5 files changed, 25 insertions, 15 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 60398a0d947c..5fb490c6ee5c 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1702,7 +1702,6 @@ 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;
@@ -1714,4 +1713,3 @@ 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
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index bfba6019d762..b2258ca91003 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -618,8 +618,8 @@ int kgdb_arch_init(void)
          * portion of kgdb because this operation requires mutexs to
          * complete.
          */
+        hw_breakpoint_init(&attr);
         attr.bp_addr = (unsigned long)kgdb_arch_init;
-        attr.type = PERF_TYPE_BREAKPOINT;
         attr.bp_len = HW_BREAKPOINT_LEN_1;
         attr.bp_type = HW_BREAKPOINT_W;
         attr.disabled = 1;
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 95477038a72a..c8e375440403 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -842,13 +842,6 @@ extern atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX];
 
 extern void __perf_sw_event(u32, u64, int, struct pt_regs *, u64);
 
-static inline void
-perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr)
-{
-        if (atomic_read(&perf_swevent_enabled[event_id]))
-                __perf_sw_event(event_id, nr, nmi, regs, addr);
-}
-
 extern void
 perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip);
 
@@ -887,6 +880,20 @@ static inline void perf_fetch_caller_regs(struct pt_regs *regs, int skip)
         return perf_arch_fetch_caller_regs(regs, ip, skip);
 }
 
+static inline void
+perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr)
+{
+        if (atomic_read(&perf_swevent_enabled[event_id])) {
+                struct pt_regs hot_regs;
+
+                if (!regs) {
+                        perf_fetch_caller_regs(&hot_regs, 1);
+                        regs = &hot_regs;
+                }
+                __perf_sw_event(event_id, nr, nmi, regs, addr);
+        }
+}
+
 extern void __perf_event_mmap(struct vm_area_struct *vma);
 
 static inline void perf_event_mmap(struct vm_area_struct *vma)
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 574ee58a3046..b0feb4795af3 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -1164,11 +1164,9 @@ void perf_event_task_sched_out(struct task_struct *task,
         struct perf_event_context *ctx = task->perf_event_ctxp;
         struct perf_event_context *next_ctx;
         struct perf_event_context *parent;
-        struct pt_regs *regs;
         int do_switch = 1;
 
-        regs = task_pt_regs(task);
-        perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, regs, 0);
+        perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, NULL, 0);
 
         if (likely(!ctx || !cpuctx->task_ctx))
                 return;
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 81f691eb3a30..0565bb42566f 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -17,7 +17,12 @@ EXPORT_SYMBOL_GPL(perf_arch_fetch_caller_regs);
 static char *perf_trace_buf;
 static char *perf_trace_buf_nmi;
 
-typedef typeof(char [PERF_MAX_TRACE_SIZE]) perf_trace_t ;
+/*
+ * Force it to be aligned to unsigned long to avoid misaligned accesses
+ * suprises
+ */
+typedef typeof(unsigned long [PERF_MAX_TRACE_SIZE / sizeof(unsigned long)])
+        perf_trace_t;
 
 /* Count the events in use (per event id, not per instance) */
 static int      total_ref_count;
@@ -130,6 +135,8 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
         char *trace_buf, *raw_data;
         int pc, cpu;
 
+        BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long));
+
         pc = preempt_count();
 
         /* Protect the per cpu buffer, begin the rcu read side */
@@ -152,7 +159,7 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
         raw_data = per_cpu_ptr(trace_buf, cpu);
 
         /* zero the dead bytes from align to not leak stack to user */
-        *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+        memset(&raw_data[size - sizeof(u64)], 0, sizeof(u64));
 
         entry = (struct trace_entry *)raw_data;
         tracing_generic_entry_update(entry, *irq_flags, pc);