Date: Mon, 6 May 2013 06:17:58 -0400 From: John Baldwin <jhb@freebsd.org> To: Mikolaj Golub <trociny@freebsd.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r250223 - in head: lib/libprocstat sys/kern sys/sys usr.bin/fstat Message-ID: <201305060617.59143.jhb@freebsd.org> In-Reply-To: <20130504185419.GA32075@gmail.com> References: <201305032111.r43LBvZ3040508@svn.freebsd.org> <20130504185419.GA32075@gmail.com>
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On Saturday, May 04, 2013 02:54:20 PM Mikolaj Golub wrote:
> On Fri, May 03, 2013 at 09:11:57PM +0000, John Baldwin wrote:
> > +static int
> > +procstat_get_sem_info_kvm(kvm_t *kd, struct filestat *fst,
> > + struct semstat *sem, char *errbuf)
> > +{
> > + struct ksem ksem;
> > + void *ksemp;
> > + char *path;
> > + int i;
> > +
> > + assert(kd);
> > + assert(sem);
> > + assert(fst);
> > + bzero(sem, sizeof(*sem));
> > + ksemp = fst->fs_typedep;
> > + if (ksemp == NULL)
> > + goto fail;
> > + if (!kvm_read_all(kd, (unsigned long)ksemp, &ksem,
> > + sizeof(struct ksem))) {
> > + warnx("can't read ksem at %p", (void *)ksemp);
> > + goto fail;
> > + }
> > + sem->mode = S_IFREG | ksem.ks_mode;
> > + sem->value = ksem.ks_value;
> > + if (fst->fs_path == NULL && ksem.ks_path != NULL) {
> > + path = malloc(MAXPATHLEN);
> > + for (i = 0; i < MAXPATHLEN - 1; i++) {
> > + if (!kvm_read_all(kd, (unsigned long)ksem.ks_path + i,
> > + path + i, 1))
> > + break;
> > + if (path[i] == '\0')
> > + break;
> > + }
> > + path[i] = '\0';
> > + if (i == 0)
> > + free(path);
> > + else
> > + fst->fs_path = path;
> > + }
> > + return (0);
> > +
> > +fail:
> > + snprintf(errbuf, _POSIX2_LINE_MAX, "error");
> > + return (1);
> > +}
>
> I would like to make errbuf optional (for all libprocstat functions
> that provide it) adding a check before printing to errbuf:
>
> if (errbuf != NULL)
> snprintf(errbuf, ...
>
> It looks like there are callers who are not interested in errbuf
> content. E.g. currently procstat(1) passes NULL when calling functions
> that require errbuf, namely procstat_get_socket_info and
> procstat_get_vnode_info, potentially crashing here if an error occurs.
>
> Do you (anyone) have objections?
Oh, no not at all. I just used the shm_info version as my template, so it
probably has the same issue as well.
--
John Baldwin
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