diff options
| author |   Ben Zhang <benzh@chromium.org> | 2014-10-30 17:14:21 -0700 |
|---|---|---|
| committer |   Tony Luck <tony.luck@intel.com> | 2014-11-05 09:58:17 -0800 |
| commit | a28726b4fb624f81d637a8afb9ea12fc16500f61 (patch) | |
| tree | 97dbec898efa336bca564174d2311acb35eb2c78 /fs/pstore | |
| parent | Linux 3.18-rc3 (diff) | |
| download | linux-dev-a28726b4fb624f81d637a8afb9ea12fc16500f61.tar.xz linux-dev-a28726b4fb624f81d637a8afb9ea12fc16500f61.zip | |
pstore/ram: Strip ramoops header for correct decompression
pstore compression/decompression was added during 3.12.
The ramoops driver prepends a "====timestamp.timestamp-C|D\n"
header to the compressed record before handing it over to pstore
driver which doesn't know about the header. In pstore_decompress(),
the pstore driver reads the first "==" as a zlib header, so the
decompression always fails. For example, this causes the driver
to write /dev/pstore/dmesg-ramoops-0.enc.z instead of
/dev/pstore/dmesg-ramoops-0.
This patch makes the ramoops driver remove the header before
pstore decompression.
Signed-off-by: Ben Zhang <benzh@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'fs/pstore')
| -rw-r--r-- | fs/pstore/ram.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 3b5744306ed8..ec881b312700 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -135,25 +135,27 @@ ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max, return prz; } -static void ramoops_read_kmsg_hdr(char *buffer, struct timespec *time, +static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time, bool *compressed) { char data_type; + int header_length = 0; - if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n", - &time->tv_sec, &time->tv_nsec, &data_type) == 3) { + if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec, + &time->tv_nsec, &data_type, &header_length) == 3) { if (data_type == 'C') *compressed = true; else *compressed = false; - } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n", - &time->tv_sec, &time->tv_nsec) == 2) { + } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n", + &time->tv_sec, &time->tv_nsec, &header_length) == 2) { *compressed = false; } else { time->tv_sec = 0; time->tv_nsec = 0; *compressed = false; } + return header_length; } static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, @@ -165,6 +167,7 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, ssize_t ecc_notice_size; struct ramoops_context *cxt = psi->data; struct persistent_ram_zone *prz; + int header_length; prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt, cxt->max_dump_cnt, id, type, @@ -178,7 +181,13 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, if (!prz) return 0; + if (!persistent_ram_old(prz)) + return 0; + size = persistent_ram_old_size(prz); + header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz), time, + compressed); + size -= header_length; /* ECC correction notice */ ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0); @@ -187,8 +196,7 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type, if (*buf == NULL) return -ENOMEM; - memcpy(*buf, persistent_ram_old(prz), size); - ramoops_read_kmsg_hdr(*buf, time, compressed); + memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size); persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1); return size + ecc_notice_size; |