Then tracing syscall exit event it is extremely useful to filter exit
codes equal to some negative value, to react only to required errors.
But negative numbers does not work:
[root@snorch sys_exit_read]# echo "ret == -1" > filter
bash: echo: write error: Invalid argument
[root@snorch sys_exit_read]# cat filter
ret == -1
^
parse_error: Invalid value (did you forget quotes)?
Similar thing happens when setting triggers.
These is a regression in v4.17 introduced by the commit mentioned below,
testing without these commit shows no problem with negative numbers.
Fixes: 80765597bc58 ("tracing: Rewrite filter logic to be simpler and faster")
Signed-off-by: Pavel Tikhomirov <[email protected]>
---
kernel/trace/trace_events_filter.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 84a65173b1e9..2ba449292561 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1299,7 +1299,7 @@ static int parse_pred(const char *str, void *data,
/* go past the last quote */
i++;
- } else if (isdigit(str[i])) {
+ } else if (isdigit(str[i]) || str[i] == '-') {
/* Make sure the field is not a string */
if (is_string_field(field)) {
@@ -1312,6 +1312,9 @@ static int parse_pred(const char *str, void *data,
goto err_free;
}
+ if (str[i] == '-')
+ i++;
+
/* We allow 0xDEADBEEF */
while (isalnum(str[i]))
i++;
--
2.17.1
On Thu, 23 Aug 2018 13:25:34 +0300
Pavel Tikhomirov <[email protected]> wrote:
> Then tracing syscall exit event it is extremely useful to filter exit
> codes equal to some negative value, to react only to required errors.
> But negative numbers does not work:
>
> [root@snorch sys_exit_read]# echo "ret == -1" > filter
> bash: echo: write error: Invalid argument
> [root@snorch sys_exit_read]# cat filter
> ret == -1
> ^
> parse_error: Invalid value (did you forget quotes)?
Thanks for the patch. I'll apply it and then start testing it!
-- Steve
>
> Similar thing happens when setting triggers.
>
> These is a regression in v4.17 introduced by the commit mentioned below,
> testing without these commit shows no problem with negative numbers.
>
> Fixes: 80765597bc58 ("tracing: Rewrite filter logic to be simpler and faster")
> Signed-off-by: Pavel Tikhomirov <[email protected]>
> ---
> kernel/trace/trace_events_filter.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
> index 84a65173b1e9..2ba449292561 100644
> --- a/kernel/trace/trace_events_filter.c
> +++ b/kernel/trace/trace_events_filter.c
> @@ -1299,7 +1299,7 @@ static int parse_pred(const char *str, void *data,
> /* go past the last quote */
> i++;
>
> - } else if (isdigit(str[i])) {
> + } else if (isdigit(str[i]) || str[i] == '-') {
>
> /* Make sure the field is not a string */
> if (is_string_field(field)) {
> @@ -1312,6 +1312,9 @@ static int parse_pred(const char *str, void *data,
> goto err_free;
> }
>
> + if (str[i] == '-')
> + i++;
> +
> /* We allow 0xDEADBEEF */
> while (isalnum(str[i]))
> i++;
ping, looks like the patch was lost
On 8/24/18 3:48 AM, Steven Rostedt wrote:
> On Thu, 23 Aug 2018 13:25:34 +0300
> Pavel Tikhomirov <[email protected]> wrote:
>
>> Then tracing syscall exit event it is extremely useful to filter exit
>> codes equal to some negative value, to react only to required errors.
>> But negative numbers does not work:
>>
>> [root@snorch sys_exit_read]# echo "ret == -1" > filter
>> bash: echo: write error: Invalid argument
>> [root@snorch sys_exit_read]# cat filter
>> ret == -1
>> ^
>> parse_error: Invalid value (did you forget quotes)?
>
> Thanks for the patch. I'll apply it and then start testing it!
>
> -- Steve
>
>>
>> Similar thing happens when setting triggers.
>>
>> These is a regression in v4.17 introduced by the commit mentioned below,
>> testing without these commit shows no problem with negative numbers.
>>
>> Fixes: 80765597bc58 ("tracing: Rewrite filter logic to be simpler and faster")
>> Signed-off-by: Pavel Tikhomirov <[email protected]>
>> ---
>> kernel/trace/trace_events_filter.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
>> index 84a65173b1e9..2ba449292561 100644
>> --- a/kernel/trace/trace_events_filter.c
>> +++ b/kernel/trace/trace_events_filter.c
>> @@ -1299,7 +1299,7 @@ static int parse_pred(const char *str, void *data,
>> /* go past the last quote */
>> i++;
>>
>> - } else if (isdigit(str[i])) {
>> + } else if (isdigit(str[i]) || str[i] == '-') {
>>
>> /* Make sure the field is not a string */
>> if (is_string_field(field)) {
>> @@ -1312,6 +1312,9 @@ static int parse_pred(const char *str, void *data,
>> goto err_free;
>> }
>>
>> + if (str[i] == '-')
>> + i++;
>> +
>> /* We allow 0xDEADBEEF */
>> while (isalnum(str[i]))
>> i++;
>
--
Best regards, Tikhomirov Pavel
Software Developer, Virtuozzo.
On Thu, 28 Feb 2019 09:11:37 +0000
Pavel Tikhomirov <[email protected]> wrote:
> ping, looks like the patch was lost
>
> On 8/24/18 3:48 AM, Steven Rostedt wrote:
> > On Thu, 23 Aug 2018 13:25:34 +0300
> > Pavel Tikhomirov <[email protected]> wrote:
> >
> >> Then tracing syscall exit event it is extremely useful to filter exit
> >> codes equal to some negative value, to react only to required errors.
> >> But negative numbers does not work:
> >>
> >> [root@snorch sys_exit_read]# echo "ret == -1" > filter
> >> bash: echo: write error: Invalid argument
> >> [root@snorch sys_exit_read]# cat filter
> >> ret == -1
> >> ^
> >> parse_error: Invalid value (did you forget quotes)?
> >
> > Thanks for the patch. I'll apply it and then start testing it!
?!?
I remember applying this to my git queue (I don't reply like this
before doing so). Not sure how it got lost. All I can think of is that
it might have been added with commits that ended up failing the tests,
and got reverted with that code :-/
I'm currently traveling. Hopefully I remember tomorrow to add this.
Thanks for pointing this out, and I need to be a bit more careful when
reverting failed commits :-p
-- Steve