From: Waiman Long <longman@redhat.com>
To: David Howells <dhowells@redhat.com>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
Mimi Zohar <zohar@linux.ibm.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>
Cc: keyrings@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-integrity@vger.kernel.org, netdev@vger.kernel.org,
linux-afs@lists.infradead.org, Sumit Garg <sumit.garg@linaro.org>,
Jerry Snitselaar <jsnitsel@redhat.com>,
Roberto Sassu <roberto.sassu@huawei.com>,
Eric Biggers <ebiggers@google.com>,
Chris von Recklinghausen <crecklin@redhat.com>,
Waiman Long <longman@redhat.com>
Subject: [PATCH v4 2/4] KEYS: Remove __user annotation from rxrpc_read()
Date: Tue, 17 Mar 2020 15:41:38 -0400 [thread overview]
Message-ID: <20200317194140.6031-3-longman@redhat.com> (raw)
In-Reply-To: <20200317194140.6031-1-longman@redhat.com>
As the keyctl_read_key() has been modified to use a temporary kernel
buffer to read out the key data instead of passing in the user-supplied
buffer directly, there is no need to use the __user annotation for
rxrpc_read(). In addition,
1) The put_user() call is replaced by a direct copy.
2) The copy_to_user() call is replaced by memcpy().
3) All the fault handling code is removed.
Compiling on a x86-64 system, the size of the rxrpc_read() function is
reduced from 3795 bytes to 2384 bytes with this patch.
Signed-off-by: Waiman Long <longman@redhat.com>
---
net/rxrpc/key.c | 27 +++++++++------------------
1 file changed, 9 insertions(+), 18 deletions(-)
diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c
index 6c3f35fac42d..0c98313dd7a8 100644
--- a/net/rxrpc/key.c
+++ b/net/rxrpc/key.c
@@ -31,7 +31,7 @@ static void rxrpc_free_preparse_s(struct key_preparsed_payload *);
static void rxrpc_destroy(struct key *);
static void rxrpc_destroy_s(struct key *);
static void rxrpc_describe(const struct key *, struct seq_file *);
-static long rxrpc_read(const struct key *, char __user *, size_t);
+static long rxrpc_read(const struct key *, char *, size_t);
/*
* rxrpc defined keys take an arbitrary string as the description and an
@@ -1042,12 +1042,12 @@ EXPORT_SYMBOL(rxrpc_get_null_key);
* - this returns the result in XDR form
*/
static long rxrpc_read(const struct key *key,
- char __user *buffer, size_t buflen)
+ char *buffer, size_t buflen)
{
const struct rxrpc_key_token *token;
const struct krb5_principal *princ;
size_t size;
- __be32 __user *xdr, *oldxdr;
+ __be32 *xdr, *oldxdr;
u32 cnlen, toksize, ntoks, tok, zero;
u16 toksizes[AFSTOKEN_MAX];
int loop;
@@ -1124,30 +1124,25 @@ static long rxrpc_read(const struct key *key,
if (!buffer || buflen < size)
return size;
- xdr = (__be32 __user *) buffer;
+ xdr = (__be32 *)buffer;
zero = 0;
#define ENCODE(x) \
do { \
- __be32 y = htonl(x); \
- if (put_user(y, xdr++) < 0) \
- goto fault; \
+ *xdr++ = htonl(x); \
} while(0)
#define ENCODE_DATA(l, s) \
do { \
u32 _l = (l); \
ENCODE(l); \
- if (copy_to_user(xdr, (s), _l) != 0) \
- goto fault; \
- if (_l & 3 && \
- copy_to_user((u8 __user *)xdr + _l, &zero, 4 - (_l & 3)) != 0) \
- goto fault; \
+ memcpy(xdr, (s), _l); \
+ if (_l & 3) \
+ memcpy((u8 *)xdr + _l, &zero, 4 - (_l & 3)); \
xdr += (_l + 3) >> 2; \
} while(0)
#define ENCODE64(x) \
do { \
__be64 y = cpu_to_be64(x); \
- if (copy_to_user(xdr, &y, 8) != 0) \
- goto fault; \
+ memcpy(xdr, &y, 8); \
xdr += 8 >> 2; \
} while(0)
#define ENCODE_STR(s) \
@@ -1238,8 +1233,4 @@ static long rxrpc_read(const struct key *key,
ASSERTCMP((char __user *) xdr - buffer, ==, size);
_leave(" = %zu", size);
return size;
-
-fault:
- _leave(" = -EFAULT");
- return -EFAULT;
}
--
2.18.1
next prev parent reply other threads:[~2020-03-17 19:42 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-17 19:41 [PATCH v4 0/4] KEYS: Read keys to internal buffer & then copy to userspace Waiman Long
2020-03-17 19:41 ` [PATCH v4 1/4] KEYS: Don't write out to userspace while holding key semaphore Waiman Long
2020-03-17 19:41 ` Waiman Long [this message]
2020-03-17 19:41 ` [PATCH v4 3/4] KEYS: Remove __user annotation from dns_resolver_read() Waiman Long
2020-03-17 19:41 ` [PATCH v4 4/4] KEYS: Avoid false positive ENOMEM error on key read Waiman Long
2020-03-18 8:23 ` [PATCH v4 2/4] KEYS: Remove __user annotation from rxrpc_read() David Howells
2020-03-18 14:32 ` Waiman Long
2020-03-18 8:27 ` [PATCH v4 4/4] KEYS: Avoid false positive ENOMEM error on key read David Howells
2020-03-18 14:34 ` Waiman Long
2020-03-18 15:14 ` David Howells
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=20200317194140.6031-3-longman@redhat.com \
--to=longman@redhat.com \
--cc=crecklin@redhat.com \
--cc=davem@davemloft.net \
--cc=dhowells@redhat.com \
--cc=ebiggers@google.com \
--cc=jarkko.sakkinen@linux.intel.com \
--cc=jmorris@namei.org \
--cc=jsnitsel@redhat.com \
--cc=keyrings@vger.kernel.org \
--cc=kuba@kernel.org \
--cc=linux-afs@lists.infradead.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=roberto.sassu@huawei.com \
--cc=serge@hallyn.com \
--cc=sumit.garg@linaro.org \
--cc=zohar@linux.ibm.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 NNTP newsgroup(s).