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authorKees Cook <keescook@chromium.org>2019-03-15 10:14:43 +0100
committerSascha Hauer <s.hauer@pengutronix.de>2019-03-18 09:43:35 +0100
commit97885140bf64b43adee76e23179eae9bd1393296 (patch)
tree4a3d804428f2eb42e294b3d3c1deaf81f52def8f /fs
parent478035df0705687cf3cfbb32644f434353189672 (diff)
downloadbarebox-97885140bf64b43adee76e23179eae9bd1393296.tar.gz
pstore/ram: Do not use stack VLA for parity workspace
Instead of using a stack VLA for the parity workspace, preallocate a memory region. The preallocation is done to keep from needing to perform allocations during crash dump writing, etc. This also fixes a missed release of librs on free. Signed-off-by: Kees Cook <keescook@chromium.org> [p.zabel@pengutronix.de: ported to Barebox from Linux commit f2531f1976d9] Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'fs')
-rw-r--r--fs/pstore/ram_core.c28
1 files changed, 21 insertions, 7 deletions
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 9de6dc6..ed48dcd 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -80,24 +80,23 @@ static void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz,
uint8_t *data, size_t len, uint8_t *ecc)
{
int i;
- uint16_t par[prz->ecc_info.ecc_size];
/* Initialize the parity buffer */
- memset(par, 0, sizeof(par));
- encode_rs8(prz->rs_decoder, data, len, par, 0);
+ memset(prz->ecc_info.par, 0,
+ prz->ecc_info.ecc_size * sizeof(prz->ecc_info.par[0]));
+ encode_rs8(prz->rs_decoder, data, len, prz->ecc_info.par, 0);
for (i = 0; i < prz->ecc_info.ecc_size; i++)
- ecc[i] = par[i];
+ ecc[i] = prz->ecc_info.par[i];
}
static int persistent_ram_decode_rs8(struct persistent_ram_zone *prz,
void *data, size_t len, uint8_t *ecc)
{
int i;
- uint16_t par[prz->ecc_info.ecc_size];
for (i = 0; i < prz->ecc_info.ecc_size; i++)
- par[i] = ecc[i];
- return decode_rs8(prz->rs_decoder, data, par, len,
+ prz->ecc_info.par[i] = ecc[i];
+ return decode_rs8(prz->rs_decoder, data, prz->ecc_info.par, len,
NULL, 0, NULL, 0, NULL);
}
@@ -210,6 +209,15 @@ static int persistent_ram_init_ecc(struct persistent_ram_zone *prz,
return -EINVAL;
}
+ /* allocate workspace instead of using stack VLA */
+ prz->ecc_info.par = kmalloc_array(prz->ecc_info.ecc_size,
+ sizeof(*prz->ecc_info.par),
+ GFP_KERNEL);
+ if (!prz->ecc_info.par) {
+ pr_err("cannot allocate ECC parity workspace\n");
+ return -ENOMEM;
+ }
+
prz->corrected_bytes = 0;
prz->bad_blocks = 0;
@@ -393,6 +401,12 @@ void persistent_ram_free(struct persistent_ram_zone *prz)
release_sdram_region(prz->res);
prz->res = NULL;
}
+ if (prz->rs_decoder) {
+ free_rs(prz->rs_decoder);
+ prz->rs_decoder = NULL;
+ }
+ kfree(prz->ecc_info.par);
+ prz->ecc_info.par = NULL;
persistent_ram_free_old(prz);
kfree(prz);