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

Pull perf fixes from Ingo Molnar:
 "Misc fixlets"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix error return code
  ftrace: Fix strncpy() use, use strlcpy() instead of strncpy()
  perf: Fix strncpy() use, use strlcpy() instead of strncpy()
  perf: Fix strncpy() use, always make sure it's NUL terminated
  perf: Fix ring_buffer perf_output_space() boundary calculation
  perf/x86: Fix uninitialized pt_regs in intel_pmu_drain_bts_buffer()

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index b05a575..26830f3 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -314,10 +314,11 @@ int intel_pmu_drain_bts_buffer(void)
        if (top <= at)
                return 0;
 
+       memset(&regs, 0, sizeof(regs));
+
        ds->bts_index = ds->bts_buffer_base;
 
        perf_sample_data_init(&data, 0, event->hw.last_period);
-       regs.ip     = 0;
 
        /*
         * Prepare a generic sample, i.e. fill in the invariant fields.

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 59412d0..7e0962e 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4737,7 +4737,8 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
        } else {
                if (arch_vma_name(mmap_event->vma)) {
                        name = strncpy(tmp, arch_vma_name(mmap_event->vma),
-                                      sizeof(tmp));
+                                      sizeof(tmp) - 1);
+                       tmp[sizeof(tmp) - 1] = '\0';
                        goto got_name;
                }
 
@@ -5986,6 +5987,7 @@ skip_type:
        if (pmu->pmu_cpu_context)
                goto got_cpu_context;
 
+       ret = -ENOMEM;
        pmu->pmu_cpu_context = alloc_percpu(struct perf_cpu_context);
        if (!pmu->pmu_cpu_context)
                goto free_dev;

diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index d56a64c..eb675c4 100644 (file)
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -16,7 +16,7 @@ struct ring_buffer {
        int                             page_order;     /* allocation order  */
 #endif
        int                             nr_pages;       /* nr of data pages  */
-       int                             writable;       /* are we writable   */
+       int                             overwrite;      /* can overwrite itself */
 
        atomic_t                        poll;           /* POLL_ for wakeups */
 

diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 23cb34f..97fddb0 100644 (file)
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -18,12 +18,24 @@
 static bool perf_output_space(struct ring_buffer *rb, unsigned long tail,
                              unsigned long offset, unsigned long head)
 {
-       unsigned long mask;
+       unsigned long sz = perf_data_size(rb);
+       unsigned long mask = sz - 1;
 
-       if (!rb->writable)
+       /*
+        * check if user-writable
+        * overwrite : over-write its own tail
+        * !overwrite: buffer possibly drops events.
+        */
+       if (rb->overwrite)
                return true;
 
-       mask = perf_data_size(rb) - 1;
+       /*
+        * verify that payload is not bigger than buffer
+        * otherwise masking logic may fail to detect
+        * the "not enough space" condition
+        */
+       if ((head - offset) > sz)
+               return false;
 
        offset = (offset - tail) & mask;
        head   = (head   - tail) & mask;
@@ -212,7 +224,9 @@ ring_buffer_init(struct ring_buffer *rb, long watermark, int flags)
                rb->watermark = max_size / 2;
 
        if (flags & RING_BUFFER_WRITABLE)
-               rb->writable = 1;
+               rb->overwrite = 0;
+       else
+               rb->overwrite = 1;
 
        atomic_set(&rb->refcount, 1);
 

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2461ede..b3fde6d 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3440,14 +3440,14 @@ static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
 
 static int __init set_ftrace_notrace(char *str)
 {
-       strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
+       strlcpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
        return 1;
 }
 __setup("ftrace_notrace=", set_ftrace_notrace);
 
 static int __init set_ftrace_filter(char *str)
 {
-       strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
+       strlcpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
        return 1;
 }
 __setup("ftrace_filter=", set_ftrace_filter);

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 7ba7fc7..66338c4 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -132,7 +132,7 @@ static char *default_bootup_tracer;
 
 static int __init set_cmdline_ftrace(char *str)
 {
-       strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
+       strlcpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
        default_bootup_tracer = bootup_tracer_buf;
        /* We are using ftrace early, expand it */
        ring_buffer_expanded = 1;
@@ -162,7 +162,7 @@ static char *trace_boot_options __initdata;
 
 static int __init set_trace_boot_options(char *str)
 {
-       strncpy(trace_boot_options_buf, str, MAX_TRACER_SIZE);
+       strlcpy(trace_boot_options_buf, str, MAX_TRACER_SIZE);
        trace_boot_options = trace_boot_options_buf;
        return 0;
 }