| Message ID | 20241217225811.2437150-4-mtodorovac69@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
On Tue, Dec 17, 2024 at 11:58:12PM +0100, Mirsad Todorovac wrote: > The source static analysis tool gave the following advice: > > ./fs/xfs/libxfs/xfs_dir2.c:382:15-22: WARNING opportunity for kmemdup > > → 382 args->value = kmalloc(len, > 383 GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_RETRY_MAYFAIL); > 384 if (!args->value) > 385 return -ENOMEM; > 386 > → 387 memcpy(args->value, name, len); > 388 args->valuelen = len; > 389 return -EEXIST; > > Replacing kmalloc() + memcpy() with kmemdump() doesn't change semantics. > Original code works without fault, so this is not a bug fix but proposed improvement. I guess this is all right, but seeing as this code is shared with userspace ("libxfs"), making this change will just add to the wrappers that we have to have: void *kmemdup_noprof(const void *src, size_t len, gfp_t gfp) { void *p; p = kmalloc_node_track_caller_noprof(len, gfp, NUMA_NO_NODE, _RET_IP_); if (p) memcpy(p, src, len); return p; } Is this sufficiently better? That's a question for the kernel maintainer (cem) and the userspace maintainer (andrey, now cc'd). --D > Link: https://lwn.net/Articles/198928/ > Fixes: 94a69db2367ef ("xfs: use __GFP_NOLOCKDEP instead of GFP_NOFS") > Fixes: 384f3ced07efd ("[XFS] Return case-insensitive match for dentry cache") > Fixes: 2451337dd0439 ("xfs: global error sign conversion") > Cc: Carlos Maiolino <cem@kernel.org> > Cc: "Darrick J. Wong" <djwong@kernel.org> > Cc: Chandan Babu R <chandanbabu@kernel.org> > Cc: Dave Chinner <dchinner@redhat.com> > Cc: linux-xfs@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Mirsad Todorovac <mtodorovac69@gmail.com> > --- > v1: > initial version. > > fs/xfs/libxfs/xfs_dir2.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_dir2.c b/fs/xfs/libxfs/xfs_dir2.c > index 202468223bf9..24251e42bdeb 100644 > --- a/fs/xfs/libxfs/xfs_dir2.c > +++ b/fs/xfs/libxfs/xfs_dir2.c > @@ -379,12 +379,11 @@ xfs_dir_cilookup_result( > !(args->op_flags & XFS_DA_OP_CILOOKUP)) > return -EEXIST; > > - args->value = kmalloc(len, > + args->value = kmemdup(name, len, > GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_RETRY_MAYFAIL); > if (!args->value) > return -ENOMEM; > > - memcpy(args->value, name, len); > args->valuelen = len; > return -EEXIST; > } > -- > 2.43.0 > >
diff --git a/fs/xfs/libxfs/xfs_dir2.c b/fs/xfs/libxfs/xfs_dir2.c index 202468223bf9..24251e42bdeb 100644 --- a/fs/xfs/libxfs/xfs_dir2.c +++ b/fs/xfs/libxfs/xfs_dir2.c @@ -379,12 +379,11 @@ xfs_dir_cilookup_result( !(args->op_flags & XFS_DA_OP_CILOOKUP)) return -EEXIST; - args->value = kmalloc(len, + args->value = kmemdup(name, len, GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_RETRY_MAYFAIL); if (!args->value) return -ENOMEM; - memcpy(args->value, name, len); args->valuelen = len; return -EEXIST; }
The source static analysis tool gave the following advice: ./fs/xfs/libxfs/xfs_dir2.c:382:15-22: WARNING opportunity for kmemdup → 382 args->value = kmalloc(len, 383 GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_RETRY_MAYFAIL); 384 if (!args->value) 385 return -ENOMEM; 386 → 387 memcpy(args->value, name, len); 388 args->valuelen = len; 389 return -EEXIST; Replacing kmalloc() + memcpy() with kmemdump() doesn't change semantics. Original code works without fault, so this is not a bug fix but proposed improvement. Link: https://lwn.net/Articles/198928/ Fixes: 94a69db2367ef ("xfs: use __GFP_NOLOCKDEP instead of GFP_NOFS") Fixes: 384f3ced07efd ("[XFS] Return case-insensitive match for dentry cache") Fixes: 2451337dd0439 ("xfs: global error sign conversion") Cc: Carlos Maiolino <cem@kernel.org> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Chandan Babu R <chandanbabu@kernel.org> Cc: Dave Chinner <dchinner@redhat.com> Cc: linux-xfs@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Mirsad Todorovac <mtodorovac69@gmail.com> --- v1: initial version. fs/xfs/libxfs/xfs_dir2.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)