Merge branch 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

[linux-2.6-block.git] / kernel / events / core.c

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 8be3e34274b9116871b6359ca82e412f1a192b06..b1c663593f5c9f082cb3dd997f94978a723b7599 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -41,6 +41,7 @@
 #include <linux/cgroup.h>
 #include <linux/module.h>
 #include <linux/mman.h>
+#include <linux/compat.h>
 
 #include "internal.h"
 
@@ -1518,6 +1519,11 @@ retry:
         */
        if (ctx->is_active) {
                raw_spin_unlock_irq(&ctx->lock);
+               /*
+                * Reload the task pointer, it might have been changed by
+                * a concurrent perf_event_context_sched_out().
+                */
+               task = ctx->task;
                goto retry;
        }
 
@@ -1961,6 +1967,11 @@ retry:
         */
        if (ctx->is_active) {
                raw_spin_unlock_irq(&ctx->lock);
+               /*
+                * Reload the task pointer, it might have been changed by
+                * a concurrent perf_event_context_sched_out().
+                */
+               task = ctx->task;
                goto retry;
        }
 
@@ -3712,6 +3723,26 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
        return 0;
 }
 
+#ifdef CONFIG_COMPAT
+static long perf_compat_ioctl(struct file *file, unsigned int cmd,
+                               unsigned long arg)
+{
+       switch (_IOC_NR(cmd)) {
+       case _IOC_NR(PERF_EVENT_IOC_SET_FILTER):
+       case _IOC_NR(PERF_EVENT_IOC_ID):
+               /* Fix up pointer size (usually 4 -> 8 in 32-on-64-bit case */
+               if (_IOC_SIZE(cmd) == sizeof(compat_uptr_t)) {
+                       cmd &= ~IOCSIZE_MASK;
+                       cmd |= sizeof(void *) << IOCSIZE_SHIFT;
+               }
+               break;
+       }
+       return perf_ioctl(file, cmd, arg);
+}
+#else
+# define perf_compat_ioctl NULL
+#endif
+
 int perf_event_task_enable(void)
 {
        struct perf_event *event;
@@ -4217,7 +4248,7 @@ static const struct file_operations perf_fops = {
        .read                   = perf_read,
        .poll                   = perf_poll,
        .unlocked_ioctl         = perf_ioctl,
-       .compat_ioctl           = perf_ioctl,
+       .compat_ioctl           = perf_compat_ioctl,
        .mmap                   = perf_mmap,
        .fasync                 = perf_fasync,
 };
@@ -7912,8 +7943,10 @@ int perf_event_init_task(struct task_struct *child)
 
        for_each_task_context_nr(ctxn) {
                ret = perf_event_init_context(child, ctxn);
-               if (ret)
+               if (ret) {
+                       perf_event_free_task(child);
                        return ret;
+               }
        }
 
        return 0;