Re: svn commit: r314322 - head/lib/librss
In message
Re: svn commit: r314322 - head/lib/librss
> Then why even test for RC being NULL? So rc->rss_bucket_map doesn't dereference a null pointer and core dump maybe? Warner ___ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
Re: svn commit: r314322 - head/lib/librss
On 2/26/2017 9:37 PM, Cy Schubert wrote: In message <404d743b-735b-0605-5ab5-ccb95ce24...@freebsd.org>, Pedro Giffuni wr ites: This is a multi-part message in MIME format. --C3FC59CAC7D072A09BF70AAF Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Hello; On 2/26/2017 8:51 PM, Cy Schubert wrote: In message <201702270010.v1r0a1wm074...@repo.freebsd.org>, "Pedro F. Giffuni" w rites: Author: pfg Date: Mon Feb 27 00:10:00 2017 New Revision: 314322 URL: https://svnweb.freebsd.org/changeset/base/314322 Log: librss: simplify some NULL checks. MFC after: 1 week Modified: head/lib/librss/librss.c Modified: head/lib/librss/librss.c == === = --- head/lib/librss/librss.cSun Feb 26 22:17:06 2017(r31432 1) +++ head/lib/librss/librss.cMon Feb 27 00:10:00 2017(r31432 2) @@ -244,10 +244,10 @@ rss_config_get(void) return (rc); error: - if ((rc != NULL) && rc->rss_bucket_map) + if (rc != NULL) { free(rc->rss_bucket_map); What happens if rc is not NULL and rc->rss_bucket_map is NULL? According the free(3): " If /ptr/ is *NULL*, no action occurs." Good point. Then why even test for RC being NULL? If rc is NULL, there is a chance that rc->rss_bucket_map is random garbage and you might be "double freeing" something. The only reason I can think of doing any test for NULL before free(3) is that if the likelihood of *ptr being NULL is greater than the likelihood of *ptr not being NULL then you save running the extra instructions to make that determination in free(), e.g. pushes, call, return, pops. The check for rc NULL is necessary, the only optimization is that having done the check we already know if we need to free(rc), so while we could leave the second free() outside the branch it is better to leave it within the "if" . Pedro. ___ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
Re: svn commit: r314322 - head/lib/librss
In message <404d743b-735b-0605-5ab5-ccb95ce24...@freebsd.org>, Pedro Giffuni wr ites: > This is a multi-part message in MIME format. > --C3FC59CAC7D072A09BF70AAF > Content-Type: text/plain; charset=windows-1252; format=flowed > Content-Transfer-Encoding: 7bit > > Hello; > > On 2/26/2017 8:51 PM, Cy Schubert wrote: > > In message <201702270010.v1r0a1wm074...@repo.freebsd.org>, "Pedro F. > > Giffuni" w > > rites: > >> Author: pfg > >> Date: Mon Feb 27 00:10:00 2017 > >> New Revision: 314322 > >> URL: https://svnweb.freebsd.org/changeset/base/314322 > >> > >> Log: > >>librss: simplify some NULL checks. > >> > >>MFC after: 1 week > >> > >> Modified: > >>head/lib/librss/librss.c > >> > >> Modified: head/lib/librss/librss.c > >> == > === > >> = > >> --- head/lib/librss/librss.c Sun Feb 26 22:17:06 2017(r31432 > 1) > >> +++ head/lib/librss/librss.c Mon Feb 27 00:10:00 2017(r31432 > 2) > >> @@ -244,10 +244,10 @@ rss_config_get(void) > >>return (rc); > >> > >> error: > >> - if ((rc != NULL) && rc->rss_bucket_map) > >> + if (rc != NULL) { > >>free(rc->rss_bucket_map); > > What happens if rc is not NULL and rc->rss_bucket_map is NULL? > > According the free(3): " If /ptr/ is *NULL*, no action occurs." > Good point. Then why even test for RC being NULL? The only reason I can think of doing any test for NULL before free(3) is that if the likelihood of *ptr being NULL is greater than the likelihood of *ptr not being NULL then you save running the extra instructions to make that determination in free(), e.g. pushes, call, return, pops. -- Cheers, Cy SchubertFreeBSD UNIX: Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few. ___ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
Re: svn commit: r314322 - head/lib/librss
Hello; On 2/26/2017 8:51 PM, Cy Schubert wrote: In message <201702270010.v1r0a1wm074...@repo.freebsd.org>, "Pedro F. Giffuni" w rites: Author: pfg Date: Mon Feb 27 00:10:00 2017 New Revision: 314322 URL: https://svnweb.freebsd.org/changeset/base/314322 Log: librss: simplify some NULL checks. MFC after: 1 week Modified: head/lib/librss/librss.c Modified: head/lib/librss/librss.c = = --- head/lib/librss/librss.cSun Feb 26 22:17:06 2017(r314321) +++ head/lib/librss/librss.cMon Feb 27 00:10:00 2017(r314322) @@ -244,10 +244,10 @@ rss_config_get(void) return (rc); error: - if ((rc != NULL) && rc->rss_bucket_map) + if (rc != NULL) { free(rc->rss_bucket_map); What happens if rc is not NULL and rc->rss_bucket_map is NULL? According the free(3): " If /ptr/ is *NULL*, no action occurs." Pedro. ___ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
Re: svn commit: r314322 - head/lib/librss
In message <201702270010.v1r0a1wm074...@repo.freebsd.org>, "Pedro F. Giffuni" w rites: > Author: pfg > Date: Mon Feb 27 00:10:00 2017 > New Revision: 314322 > URL: https://svnweb.freebsd.org/changeset/base/314322 > > Log: > librss: simplify some NULL checks. > > MFC after: 1 week > > Modified: > head/lib/librss/librss.c > > Modified: head/lib/librss/librss.c > = > = > --- head/lib/librss/librss.c Sun Feb 26 22:17:06 2017(r314321) > +++ head/lib/librss/librss.c Mon Feb 27 00:10:00 2017(r314322) > @@ -244,10 +244,10 @@ rss_config_get(void) > return (rc); > > error: > - if ((rc != NULL) && rc->rss_bucket_map) > + if (rc != NULL) { > free(rc->rss_bucket_map); What happens if rc is not NULL and rc->rss_bucket_map is NULL? > - if (rc != NULL) > free(rc); > + } > return (NULL); > } > > > -- Cheers, Cy SchubertFreeBSD UNIX: Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few. ___ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
svn commit: r314322 - head/lib/librss
Author: pfg Date: Mon Feb 27 00:10:00 2017 New Revision: 314322 URL: https://svnweb.freebsd.org/changeset/base/314322 Log: librss: simplify some NULL checks. MFC after:1 week Modified: head/lib/librss/librss.c Modified: head/lib/librss/librss.c == --- head/lib/librss/librss.cSun Feb 26 22:17:06 2017(r314321) +++ head/lib/librss/librss.cMon Feb 27 00:10:00 2017(r314322) @@ -244,10 +244,10 @@ rss_config_get(void) return (rc); error: - if ((rc != NULL) && rc->rss_bucket_map) + if (rc != NULL) { free(rc->rss_bucket_map); - if (rc != NULL) free(rc); + } return (NULL); } ___ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"