On Wed, Dec 06, 2017 at 01:10:14PM -0700, Ross Zwisler wrote: > On Wed, Dec 06, 2017 at 11:27:43AM +1100, Dave Chinner wrote: > > On Tue, Dec 05, 2017 at 04:56:49PM -0700, Ross Zwisler wrote: > > > I recently upgraded my compiler from > > > gcc (GCC) 6.4.1 20170727 (Red Hat 6.4.1-1) > > > to > > > gcc (GCC) 7.2.1 20170915 (Red Hat 7.2.1-2) > > > and started getting a bunch of compiler warnings in io/fsmap.c: > > > > > > fsmap.c: In function ‘fsmap_f’: > > > fsmap.c:228:40: warning: ‘%lld’ directive output may be truncated > > > writing > > > between 1 and 17 bytes into a region of size between 12 and 28 > > > [-Wformat-truncation=] > > > snprintf(bbuf, sizeof(bbuf), "[%lld..%lld]:", > > > ^~~~ > > > fsmap.c:228:32: note: directive argument in the range [0, > > > 36028797018963967] > > > snprintf(bbuf, sizeof(bbuf), "[%lld..%lld]:", > > > ^~~~~~~~~~~~~~~ > > > fsmap.c:228:3: note: ‘snprintf’ output between 8 and 40 bytes into a > > > destination of size 32 > > > snprintf(bbuf, sizeof(bbuf), "[%lld..%lld]:", > > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > (long long)BTOBBT(p->fmr_physical), > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > (long long)BTOBBT(p->fmr_physical + p->fmr_length - 1)); > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > > > > The issue is that 'bbuf' is only defined to be 32 characters wide, but > > > each > > > signed long long can potentially print as many as 19 characters > > > (9223372036854775807 is the max value). The format we're using for bbuf > > > is > > > "[%lld..%lld]:" which has 2 signed long longs plus 6 other characters > > > "[..]:\0", which means it's possible we'll print up to 44 characters, > > > overflowing our 32 char buffer. > > > > > > Fix this by bumping all the buffer sizes in dump_map_verbose() to 64 > > > characters. > > > > > > Signed-off-by: Ross Zwisler <[email protected]> > > > Cc: Darrick J. Wong <[email protected]> > > > Fixes: 3fcab549a234 ("xfs_io: support the new getfsmap ioctl") > > > > FYI, I posted a fix for this weeks ago. I think Eric has already > > picked it up, but it hasn't been pushed out into the for-next branch > > yet. > > I'm seeing similar new compiler warnings when compiling xfstests: > > write_log.c: In function ‘wlog_open’: > write_log.c:124:37: warning: ‘%s’ directive writing up to 1023 bytes into a > region of size 224 [-Wformat-overflow=] > "Could not open write_log - open(%s, %#o, %#o) failed: %s\n", > ^~ > write_log.c:124:4: note: directive argument in the range [1089, 2047] > "Could not open write_log - open(%s, %#o, %#o) failed: %s\n", > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > etc. > > I don't see any patches posted that fix these, as of yet. As far as you know, > am I correct in thinking that these still need to be fixed?
It sure looks that way. --D > - Ross > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html _______________________________________________ Linux-nvdimm mailing list [email protected] https://lists.01.org/mailman/listinfo/linux-nvdimm
