From: Arnd Bergmann <arnd@arndb.de>
To: Herbert Xu <herbert@gondor.apana.org.au>, x86@kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
"David S. Miller" <davem@davemloft.net>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Borislav Petkov <bp@suse.de>,
Stephan Mueller <smueller@chronox.de>,
linux-crypto@vger.kernel.org
Subject: [PATCH 15/28] crypto: aesni: avoid -Wmaybe-uninitialized warning
Date: Tue, 18 Oct 2016 00:13:36 +0200 [thread overview]
Message-ID: <20161017221355.1861551-3-arnd@arndb.de> (raw)
In-Reply-To: <20161017220342.1627073-1-arnd@arndb.de>
The rfc4106 encrypy/decrypt helper functions cause an annoying
false-positive warning in allmodconfig if we turn on
-Wmaybe-uninitialized warnings again:
arch/x86/crypto/aesni-intel_glue.c: In function ‘helper_rfc4106_decrypt’:
include/linux/scatterlist.h:67:31: warning: ‘dst_sg_walk.sg’ may be used uninitialized in this function [-Wmaybe-uninitialized]
The problem seems to be that the compiler doesn't track the state of the
'one_entry_in_sg' variable across the kernel_fpu_begin/kernel_fpu_end
section.
This reorganizes the code to avoid that variable and have the shared
code in a separate function to avoid some of the conditional branches.
The resulting functions are a bit longer but also slightly less complex,
leaving no room for speculation on the part of the compiler.
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
The conversion is nontrivial, and I have only build-tested it, so this
could use a careful review and testing.
---
arch/x86/crypto/aesni-intel_glue.c | 121 ++++++++++++++++++++++---------------
1 file changed, 73 insertions(+), 48 deletions(-)
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 0ab5ee1..054155b 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -269,6 +269,34 @@ static void (*aesni_gcm_dec_tfm)(void *ctx, u8 *out,
u8 *hash_subkey, const u8 *aad, unsigned long aad_len,
u8 *auth_tag, unsigned long auth_tag_len);
+static inline void aesni_do_gcm_enc_tfm(void *ctx, u8 *out,
+ const u8 *in, unsigned long plaintext_len, u8 *iv,
+ u8 *hash_subkey, const u8 *aad, unsigned long aad_len,
+ u8 *auth_tag, unsigned long auth_tag_len)
+{
+ kernel_fpu_begin();
+ aesni_gcm_enc_tfm(ctx, out, in, plaintext_len, iv, hash_subkey,
+ aad, aad_len, auth_tag, auth_tag_len);
+ kernel_fpu_end();
+}
+
+static inline int aesni_do_gcm_dec_tfm(void *ctx, u8 *out,
+ const u8 *in, unsigned long ciphertext_len, u8 *iv,
+ u8 *hash_subkey, const u8 *aad, unsigned long aad_len,
+ u8 *auth_tag, unsigned long auth_tag_len)
+{
+ kernel_fpu_begin();
+ aesni_gcm_dec_tfm(ctx, out, in, ciphertext_len, iv, hash_subkey, aad,
+ aad_len, auth_tag, auth_tag_len);
+ kernel_fpu_end();
+
+ /* Compare generated tag with passed in tag. */
+ if (crypto_memneq(in + ciphertext_len, auth_tag, auth_tag_len))
+ return -EBADMSG;
+
+ return 0;
+}
+
static inline struct
aesni_rfc4106_gcm_ctx *aesni_rfc4106_gcm_ctx_get(struct crypto_aead *tfm)
{
@@ -879,7 +907,6 @@ static int rfc4106_set_authsize(struct crypto_aead *parent,
static int helper_rfc4106_encrypt(struct aead_request *req)
{
- u8 one_entry_in_sg = 0;
u8 *src, *dst, *assoc;
__be32 counter = cpu_to_be32(1);
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
@@ -908,7 +935,6 @@ static int helper_rfc4106_encrypt(struct aead_request *req)
req->src->offset + req->src->length <= PAGE_SIZE &&
sg_is_last(req->dst) &&
req->dst->offset + req->dst->length <= PAGE_SIZE) {
- one_entry_in_sg = 1;
scatterwalk_start(&src_sg_walk, req->src);
assoc = scatterwalk_map(&src_sg_walk);
src = assoc + req->assoclen;
@@ -916,7 +942,23 @@ static int helper_rfc4106_encrypt(struct aead_request *req)
if (unlikely(req->src != req->dst)) {
scatterwalk_start(&dst_sg_walk, req->dst);
dst = scatterwalk_map(&dst_sg_walk) + req->assoclen;
+
+ aesni_do_gcm_enc_tfm(aes_ctx, dst, src, req->cryptlen, iv,
+ ctx->hash_subkey, assoc, req->assoclen - 8,
+ dst + req->cryptlen, auth_tag_len);
+
+ scatterwalk_unmap(dst - req->assoclen);
+ scatterwalk_advance(&dst_sg_walk, req->dst->length);
+ scatterwalk_done(&dst_sg_walk, 1, 0);
+ } else {
+ aesni_do_gcm_enc_tfm(aes_ctx, dst, src, req->cryptlen, iv,
+ ctx->hash_subkey, assoc, req->assoclen - 8,
+ dst + req->cryptlen, auth_tag_len);
}
+
+ scatterwalk_unmap(assoc);
+ scatterwalk_advance(&src_sg_walk, req->src->length);
+ scatterwalk_done(&src_sg_walk, req->src == req->dst, 0);
} else {
/* Allocate memory for src, dst, assoc */
assoc = kmalloc(req->cryptlen + auth_tag_len + req->assoclen,
@@ -925,28 +967,14 @@ static int helper_rfc4106_encrypt(struct aead_request *req)
return -ENOMEM;
scatterwalk_map_and_copy(assoc, req->src, 0,
req->assoclen + req->cryptlen, 0);
- src = assoc + req->assoclen;
- dst = src;
- }
+ dst = src = assoc + req->assoclen;
- kernel_fpu_begin();
- aesni_gcm_enc_tfm(aes_ctx, dst, src, req->cryptlen, iv,
- ctx->hash_subkey, assoc, req->assoclen - 8,
- dst + req->cryptlen, auth_tag_len);
- kernel_fpu_end();
+ aesni_gcm_enc_tfm(aes_ctx, dst, src, req->cryptlen, iv,
+ ctx->hash_subkey, assoc, req->assoclen - 8,
+ dst + req->cryptlen, auth_tag_len);
- /* The authTag (aka the Integrity Check Value) needs to be written
- * back to the packet. */
- if (one_entry_in_sg) {
- if (unlikely(req->src != req->dst)) {
- scatterwalk_unmap(dst - req->assoclen);
- scatterwalk_advance(&dst_sg_walk, req->dst->length);
- scatterwalk_done(&dst_sg_walk, 1, 0);
- }
- scatterwalk_unmap(assoc);
- scatterwalk_advance(&src_sg_walk, req->src->length);
- scatterwalk_done(&src_sg_walk, req->src == req->dst, 0);
- } else {
+ /* The authTag (aka the Integrity Check Value) needs to be written
+ * back to the packet. */
scatterwalk_map_and_copy(dst, req->dst, req->assoclen,
req->cryptlen + auth_tag_len, 1);
kfree(assoc);
@@ -956,7 +984,6 @@ static int helper_rfc4106_encrypt(struct aead_request *req)
static int helper_rfc4106_decrypt(struct aead_request *req)
{
- u8 one_entry_in_sg = 0;
u8 *src, *dst, *assoc;
unsigned long tempCipherLen = 0;
__be32 counter = cpu_to_be32(1);
@@ -990,47 +1017,45 @@ static int helper_rfc4106_decrypt(struct aead_request *req)
req->src->offset + req->src->length <= PAGE_SIZE &&
sg_is_last(req->dst) &&
req->dst->offset + req->dst->length <= PAGE_SIZE) {
- one_entry_in_sg = 1;
scatterwalk_start(&src_sg_walk, req->src);
assoc = scatterwalk_map(&src_sg_walk);
src = assoc + req->assoclen;
- dst = src;
if (unlikely(req->src != req->dst)) {
scatterwalk_start(&dst_sg_walk, req->dst);
dst = scatterwalk_map(&dst_sg_walk) + req->assoclen;
- }
-
- } else {
- /* Allocate memory for src, dst, assoc */
- assoc = kmalloc(req->cryptlen + req->assoclen, GFP_ATOMIC);
- if (!assoc)
- return -ENOMEM;
- scatterwalk_map_and_copy(assoc, req->src, 0,
- req->assoclen + req->cryptlen, 0);
- src = assoc + req->assoclen;
- dst = src;
- }
- kernel_fpu_begin();
- aesni_gcm_dec_tfm(aes_ctx, dst, src, tempCipherLen, iv,
- ctx->hash_subkey, assoc, req->assoclen - 8,
- authTag, auth_tag_len);
- kernel_fpu_end();
-
- /* Compare generated tag with passed in tag. */
- retval = crypto_memneq(src + tempCipherLen, authTag, auth_tag_len) ?
- -EBADMSG : 0;
+ retval = aesni_do_gcm_dec_tfm(aes_ctx, dst, src,
+ tempCipherLen, iv, ctx->hash_subkey,
+ assoc, req->assoclen - 8, authTag,
+ auth_tag_len);
- if (one_entry_in_sg) {
- if (unlikely(req->src != req->dst)) {
scatterwalk_unmap(dst - req->assoclen);
scatterwalk_advance(&dst_sg_walk, req->dst->length);
scatterwalk_done(&dst_sg_walk, 1, 0);
+ } else {
+ dst = src;
+ retval = aesni_do_gcm_dec_tfm(aes_ctx, dst, src,
+ tempCipherLen, iv, ctx->hash_subkey,
+ assoc, req->assoclen - 8, authTag,
+ auth_tag_len);
}
scatterwalk_unmap(assoc);
scatterwalk_advance(&src_sg_walk, req->src->length);
scatterwalk_done(&src_sg_walk, req->src == req->dst, 0);
} else {
+ /* Allocate memory for src, dst, assoc */
+ assoc = kmalloc(req->cryptlen + req->assoclen, GFP_ATOMIC);
+ if (!assoc)
+ return -ENOMEM;
+ scatterwalk_map_and_copy(assoc, req->src, 0,
+ req->assoclen + req->cryptlen, 0);
+ dst = src = assoc + req->assoclen;
+
+ retval = aesni_do_gcm_dec_tfm(aes_ctx, dst, src, tempCipherLen,
+ iv, ctx->hash_subkey, assoc,
+ req->assoclen - 8, authTag,
+ auth_tag_len);
+
scatterwalk_map_and_copy(dst, req->dst, req->assoclen,
tempCipherLen, 1);
kfree(assoc);
--
2.9.0
next prev parent reply other threads:[~2016-10-17 22:17 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-17 22:03 [PATCH 00/28] Reenable maybe-uninitialized warnings Arnd Bergmann
2016-10-17 22:05 ` [PATCH 01/28] [v2] netfilter: nf_tables: avoid uninitialized variable warning Arnd Bergmann
2016-10-18 15:23 ` Pablo Neira Ayuso
2016-10-17 22:05 ` [PATCH 02/28] [v2] mtd: mtk: avoid warning in mtk_ecc_encode Arnd Bergmann
2016-10-18 5:19 ` Boris Brezillon
[not found] ` <1476785552.24626.4.camel@mtkswgap22>
2016-10-18 19:45 ` Boris Brezillon
2016-10-17 22:05 ` [PATCH 03/28] [v2] infiniband: shut up a maybe-uninitialized warning Arnd Bergmann
2016-10-18 6:47 ` Haggai Eran
2016-10-18 10:18 ` Arnd Bergmann
2016-10-18 10:32 ` Haggai Eran
2016-10-17 22:05 ` [PATCH 04/28] f2fs: replace a build-time warning with runtime WARN_ON Arnd Bergmann
2016-10-26 14:05 ` [f2fs-dev] " Chao Yu
2016-10-26 14:57 ` Arnd Bergmann
2016-10-27 11:41 ` Chao Yu
2016-10-17 22:05 ` [PATCH 05/28] ext2: avoid bogus -Wmaybe-uninitialized warning Arnd Bergmann
2016-10-18 5:15 ` Christoph Hellwig
2016-10-18 9:30 ` Jan Kara
2016-10-17 22:05 ` [PATCH 06/28] NFSv4.1: work around " Arnd Bergmann
2016-10-17 22:08 ` [PATCH 07/28] ceph: avoid false positive maybe-uninitialized warning Arnd Bergmann
2016-10-18 2:07 ` Yan, Zheng
2016-10-17 22:08 ` [PATCH 08/28] staging: lustre: restore initialization of return code Arnd Bergmann
[not found] ` <CY4PR11MB1751050A7C7AF840E94DDE60CBD00@CY4PR11MB1751.namprd11.prod.outlook.com>
2016-10-17 22:29 ` [lustre-devel] " Arnd Bergmann
2016-10-17 22:37 ` Linus Torvalds
2016-10-17 23:00 ` Arnd Bergmann
2016-10-17 22:42 ` [PATCH 08/28 v2] " Arnd Bergmann
2016-10-17 22:08 ` [PATCH 09/28] staging: lustre: remove broken dead code in cfs_cpt_table_create_pattern Arnd Bergmann
2016-10-17 22:10 ` [PATCH 10/28] UBI: fix uninitialized access of vid_hdr pointer Arnd Bergmann
2016-10-18 5:17 ` Boris Brezillon
2016-10-17 22:10 ` [PATCH 11/28] block: rdb: false-postive gcc-4.9 -Wmaybe-uninitialized Arnd Bergmann
2016-10-18 9:57 ` Ilya Dryomov
2016-10-18 10:04 ` Arnd Bergmann
2016-10-17 22:12 ` [PATCH 12/28] [media] rc: print correct variable for z8f0811 Arnd Bergmann
2016-10-17 22:13 ` [PATCH 13/28] [media] dib0700: fix uninitialized data on 'repeat' event Arnd Bergmann
2016-10-17 22:13 ` [PATCH 14/28] iio: accel: sca3000_core: avoid potentially uninitialized variable Arnd Bergmann
2016-10-23 21:25 ` Jonathan Cameron
2016-10-17 22:13 ` Arnd Bergmann [this message]
2016-10-17 22:13 ` [PATCH 16/28] pcmcia: fix return value of soc_pcmcia_regulator_set Arnd Bergmann
2016-10-18 9:42 ` Russell King - ARM Linux
2016-10-17 22:13 ` [PATCH 17/28] spi: fsl-espi: avoid processing uninitalized data on error Arnd Bergmann
2016-10-24 17:27 ` Mark Brown
2016-10-24 18:36 ` Heiner Kallweit
2016-10-24 18:45 ` Mark Brown
2016-10-24 20:37 ` Arnd Bergmann
2016-10-25 19:13 ` Mark Brown
2016-10-25 20:57 ` Arnd Bergmann
2016-10-26 10:15 ` Applied "spi: fsl-espi: avoid processing uninitalized data on error" to the spi tree Mark Brown
2016-10-26 18:11 ` Merge problem: " Heiner Kallweit
2016-10-26 21:59 ` Mark Brown
2016-10-17 22:13 ` [PATCH 18/28] drm: avoid uninitialized timestamp use in wait_vblank Arnd Bergmann
2016-10-17 23:47 ` Mario Kleiner
2016-10-18 7:46 ` Daniel Vetter
2016-10-17 22:13 ` [PATCH 19/28] brcmfmac: avoid maybe-uninitialized warning in brcmf_cfg80211_start_ap Arnd Bergmann
2016-10-26 6:49 ` Kalle Valo
2016-10-26 9:57 ` Arnd Bergmann
2016-10-26 11:11 ` Kalle Valo
2016-10-27 15:05 ` [19/28] " Kalle Valo
2016-10-17 22:16 ` [PATCH 20/28] net: bcm63xx: avoid referencing uninitialized variable Arnd Bergmann
2016-10-18 18:21 ` David Miller
2016-10-17 22:16 ` [PATCH 21/28] net/hyperv: avoid " Arnd Bergmann
2016-10-18 18:21 ` David Miller
2016-10-17 22:16 ` [PATCH 22/28] x86: apm: avoid uninitialized data Arnd Bergmann
2016-10-18 13:05 ` Jiri Kosina
2016-10-18 21:35 ` Luis R. Rodriguez
2016-10-17 22:16 ` [PATCH 23/28] x86: mark target address as output in 'insb' asm Arnd Bergmann
2016-10-17 22:16 ` [PATCH 24/28] x86: math-emu: possible uninitialized variable use Arnd Bergmann
2016-10-17 22:16 ` [PATCH 25/28] s390: pci: don't print uninitialized data for debugging Arnd Bergmann
2016-10-18 6:48 ` Martin Schwidefsky
2016-10-18 8:53 ` Sebastian Ott
2016-10-17 22:16 ` [PATCH 26/28] nios2: fix timer initcall return value Arnd Bergmann
2016-10-24 0:54 ` Ley Foon Tan
2016-10-17 22:16 ` [PATCH 27/28] rocker: fix maybe-uninitialized warning Arnd Bergmann
2016-10-18 18:21 ` David Miller
2016-10-17 22:19 ` [PATCH 28/28] Kbuild: bring back -Wmaybe-uninitialized warning Arnd Bergmann
2016-10-18 5:08 ` [PATCH 00/28] Reenable maybe-uninitialized warnings Christoph Hellwig
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