linux/net/sunrpc
Rasmus Villemoes 41416f2330 lib/string_helpers.c: change semantics of string_escape_mem
The current semantics of string_escape_mem are inadequate for one of its
current users, vsnprintf().  If that is to honour its contract, it must
know how much space would be needed for the entire escaped buffer, and
string_escape_mem provides no way of obtaining that (short of allocating a
large enough buffer (~4 times input string) to let it play with, and
that's definitely a big no-no inside vsnprintf).

So change the semantics for string_escape_mem to be more snprintf-like:
Return the size of the output that would be generated if the destination
buffer was big enough, but of course still only write to the part of dst
it is allowed to, and (contrary to snprintf) don't do '\0'-termination.
It is then up to the caller to detect whether output was truncated and to
append a '\0' if desired.  Also, we must output partial escape sequences,
otherwise a call such as snprintf(buf, 3, "%1pE", "\123") would cause
printf to write a \0 to buf[2] but leaving buf[0] and buf[1] with whatever
they previously contained.

This also fixes a bug in the escaped_string() helper function, which used
to unconditionally pass a length of "end-buf" to string_escape_mem();
since the latter doesn't check osz for being insanely large, it would
happily write to dst.  For example, kasprintf(GFP_KERNEL, "something and
then %pE", ...); is an easy way to trigger an oops.

In test-string_helpers.c, the -ENOMEM test is replaced with testing for
getting the expected return value even if the buffer is too small.  We
also ensure that nothing is written (by relying on a NULL pointer deref)
if the output size is 0 by passing NULL - this has to work for
kasprintf("%pE") to work.

In net/sunrpc/cache.c, I think qword_add still has the same semantics.
Someone should definitely double-check this.

In fs/proc/array.c, I made the minimum possible change, but longer-term it
should stop poking around in seq_file internals.

[andriy.shevchenko@linux.intel.com: simplify qword_add]
[andriy.shevchenko@linux.intel.com: add missed curly braces]
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:24 -07:00
..
auth_gss sunrpc: integer underflow in rsc_parse() 2015-02-26 15:40:16 -05:00
xprtrdma Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2015-04-14 09:50:27 -07:00
addr.c replace strict_strto calls 2014-07-12 18:45:49 -04:00
auth.c sunrpc: eliminate RPC_DEBUG 2014-11-24 17:31:46 -05:00
auth_generic.c sunrpc: eliminate RPC_DEBUG 2014-11-24 17:31:46 -05:00
auth_null.c sunrpc: eliminate RPC_DEBUG 2014-11-24 17:31:46 -05:00
auth_unix.c sunrpc: eliminate RPC_DEBUG 2014-11-24 17:31:46 -05:00
backchannel_rqst.c SUNRPC: Always manipulate rpc_rqst::rq_bc_pa_list under xprt->bc_pa_lock 2015-02-13 17:41:10 -05:00
bc_svc.c SUNRPC: remove BUG_ON from bc_send 2012-11-04 14:43:41 -05:00
cache.c lib/string_helpers.c: change semantics of string_escape_mem 2015-04-15 16:35:24 -07:00
clnt.c sunrpc: make debugfs file creation failure non-fatal 2015-03-31 14:15:08 -04:00
debugfs.c sunrpc: make debugfs file creation failure non-fatal 2015-03-31 14:15:08 -04:00
Kconfig kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
Makefile sunrpc: add debugfs file for displaying client rpc_task queue 2014-11-27 13:14:51 -05:00
netns.h Merge branch 'for-3.14' of git://linux-nfs.org/~bfields/linux 2014-01-30 10:18:43 -08:00
rpc_pipe.c rpc_pipe: Drop memory allocation cast 2014-07-12 18:43:44 -04:00
rpcb_clnt.c SUNRPC: NULL utsname dereference on NFS umount during namespace cleanup 2015-02-03 16:40:17 -05:00
sched.c SUNRPC: Allow waiting on memory allocation 2015-01-24 18:46:50 -05:00
socklib.c net: Save software checksum complete 2014-06-11 15:46:13 -07:00
stats.c sunrpc: add rpc_count_iostats_idx 2015-02-03 11:06:38 -08:00
sunrpc.h SUNRPC: track whether a request is coming from a loop-back interface. 2014-05-22 15:59:18 -04:00
sunrpc_syms.c sunrpc: make debugfs file creation failure non-fatal 2015-03-31 14:15:08 -04:00
svc.c sunrpc/lockd: fix references to the BKL 2015-01-23 10:29:12 -05:00
svc_xprt.c sunrpc/lockd: fix references to the BKL 2015-01-23 10:29:12 -05:00
svcauth.c nfsd4: better reservation of head space for krb5 2014-05-30 17:32:17 -04:00
svcauth_unix.c svcrpc: fix failures to handle -1 uid's 2013-07-08 17:27:23 -04:00
svcsock.c get rid of the size argument of sock_sendmsg() 2015-04-11 15:27:37 -04:00
sysctl.c sunrpc: eliminate RPC_DEBUG 2014-11-24 17:31:46 -05:00
timer.c net: cleanup unsigned to unsigned int 2012-04-15 12:44:40 -04:00
xdr.c rpc: fix xdr_truncate_encode to handle buffer ending on page boundary 2015-01-07 14:03:58 -05:00
xprt.c sunrpc: make debugfs file creation failure non-fatal 2015-03-31 14:15:08 -04:00
xprtsock.c SUNRPC: Cleanup to remove xs_tcp_close() 2015-02-10 11:06:04 -05:00