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index b961af8..b9338b8 100644 (file)
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -390,7 +390,8 @@ static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
 
 /*
  * If mask=1, the LVT entry does not generate interrupts while mask=0
- * enables the vector. See also the BKDGs.
+ * enables the vector. See also the BKDGs. Must be called with
+ * preemption disabled.
  */
 
 int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)

diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index 9fd8a56..9cbb710 100644 (file)
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -609,16 +609,21 @@ static int setup_ibs_ctl(int ibs_eilvt_off)
        return 0;
 }
 
+/*
+ * This runs only on the current cpu. We try to find an LVT offset and
+ * setup the local APIC. For this we must disable preemption. On
+ * success we initialize all nodes with this offset. This updates then
+ * the offset in the IBS_CTL per-node msr. The per-core APIC setup of
+ * the IBS interrupt vector is called from op_amd_setup_ctrs()/op_-
+ * amd_cpu_shutdown() using the new offset.
+ */
 static int force_ibs_eilvt_setup(void)
 {
        int offset;
        int ret;
 
-       /*
-        * find the next free available EILVT entry, skip offset 0,
-        * pin search to this cpu
-        */
        preempt_disable();
+       /* find the next free available EILVT entry, skip offset 0 */
        for (offset = 1; offset < APIC_EILVT_NR_MAX; offset++) {
                if (get_eilvt(offset))
                        break;

diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index a3984f4..f34b5b2 100644 (file)
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -141,6 +141,13 @@ static struct notifier_block module_load_nb = {
        .notifier_call = module_load_notify,
 };
 
+static void free_all_tasks(void)
+{
+       /* make sure we don't leak task structs */
+       process_task_mortuary();
+       process_task_mortuary();
+}
+
 int sync_start(void)
 {
        int err;
@@ -148,8 +155,6 @@ int sync_start(void)
        if (!zalloc_cpumask_var(&marked_cpus, GFP_KERNEL))
                return -ENOMEM;
 
-       mutex_lock(&buffer_mutex);
-
        err = task_handoff_register(&task_free_nb);
        if (err)
                goto out1;
@@ -166,7 +171,6 @@ int sync_start(void)
        start_cpu_work();
 
 out:
-       mutex_unlock(&buffer_mutex);
        return err;
 out4:
        profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
@@ -174,6 +178,7 @@ out3:
        profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
 out2:
        task_handoff_unregister(&task_free_nb);
+       free_all_tasks();
 out1:
        free_cpumask_var(marked_cpus);
        goto out;
@@ -182,20 +187,16 @@ out1:
 
 void sync_stop(void)
 {
-       /* flush buffers */
-       mutex_lock(&buffer_mutex);
        end_cpu_work();
        unregister_module_notifier(&module_load_nb);
        profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
        profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
        task_handoff_unregister(&task_free_nb);
-       mutex_unlock(&buffer_mutex);
-       flush_cpu_work();
+       barrier();                      /* do all of the above first */
 
-       /* make sure we don't leak task structs */
-       process_task_mortuary();
-       process_task_mortuary();
+       flush_cpu_work();
 
+       free_all_tasks();
        free_cpumask_var(marked_cpus);
 }
 

diff --git a/fs/dcookies.c b/fs/dcookies.c
index a21cabd..dda0dc7 100644 (file)
--- a/fs/dcookies.c
+++ b/fs/dcookies.c
@@ -178,6 +178,8 @@ SYSCALL_DEFINE(lookup_dcookie)(u64 cookie64, char __user * buf, size_t len)
        /* FIXME: (deleted) ? */
        path = d_path(&dcs->path, kbuf, PAGE_SIZE);
 
+       mutex_unlock(&dcookie_mutex);
+
        if (IS_ERR(path)) {
                err = PTR_ERR(path);
                goto out_free;
@@ -194,6 +196,7 @@ SYSCALL_DEFINE(lookup_dcookie)(u64 cookie64, char __user * buf, size_t len)
 
 out_free:
        kfree(kbuf);
+       return err;
 out:
        mutex_unlock(&dcookie_mutex);
        return err;

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1ee417f..908038f 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2740,7 +2740,7 @@ static int ftrace_process_regex(struct ftrace_hash *hash,
 {
        char *func, *command, *next = buff;
        struct ftrace_func_command *p;
-       int ret;
+       int ret = -EINVAL;
 
        func = strsep(&next, ":");
 
@@ -3330,6 +3330,7 @@ static int ftrace_process_locs(struct module *mod,
 {
        unsigned long *p;
        unsigned long addr;
+       unsigned long flags;
 
        mutex_lock(&ftrace_lock);
        p = start;
@@ -3346,7 +3347,13 @@ static int ftrace_process_locs(struct module *mod,
                ftrace_record_ip(addr);
        }
 
+       /*
+        * Disable interrupts to prevent interrupts from executing
+        * code that is being modified.
+        */
+       local_irq_save(flags);
        ftrace_update_code(mod);
+       local_irq_restore(flags);
        mutex_unlock(&ftrace_lock);
 
        return 0;

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index f925c45..27d13b3 100644 (file)
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1870,8 +1870,12 @@ fs_initcall(init_kprobe_trace);
 
 #ifdef CONFIG_FTRACE_STARTUP_TEST
 
-static int kprobe_trace_selftest_target(int a1, int a2, int a3,
-                                       int a4, int a5, int a6)
+/*
+ * The "__used" keeps gcc from removing the function symbol
+ * from the kallsyms table.
+ */
+static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
+                                              int a4, int a5, int a6)
 {
        return a1 + a2 + a3 + a4 + a5 + a6;
 }