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authorArnd Bergmann <arnd@arndb.de>2019-03-24 22:44:51 +0300
committerRichard Weinberger <richard@nod.at>2019-05-07 22:36:39 +0300
commitf4844b35d68ab49c41d542c501fffb46ad81009a (patch)
treeba3a0defe190b28fabc143601fe5a79f45b511bc /fs/ubifs
parentfb9a5a3edb4c34ac0d7e6996278604e53a43245f (diff)
downloadlinux-f4844b35d68ab49c41d542c501fffb46ad81009a.tar.xz
ubifs: work around high stack usage with clang
Building this file with clang can result in large stack usage as seen from this warning: fs/ubifs/auth.c:78:5: error: stack frame size of 1152 bytes in function 'ubifs_prepare_auth_node' The problem is that inlining ubifs_hash_calc_hmac() leads to two SHASH_DESC_ON_STACK() blocks in the same function, and clang for some reason does not reuse the stack space as it should. Putting the first declaration into a separate basic block avoids this problem and reduces the stack allocation to 640 bytes. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'fs/ubifs')
-rw-r--r--fs/ubifs/auth.c17
1 files changed, 10 insertions, 7 deletions
diff --git a/fs/ubifs/auth.c b/fs/ubifs/auth.c
index 2a40cccee5bd..3d049194afa4 100644
--- a/fs/ubifs/auth.c
+++ b/fs/ubifs/auth.c
@@ -78,7 +78,6 @@ static int ubifs_hash_calc_hmac(const struct ubifs_info *c, const u8 *hash,
int ubifs_prepare_auth_node(struct ubifs_info *c, void *node,
struct shash_desc *inhash)
{
- SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm);
struct ubifs_auth_node *auth = node;
u8 *hash;
int err;
@@ -87,13 +86,17 @@ int ubifs_prepare_auth_node(struct ubifs_info *c, void *node,
if (!hash)
return -ENOMEM;
- hash_desc->tfm = c->hash_tfm;
- hash_desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
- ubifs_shash_copy_state(c, inhash, hash_desc);
+ {
+ SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm);
- err = crypto_shash_final(hash_desc, hash);
- if (err)
- goto out;
+ hash_desc->tfm = c->hash_tfm;
+ hash_desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+ ubifs_shash_copy_state(c, inhash, hash_desc);
+
+ err = crypto_shash_final(hash_desc, hash);
+ if (err)
+ goto out;
+ }
err = ubifs_hash_calc_hmac(c, hash, auth->hmac);
if (err)