| Message ID | 1392864546-545-2-git-send-email-guihc.fnst@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | Under Review, archived |
| Headers | show |
On 20 February 2014 02:49, Gui Hecheng <guihc.fnst@cn.fujitsu.com> wrote: > When exec btrfs-debug-tree as non-root user, we get a segment fault. > Because the btrfs_scan_block_devices return a success 0 when we fail > to open a device. Now we just return the errno if this case happens. > > Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com> > --- > utils.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/utils.c b/utils.c > index 97e23d5..1878abc 100644 > --- a/utils.c > +++ b/utils.c > @@ -1517,7 +1517,8 @@ scan_again: > scans++; > goto scan_again; > } > - return 0; > + > + return errno ? -errno : 0; > } > > u64 parse_size(char *s) > -- > 1.8.1.4 Hi Gui, This strikes me as not not right because errno is only documented as being set when open() returns -1 on failure. In the success case errno is not set so you can't assume it will be 0. I think the following might work: 1) Initilase ret = 0 at the start of btrfs_scan_block_devices() 2) In the open(fullpath, O_RDONLY) failure case set ret = fd 3) return ret Thanks, Mike -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2014-02-20 at 08:48 +0000, Mike Fleetwood wrote: > On 20 February 2014 02:49, Gui Hecheng <guihc.fnst@cn.fujitsu.com> wrote: > > When exec btrfs-debug-tree as non-root user, we get a segment fault. > > Because the btrfs_scan_block_devices return a success 0 when we fail > > to open a device. Now we just return the errno if this case happens. > > > > Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com> > > --- > > utils.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/utils.c b/utils.c > > index 97e23d5..1878abc 100644 > > --- a/utils.c > > +++ b/utils.c > > @@ -1517,7 +1517,8 @@ scan_again: > > scans++; > > goto scan_again; > > } > > - return 0; > > + > > + return errno ? -errno : 0; > > } > > > > u64 parse_size(char *s) > > -- > > 1.8.1.4 > > Hi Gui, > > This strikes me as not not right because errno is only documented as > being set when open() returns -1 on failure. In the success case > errno is not set so you can't assume it will be 0. > > I think the following might work: > 1) Initilase ret = 0 at the start of btrfs_scan_block_devices() > 2) In the open(fullpath, O_RDONLY) failure case set ret = fd > 3) return ret > > Thanks, > Mike Hi Mike, Thanks for your comment, I think it is a reasonable way to fix the ret value problem. But I am sorry that my patch does not really address the segmentfault problem. Please *ignore* this patch... -Gui > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/utils.c b/utils.c index 97e23d5..1878abc 100644 --- a/utils.c +++ b/utils.c @@ -1517,7 +1517,8 @@ scan_again: scans++; goto scan_again; } - return 0; + + return errno ? -errno : 0; } u64 parse_size(char *s)
When exec btrfs-debug-tree as non-root user, we get a segment fault. Because the btrfs_scan_block_devices return a success 0 when we fail to open a device. Now we just return the errno if this case happens. Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com> --- utils.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)