The struct resctrl_val_param has control and monitor groups as char
arrays but they are not supposed to be mutated within resctrl_val().
Convert the ctrlgrp and mongrp char array within resctrl_val_param to
plain const char pointers and adjust the strlen() based checks to
check NULL instead.
Signed-off-by: Ilpo Järvinen <[email protected]>
---
tools/testing/selftests/resctrl/resctrl.h | 4 ++--
tools/testing/selftests/resctrl/resctrlfs.c | 8 ++++----
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index 52769b075233..54e5bce4c698 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -89,8 +89,8 @@ struct resctrl_test {
*/
struct resctrl_val_param {
char *resctrl_val;
- char ctrlgrp[64];
- char mongrp[64];
+ const char *ctrlgrp;
+ const char *mongrp;
char filename[64];
unsigned long mask;
int num_of_runs;
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 79cf1c593106..dbe0cc6d74fa 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -469,7 +469,7 @@ static int create_grp(const char *grp_name, char *grp, const char *parent_grp)
* length of grp_name == 0, it means, user wants to use root con_mon
* grp, so do nothing
*/
- if (strlen(grp_name) == 0)
+ if (!grp_name)
return 0;
/* Check if requested grp exists or not */
@@ -541,7 +541,7 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, const char *ctrlgrp,
char tasks[1024];
int ret = 0;
- if (strlen(ctrlgrp))
+ if (ctrlgrp)
sprintf(controlgroup, "%s/%s", RESCTRL_PATH, ctrlgrp);
else
sprintf(controlgroup, "%s", RESCTRL_PATH);
@@ -558,7 +558,7 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, const char *ctrlgrp,
/* Create mon grp and write pid into it for "mbm" and "cmt" test */
if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)) ||
!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) {
- if (strlen(mongrp)) {
+ if (mongrp) {
sprintf(monitorgroup_p, "%s/mon_groups", controlgroup);
sprintf(monitorgroup, "%s/%s", monitorgroup_p, mongrp);
ret = create_grp(mongrp, monitorgroup, monitorgroup_p);
@@ -612,7 +612,7 @@ int write_schemata(const char *ctrlgrp, char *schemata, int cpu_no,
goto out;
}
- if (strlen(ctrlgrp) != 0)
+ if (ctrlgrp)
sprintf(controlgroup, "%s/%s/schemata", RESCTRL_PATH, ctrlgrp);
else
sprintf(controlgroup, "%s/schemata", RESCTRL_PATH);
--
2.39.2
Hi Ilpo,
On 3/11/2024 6:52 AM, Ilpo Järvinen wrote:
> The struct resctrl_val_param has control and monitor groups as char
> arrays but they are not supposed to be mutated within resctrl_val().
>
> Convert the ctrlgrp and mongrp char array within resctrl_val_param to
> plain const char pointers and adjust the strlen() based checks to
> check NULL instead.
>
> Signed-off-by: Ilpo Järvinen <[email protected]>
> ---
> tools/testing/selftests/resctrl/resctrl.h | 4 ++--
> tools/testing/selftests/resctrl/resctrlfs.c | 8 ++++----
> 2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
> index 52769b075233..54e5bce4c698 100644
> --- a/tools/testing/selftests/resctrl/resctrl.h
> +++ b/tools/testing/selftests/resctrl/resctrl.h
> @@ -89,8 +89,8 @@ struct resctrl_test {
> */
> struct resctrl_val_param {
> char *resctrl_val;
> - char ctrlgrp[64];
> - char mongrp[64];
> + const char *ctrlgrp;
> + const char *mongrp;
> char filename[64];
> unsigned long mask;
> int num_of_runs;
> diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
> index 79cf1c593106..dbe0cc6d74fa 100644
> --- a/tools/testing/selftests/resctrl/resctrlfs.c
> +++ b/tools/testing/selftests/resctrl/resctrlfs.c
> @@ -469,7 +469,7 @@ static int create_grp(const char *grp_name, char *grp, const char *parent_grp)
> * length of grp_name == 0, it means, user wants to use root con_mon
> * grp, so do nothing
> */
Could you please confirm that the comments are still accurate?
> - if (strlen(grp_name) == 0)
> + if (!grp_name)
> return 0;
>
Reinette
On Wed, 20 Mar 2024, Reinette Chatre wrote:
> On 3/11/2024 6:52 AM, Ilpo Järvinen wrote:
> > The struct resctrl_val_param has control and monitor groups as char
> > arrays but they are not supposed to be mutated within resctrl_val().
> >
> > Convert the ctrlgrp and mongrp char array within resctrl_val_param to
> > plain const char pointers and adjust the strlen() based checks to
> > check NULL instead.
> >
> > Signed-off-by: Ilpo Järvinen <[email protected]>
> > ---
> > tools/testing/selftests/resctrl/resctrl.h | 4 ++--
> > tools/testing/selftests/resctrl/resctrlfs.c | 8 ++++----
> > 2 files changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
> > index 52769b075233..54e5bce4c698 100644
> > --- a/tools/testing/selftests/resctrl/resctrl.h
> > +++ b/tools/testing/selftests/resctrl/resctrl.h
> > @@ -89,8 +89,8 @@ struct resctrl_test {
> > */
> > struct resctrl_val_param {
> > char *resctrl_val;
> > - char ctrlgrp[64];
> > - char mongrp[64];
> > + const char *ctrlgrp;
> > + const char *mongrp;
> > char filename[64];
> > unsigned long mask;
> > int num_of_runs;
> > diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
> > index 79cf1c593106..dbe0cc6d74fa 100644
> > --- a/tools/testing/selftests/resctrl/resctrlfs.c
> > +++ b/tools/testing/selftests/resctrl/resctrlfs.c
> > @@ -469,7 +469,7 @@ static int create_grp(const char *grp_name, char *grp, const char *parent_grp)
> > * length of grp_name == 0, it means, user wants to use root con_mon
> > * grp, so do nothing
> > */
>
> Could you please confirm that the comments are still accurate?
It's not, I missed it.
> > - if (strlen(grp_name) == 0)
> > + if (!grp_name)
> > return 0;
But now when looking into the surrounding code, to me it looks the correct
action here is to remove the comment and return -1 instead of 0. It makes
this just an internal sanity check that grp_name is provided by the
caller.
--
i.
Hi Ilpo,
On 3/22/2024 5:30 AM, Ilpo Järvinen wrote:
> On Wed, 20 Mar 2024, Reinette Chatre wrote:
>> On 3/11/2024 6:52 AM, Ilpo Järvinen wrote:
>>> The struct resctrl_val_param has control and monitor groups as char
>>> arrays but they are not supposed to be mutated within resctrl_val().
>>>
>>> Convert the ctrlgrp and mongrp char array within resctrl_val_param to
>>> plain const char pointers and adjust the strlen() based checks to
>>> check NULL instead.
>>>
>>> Signed-off-by: Ilpo Järvinen <[email protected]>
>>> ---
>>> tools/testing/selftests/resctrl/resctrl.h | 4 ++--
>>> tools/testing/selftests/resctrl/resctrlfs.c | 8 ++++----
>>> 2 files changed, 6 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
>>> index 52769b075233..54e5bce4c698 100644
>>> --- a/tools/testing/selftests/resctrl/resctrl.h
>>> +++ b/tools/testing/selftests/resctrl/resctrl.h
>>> @@ -89,8 +89,8 @@ struct resctrl_test {
>>> */
>>> struct resctrl_val_param {
>>> char *resctrl_val;
>>> - char ctrlgrp[64];
>>> - char mongrp[64];
>>> + const char *ctrlgrp;
>>> + const char *mongrp;
>>> char filename[64];
>>> unsigned long mask;
>>> int num_of_runs;
>>> diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
>>> index 79cf1c593106..dbe0cc6d74fa 100644
>>> --- a/tools/testing/selftests/resctrl/resctrlfs.c
>>> +++ b/tools/testing/selftests/resctrl/resctrlfs.c
>>> @@ -469,7 +469,7 @@ static int create_grp(const char *grp_name, char *grp, const char *parent_grp)
>>> * length of grp_name == 0, it means, user wants to use root con_mon
>>> * grp, so do nothing
>>> */
>>
>> Could you please confirm that the comments are still accurate?
>
> It's not, I missed it.
>
>>> - if (strlen(grp_name) == 0)
>>> + if (!grp_name)
>>> return 0;
>
> But now when looking into the surrounding code, to me it looks the correct
> action here is to remove the comment and return -1 instead of 0. It makes
> this just an internal sanity check that grp_name is provided by the
> caller.
>
hmmm ... this should not be an error because the caller is not required
to provide grp_name. Not providing grp_name has a specific meaning
of this operating on the CON_MON group and a failure would break flows
operating on the CON_MON group.
Reinette
On Fri, 22 Mar 2024, Reinette Chatre wrote:
> On 3/22/2024 5:30 AM, Ilpo Järvinen wrote:
> > On Wed, 20 Mar 2024, Reinette Chatre wrote:
> >> On 3/11/2024 6:52 AM, Ilpo Järvinen wrote:
> >>> The struct resctrl_val_param has control and monitor groups as char
> >>> arrays but they are not supposed to be mutated within resctrl_val().
> >>>
> >>> Convert the ctrlgrp and mongrp char array within resctrl_val_param to
> >>> plain const char pointers and adjust the strlen() based checks to
> >>> check NULL instead.
> >>>
> >>> Signed-off-by: Ilpo Järvinen <[email protected]>
> >>> ---
> >>> tools/testing/selftests/resctrl/resctrl.h | 4 ++--
> >>> tools/testing/selftests/resctrl/resctrlfs.c | 8 ++++----
> >>> 2 files changed, 6 insertions(+), 6 deletions(-)
> >>>
> >>> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
> >>> index 52769b075233..54e5bce4c698 100644
> >>> --- a/tools/testing/selftests/resctrl/resctrl.h
> >>> +++ b/tools/testing/selftests/resctrl/resctrl.h
> >>> @@ -89,8 +89,8 @@ struct resctrl_test {
> >>> */
> >>> struct resctrl_val_param {
> >>> char *resctrl_val;
> >>> - char ctrlgrp[64];
> >>> - char mongrp[64];
> >>> + const char *ctrlgrp;
> >>> + const char *mongrp;
> >>> char filename[64];
> >>> unsigned long mask;
> >>> int num_of_runs;
> >>> diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
> >>> index 79cf1c593106..dbe0cc6d74fa 100644
> >>> --- a/tools/testing/selftests/resctrl/resctrlfs.c
> >>> +++ b/tools/testing/selftests/resctrl/resctrlfs.c
> >>> @@ -469,7 +469,7 @@ static int create_grp(const char *grp_name, char *grp, const char *parent_grp)
> >>> * length of grp_name == 0, it means, user wants to use root con_mon
> >>> * grp, so do nothing
> >>> */
> >>
> >> Could you please confirm that the comments are still accurate?
> >
> > It's not, I missed it.
> >
> >>> - if (strlen(grp_name) == 0)
> >>> + if (!grp_name)
> >>> return 0;
> >
> > But now when looking into the surrounding code, to me it looks the correct
> > action here is to remove the comment and return -1 instead of 0. It makes
> > this just an internal sanity check that grp_name is provided by the
> > caller.
> >
>
> hmmm ... this should not be an error because the caller is not required
> to provide grp_name. Not providing grp_name has a specific meaning
> of this operating on the CON_MON group and a failure would break flows
> operating on the CON_MON group.
write_bm_pid_to_resctrl() checks for non-NULL mongrp before it calls into
create_grp() so with current code, I don't think it changes anything. And
param->ctrlgrp is always non-NULL too so I don't think the return ever
triggers with the current codebase.
However, I was more talking from API point of view. It feels more natural
for "create group" function to return error if the caller is inconsistent
with itself by asking to create a group but doesn't want to create a
group.
--
i.