From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> To: Greg Kurz <groug@kaod.org> Cc: virtio-fs@redhat.com, qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>, misono.tomohiro@jp.fujitsu.com Subject: Re: [PATCH] virtiofsd: Fix side-effect in assert() Date: Thu, 6 May 2021 16:46:45 +0100 [thread overview] Message-ID: <YJQPZcyfM6DAtHcn@work-vm> (raw) In-Reply-To: <20210409100627.451573-1-groug@kaod.org> * Greg Kurz (groug@kaod.org) wrote: > It is bad practice to put an expression with a side-effect in > assert() because the side-effect won't happen if the code is > compiled with -DNDEBUG. > > Use an intermediate variable. Consolidate this in an macro to > have proper line numbers when the assertion is hit. > > virtiofsd: ../../tools/virtiofsd/passthrough_ll.c:2797: lo_getxattr: > Assertion `fchdir_res == 0' failed. > Aborted > > 2796 /* fchdir should not fail here */ > =>2797 FCHDIR_NOFAIL(lo->proc_self_fd); > 2798 ret = getxattr(procname, name, value, size); > 2799 FCHDIR_NOFAIL(lo->root.fd); > > Fixes: bdfd66788349 ("virtiofsd: Fix xattr operations") > Cc: misono.tomohiro@jp.fujitsu.com > Signed-off-by: Greg Kurz <groug@kaod.org> Queued > --- > tools/virtiofsd/passthrough_ll.c | 21 +++++++++++++-------- > 1 file changed, 13 insertions(+), 8 deletions(-) > > diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c > index 1553d2ef454f..6592f96f685e 100644 > --- a/tools/virtiofsd/passthrough_ll.c > +++ b/tools/virtiofsd/passthrough_ll.c > @@ -2723,6 +2723,11 @@ static int xattr_map_server(const struct lo_data *lo, const char *server_name, > return -ENODATA; > } > > +#define FCHDIR_NOFAIL(fd) do { \ > + int fchdir_res = fchdir(fd); \ > + assert(fchdir_res == 0); \ > + } while (0) > + > static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > size_t size) > { > @@ -2789,9 +2794,9 @@ static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > ret = fgetxattr(fd, name, value, size); > } else { > /* fchdir should not fail here */ > - assert(fchdir(lo->proc_self_fd) == 0); > + FCHDIR_NOFAIL(lo->proc_self_fd); > ret = getxattr(procname, name, value, size); > - assert(fchdir(lo->root.fd) == 0); > + FCHDIR_NOFAIL(lo->root.fd); > } > > if (ret == -1) { > @@ -2864,9 +2869,9 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) > ret = flistxattr(fd, value, size); > } else { > /* fchdir should not fail here */ > - assert(fchdir(lo->proc_self_fd) == 0); > + FCHDIR_NOFAIL(lo->proc_self_fd); > ret = listxattr(procname, value, size); > - assert(fchdir(lo->root.fd) == 0); > + FCHDIR_NOFAIL(lo->root.fd); > } > > if (ret == -1) { > @@ -3000,9 +3005,9 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > ret = fsetxattr(fd, name, value, size, flags); > } else { > /* fchdir should not fail here */ > - assert(fchdir(lo->proc_self_fd) == 0); > + FCHDIR_NOFAIL(lo->proc_self_fd); > ret = setxattr(procname, name, value, size, flags); > - assert(fchdir(lo->root.fd) == 0); > + FCHDIR_NOFAIL(lo->root.fd); > } > > saverr = ret == -1 ? errno : 0; > @@ -3066,9 +3071,9 @@ static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *in_name) > ret = fremovexattr(fd, name); > } else { > /* fchdir should not fail here */ > - assert(fchdir(lo->proc_self_fd) == 0); > + FCHDIR_NOFAIL(lo->proc_self_fd); > ret = removexattr(procname, name); > - assert(fchdir(lo->root.fd) == 0); > + FCHDIR_NOFAIL(lo->root.fd); > } > > saverr = ret == -1 ? errno : 0; > -- > 2.26.3 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
WARNING: multiple messages have this Message-ID (diff)
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> To: Greg Kurz <groug@kaod.org> Cc: virtio-fs@redhat.com, qemu-devel@nongnu.org Subject: Re: [Virtio-fs] [PATCH] virtiofsd: Fix side-effect in assert() Date: Thu, 6 May 2021 16:46:45 +0100 [thread overview] Message-ID: <YJQPZcyfM6DAtHcn@work-vm> (raw) In-Reply-To: <20210409100627.451573-1-groug@kaod.org> * Greg Kurz (groug@kaod.org) wrote: > It is bad practice to put an expression with a side-effect in > assert() because the side-effect won't happen if the code is > compiled with -DNDEBUG. > > Use an intermediate variable. Consolidate this in an macro to > have proper line numbers when the assertion is hit. > > virtiofsd: ../../tools/virtiofsd/passthrough_ll.c:2797: lo_getxattr: > Assertion `fchdir_res == 0' failed. > Aborted > > 2796 /* fchdir should not fail here */ > =>2797 FCHDIR_NOFAIL(lo->proc_self_fd); > 2798 ret = getxattr(procname, name, value, size); > 2799 FCHDIR_NOFAIL(lo->root.fd); > > Fixes: bdfd66788349 ("virtiofsd: Fix xattr operations") > Cc: misono.tomohiro@jp.fujitsu.com > Signed-off-by: Greg Kurz <groug@kaod.org> Queued > --- > tools/virtiofsd/passthrough_ll.c | 21 +++++++++++++-------- > 1 file changed, 13 insertions(+), 8 deletions(-) > > diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c > index 1553d2ef454f..6592f96f685e 100644 > --- a/tools/virtiofsd/passthrough_ll.c > +++ b/tools/virtiofsd/passthrough_ll.c > @@ -2723,6 +2723,11 @@ static int xattr_map_server(const struct lo_data *lo, const char *server_name, > return -ENODATA; > } > > +#define FCHDIR_NOFAIL(fd) do { \ > + int fchdir_res = fchdir(fd); \ > + assert(fchdir_res == 0); \ > + } while (0) > + > static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > size_t size) > { > @@ -2789,9 +2794,9 @@ static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > ret = fgetxattr(fd, name, value, size); > } else { > /* fchdir should not fail here */ > - assert(fchdir(lo->proc_self_fd) == 0); > + FCHDIR_NOFAIL(lo->proc_self_fd); > ret = getxattr(procname, name, value, size); > - assert(fchdir(lo->root.fd) == 0); > + FCHDIR_NOFAIL(lo->root.fd); > } > > if (ret == -1) { > @@ -2864,9 +2869,9 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) > ret = flistxattr(fd, value, size); > } else { > /* fchdir should not fail here */ > - assert(fchdir(lo->proc_self_fd) == 0); > + FCHDIR_NOFAIL(lo->proc_self_fd); > ret = listxattr(procname, value, size); > - assert(fchdir(lo->root.fd) == 0); > + FCHDIR_NOFAIL(lo->root.fd); > } > > if (ret == -1) { > @@ -3000,9 +3005,9 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, > ret = fsetxattr(fd, name, value, size, flags); > } else { > /* fchdir should not fail here */ > - assert(fchdir(lo->proc_self_fd) == 0); > + FCHDIR_NOFAIL(lo->proc_self_fd); > ret = setxattr(procname, name, value, size, flags); > - assert(fchdir(lo->root.fd) == 0); > + FCHDIR_NOFAIL(lo->root.fd); > } > > saverr = ret == -1 ? errno : 0; > @@ -3066,9 +3071,9 @@ static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *in_name) > ret = fremovexattr(fd, name); > } else { > /* fchdir should not fail here */ > - assert(fchdir(lo->proc_self_fd) == 0); > + FCHDIR_NOFAIL(lo->proc_self_fd); > ret = removexattr(procname, name); > - assert(fchdir(lo->root.fd) == 0); > + FCHDIR_NOFAIL(lo->root.fd); > } > > saverr = ret == -1 ? errno : 0; > -- > 2.26.3 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
next prev parent reply other threads:[~2021-05-06 15:57 UTC|newest] Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-04-09 10:06 [PATCH] virtiofsd: Fix side-effect in assert() Greg Kurz 2021-04-09 10:06 ` [Virtio-fs] " Greg Kurz 2021-04-09 10:23 ` Philippe Mathieu-Daudé 2021-04-09 10:23 ` [Virtio-fs] " Philippe Mathieu-Daudé 2021-04-09 13:30 ` Vivek Goyal 2021-04-09 14:40 ` Wainer dos Santos Moschetta 2021-04-09 14:40 ` [Virtio-fs] " Wainer dos Santos Moschetta 2021-04-09 14:56 ` Alex Bennée 2021-04-09 14:56 ` [Virtio-fs] " Alex Bennée 2021-04-09 15:11 ` Stefan Weil 2021-04-09 15:11 ` [Virtio-fs] " Stefan Weil 2021-04-09 15:24 ` Philippe Mathieu-Daudé 2021-04-09 15:24 ` [Virtio-fs] " Philippe Mathieu-Daudé 2021-05-06 15:46 ` Dr. David Alan Gilbert [this message] 2021-05-06 15:46 ` Dr. David Alan Gilbert
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