Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' into staging

Pull request

Compilation fixes and cleanups for QEMU 4.0.0.

# gpg: Signature made Mon 25 Mar 2019 15:58:28 GMT
# gpg:                using RSA key 9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/tracing-pull-request:
  trace-events: Fix attribution of trace points to source
  trace-events: Delete unused trace points
  scripts/cleanup-trace-events: Update for current practice
  trace-events: Shorten file names in comments
  trace-events: Consistently point to docs/devel/tracing.txt
  trace: avoid SystemTap dtrace(1) warnings on empty files
  trace: handle tracefs path truncation

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 10 insertions, 2 deletions

diff --git a/trace/ftrace.c b/trace/ftrace.c
index 61692a8682..9749543d9b 100644
--- a/trace/ftrace.c
+++ b/trace/ftrace.c
@@ -53,7 +53,11 @@ bool ftrace_init(void)
     }
 
     if (tracefs_found) {
-        snprintf(path, PATH_MAX, "%s%s/tracing_on", mount_point, subdir);
+        if (snprintf(path, PATH_MAX, "%s%s/tracing_on", mount_point, subdir)
+                >= sizeof(path)) {
+            fprintf(stderr, "Using tracefs mountpoint would exceed PATH_MAX\n");
+            return false;
+        }
         trace_fd = open(path, O_WRONLY);
         if (trace_fd < 0) {
             if (errno == EACCES) {
@@ -72,7 +76,11 @@ bool ftrace_init(void)
             }
             close(trace_fd);
         }
-        snprintf(path, PATH_MAX, "%s%s/trace_marker", mount_point, subdir);
+        if (snprintf(path, PATH_MAX, "%s%s/trace_marker", mount_point, subdir)
+                >= sizeof(path)) {
+            fprintf(stderr, "Using tracefs mountpoint would exceed PATH_MAX\n");
+            return false;
+        }
         trace_marker_fd = open(path, O_WRONLY);
         if (trace_marker_fd < 0) {
             perror("Could not open ftrace 'trace_marker' file");