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| author | Nicolas Pitre <nico@cam.org> | 2007-04-09 01:06:29 -0400 |
|---|---|---|
| committer | Junio C Hamano <junkio@cox.net> | 2007-04-10 12:48:14 -0700 |
| commit | 8723f216263ba4a0f06be7b93fada863c0931e09 (patch) | |
| tree | 6d357724c891ce009a8c7ae1a0a4083bc39ff1f5 | |
| parent | 57059091fad25427bce9b3d47e073ce0518d164b (diff) | |
| download | git-8723f216263ba4a0f06be7b93fada863c0931e09.tar.gz git-8723f216263ba4a0f06be7b93fada863c0931e09.tar.xz | |
make overflow test on delta base offset work regardless of variable size
This patch introduces the MSB() macro to obtain the desired number of
most significant bits from a given variable independently of the variable
type.
It is then used to better implement the overflow test on the OBJ_OFS_DELTA
base offset variable with the property of always working correctly
regardless of the type/size of that variable.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
| -rw-r--r-- | builtin-pack-objects.c | 2 | ||||
| -rw-r--r-- | builtin-unpack-objects.c | 2 | ||||
| -rw-r--r-- | git-compat-util.h | 8 | ||||
| -rw-r--r-- | index-pack.c | 2 | ||||
| -rw-r--r-- | sha1_file.c | 2 |
5 files changed, 12 insertions, 4 deletions
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c index 6bff17b13..ee607a0d2 100644 --- a/builtin-pack-objects.c +++ b/builtin-pack-objects.c @@ -1014,7 +1014,7 @@ static void check_object(struct object_entry *entry) ofs = c & 127; while (c & 128) { ofs += 1; - if (!ofs || ofs & ~(~0UL >> 7)) + if (!ofs || MSB(ofs, 7)) die("delta base offset overflow in pack for %s", sha1_to_hex(entry->sha1)); c = buf[used_0++]; diff --git a/builtin-unpack-objects.c b/builtin-unpack-objects.c index 3956c5633..63f7db683 100644 --- a/builtin-unpack-objects.c +++ b/builtin-unpack-objects.c @@ -209,7 +209,7 @@ static void unpack_delta_entry(enum object_type type, unsigned long delta_size, base_offset = c & 127; while (c & 128) { base_offset += 1; - if (!base_offset || base_offset & ~(~0UL >> 7)) + if (!base_offset || MSB(base_offset, 7)) die("offset value overflow for delta base object"); pack = fill(1); c = *pack; diff --git a/git-compat-util.h b/git-compat-util.h index 139fc1910..bcfcb35ec 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -13,6 +13,14 @@ #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0])) +#ifdef __GNUC__ +#define TYPEOF(x) (__typeof__(x)) +#else +#define TYPEOF(x) +#endif + +#define MSB(x, bits) ((x) & TYPEOF(x)(~0ULL << (sizeof(x) * 8 - (bits)))) + #if !defined(__APPLE__) && !defined(__FreeBSD__) #define _XOPEN_SOURCE 600 /* glibc2 and AIX 5.3L need 500, OpenBSD needs 600 for S_ISLNK() */ #define _XOPEN_SOURCE_EXTENDED 1 /* AIX 5.3L needs this */ diff --git a/index-pack.c b/index-pack.c index 3c768fbc6..0e54aa684 100644 --- a/index-pack.c +++ b/index-pack.c @@ -249,7 +249,7 @@ static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_ base_offset = c & 127; while (c & 128) { base_offset += 1; - if (!base_offset || base_offset & ~(~0UL >> 7)) + if (!base_offset || MSB(base_offset, 7)) bad_object(obj->offset, "offset value overflow for delta base object"); p = fill(1); c = *p; diff --git a/sha1_file.c b/sha1_file.c index d9ca69a91..ebdd497ba 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -1150,7 +1150,7 @@ static off_t get_delta_base(struct packed_git *p, base_offset = c & 127; while (c & 128) { base_offset += 1; - if (!base_offset || base_offset & ~(~0UL >> 7)) + if (!base_offset || MSB(base_offset, 7)) die("offset value overflow for delta base object"); c = base_info[used++]; base_offset = (base_offset << 7) + (c & 127); |