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authorGustavo A. R. Silva <gustavoars@kernel.org>2021-08-10 18:31:01 -0500
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2022-01-06 14:00:20 -0500
commitc72a826829ccfb38019187a3a5ba6d3584b7b7dc (patch)
tree11a21fd0e943c5dbdf2ef791e14b2c4a443485ab
parent4b0c359b813bbf115f5e2219ea8c0e4fad92400b (diff)
downloadlinux-c72a826829ccfb38019187a3a5ba6d3584b7b7dc.tar.bz2
nfs41: pnfs: filelayout: Replace one-element array with flexible-array member
There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Refactor the code a bit according to the use of a flexible-array member in struct nfs4_file_layout_dsaddr instead of a one-element array, and use the struct_size() helper. This helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). This issue was found with the help of Coccinelle and audited and fixed, manually. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/109 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
-rw-r--r--fs/nfs/filelayout/filelayout.h2
-rw-r--r--fs/nfs/filelayout/filelayoutdev.c4
2 files changed, 2 insertions, 4 deletions
diff --git a/fs/nfs/filelayout/filelayout.h b/fs/nfs/filelayout/filelayout.h
index 79323b5dab0c..aed0748fd6ec 100644
--- a/fs/nfs/filelayout/filelayout.h
+++ b/fs/nfs/filelayout/filelayout.h
@@ -51,7 +51,7 @@ struct nfs4_file_layout_dsaddr {
u32 stripe_count;
u8 *stripe_indices;
u32 ds_num;
- struct nfs4_pnfs_ds *ds_list[1];
+ struct nfs4_pnfs_ds *ds_list[];
};
struct nfs4_filelayout_segment {
diff --git a/fs/nfs/filelayout/filelayoutdev.c b/fs/nfs/filelayout/filelayoutdev.c
index 86c3f7e69ec4..acf4b88889dc 100644
--- a/fs/nfs/filelayout/filelayoutdev.c
+++ b/fs/nfs/filelayout/filelayoutdev.c
@@ -136,9 +136,7 @@ nfs4_fl_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
goto out_err_free_stripe_indices;
}
- dsaddr = kzalloc(sizeof(*dsaddr) +
- (sizeof(struct nfs4_pnfs_ds *) * (num - 1)),
- gfp_flags);
+ dsaddr = kzalloc(struct_size(dsaddr, ds_list, num), gfp_flags);
if (!dsaddr)
goto out_err_free_stripe_indices;