[PATCH] tools lib traceevent: Fix off-by-one bug in pevent_strerror()

[PATCH] tools lib traceevent: Fix off-by-one bug in pevent_strerror()

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

As pevent_errno is defined using PEVENT_ERRORS which uses _PE macro
magic, the first errno is bigger than __PEVENT_ERRNO_START by 1. So we
need to subtract the 1 also when calculating the index of the error
strings.

Cc: Fredereic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/lib/traceevent/event-parse.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index f978c59f67bf..b5b4d806ffa2 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -4822,7 +4822,7 @@ int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum,
 	    errnum >= __PEVENT_ERRNO__END)
 		return -1;
 
-	idx = errnum - __PEVENT_ERRNO__START;
+	idx = errnum - __PEVENT_ERRNO__START - 1;
 	msg = pevent_error_str[idx];
 
 	switch (errnum) {
-- 
1.7.11.4

Re: [PATCH] tools lib traceevent: Fix off-by-one bug in pevent_strerror()

[Steven Rostedt]

On Thu, 2012-08-23 at 16:37 +0900, Namhyung Kim wrote:
> From: Namhyung Kim <namhyung.kim@lge.com>
> 
> As pevent_errno is defined using PEVENT_ERRORS which uses _PE macro
> magic, the first errno is bigger than __PEVENT_ERRNO_START by 1. So we
> need to subtract the 1 also when calculating the index of the error
> strings.
> 
> Cc: Fredereic Weisbecker <fweisbec@gmail.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/lib/traceevent/event-parse.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
> index f978c59f67bf..b5b4d806ffa2 100644
> --- a/tools/lib/traceevent/event-parse.c
> +++ b/tools/lib/traceevent/event-parse.c
> @@ -4822,7 +4822,7 @@ int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum,
>  	    errnum >= __PEVENT_ERRNO__END)
>  		return -1;
>  
> -	idx = errnum - __PEVENT_ERRNO__START;
> +	idx = errnum - __PEVENT_ERRNO__START - 1;
>  	msg = pevent_error_str[idx];
>  

Note, if you had kept my original way, you wouldn't have this bug ;-)

http://marc.info/?l=linux-kernel&m=133976417632111

-- Steve

>  	switch (errnum) {

Re: [PATCH] tools lib traceevent: Fix off-by-one bug in pevent_strerror()

[Namhyung Kim]

Hi, Steve

On Thu, 23 Aug 2012 05:30:23 -0400, Steven Rostedt wrote:
> On Thu, 2012-08-23 at 16:37 +0900, Namhyung Kim wrote:
>> From: Namhyung Kim <namhyung.kim@lge.com>
>> 
>> As pevent_errno is defined using PEVENT_ERRORS which uses _PE macro
>> magic, the first errno is bigger than __PEVENT_ERRNO_START by 1. So we
>> need to subtract the 1 also when calculating the index of the error
>> strings.
>> 
>> Cc: Fredereic Weisbecker <fweisbec@gmail.com>
>> Cc: Steven Rostedt <rostedt@goodmis.org>
>> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
>> ---
>>  tools/lib/traceevent/event-parse.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
>> index f978c59f67bf..b5b4d806ffa2 100644
>> --- a/tools/lib/traceevent/event-parse.c
>> +++ b/tools/lib/traceevent/event-parse.c
>> @@ -4822,7 +4822,7 @@ int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum,
>>  	    errnum >= __PEVENT_ERRNO__END)
>>  		return -1;
>>  
>> -	idx = errnum - __PEVENT_ERRNO__START;
>> +	idx = errnum - __PEVENT_ERRNO__START - 1;
>>  	msg = pevent_error_str[idx];
>>  
>
> Note, if you had kept my original way, you wouldn't have this bug ;-)
>
> http://marc.info/?l=linux-kernel&m=133976417632111

Oh, I missed the BEFORE_START part at that time, sorry. :)

Thanks,
Namhyung

[tip:perf/core] tools lib traceevent: Fix off-by-one bug in pevent_strerror()

[tip-bot for Namhyung Kim]

Commit-ID:  f63fe79fa0b1362e8ea1c1e4996cf70d14917b02
Gitweb:     http://git.kernel.org/tip/f63fe79fa0b1362e8ea1c1e4996cf70d14917b02
Author:     Namhyung Kim <namhyung.kim@lge.com>
AuthorDate: Thu, 23 Aug 2012 16:37:00 +0900
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Thu, 23 Aug 2012 11:29:20 -0300

tools lib traceevent: Fix off-by-one bug in pevent_strerror()

As pevent_errno is defined using PEVENT_ERRORS which uses _PE macro
magic, the first errno is bigger than __PEVENT_ERRNO_START by 1. So we
need to subtract the 1 also when calculating the index of the error
strings.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1345707420-21767-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/lib/traceevent/event-parse.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index f978c59..b5b4d80 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -4822,7 +4822,7 @@ int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum,
 	    errnum >= __PEVENT_ERRNO__END)
 		return -1;
 
-	idx = errnum - __PEVENT_ERRNO__START;
+	idx = errnum - __PEVENT_ERRNO__START - 1;
 	msg = pevent_error_str[idx];
 
 	switch (errnum) {