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authorDavid Woodhouse <David.Woodhouse@intel.com>2010-05-10 14:32:46 +0100
committerDavid Woodhouse <David.Woodhouse@intel.com>2010-05-10 14:32:46 +0100
commit0ae28a35bcb7984838acbf28bfba9c030f8b74f0 (patch)
tree4f449d929b5df9e126e839f388ff0fd2b52028a0 /kernel/trace/trace_event_perf.c
parent6f1f3d0ab5c3eeea9f04486481c25e9afdfa26c5 (diff)
parentb57f95a38233a2e73b679bea4a5453a1cc2a1cc9 (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts: drivers/mtd/mtdcore.c Pull in the bdi fixes and ARM platform changes that other outstanding patches depend on.
Diffstat (limited to 'kernel/trace/trace_event_perf.c')
-rw-r--r--kernel/trace/trace_event_perf.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 81f691eb3a3..0565bb42566 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);