1 files changed, 44 insertions, 10 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 0316ffe851bd..db5bdc8addf8 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -29,6 +29,7 @@
 #include <asm/apic.h>
 #include <asm/stacktrace.h>
 #include <asm/nmi.h>
+#include <asm/compat.h>
 
 static u64 perf_event_mask __read_mostly;
 
@@ -159,7 +160,7 @@ struct x86_pmu {
                                                  struct perf_event *event);
         struct event_constraint *event_constraints;
 
-        void            (*cpu_prepare)(int cpu);
+        int             (*cpu_prepare)(int cpu);
         void            (*cpu_starting)(int cpu);
         void            (*cpu_dying)(int cpu);
         void            (*cpu_dead)(int cpu);
@@ -1334,11 +1335,12 @@ static int __cpuinit
 x86_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
 {
         unsigned int cpu = (long)hcpu;
+        int ret = NOTIFY_OK;
 
         switch (action & ~CPU_TASKS_FROZEN) {
         case CPU_UP_PREPARE:
                 if (x86_pmu.cpu_prepare)
-                        x86_pmu.cpu_prepare(cpu);
+                        ret = x86_pmu.cpu_prepare(cpu);
                 break;
 
         case CPU_STARTING:
@@ -1351,6 +1353,7 @@ x86_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
                         x86_pmu.cpu_dying(cpu);
                 break;
 
+        case CPU_UP_CANCELED:
         case CPU_DEAD:
                 if (x86_pmu.cpu_dead)
                         x86_pmu.cpu_dead(cpu);
@@ -1360,7 +1363,7 @@ x86_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
                 break;
         }
 
-        return NOTIFY_OK;
+        return ret;
 }
 
 static void __init pmu_check_apic(void)
@@ -1629,14 +1632,42 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
         return len;
 }
 
-static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
+#ifdef CONFIG_COMPAT
+static inline int
+perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
 {
-        unsigned long bytes;
+        /* 32-bit process in 64-bit kernel. */
+        struct stack_frame_ia32 frame;
+        const void __user *fp;
 
-        bytes = copy_from_user_nmi(frame, fp, sizeof(*frame));
+        if (!test_thread_flag(TIF_IA32))
+                return 0;
+
+        fp = compat_ptr(regs->bp);
+        while (entry->nr < PERF_MAX_STACK_DEPTH) {
+                unsigned long bytes;
+                frame.next_frame     = 0;
+                frame.return_address = 0;
+
+                bytes = copy_from_user_nmi(&frame, fp, sizeof(frame));
+                if (bytes != sizeof(frame))
+                        break;
+
+                if (fp < compat_ptr(regs->sp))
+                        break;
 
-        return bytes == sizeof(*frame);
+                callchain_store(entry, frame.return_address);
+                fp = compat_ptr(frame.next_frame);
+        }
+        return 1;
+}
+#else
+static inline int
+perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
+{
+    return 0;
 }
+#endif
 
 static void
 perf_callchain_user(struct pt_regs *regs, struct perf_callchain_entry *entry)
@@ -1652,11 +1683,16 @@ perf_callchain_user(struct pt_regs *regs, struct perf_callchain_entry *entry)
         callchain_store(entry, PERF_CONTEXT_USER);
         callchain_store(entry, regs->ip);
 
+        if (perf_callchain_user32(regs, entry))
+                return;
+
         while (entry->nr < PERF_MAX_STACK_DEPTH) {
+                unsigned long bytes;
                 frame.next_frame             = NULL;
                 frame.return_address = 0;
 
-                if (!copy_stack_frame(fp, &frame))
+                bytes = copy_from_user_nmi(&frame, fp, sizeof(frame));
+                if (bytes != sizeof(frame))
                         break;
 
                 if ((unsigned long)fp < regs->sp)
@@ -1703,7 +1739,6 @@ struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
         return entry;
 }
 
-#ifdef CONFIG_EVENT_TRACING
 void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip)
 {
         regs->ip = ip;
@@ -1715,4 +1750,3 @@ void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int ski
         regs->cs = __KERNEL_CS;
         local_save_flags(regs->flags);
 }
-#endif