From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
To: Haren Myneni <haren@us.ibm.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Nicholas Piggin <npiggin@gmail.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
"Aneesh Kumar K.V" <aneesh.kumar@kernel.org>,
"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
"David S. Miller" <davem@davemloft.net>
Cc: linuxppc-dev@lists.ozlabs.org, linux-crypto@vger.kernel.org,
linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
linux-hardening@vger.kernel.org,
Kees Cook <keescook@chromium.org>
Subject: [PATCH][next] crypto/nx: Avoid -Wflex-array-member-not-at-end warning
Date: Tue, 5 Mar 2024 13:57:56 -0600 [thread overview]
Message-ID: <Zed5RIGqPgxUt/9T@neat> (raw)
-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
ready to enable it globally. So, we are deprecating flexible-array
members in the middle of another structure.
There is currently an object (`header`) in `struct nx842_crypto_ctx`
that contains a flexible structure (`struct nx842_crypto_header`):
struct nx842_crypto_ctx {
...
struct nx842_crypto_header header;
struct nx842_crypto_header_group group[NX842_CRYPTO_GROUP_MAX];
...
};
So, in order to avoid ending up with a flexible-array member in the
middle of another struct, we use the `struct_group_tagged()` helper to
separate the flexible array from the rest of the members in the flexible
structure:
struct nx842_crypto_header {
struct_group_tagged(nx842_crypto_header_hdr, hdr,
... the rest of the members
);
struct nx842_crypto_header_group group[];
} __packed;
With the change described above, we can now declare an object of the
type of the tagged struct, without embedding the flexible array in the
middle of another struct:
struct nx842_crypto_ctx {
...
struct nx842_crypto_header_hdr header;
struct nx842_crypto_header_group group[NX842_CRYPTO_GROUP_MAX];
...
} __packed;
We also use `container_of()` whenever we need to retrieve a pointer to
the flexible structure, through which we can access the flexible
array if needed.
So, with these changes, fix the following warning:
In file included from drivers/crypto/nx/nx-842.c:55:
drivers/crypto/nx/nx-842.h:174:36: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
174 | struct nx842_crypto_header header;
| ^~~~~~
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
drivers/crypto/nx/nx-842.c | 6 ++++--
drivers/crypto/nx/nx-842.h | 10 ++++++----
2 files changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/crypto/nx/nx-842.c b/drivers/crypto/nx/nx-842.c
index 2ab90ec10e61..82214cde2bcd 100644
--- a/drivers/crypto/nx/nx-842.c
+++ b/drivers/crypto/nx/nx-842.c
@@ -251,7 +251,9 @@ int nx842_crypto_compress(struct crypto_tfm *tfm,
u8 *dst, unsigned int *dlen)
{
struct nx842_crypto_ctx *ctx = crypto_tfm_ctx(tfm);
- struct nx842_crypto_header *hdr = &ctx->header;
+ struct nx842_crypto_header *hdr =
+ container_of(&ctx->header,
+ struct nx842_crypto_header, hdr);
struct nx842_crypto_param p;
struct nx842_constraints c = *ctx->driver->constraints;
unsigned int groups, hdrsize, h;
@@ -490,7 +492,7 @@ int nx842_crypto_decompress(struct crypto_tfm *tfm,
}
memcpy(&ctx->header, src, hdr_len);
- hdr = &ctx->header;
+ hdr = container_of(&ctx->header, struct nx842_crypto_header, hdr);
for (n = 0; n < hdr->groups; n++) {
/* ignore applies to last group */
diff --git a/drivers/crypto/nx/nx-842.h b/drivers/crypto/nx/nx-842.h
index 7590bfb24d79..25fa70b2112c 100644
--- a/drivers/crypto/nx/nx-842.h
+++ b/drivers/crypto/nx/nx-842.h
@@ -157,9 +157,11 @@ struct nx842_crypto_header_group {
} __packed;
struct nx842_crypto_header {
- __be16 magic; /* NX842_CRYPTO_MAGIC */
- __be16 ignore; /* decompressed end bytes to ignore */
- u8 groups; /* total groups in this header */
+ struct_group_tagged(nx842_crypto_header_hdr, hdr,
+ __be16 magic; /* NX842_CRYPTO_MAGIC */
+ __be16 ignore; /* decompressed end bytes to ignore */
+ u8 groups; /* total groups in this header */
+ );
struct nx842_crypto_header_group group[];
} __packed;
@@ -171,7 +173,7 @@ struct nx842_crypto_ctx {
u8 *wmem;
u8 *sbounce, *dbounce;
- struct nx842_crypto_header header;
+ struct nx842_crypto_header_hdr header;
struct nx842_crypto_header_group group[NX842_CRYPTO_GROUP_MAX];
struct nx842_driver *driver;
--
2.34.1
next reply other threads:[~2024-03-05 19:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-05 19:57 Gustavo A. R. Silva [this message]
2024-03-28 10:46 ` [PATCH][next] crypto/nx: Avoid -Wflex-array-member-not-at-end warning Herbert Xu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Zed5RIGqPgxUt/9T@neat \
--to=gustavoars@kernel.org \
--cc=aneesh.kumar@kernel.org \
--cc=christophe.leroy@csgroup.eu \
--cc=davem@davemloft.net \
--cc=haren@us.ibm.com \
--cc=herbert@gondor.apana.org.au \
--cc=keescook@chromium.org \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-hardening@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mpe@ellerman.id.au \
--cc=naveen.n.rao@linux.ibm.com \
--cc=npiggin@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).