| Message ID | 20190325130256.1437810-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: use BUG() instead of BUG_ON(1) | expand |
On 25.03.19 г. 15:02 ч., Arnd Bergmann wrote: > BUG_ON(1) leads to bogus warnings from clang when > CONFIG_PROFILE_ANNOTATED_BRANCHES is set: > > fs/btrfs/volumes.c:5041:3: error: variable 'max_chunk_size' is used uninitialized whenever 'if' condition is false > [-Werror,-Wsometimes-uninitialized] > BUG_ON(1); > ^~~~~~~~~ > include/asm-generic/bug.h:61:36: note: expanded from macro 'BUG_ON' > #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) > ^~~~~~~~~~~~~~~~~~~ > include/linux/compiler.h:48:23: note: expanded from macro 'unlikely' > # define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x))) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > fs/btrfs/volumes.c:5046:9: note: uninitialized use occurs here > max_chunk_size); > ^~~~~~~~~~~~~~ > include/linux/kernel.h:860:36: note: expanded from macro 'min' > #define min(x, y) __careful_cmp(x, y, <) > ^ > include/linux/kernel.h:853:17: note: expanded from macro '__careful_cmp' > __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op)) > ^ > include/linux/kernel.h:847:25: note: expanded from macro '__cmp_once' > typeof(y) unique_y = (y); \ > ^ > fs/btrfs/volumes.c:5041:3: note: remove the 'if' if its condition is always true > BUG_ON(1); > ^ > include/asm-generic/bug.h:61:32: note: expanded from macro 'BUG_ON' > #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) > ^ > fs/btrfs/volumes.c:4993:20: note: initialize the variable 'max_chunk_size' to silence this warning > u64 max_chunk_size; > ^ > = 0 > > Change it to BUG() so clang can see that this code path can never > continue. Long-term we have to eliminate to bug_on's but until then: Reviewed-by: Nikolay Borisov <nborisov@suse.com> > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > fs/btrfs/backref.c | 4 ++-- > fs/btrfs/ctree.c | 4 ++-- > fs/btrfs/extent_io.c | 8 ++++---- > fs/btrfs/file.c | 2 +- > fs/btrfs/inode.c | 2 +- > fs/btrfs/root-tree.c | 2 +- > fs/btrfs/volumes.c | 2 +- > 7 files changed, 12 insertions(+), 12 deletions(-) > > diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c > index 11459fe84a29..2602072ed906 100644 > --- a/fs/btrfs/backref.c > +++ b/fs/btrfs/backref.c > @@ -791,7 +791,7 @@ static int add_delayed_refs(const struct btrfs_fs_info *fs_info, > count = node->ref_mod * -1; > break; > default: > - BUG_ON(1); > + BUG(); > } > *total_refs += count; > switch (node->type) { > @@ -1747,7 +1747,7 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, > else if (flags & BTRFS_EXTENT_FLAG_DATA) > *flags_ret = BTRFS_EXTENT_FLAG_DATA; > else > - BUG_ON(1); > + BUG(); > return 0; > } > > diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c > index 324df36d28bf..75c69829d975 100644 > --- a/fs/btrfs/ctree.c > +++ b/fs/btrfs/ctree.c > @@ -4674,7 +4674,7 @@ void btrfs_extend_item(struct btrfs_fs_info *fs_info, struct btrfs_path *path, > btrfs_print_leaf(leaf); > btrfs_crit(fs_info, "slot %d too large, nritems %d", > slot, nritems); > - BUG_ON(1); > + BUG(); > } > > /* > @@ -4754,7 +4754,7 @@ void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, > btrfs_print_leaf(leaf); > btrfs_crit(fs_info, "slot %d old_data %d data_end %d", > slot, old_data, data_end); > - BUG_ON(1); > + BUG(); > } > /* > * item0..itemN ... dataN.offset..dataN.size .. data0.size > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > index ca8b8e785cf3..610a98857e22 100644 > --- a/fs/btrfs/extent_io.c > +++ b/fs/btrfs/extent_io.c > @@ -5746,13 +5746,13 @@ void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, > btrfs_err(fs_info, > "memmove bogus src_offset %lu move len %lu dst len %lu", > src_offset, len, dst->len); > - BUG_ON(1); > + BUG(); > } > if (dst_offset + len > dst->len) { > btrfs_err(fs_info, > "memmove bogus dst_offset %lu move len %lu dst len %lu", > dst_offset, len, dst->len); > - BUG_ON(1); > + BUG(); > } > > while (len > 0) { > @@ -5793,13 +5793,13 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, > btrfs_err(fs_info, > "memmove bogus src_offset %lu move len %lu len %lu", > src_offset, len, dst->len); > - BUG_ON(1); > + BUG(); > } > if (dst_offset + len > dst->len) { > btrfs_err(fs_info, > "memmove bogus dst_offset %lu move len %lu len %lu", > dst_offset, len, dst->len); > - BUG_ON(1); > + BUG(); > } > if (dst_offset < src_offset) { > memcpy_extent_buffer(dst, dst_offset, src_offset, len); > diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c > index 34fe8a58b0e9..f28aed471693 100644 > --- a/fs/btrfs/file.c > +++ b/fs/btrfs/file.c > @@ -1025,7 +1025,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans, > continue; > } > > - BUG_ON(1); > + BUG(); > } > > if (!ret && del_nr > 0) { > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 82fdda8ff5ab..98bc66d34e6c 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -1451,7 +1451,7 @@ static noinline int run_delalloc_nocow(struct inode *inode, > extent_end = ALIGN(extent_end, > fs_info->sectorsize); > } else { > - BUG_ON(1); > + BUG(); > } > out_check: > if (extent_end <= start) { > diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c > index 893d12fbfda0..552efc88a016 100644 > --- a/fs/btrfs/root-tree.c > +++ b/fs/btrfs/root-tree.c > @@ -141,7 +141,7 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root > btrfs_print_leaf(path->nodes[0]); > btrfs_crit(fs_info, "unable to update root key %llu %u %llu", > key->objectid, key->type, key->offset); > - BUG_ON(1); > + BUG(); > } > > l = path->nodes[0]; > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 9024eee889b9..95223fd9f9d0 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -5038,7 +5038,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, > } else { > btrfs_err(info, "invalid chunk type 0x%llx requested", > type); > - BUG_ON(1); > + BUG(); > } > > /* We don't want a chunk larger than 10% of writable space */ >
On Mon, Mar 25, 2019 at 03:06:12PM +0200, Nikolay Borisov wrote: > > > On 25.03.19 г. 15:02 ч., Arnd Bergmann wrote: > > BUG_ON(1) leads to bogus warnings from clang when > > CONFIG_PROFILE_ANNOTATED_BRANCHES is set: > > > > fs/btrfs/volumes.c:5041:3: error: variable 'max_chunk_size' is used uninitialized whenever 'if' condition is false > > [-Werror,-Wsometimes-uninitialized] > > BUG_ON(1); > > ^~~~~~~~~ > > include/asm-generic/bug.h:61:36: note: expanded from macro 'BUG_ON' > > #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) > > ^~~~~~~~~~~~~~~~~~~ > > include/linux/compiler.h:48:23: note: expanded from macro 'unlikely' > > # define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x))) > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > fs/btrfs/volumes.c:5046:9: note: uninitialized use occurs here > > max_chunk_size); > > ^~~~~~~~~~~~~~ > > include/linux/kernel.h:860:36: note: expanded from macro 'min' > > #define min(x, y) __careful_cmp(x, y, <) > > ^ > > include/linux/kernel.h:853:17: note: expanded from macro '__careful_cmp' > > __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op)) > > ^ > > include/linux/kernel.h:847:25: note: expanded from macro '__cmp_once' > > typeof(y) unique_y = (y); \ > > ^ > > fs/btrfs/volumes.c:5041:3: note: remove the 'if' if its condition is always true > > BUG_ON(1); > > ^ > > include/asm-generic/bug.h:61:32: note: expanded from macro 'BUG_ON' > > #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) > > ^ > > fs/btrfs/volumes.c:4993:20: note: initialize the variable 'max_chunk_size' to silence this warning > > u64 max_chunk_size; > > ^ > > = 0 > > > > Change it to BUG() so clang can see that this code path can never > > continue. > > Long-term we have to eliminate to bug_on's but until then: I think in those places it's "this must never happen", so it's not the the typical example of BUG_ON misuse we want to eliminate. Fixing the compiler waring is ok though.
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 11459fe84a29..2602072ed906 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -791,7 +791,7 @@ static int add_delayed_refs(const struct btrfs_fs_info *fs_info, count = node->ref_mod * -1; break; default: - BUG_ON(1); + BUG(); } *total_refs += count; switch (node->type) { @@ -1747,7 +1747,7 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, else if (flags & BTRFS_EXTENT_FLAG_DATA) *flags_ret = BTRFS_EXTENT_FLAG_DATA; else - BUG_ON(1); + BUG(); return 0; } diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 324df36d28bf..75c69829d975 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -4674,7 +4674,7 @@ void btrfs_extend_item(struct btrfs_fs_info *fs_info, struct btrfs_path *path, btrfs_print_leaf(leaf); btrfs_crit(fs_info, "slot %d too large, nritems %d", slot, nritems); - BUG_ON(1); + BUG(); } /* @@ -4754,7 +4754,7 @@ void setup_items_for_insert(struct btrfs_root *root, struct btrfs_path *path, btrfs_print_leaf(leaf); btrfs_crit(fs_info, "slot %d old_data %d data_end %d", slot, old_data, data_end); - BUG_ON(1); + BUG(); } /* * item0..itemN ... dataN.offset..dataN.size .. data0.size diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index ca8b8e785cf3..610a98857e22 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5746,13 +5746,13 @@ void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, btrfs_err(fs_info, "memmove bogus src_offset %lu move len %lu dst len %lu", src_offset, len, dst->len); - BUG_ON(1); + BUG(); } if (dst_offset + len > dst->len) { btrfs_err(fs_info, "memmove bogus dst_offset %lu move len %lu dst len %lu", dst_offset, len, dst->len); - BUG_ON(1); + BUG(); } while (len > 0) { @@ -5793,13 +5793,13 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, btrfs_err(fs_info, "memmove bogus src_offset %lu move len %lu len %lu", src_offset, len, dst->len); - BUG_ON(1); + BUG(); } if (dst_offset + len > dst->len) { btrfs_err(fs_info, "memmove bogus dst_offset %lu move len %lu len %lu", dst_offset, len, dst->len); - BUG_ON(1); + BUG(); } if (dst_offset < src_offset) { memcpy_extent_buffer(dst, dst_offset, src_offset, len); diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 34fe8a58b0e9..f28aed471693 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1025,7 +1025,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans, continue; } - BUG_ON(1); + BUG(); } if (!ret && del_nr > 0) { diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 82fdda8ff5ab..98bc66d34e6c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1451,7 +1451,7 @@ static noinline int run_delalloc_nocow(struct inode *inode, extent_end = ALIGN(extent_end, fs_info->sectorsize); } else { - BUG_ON(1); + BUG(); } out_check: if (extent_end <= start) { diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index 893d12fbfda0..552efc88a016 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -141,7 +141,7 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root btrfs_print_leaf(path->nodes[0]); btrfs_crit(fs_info, "unable to update root key %llu %u %llu", key->objectid, key->type, key->offset); - BUG_ON(1); + BUG(); } l = path->nodes[0]; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 9024eee889b9..95223fd9f9d0 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5038,7 +5038,7 @@ static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans, } else { btrfs_err(info, "invalid chunk type 0x%llx requested", type); - BUG_ON(1); + BUG(); } /* We don't want a chunk larger than 10% of writable space */
BUG_ON(1) leads to bogus warnings from clang when CONFIG_PROFILE_ANNOTATED_BRANCHES is set: fs/btrfs/volumes.c:5041:3: error: variable 'max_chunk_size' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] BUG_ON(1); ^~~~~~~~~ include/asm-generic/bug.h:61:36: note: expanded from macro 'BUG_ON' #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) ^~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:48:23: note: expanded from macro 'unlikely' # define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x))) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/btrfs/volumes.c:5046:9: note: uninitialized use occurs here max_chunk_size); ^~~~~~~~~~~~~~ include/linux/kernel.h:860:36: note: expanded from macro 'min' #define min(x, y) __careful_cmp(x, y, <) ^ include/linux/kernel.h:853:17: note: expanded from macro '__careful_cmp' __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op)) ^ include/linux/kernel.h:847:25: note: expanded from macro '__cmp_once' typeof(y) unique_y = (y); \ ^ fs/btrfs/volumes.c:5041:3: note: remove the 'if' if its condition is always true BUG_ON(1); ^ include/asm-generic/bug.h:61:32: note: expanded from macro 'BUG_ON' #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) ^ fs/btrfs/volumes.c:4993:20: note: initialize the variable 'max_chunk_size' to silence this warning u64 max_chunk_size; ^ = 0 Change it to BUG() so clang can see that this code path can never continue. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- fs/btrfs/backref.c | 4 ++-- fs/btrfs/ctree.c | 4 ++-- fs/btrfs/extent_io.c | 8 ++++---- fs/btrfs/file.c | 2 +- fs/btrfs/inode.c | 2 +- fs/btrfs/root-tree.c | 2 +- fs/btrfs/volumes.c | 2 +- 7 files changed, 12 insertions(+), 12 deletions(-)