From ffbe1addd5a5b7b7c2f987625a5aa6c1d22e3705 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Fri, 6 May 2005 15:45:01 +0200 Subject: [PATCH] [PATCH] fix compare symlink against readlink not data Fix update-cache to compare the blob of a symlink against the link-target and not the file it points to. Also ignore all permissions applied to links. Thanks to Greg for recognizing this while he added our list of symlinks back to the udev repository. Signed-off-by: Kay Sievers Signed-off-by: Linus Torvalds --- diff-files.c | 2 +- read-cache.c | 6 +++--- update-cache.c | 50 +++++++++++++++++++++++++++++++++++++++++++++----- 3 files changed, 49 insertions(+), 9 deletions(-) diff --git a/diff-files.c b/diff-files.c index 0cf2c2441..c51edc331 100644 --- a/diff-files.c +++ b/diff-files.c @@ -111,7 +111,7 @@ int main(int argc, char **argv) continue; } - if (stat(ce->name, &st) < 0) { + if (lstat(ce->name, &st) < 0) { if (errno != ENOENT) { perror(ce->name); continue; diff --git a/read-cache.c b/read-cache.c index 5703f30b6..2a88d18b1 100644 --- a/read-cache.c +++ b/read-cache.c @@ -16,6 +16,9 @@ int cache_match_stat(struct cache_entry *ce, struct stat *st) switch (ntohl(ce->ce_mode) & S_IFMT) { case S_IFREG: changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0; + /* We consider only the owner x bit to be relevant for "mode changes" */ + if (0100 & (ntohl(ce->ce_mode) ^ st->st_mode)) + changed |= MODE_CHANGED; break; case S_IFLNK: changed |= !S_ISLNK(st->st_mode) ? TYPE_CHANGED : 0; @@ -43,9 +46,6 @@ int cache_match_stat(struct cache_entry *ce, struct stat *st) if (ce->ce_uid != htonl(st->st_uid) || ce->ce_gid != htonl(st->st_gid)) changed |= OWNER_CHANGED; - /* We consider only the owner x bit to be relevant for "mode changes" */ - if (0100 & (ntohl(ce->ce_mode) ^ st->st_mode)) - changed |= MODE_CHANGED; if (ce->ce_dev != htonl(st->st_dev) || ce->ce_ino != htonl(st->st_ino)) changed |= INODE_CHANGED; diff --git a/update-cache.c b/update-cache.c index 893ba8679..210c786af 100644 --- a/update-cache.c +++ b/update-cache.c @@ -64,7 +64,7 @@ static int add_file_to_cache_1(char *path) struct stat st; int fd; unsigned int len; - char target[1024]; + char *target; if (lstat(path, &st) < 0) { if (errno == ENOENT || errno == ENOTDIR) { @@ -90,11 +90,14 @@ static int add_file_to_cache_1(char *path) return -1; break; case S_IFLNK: - len = readlink(path, target, sizeof(target)); - if (len == -1 || len+1 > sizeof(target)) + target = xmalloc(st.st_size+1); + if (readlink(path, target, st.st_size+1) != st.st_size) { + free(target); return -1; - if (write_sha1_file(target, len, "blob", ce->sha1)) + } + if (write_sha1_file(target, st.st_size, "blob", ce->sha1)) return -1; + free(target); break; default: return -1; @@ -163,6 +166,33 @@ static int compare_data(struct cache_entry *ce, unsigned long expected_size) return match; } +static int compare_link(struct cache_entry *ce, unsigned long expected_size) +{ + int match = -1; + char *target; + void *buffer; + unsigned long size; + char type[10]; + int len; + + target = xmalloc(expected_size); + len = readlink(ce->name, target, expected_size); + if (len != expected_size) { + free(target); + return -1; + } + buffer = read_sha1_file(ce->sha1, type, &size); + if (!buffer) { + free(target); + return -1; + } + if (size == expected_size) + match = memcmp(buffer, target, size); + free(buffer); + free(target); + return match; +} + /* * "refresh" does not calculate a new sha1 file or bring the * cache up-to-date for mode/content changes. But what it @@ -194,8 +224,18 @@ static struct cache_entry *refresh_entry(struct cache_entry *ce) if (changed & (MODE_CHANGED | TYPE_CHANGED)) return ERR_PTR(-EINVAL); - if (compare_data(ce, st.st_size)) + switch (st.st_mode & S_IFMT) { + case S_IFREG: + if (compare_data(ce, st.st_size)) + return ERR_PTR(-EINVAL); + break; + case S_IFLNK: + if (compare_link(ce, st.st_size)) + return ERR_PTR(-EINVAL); + break; + default: return ERR_PTR(-EINVAL); + } cache_changed = 1; size = ce_size(ce); -- 2.26.2