From 7c27f78a297b54c3c2f5075cb15d33431b7f6333 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 24 Mar 2015 14:58:13 -0400 Subject: [PATCH] tools lib traceevent: Zero should not be considered "not found" in eval_flag() Guilherme Cox found that: There is, however, a potential bug if there is an item with code zero that is not the first one in the symbol list, since eval_flag(..) returns 0 when it doesn't find anything. That is, if you have the following enums: enum { FOO_START = 0, FOO_GO = 1, FOO_END = 2 } and then have: __print_symbolic(foo, FOO_GO, "go", FOO_START, "start", FOO_END, "end") If none of the enums are known to pevent, then eval_flag() will return zero, and it will match it to the first item in the list, which would be FOO_GO, which is not zero. Luckily, in most cases, the first element would be zero, and the parsing would match out of sheer luck. Reported-by: Guilherme Cox Signed-off-by: Steven Rostedt Cc: Jiri Olsa Cc: Namhyung Kim Link: http://lkml.kernel.org/r/20150324145813.0bfe95ba@gandalf.local.home Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/traceevent/event-parse.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index b6d11eea8a57..6d31b6419d37 100644 --- a/tools/lib/traceevent/event-parse.c +++ b/tools/lib/traceevent/event-parse.c @@ -3615,7 +3615,7 @@ static const struct flag flags[] = { { "HRTIMER_RESTART", 1 }, }; -static unsigned long long eval_flag(const char *flag) +static long long eval_flag(const char *flag) { int i; @@ -3631,7 +3631,7 @@ static unsigned long long eval_flag(const char *flag) if (strcmp(flags[i].name, flag) == 0) return flags[i].value; - return 0; + return -1LL; } static void print_str_to_seq(struct trace_seq *s, const char *format, @@ -3705,7 +3705,7 @@ static void print_str_arg(struct trace_seq *s, void *data, int size, struct print_flag_sym *flag; struct format_field *field; struct printk_map *printk; - unsigned long long val, fval; + long long val, fval; unsigned long addr; char *str; unsigned char *hex; @@ -3764,11 +3764,11 @@ static void print_str_arg(struct trace_seq *s, void *data, int size, print = 0; for (flag = arg->flags.flags; flag; flag = flag->next) { fval = eval_flag(flag->value); - if (!val && !fval) { + if (!val && fval < 0) { print_str_to_seq(s, format, len_arg, flag->str); break; } - if (fval && (val & fval) == fval) { + if (fval > 0 && (val & fval) == fval) { if (print && arg->flags.delim) trace_seq_puts(s, arg->flags.delim); print_str_to_seq(s, format, len_arg, flag->str);