[3/8] trace: fix leak with regexp

Message ID 20220921120359.2201131-4-david.marchand@redhat.com (mailing list archive)
State Changes Requested, archived
Delegated to: Thomas Monjalon
Headers
Series Trace subsystem fixes |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

David Marchand Sept. 21, 2022, 12:03 p.m. UTC
  The precompiled buffer initialised in regcomp must be freed before
leaving rte_trace_regexp.

Fixes: 84c4fae4628f ("trace: implement operation APIs")
Cc: stable@dpdk.org

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 lib/eal/common/eal_common_trace.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)
  

Comments

Sunil Kumar Kori Sept. 22, 2022, 11 a.m. UTC | #1
> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Wednesday, September 21, 2022 5:34 PM
> To: dev@dpdk.org
> Cc: stable@dpdk.org; Jerin Jacob Kollanukkaran <jerinj@marvell.com>; Sunil
> Kumar Kori <skori@marvell.com>
> Subject: [EXT] [PATCH 3/8] trace: fix leak with regexp
> 
> External Email
> 
> ----------------------------------------------------------------------
> The precompiled buffer initialised in regcomp must be freed before leaving
> rte_trace_regexp.
> 
> Fixes: 84c4fae4628f ("trace: implement operation APIs")
> Cc: stable@dpdk.org
> 
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> ---
>  lib/eal/common/eal_common_trace.c | 19 +++++++++++--------
>  1 file changed, 11 insertions(+), 8 deletions(-)
> 
> diff --git a/lib/eal/common/eal_common_trace.c
> b/lib/eal/common/eal_common_trace.c
> index 1db28a441d..c835b0d16e 100644
> --- a/lib/eal/common/eal_common_trace.c
> +++ b/lib/eal/common/eal_common_trace.c
> @@ -210,15 +210,18 @@ rte_trace_regexp(const char *regex, bool enable)
>  		return -EINVAL;
> 
>  	STAILQ_FOREACH(tp, &tp_list, next) {
> -		if (regexec(&r, tp->name, 0, NULL, 0) == 0) {
> -			if (enable)
> -				rc = rte_trace_point_enable(tp->handle);
> -			else
> -				rc = rte_trace_point_disable(tp->handle);
> -			found = 1;
> +		if (regexec(&r, tp->name, 0, NULL, 0) != 0)
> +			continue;
> +
> +		if (enable)
> +			rc = rte_trace_point_enable(tp->handle);
> +		else
> +			rc = rte_trace_point_disable(tp->handle);
> +		if (rc < 0) {
> +			found = 0;
> +			break;
>  		}
> -		if (rc < 0)
> -			return rc;
> +		found = 1;
>  	}
>  	regfree(&r);
> 
> --

I understand the problem addressed by this fix but may be following changes will be sufficient to fix it.
Please highlight, If I am missing. Just trying to reduce the line of changes.

@@ -220,8 +220,10 @@ rte_trace_regexp(const char *regex, bool enable)
                                rc = rte_trace_point_disable(tp->handle);
                        found = 1;
                }
-               if (rc < 0)
-                       return rc;
+               if (rc < 0) {
+                       found = 0;
+                       break;
+               }
        }
> 2.37.3
  
David Marchand Sept. 23, 2022, 6:35 a.m. UTC | #2
On Thu, Sep 22, 2022 at 1:00 PM Sunil Kumar Kori <skori@marvell.com> wrote:
> > @@ -210,15 +210,18 @@ rte_trace_regexp(const char *regex, bool enable)
> >               return -EINVAL;
> >
> >       STAILQ_FOREACH(tp, &tp_list, next) {
> > -             if (regexec(&r, tp->name, 0, NULL, 0) == 0) {
> > -                     if (enable)
> > -                             rc = rte_trace_point_enable(tp->handle);
> > -                     else
> > -                             rc = rte_trace_point_disable(tp->handle);
> > -                     found = 1;
> > +             if (regexec(&r, tp->name, 0, NULL, 0) != 0)
> > +                     continue;
> > +
> > +             if (enable)
> > +                     rc = rte_trace_point_enable(tp->handle);
> > +             else
> > +                     rc = rte_trace_point_disable(tp->handle);
> > +             if (rc < 0) {
> > +                     found = 0;
> > +                     break;
> >               }
> > -             if (rc < 0)
> > -                     return rc;
> > +             found = 1;
> >       }
> >       regfree(&r);
> >
> > --
>
> I understand the problem addressed by this fix but may be following changes will be sufficient to fix it.
> Please highlight, If I am missing. Just trying to reduce the line of changes.
>
> @@ -220,8 +220,10 @@ rte_trace_regexp(const char *regex, bool enable)
>                                 rc = rte_trace_point_disable(tp->handle);
>                         found = 1;
>                 }
> -               if (rc < 0)
> -                       return rc;
> +               if (rc < 0) {
> +                       found = 0;
> +                       break;
> +               }
>         }


rc is compared against 0 for all non-matching tracepoints.
This is unnecessary and fragile.

I can split this change in two: one for the fix, and one other where
the loop is updated with a continue and an inverted matching condition
like above.
If going like this, I would update rte_trace_pattern() too, in the second patch.

WDYT?
  
Sunil Kumar Kori Sept. 23, 2022, 7:37 a.m. UTC | #3
> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Friday, September 23, 2022 12:05 PM
> To: Sunil Kumar Kori <skori@marvell.com>
> Cc: dev@dpdk.org; stable@dpdk.org; Jerin Jacob Kollanukkaran
> <jerinj@marvell.com>
> Subject: Re: [EXT] [PATCH 3/8] trace: fix leak with regexp
> 
> On Thu, Sep 22, 2022 at 1:00 PM Sunil Kumar Kori <skori@marvell.com>
> wrote:
> > > @@ -210,15 +210,18 @@ rte_trace_regexp(const char *regex, bool
> enable)
> > >               return -EINVAL;
> > >
> > >       STAILQ_FOREACH(tp, &tp_list, next) {
> > > -             if (regexec(&r, tp->name, 0, NULL, 0) == 0) {
> > > -                     if (enable)
> > > -                             rc = rte_trace_point_enable(tp->handle);
> > > -                     else
> > > -                             rc = rte_trace_point_disable(tp->handle);
> > > -                     found = 1;
> > > +             if (regexec(&r, tp->name, 0, NULL, 0) != 0)
> > > +                     continue;
> > > +
> > > +             if (enable)
> > > +                     rc = rte_trace_point_enable(tp->handle);
> > > +             else
> > > +                     rc = rte_trace_point_disable(tp->handle);
> > > +             if (rc < 0) {
> > > +                     found = 0;
> > > +                     break;
> > >               }
> > > -             if (rc < 0)
> > > -                     return rc;
> > > +             found = 1;
> > >       }
> > >       regfree(&r);
> > >
> > > --
> >
> > I understand the problem addressed by this fix but may be following
> changes will be sufficient to fix it.
> > Please highlight, If I am missing. Just trying to reduce the line of changes.
> >
> > @@ -220,8 +220,10 @@ rte_trace_regexp(const char *regex, bool enable)
> >                                 rc = rte_trace_point_disable(tp->handle);
> >                         found = 1;
> >                 }
> > -               if (rc < 0)
> > -                       return rc;
> > +               if (rc < 0) {
> > +                       found = 0;
> > +                       break;
> > +               }
> >         }
> 
> 
> rc is compared against 0 for all non-matching tracepoints.
> This is unnecessary and fragile.
> 
> I can split this change in two: one for the fix, and one other where the loop is
> updated with a continue and an inverted matching condition like above.
> If going like this, I would update rte_trace_pattern() too, in the second patch.
> 
> WDYT?

Sounds okay. You can proceed in either way. No hard opinion on it. 
> 
> 
> --
> David Marchand
  

Patch

diff --git a/lib/eal/common/eal_common_trace.c b/lib/eal/common/eal_common_trace.c
index 1db28a441d..c835b0d16e 100644
--- a/lib/eal/common/eal_common_trace.c
+++ b/lib/eal/common/eal_common_trace.c
@@ -210,15 +210,18 @@  rte_trace_regexp(const char *regex, bool enable)
 		return -EINVAL;
 
 	STAILQ_FOREACH(tp, &tp_list, next) {
-		if (regexec(&r, tp->name, 0, NULL, 0) == 0) {
-			if (enable)
-				rc = rte_trace_point_enable(tp->handle);
-			else
-				rc = rte_trace_point_disable(tp->handle);
-			found = 1;
+		if (regexec(&r, tp->name, 0, NULL, 0) != 0)
+			continue;
+
+		if (enable)
+			rc = rte_trace_point_enable(tp->handle);
+		else
+			rc = rte_trace_point_disable(tp->handle);
+		if (rc < 0) {
+			found = 0;
+			break;
 		}
-		if (rc < 0)
-			return rc;
+		found = 1;
 	}
 	regfree(&r);