Messages in this thread Patch in this message | | | Date | Thu, 1 Jul 2021 20:06:53 -0500 | From | "Gustavo A. R. Silva" <> | Subject | [PATCH][next] btrfs: Fix multiple out-of-bounds warnings |
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Fix the following out-of-bounds warnings by using a flexible-array member *pages[] at the bottom of struct extent_buffer:
fs/btrfs/disk-io.c:225:34: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:80:46: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:101:32: warning: array subscript 1 is above array bounds of ‘struct page * const[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:133:46: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:156:32: warning: array subscript 1 is above array bounds of ‘struct page * const[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:80:46: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:101:32: warning: array subscript 1 is above array bounds of ‘struct page * const[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:133:46: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:156:32: warning: array subscript 1 is above array bounds of ‘struct page * const[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:80:46: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:101:32: warning: array subscript 1 is above array bounds of ‘struct page * const[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:133:46: warning: array subscript 1 is above array bounds of ‘struct page *[1]’ [-Warray-bounds] fs/btrfs/struct-funcs.c:156:32: warning: array subscript 1 is above array bounds of ‘struct page * const[1]’ [-Warray-bounds]
Also, make use of the struct_size() helper to properly calculate the total size of struct extent_buffer for the kmem cache allocation.
This is part of the ongoing efforts to globally enable -Warray-bounds.
The code was built with ppc64_defconfig and -Warray-bounds enabled by default in the main Makefile.
Link: https://github.com/KSPP/linux/issues/109 Cc: Qu Wenruo <quwenruo.btrfs@gmx.com> Cc: David Sterba <dsterba@suse.com> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> --- fs/btrfs/extent_io.c | 5 +++-- fs/btrfs/extent_io.h | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 9e81d25dea70..4cf0b72fdd9f 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -232,8 +232,9 @@ int __init extent_state_cache_init(void) int __init extent_io_init(void) { extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer", - sizeof(struct extent_buffer), 0, - SLAB_MEM_SPREAD, NULL); + struct_size((struct extent_buffer *)0, pages, + INLINE_EXTENT_BUFFER_PAGES), + 0, SLAB_MEM_SPREAD, NULL); if (!extent_buffer_cache) return -ENOMEM; diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 62027f551b44..b82e8b694a3b 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -94,11 +94,11 @@ struct extent_buffer { struct rw_semaphore lock; - struct page *pages[INLINE_EXTENT_BUFFER_PAGES]; struct list_head release_list; #ifdef CONFIG_BTRFS_DEBUG struct list_head leak_list; #endif + struct page *pages[]; }; /* -- 2.27.0
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