From 3de29cab1f8d62db557a4afed0fb17eebfe64438 Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Mon, 17 May 2010 12:20:43 -0300 Subject: [PATCH] perf record: Fix bug mismatch with -c option definition MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The -c option defines the user requested sampling period. It was implemented using an unsigned int variable but the type of the option was OPT_LONG. Thus, the option parser was overwriting memory belonging to other variables, namely the mmap_pages leading to a zero page sampling buffer. The bug was exposed only when compiling at -O0, probably because the compiler was padding variables at higher optimization levels. This patch fixes this problem by declaring user_interval as u64. This also avoids wrap-around issues for large period on 32-bit systems. Commiter note: Made it use OPT_U64(user_interval) after implementing OPT_U64 in the previous patch. Cc: David S. Miller Cc: Frédéric Weisbecker Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra LKML-Reference: <4bf11ae9.e88cd80a.06b0.ffffa8e3@mx.google.com> Signed-off-by: Stephane Eranian Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 0f467cf7aa7..b93573c7ac0 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -33,8 +33,8 @@ enum write_mode_t { static int *fd[MAX_NR_CPUS][MAX_COUNTERS]; -static unsigned int user_interval = UINT_MAX; -static long default_interval = 0; +static u64 user_interval = ULLONG_MAX; +static u64 default_interval = 0; static int nr_cpus = 0; static unsigned int page_size; @@ -268,7 +268,7 @@ static void create_counter(int counter, int cpu) * it a weak assumption overridable by the user. */ if (!attr->sample_period || (user_freq != UINT_MAX && - user_interval != UINT_MAX)) { + user_interval != ULLONG_MAX)) { if (freq) { attr->sample_type |= PERF_SAMPLE_PERIOD; attr->freq = 1; @@ -817,8 +817,7 @@ static const struct option options[] = { "CPU to profile on"), OPT_BOOLEAN('f', "force", &force, "overwrite existing data file (deprecated)"), - OPT_LONG('c', "count", &user_interval, - "event period to sample"), + OPT_U64('c', "count", &user_interval, "event period to sample"), OPT_STRING('o', "output", &output_name, "file", "output file name"), OPT_BOOLEAN('i', "no-inherit", &no_inherit, @@ -901,7 +900,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __used) if (!event_array) return -ENOMEM; - if (user_interval != UINT_MAX) + if (user_interval != ULLONG_MAX) default_interval = user_interval; if (user_freq != UINT_MAX) freq = user_freq; -- 2.20.1