fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2025-12-23 22:00:13 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

util/disk_cache: don't deadlock on premature EOF

Browse source 
If we get EOF earlier than expected, the current read loops will
deadlock. This may easily happen if the disk cache gets corrupted.
Fix it by using a helper function that handles EOF.

Steps to reproduce (on a build with asserts disabled):
$ glxgears
$ find ~/.cache/mesa/ -type f -exec truncate -s 0 '{}' \;
$ glxgears # deadlock

Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>
This commit is contained in:
Grazvydas Ignotas 2017-03-25 01:58:42 +02:00 • committed by Timothy Arceri
parent 7414326164
commit b9e92334f7
1 changed files with 26 additions and 17 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

29
src/util/disk_cache.c
View file

@ -641,6 +641,21 @@ disk_cache_remove(struct disk_cache *cache, const cache_key key)
p_atomic_add(cache->size, - (uint64_t)sb.st_size);
}
static ssize_t
read_all(int fd, void *buf, size_t count)
{
char *in = buf;
ssize_t read_ret;
size_t done;
for (done = 0; done < count; done += read_ret) {
read_ret = read(fd, in + done, count - done);
if (read_ret == -1 || read_ret == 0)
return -1;
}
return done;
}
static ssize_t
write_all(int fd, const void *buf, size_t count)
{
@ -938,7 +953,7 @@ inflate_cache_data(uint8_t *in_data, size_t in_data_size,
void *
disk_cache_get(struct disk_cache *cache, const cache_key key, size_t *size)
{
int fd = -1, ret, len;
int fd = -1, ret;
struct stat sb;
char *filename = NULL;
uint8_t *data = NULL;
@ -969,13 +984,11 @@ disk_cache_get(struct disk_cache *cache, const cache_key key, size_t *size)
goto fail;
assert(sb.st_size > ck_size);
for (len = 0; len < ck_size; len += ret) {
ret = read(fd, ((uint8_t *) file_header) + len, ck_size - len);
ret = read_all(fd, file_header, ck_size);
if (ret == -1) {
free(file_header);
goto fail;
}
}
assert(memcmp(cache->driver_keys_blob, file_header, ck_size) == 0);
@ -992,19 +1005,15 @@ disk_cache_get(struct disk_cache *cache, const cache_key key, size_t *size)
/* Load the CRC that was created when the file was written. */
struct cache_entry_file_data cf_data;
size_t cf_data_size = sizeof(cf_data);
for (len = 0; len < cf_data_size; len += ret) {
ret = read(fd, ((uint8_t *) &cf_data) + len, cf_data_size - len);
ret = read_all(fd, &cf_data, cf_data_size);
if (ret == -1)
goto fail;
}
/* Load the actual cache data. */
size_t cache_data_size = sb.st_size - cf_data_size - ck_size;
for (len = 0; len < cache_data_size; len += ret) {
ret = read(fd, data + len, cache_data_size - len);
ret = read_all(fd, data, cache_data_size);
if (ret == -1)
goto fail;
}
/* Uncompress the cache data */
uncompressed_data = malloc(cf_data.uncompressed_size);