| Message ID | 1411261282-26831-3-git-send-email-xnox@debian.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Sep 21, 2014 at 02:01:21AM +0100, Dimitri John Ledkov wrote: > From: Shawn Landen <shawnlandden@gmail.com> > > Bug-Debian: http://bugs.debian.org/656955 The bug seems old (2012) and agains 0.19. We've fixed a few unaligned access bugs in the meantime. Can you please retest with 3.16? > --- a/ctree.h > +++ b/ctree.h > @@ -19,6 +19,8 @@ > #ifndef __BTRFS__ > #define __BTRFS__ > > +#include <stdint.h> > + > #if BTRFS_FLAT_INCLUDES > #include "list.h" > #include "kerncompat.h" > @@ -1191,13 +1193,17 @@ struct btrfs_root { > static inline u##bits btrfs_##name(const struct extent_buffer *eb) \ > { \ > const struct btrfs_header *h = (struct btrfs_header *)eb->data; \ > - return le##bits##_to_cpu(h->member); \ > + uint##bits##_t t; \ > + memcpy(&t, &h->member, sizeof(h->member)); \ > + return le##bits##_to_cpu(t); \ The change to memcpy is safe, the compiler is smart enough to not emit any memcpy call for x86_64 and there's no change to the leXX_to_cpu macros. However, I'd like to check first if this is really necessary due to the old version in the bugreport. I'd prefer using the u8/.../u64 types instead of the stdint.h ones, for sake of consistency with the rest of the codebase. > --- a/volumes.c > +++ b/volumes.c > @@ -472,10 +472,11 @@ static int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset) > if (found_key.objectid != objectid) > *offset = 0; > else { > + u64 t; > chunk = btrfs_item_ptr(path->nodes[0], path->slots[0], > struct btrfs_chunk); > - *offset = found_key.offset + > - btrfs_chunk_length(path->nodes[0], chunk); > + t = found_key.offset + btrfs_chunk_length(path->nodes[0], chunk); > + memcpy(offset, &t, sizeof(found_key.offset)); That's not enough, there are more direct assignments to *offset in that function. The preferred way is to add 'put_unaligned' helper into kerncompat.h and use it. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/ctree.h b/ctree.h index fa73c4a..92c6ad3 100644 --- a/ctree.h +++ b/ctree.h @@ -19,6 +19,8 @@ #ifndef __BTRFS__ #define __BTRFS__ +#include <stdint.h> + #if BTRFS_FLAT_INCLUDES #include "list.h" #include "kerncompat.h" @@ -1191,13 +1193,17 @@ struct btrfs_root { static inline u##bits btrfs_##name(const struct extent_buffer *eb) \ { \ const struct btrfs_header *h = (struct btrfs_header *)eb->data; \ - return le##bits##_to_cpu(h->member); \ + uint##bits##_t t; \ + memcpy(&t, &h->member, sizeof(h->member)); \ + return le##bits##_to_cpu(t); \ } \ static inline void btrfs_set_##name(struct extent_buffer *eb, \ u##bits val) \ { \ struct btrfs_header *h = (struct btrfs_header *)eb->data; \ - h->member = cpu_to_le##bits(val); \ + uint##bits##_t t; \ + t = cpu_to_le##bits(val); \ + memcpy(&h->member, &t, sizeof(h->member)); \ } #define BTRFS_SETGET_FUNCS(name, type, member, bits) \ @@ -1219,11 +1225,15 @@ static inline void btrfs_set_##name(struct extent_buffer *eb, \ #define BTRFS_SETGET_STACK_FUNCS(name, type, member, bits) \ static inline u##bits btrfs_##name(const type *s) \ { \ - return le##bits##_to_cpu(s->member); \ + uint##bits##_t t; \ + memcpy(&t, &s->member, sizeof(s->member)); \ + return le##bits##_to_cpu(t); \ } \ static inline void btrfs_set_##name(type *s, u##bits val) \ { \ - s->member = cpu_to_le##bits(val); \ + uint##bits##_t t; \ + t = cpu_to_le##bits(val); \ + memcpy(&s->member, &t, sizeof(s->member)); \ } BTRFS_SETGET_FUNCS(device_type, struct btrfs_dev_item, type, 64); diff --git a/volumes.c b/volumes.c index 388c94e..102380b 100644 --- a/volumes.c +++ b/volumes.c @@ -472,10 +472,11 @@ static int find_next_chunk(struct btrfs_root *root, u64 objectid, u64 *offset) if (found_key.objectid != objectid) *offset = 0; else { + u64 t; chunk = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_chunk); - *offset = found_key.offset + - btrfs_chunk_length(path->nodes[0], chunk); + t = found_key.offset + btrfs_chunk_length(path->nodes[0], chunk); + memcpy(offset, &t, sizeof(found_key.offset)); } } ret = 0;