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author | 2018-02-16 19:19:27 +0100 | |
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committer | 2018-04-01 20:24:39 -0500 | |
commit | 82fb82be05585426405667dd5f0510aa953ba439 (patch) | |
tree | 48f5f72f33aa3c2c29e53cd4fee906db96f1f2ce /fs/cifs/misc.c | |
parent | Update README file for cifs.ko (diff) | |
download | linux-82fb82be05585426405667dd5f0510aa953ba439.tar.gz linux-82fb82be05585426405667dd5f0510aa953ba439.tar.bz2 linux-82fb82be05585426405667dd5f0510aa953ba439.zip |
CIFS: refactor crypto shash/sdesc allocation&free
shash and sdesc and always allocated and freed together.
* abstract this in new functions cifs_alloc_hash() and cifs_free_hash().
* make smb2/3 crypto allocation independent from each other.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: Stable <stable@vger.kernel.org>
Diffstat (limited to 'fs/cifs/misc.c')
-rw-r--r-- | fs/cifs/misc.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index a0dbced4a45c..460084a8eac5 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -848,3 +848,57 @@ setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw) iov_iter_bvec(&ctx->iter, ITER_BVEC | rw, ctx->bv, npages, ctx->len); return 0; } + +/** + * cifs_alloc_hash - allocate hash and hash context together + * + * The caller has to make sure @sdesc is initialized to either NULL or + * a valid context. Both can be freed via cifs_free_hash(). + */ +int +cifs_alloc_hash(const char *name, + struct crypto_shash **shash, struct sdesc **sdesc) +{ + int rc = 0; + size_t size; + + if (*sdesc != NULL) + return 0; + + *shash = crypto_alloc_shash(name, 0, 0); + if (IS_ERR(*shash)) { + cifs_dbg(VFS, "could not allocate crypto %s\n", name); + rc = PTR_ERR(*shash); + *shash = NULL; + *sdesc = NULL; + return rc; + } + + size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash); + *sdesc = kmalloc(size, GFP_KERNEL); + if (*sdesc == NULL) { + cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name); + crypto_free_shash(*shash); + *shash = NULL; + return -ENOMEM; + } + + (*sdesc)->shash.tfm = *shash; + (*sdesc)->shash.flags = 0x0; + return 0; +} + +/** + * cifs_free_hash - free hash and hash context together + * + * Freeing a NULL hash or context is safe. + */ +void +cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc) +{ + kfree(*sdesc); + *sdesc = NULL; + if (*shash) + crypto_free_shash(*shash); + *shash = NULL; +} |