From 43122e7e672eb170334a4467dd41cf4bd545bae5 Mon Sep 17 00:00:00 2001 From: Jamie Gennis Date: Thu, 21 Mar 2013 14:06:31 -0700 Subject: [PATCH] atrace: use creat instead of truncate Change-Id: Ie25c704f33c419c0c542249ae2841393862df0ab --- cmds/atrace/atrace.cpp | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/cmds/atrace/atrace.cpp b/cmds/atrace/atrace.cpp index 29838e455..d85a1d74d 100644 --- a/cmds/atrace/atrace.cpp +++ b/cmds/atrace/atrace.cpp @@ -176,13 +176,18 @@ static bool fileIsWritable(const char* filename) { // Truncate a file. static bool truncateFile(const char* path) { - int err = truncate(path, 0); - if (err != 0) { + // This uses creat rather than truncate because some of the debug kernel + // device nodes (e.g. k_ftraceFilterPath) currently aren't changed by + // calls to truncate, but they are cleared by calls to creat. + int traceFD = creat(path, 0); + if (traceFD == -1) { fprintf(stderr, "error truncating %s: %s (%d)\n", path, - strerror(errno), errno); + strerror(errno), errno); return false; } + close(traceFD); + return true; }