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author | Andreas Gruenbacher <agruen@gnu.org> | 2019-06-27 11:10:43 +0200 |
---|---|---|
committer | Andreas Gruenbacher <agruen@gnu.org> | 2019-06-28 11:20:31 +0200 |
commit | 61d7788b83b302207a67b82786f4fd79e3538f30 (patch) | |
tree | b680d617d6f448630da97578ea72097a5b33873a | |
parent | b7b028a77bd855f6f56b17c8837fc1cca77b469d (diff) | |
download | patch-61d7788b83b302207a67b82786f4fd79e3538f30.tar.gz |
Don't crash when RLIMIT_NOFILE is set to RLIM_INFINITY
* src/safe.c (min_cached_fds): Define minimum number of cached dir file
descriptors.
(max_cached_fds): Change type to rlim_t to allow storing RLIM_INFINITY.
(init_dirfd_cache): Set max_cached_fds to RLIM_INFINITY when RLIMIT_NOFILE is
RLIM_INFINITY. Set the initial hash table size to min_cached_fds, independent
of RLIMIT_NOFILE: patches commonly only affect one or a few files, so a small
hash table will usually suffice; if needed, the hash table will grow.
(insert_cached_dirfd): Don't shrink the cache when max_cached_fds is
RLIM_INFINITY.
-rw-r--r-- | src/safe.c | 36 |
1 files changed, 23 insertions, 13 deletions
@@ -67,7 +67,8 @@ struct cached_dirfd { }; static Hash_table *cached_dirfds = NULL; -static size_t max_cached_fds; +static rlim_t min_cached_fds = 8; +static rlim_t max_cached_fds; LIST_HEAD (lru_list); static size_t hash_cached_dirfd (const void *entry, size_t table_size) @@ -98,11 +99,17 @@ static void init_dirfd_cache (void) { struct rlimit nofile; - max_cached_fds = 8; if (getrlimit (RLIMIT_NOFILE, &nofile) == 0) - max_cached_fds = MAX (nofile.rlim_cur / 4, max_cached_fds); + { + if (nofile.rlim_cur == RLIM_INFINITY) + max_cached_fds = RLIM_INFINITY; + else + max_cached_fds = MAX (nofile.rlim_cur / 4, min_cached_fds); + } + else + max_cached_fds = min_cached_fds; - cached_dirfds = hash_initialize (max_cached_fds, + cached_dirfds = hash_initialize (min_cached_fds, NULL, hash_cached_dirfd, compare_cached_dirfds, @@ -148,20 +155,23 @@ static void insert_cached_dirfd (struct cached_dirfd *entry, int keepfd) if (cached_dirfds == NULL) init_dirfd_cache (); - /* Trim off the least recently used entries */ - while (hash_get_n_entries (cached_dirfds) >= max_cached_fds) + if (max_cached_fds != RLIM_INFINITY) { - struct cached_dirfd *last = - list_entry (lru_list.prev, struct cached_dirfd, lru_link); - if (&last->lru_link == &lru_list) - break; - if (last->fd == keepfd) + /* Trim off the least recently used entries */ + while (hash_get_n_entries (cached_dirfds) >= max_cached_fds) { - last = list_entry (last->lru_link.prev, struct cached_dirfd, lru_link); + struct cached_dirfd *last = + list_entry (lru_list.prev, struct cached_dirfd, lru_link); if (&last->lru_link == &lru_list) break; + if (last->fd == keepfd) + { + last = list_entry (last->lru_link.prev, struct cached_dirfd, lru_link); + if (&last->lru_link == &lru_list) + break; + } + remove_cached_dirfd (last); } - remove_cached_dirfd (last); } /* Only insert if the parent still exists. */ |