Re: fs/notify/fanotify/fanotify.c:198:2: note: in expansion of macro 'pr_warn_ratelimited'
From: Jan Kara
Date: Thu Mar 14 2019 - 04:38:03 EST
AFAICS this is the known problem with weird mips definitions of
__kernel_fsid_t which uses long whereas all other architectures use int,
right? Seeing that mips can actually have 8-byte longs, I guess this
bogosity is just wired in the kernel API and we cannot easily fix it in
mips (mips guys, correct me if I'm wrong). So what if we just
unconditionally typed printed values to unsigned int to silence the
warning?
Honza
On Thu 14-03-19 02:31:52, kbuild test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 5453a3df2a5eb49bc24615d4cf0d66b2aae05e5f
> commit: e9e0c8903009477b630e37a8b6364b26a00720da fanotify: encode file identifier for FAN_REPORT_FID
> date: 5 weeks ago
> config: mips-allmodconfig (attached as .config)
> compiler: mips-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
> reproduce:
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> git checkout e9e0c8903009477b630e37a8b6364b26a00720da
> # save the attached .config to linux build tree
> GCC_VERSION=7.2.0 make.cross ARCH=mips
>
> All warnings (new ones prefixed by >>):
>
> In file included from include/linux/kernel.h:14:0,
> from include/linux/list.h:9,
> from include/linux/preempt.h:11,
> from include/linux/spinlock.h:51,
> from include/linux/fdtable.h:11,
> from fs/notify/fanotify/fanotify.c:3:
> fs/notify/fanotify/fanotify.c: In function 'fanotify_encode_fid':
> include/linux/kern_levels.h:5:18: warning: format '%x' expects argument of type 'unsigned int', but argument 2 has type 'long int' [-Wformat=]
> #define KERN_SOH "\001" /* ASCII Start Of Header */
> ^
> include/linux/printk.h:424:10: note: in definition of macro 'printk_ratelimited'
> printk(fmt, ##__VA_ARGS__); \
> ^~~
> include/linux/kern_levels.h:12:22: note: in expansion of macro 'KERN_SOH'
> #define KERN_WARNING KERN_SOH "4" /* warning conditions */
> ^~~~~~~~
> include/linux/printk.h:440:21: note: in expansion of macro 'KERN_WARNING'
> printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
> ^~~~~~~~~~~~
> >> fs/notify/fanotify/fanotify.c:198:2: note: in expansion of macro 'pr_warn_ratelimited'
> pr_warn_ratelimited("fanotify: failed to encode fid (fsid=%x.%x, "
> ^~~~~~~~~~~~~~~~~~~
> fs/notify/fanotify/fanotify.c:198:61: note: format string is defined here
> pr_warn_ratelimited("fanotify: failed to encode fid (fsid=%x.%x, "
> ~^
> %lx
> In file included from include/linux/kernel.h:14:0,
> from include/linux/list.h:9,
> from include/linux/preempt.h:11,
> from include/linux/spinlock.h:51,
> from include/linux/fdtable.h:11,
> from fs/notify/fanotify/fanotify.c:3:
> include/linux/kern_levels.h:5:18: warning: format '%x' expects argument of type 'unsigned int', but argument 3 has type 'long int' [-Wformat=]
> #define KERN_SOH "\001" /* ASCII Start Of Header */
> ^
> include/linux/printk.h:424:10: note: in definition of macro 'printk_ratelimited'
> printk(fmt, ##__VA_ARGS__); \
> ^~~
> include/linux/kern_levels.h:12:22: note: in expansion of macro 'KERN_SOH'
> #define KERN_WARNING KERN_SOH "4" /* warning conditions */
> ^~~~~~~~
> include/linux/printk.h:440:21: note: in expansion of macro 'KERN_WARNING'
> printk_ratelimited(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
> ^~~~~~~~~~~~
> >> fs/notify/fanotify/fanotify.c:198:2: note: in expansion of macro 'pr_warn_ratelimited'
> pr_warn_ratelimited("fanotify: failed to encode fid (fsid=%x.%x, "
> ^~~~~~~~~~~~~~~~~~~
> fs/notify/fanotify/fanotify.c:198:64: note: format string is defined here
> pr_warn_ratelimited("fanotify: failed to encode fid (fsid=%x.%x, "
> ~^
> %lx
>
> vim +/pr_warn_ratelimited +198 fs/notify/fanotify/fanotify.c
>
> 154
> 155 static int fanotify_encode_fid(struct fanotify_event *event,
> 156 const struct path *path, gfp_t gfp)
> 157 {
> 158 struct fanotify_fid *fid = &event->fid;
> 159 int dwords, bytes = 0;
> 160 struct kstatfs stat;
> 161 int err, type;
> 162
> 163 stat.f_fsid.val[0] = stat.f_fsid.val[1] = 0;
> 164 fid->ext_fh = NULL;
> 165 dwords = 0;
> 166 err = -ENOENT;
> 167 type = exportfs_encode_inode_fh(d_inode(path->dentry), NULL, &dwords,
> 168 NULL);
> 169 if (!dwords)
> 170 goto out_err;
> 171
> 172 err = vfs_statfs(path, &stat);
> 173 if (err)
> 174 goto out_err;
> 175
> 176 bytes = dwords << 2;
> 177 if (bytes > FANOTIFY_INLINE_FH_LEN) {
> 178 /* Treat failure to allocate fh as failure to allocate event */
> 179 err = -ENOMEM;
> 180 fid->ext_fh = kmalloc(bytes, gfp);
> 181 if (!fid->ext_fh)
> 182 goto out_err;
> 183 }
> 184
> 185 type = exportfs_encode_inode_fh(d_inode(path->dentry),
> 186 fanotify_fid_fh(fid, bytes), &dwords,
> 187 NULL);
> 188 err = -EINVAL;
> 189 if (!type || type == FILEID_INVALID || bytes != dwords << 2)
> 190 goto out_err;
> 191
> 192 fid->fsid = stat.f_fsid;
> 193 event->fh_len = bytes;
> 194
> 195 return type;
> 196
> 197 out_err:
> > 198 pr_warn_ratelimited("fanotify: failed to encode fid (fsid=%x.%x, "
> 199 "type=%d, bytes=%d, err=%i)\n",
> 200 stat.f_fsid.val[0], stat.f_fsid.val[1],
> 201 type, bytes, err);
> 202 kfree(fid->ext_fh);
> 203 fid->ext_fh = NULL;
> 204 event->fh_len = 0;
> 205
> 206 return FILEID_INVALID;
> 207 }
> 208
>
> ---
> 0-DAY kernel test infrastructure Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all Intel Corporation
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR