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* include/linux/string.h: add the option of fortified string.h functionsDaniel Micay2017-07-121-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds support for compiling with a rough equivalent to the glibc _FORTIFY_SOURCE=1 feature, providing compile-time and runtime buffer overflow checks for string.h functions when the compiler determines the size of the source or destination buffer at compile-time. Unlike glibc, it covers buffer reads in addition to writes. GNU C __builtin_*_chk intrinsics are avoided because they would force a much more complex implementation. They aren't designed to detect read overflows and offer no real benefit when using an implementation based on inline checks. Inline checks don't add up to much code size and allow full use of the regular string intrinsics while avoiding the need for a bunch of _chk functions and per-arch assembly to avoid wrapper overhead. This detects various overflows at compile-time in various drivers and some non-x86 core kernel code. There will likely be issues caught in regular use at runtime too. Future improvements left out of initial implementation for simplicity, as it's all quite optional and can be done incrementally: * Some of the fortified string functions (strncpy, strcat), don't yet place a limit on reads from the source based on __builtin_object_size of the source buffer. * Extending coverage to more string functions like strlcat. * It should be possible to optionally use __builtin_object_size(x, 1) for some functions (C strings) to detect intra-object overflows (like glibc's _FORTIFY_SOURCE=2), but for now this takes the conservative approach to avoid likely compatibility issues. * The compile-time checks should be made available via a separate config option which can be enabled by default (or always enabled) once enough time has passed to get the issues it catches fixed. Kees said: "This is great to have. While it was out-of-tree code, it would have blocked at least CVE-2016-3858 from being exploitable (improper size argument to strlcpy()). I've sent a number of fixes for out-of-bounds-reads that this detected upstream already" [arnd@arndb.de: x86: fix fortified memcpy] Link: http://lkml.kernel.org/r/20170627150047.660360-1-arnd@arndb.de [keescook@chromium.org: avoid panic() in favor of BUG()] Link: http://lkml.kernel.org/r/20170626235122.GA25261@beast [keescook@chromium.org: move from -mm, add ARCH_HAS_FORTIFY_SOURCE, tweak Kconfig help] Link: http://lkml.kernel.org/r/20170526095404.20439-1-danielmicay@gmail.com Link: http://lkml.kernel.org/r/1497903987-21002-8-git-send-email-keescook@chromium.org Signed-off-by: Daniel Micay <danielmicay@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Daniel Axtens <dja@axtens.net> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'usb-4.12-rc1' of ↵Linus Torvalds2017-05-041-0/+26
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb Pull USB updates from Greg KH: "Here is the big USB patchset for 4.12-rc1. Lots of good stuff here, after many many many attempts, the kernel finally has a working typeC interface, many thanks to Heikki and Guenter and others who have taken the time to get this merged. It wasn't an easy path for them at all. There's also a staging driver that uses this new api, which is why it's coming in through this tree. Along with that, there's the usual huge number of changes for gadget drivers, xhci, and other stuff. Johan also finally refactored pretty much every driver that was looking at USB endpoints to do it in a common way, which will help prevent any "badly-formed" devices from causing problems in drivers. That too wasn't a simple task. All of these have been in linux-next for a while with no reported issues" * tag 'usb-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (263 commits) staging: typec: Fairchild FUSB302 Type-c chip driver staging: typec: Type-C Port Controller Interface driver (tcpci) staging: typec: USB Type-C Port Manager (tcpm) usb: host: xhci: remove #ifdef around PM functions usb: musb: don't mark of_dev_auxdata as initdata usb: misc: legousbtower: Fix buffers on stack USB: Revert "cdc-wdm: fix "out-of-sync" due to missing notifications" usb: Make sure usb/phy/of gets built-in USB: storage: e-mail update in drivers/usb/storage/unusual_devs.h usb: host: xhci: print correct command ring address usb: host: xhci: delete sp_dma_buffers for scratchpad usb: host: xhci: using correct specification chapter reference for DCBAAP xhci: switch to pci_alloc_irq_vectors usb: host: xhci-plat: set resume_quirk() for R-Car controllers usb: host: xhci-plat: add resume_quirk() usb: host: xhci-plat: enable clk in resume timing usb: host: plat: Enable xHCI plat runtime PM USB: serial: ftdi_sio: add device ID for Microsemi/Arrow SF2PLUS Dev Kit USB: serial: constify static arrays usb: fix some references for /proc/bus/usb ...
| * lib/string: add sysfs_match_string helperHeikki Krogerus2017-03-231-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Make a simple helper for matching strings with sysfs attribute files. In most parts the same as match_string(), except sysfs_match_string() uses sysfs_streq() instead of strcmp() for matching. This is more convenient when used with sysfs attributes. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Felipe Balbi <felipe.balbi@linux.intel.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | kernel-api.rst: fix a series of errors when parsing C filesmchehab@s-opensource.com2017-04-021-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | ./lib/string.c:134: WARNING: Inline emphasis start-string without end-string. ./mm/filemap.c:522: WARNING: Inline interpreted text or phrase reference start-string without end-string. ./mm/filemap.c:1283: ERROR: Unexpected indentation. ./mm/filemap.c:3003: WARNING: Inline interpreted text or phrase reference start-string without end-string. ./mm/vmalloc.c:1544: WARNING: Inline emphasis start-string without end-string. ./mm/page_alloc.c:4245: ERROR: Unexpected indentation. ./ipc/util.c:676: ERROR: Unexpected indentation. ./drivers/pci/irq.c:35: WARNING: Block quote ends without a blank line; unexpected unindent. ./security/security.c:109: ERROR: Unexpected indentation. ./security/security.c:110: WARNING: Definition list ends without a blank line; unexpected unindent. ./block/genhd.c:275: WARNING: Inline strong start-string without end-string. ./block/genhd.c:283: WARNING: Inline strong start-string without end-string. ./include/linux/clk.h:134: WARNING: Inline emphasis start-string without end-string. ./include/linux/clk.h:134: WARNING: Inline emphasis start-string without end-string. ./ipc/util.c:477: ERROR: Unknown target name: "s". Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* lib: move strtobool() to kstrtobool()Kees Cook2016-03-171-29/+0
| | | | | | | | | | | | | | | | | | | | | Create the kstrtobool_from_user() helper and move strtobool() logic into the new kstrtobool() (matching all the other kstrto* functions). Provides an inline wrapper for existing strtobool() callers. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Joe Perches <joe@perches.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Amitkumar Karwar <akarwar@marvell.com> Cc: Nishant Sarmukadam <nishants@marvell.com> Cc: Kalle Valo <kvalo@codeaurora.org> Cc: Steve French <sfrench@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/string: introduce match_string() helperAndy Shevchenko2016-03-171-0/+26
| | | | | | | | | | | | | | | | | | | | | | Occasionally we have to search for an occurrence of a string in an array of strings. Make a simple helper for that purpose. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: David Airlie <airlied@linux.ie> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Sebastian Reichel <sre@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/string.c: add ULL suffix to the constant definitionAndy Shevchenko2015-11-101-1/+1
| | | | | | | | | | | | 8-byte constant is too big for long and compiler complains about this. lib/string.c:907:20: warning: constant 0x0101010101010101 is so big it is long Append ULL suffix to explicitly show its type. 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>
* strscpy: zero any trailing garbage bytes in the destinationChris Metcalf2015-10-061-1/+2
| | | | | | | | It's possible that the destination can be shadowed in userspace (as, for example, the perf buffers are now). So we should take care not to leak data that could be inspected by userspace. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
* string: provide strscpy()Chris Metcalf2015-09-101-0/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The strscpy() API is intended to be used instead of strlcpy(), and instead of most uses of strncpy(). - Unlike strlcpy(), it doesn't read from memory beyond (src + size). - Unlike strlcpy() or strncpy(), the API provides an easy way to check for destination buffer overflow: an -E2BIG error return value. - The provided implementation is robust in the face of the source buffer being asynchronously changed during the copy, unlike the current implementation of strlcpy(). - Unlike strncpy(), the destination buffer will be NUL-terminated if the string in the source buffer is too long. - Also unlike strncpy(), the destination buffer will not be updated beyond the NUL termination, avoiding strncpy's behavior of zeroing the entire tail end of the destination buffer. (A memset() after the strscpy() can be used if this behavior is desired.) - The implementation should be reasonably performant on all platforms since it uses the asm/word-at-a-time.h API rather than simple byte copy. Kernel-to-kernel string copy is not considered to be performance critical in any case. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
* lib/string.c: introduce strreplace()Rasmus Villemoes2015-06-251-0/+17
| | | | | | | | | | | | | | | | | | | | | | Strings are sometimes sanitized by replacing a certain character (often '/') by another (often '!'). In a few places, this is done the same way Schlemiel the Painter would do it. Others are slightly smarter but still do multiple strchr() calls. Introduce strreplace() to do this using a single function call and a single pass over the string. One would expect the return value to be one of three things: void, s, or the number of replacements made. I chose the fourth, returning a pointer to the end of the string. This is more likely to be useful (for example allowing the caller to avoid a strlen call). Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Neil Brown <neilb@suse.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: make memzero_explicit more robust against dead store eliminationDaniel Borkmann2015-05-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In commit 0b053c951829 ("lib: memzero_explicit: use barrier instead of OPTIMIZER_HIDE_VAR"), we made memzero_explicit() more robust in case LTO would decide to inline memzero_explicit() and eventually find out it could be elimiated as dead store. While using barrier() works well for the case of gcc, recent efforts from LLVMLinux people suggest to use llvm as an alternative to gcc, and there, Stephan found in a simple stand-alone user space example that llvm could nevertheless optimize and thus elimitate the memset(). A similar issue has been observed in the referenced llvm bug report, which is regarded as not-a-bug. Based on some experiments, icc is a bit special on its own, while it doesn't seem to eliminate the memset(), it could do so with an own implementation, and then result in similar findings as with llvm. The fix in this patch now works for all three compilers (also tested with more aggressive optimization levels). Arguably, in the current kernel tree it's more of a theoretical issue, but imho, it's better to be pedantic about it. It's clearly visible with gcc/llvm though, with the below code: if we would have used barrier() only here, llvm would have omitted clearing, not so with barrier_data() variant: static inline void memzero_explicit(void *s, size_t count) { memset(s, 0, count); barrier_data(s); } int main(void) { char buff[20]; memzero_explicit(buff, sizeof(buff)); return 0; } $ gcc -O2 test.c $ gdb a.out (gdb) disassemble main Dump of assembler code for function main: 0x0000000000400400 <+0>: lea -0x28(%rsp),%rax 0x0000000000400405 <+5>: movq $0x0,-0x28(%rsp) 0x000000000040040e <+14>: movq $0x0,-0x20(%rsp) 0x0000000000400417 <+23>: movl $0x0,-0x18(%rsp) 0x000000000040041f <+31>: xor %eax,%eax 0x0000000000400421 <+33>: retq End of assembler dump. $ clang -O2 test.c $ gdb a.out (gdb) disassemble main Dump of assembler code for function main: 0x00000000004004f0 <+0>: xorps %xmm0,%xmm0 0x00000000004004f3 <+3>: movaps %xmm0,-0x18(%rsp) 0x00000000004004f8 <+8>: movl $0x0,-0x8(%rsp) 0x0000000000400500 <+16>: lea -0x18(%rsp),%rax 0x0000000000400505 <+21>: xor %eax,%eax 0x0000000000400507 <+23>: retq End of assembler dump. As gcc, clang, but also icc defines __GNUC__, it's sufficient to define this in compiler-gcc.h only to be picked up. For a fallback or otherwise unsupported compiler, we define it as a barrier. Similarly, for ecc which does not support gcc inline asm. Reference: https://llvm.org/bugs/show_bug.cgi?id=15495 Reported-by: Stephan Mueller <smueller@chronox.de> Tested-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Stephan Mueller <smueller@chronox.de> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: mancha security <mancha1@zoho.com> Cc: Mark Charlebois <charlebm@gmail.com> Cc: Behan Webster <behanw@converseincode.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* lib: memzero_explicit: use barrier instead of OPTIMIZER_HIDE_VARmancha security2015-03-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | OPTIMIZER_HIDE_VAR(), as defined when using gcc, is insufficient to ensure protection from dead store optimization. For the random driver and crypto drivers, calls are emitted ... $ gdb vmlinux (gdb) disassemble memzero_explicit Dump of assembler code for function memzero_explicit: 0xffffffff813a18b0 <+0>: push %rbp 0xffffffff813a18b1 <+1>: mov %rsi,%rdx 0xffffffff813a18b4 <+4>: xor %esi,%esi 0xffffffff813a18b6 <+6>: mov %rsp,%rbp 0xffffffff813a18b9 <+9>: callq 0xffffffff813a7120 <memset> 0xffffffff813a18be <+14>: pop %rbp 0xffffffff813a18bf <+15>: retq End of assembler dump. (gdb) disassemble extract_entropy [...] 0xffffffff814a5009 <+313>: mov %r12,%rdi 0xffffffff814a500c <+316>: mov $0xa,%esi 0xffffffff814a5011 <+321>: callq 0xffffffff813a18b0 <memzero_explicit> 0xffffffff814a5016 <+326>: mov -0x48(%rbp),%rax [...] ... but in case in future we might use facilities such as LTO, then OPTIMIZER_HIDE_VAR() is not sufficient to protect gcc from a possible eviction of the memset(). We have to use a compiler barrier instead. Minimal test example when we assume memzero_explicit() would *not* be a call, but would have been *inlined* instead: static inline void memzero_explicit(void *s, size_t count) { memset(s, 0, count); <foo> } int main(void) { char buff[20]; snprintf(buff, sizeof(buff) - 1, "test"); printf("%s", buff); memzero_explicit(buff, sizeof(buff)); return 0; } With <foo> := OPTIMIZER_HIDE_VAR(): (gdb) disassemble main Dump of assembler code for function main: [...] 0x0000000000400464 <+36>: callq 0x400410 <printf@plt> 0x0000000000400469 <+41>: xor %eax,%eax 0x000000000040046b <+43>: add $0x28,%rsp 0x000000000040046f <+47>: retq End of assembler dump. With <foo> := barrier(): (gdb) disassemble main Dump of assembler code for function main: [...] 0x0000000000400464 <+36>: callq 0x400410 <printf@plt> 0x0000000000400469 <+41>: movq $0x0,(%rsp) 0x0000000000400471 <+49>: movq $0x0,0x8(%rsp) 0x000000000040047a <+58>: movl $0x0,0x10(%rsp) 0x0000000000400482 <+66>: xor %eax,%eax 0x0000000000400484 <+68>: add $0x28,%rsp 0x0000000000400488 <+72>: retq End of assembler dump. As can be seen, movq, movq, movl are being emitted inlined via memset(). Reference: http://thread.gmane.org/gmane.linux.kernel.cryptoapi/13764/ Fixes: d4c5efdb9777 ("random: add and use memzero_explicit() for clearing data") Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: mancha security <mancha1@zoho.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds2015-02-141-0/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull crypto update from Herbert Xu: "Here is the crypto update for 3.20: - Added 192/256-bit key support to aesni GCM. - Added MIPS OCTEON MD5 support. - Fixed hwrng starvation and race conditions. - Added note that memzero_explicit is not a subsitute for memset. - Added user-space interface for crypto_rng. - Misc fixes" * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (71 commits) crypto: tcrypt - do not allocate iv on stack for aead speed tests crypto: testmgr - limit IV copy length in aead tests crypto: tcrypt - fix buflen reminder calculation crypto: testmgr - mark rfc4106(gcm(aes)) as fips_allowed crypto: caam - fix resource clean-up on error path for caam_jr_init crypto: caam - pair irq map and dispose in the same function crypto: ccp - terminate ccp_support array with empty element crypto: caam - remove unused local variable crypto: caam - remove dead code crypto: caam - don't emit ICV check failures to dmesg hwrng: virtio - drop extra empty line crypto: replace scatterwalk_sg_next with sg_next crypto: atmel - Free memory in error path crypto: doc - remove colons in comments crypto: seqiv - Ensure that IV size is at least 8 bytes crypto: cts - Weed out non-CBC algorithms MAINTAINERS: add linux-crypto to hw random crypto: cts - Remove bogus use of seqiv crypto: qat - don't need qat_auth_state struct crypto: algif_rng - fix sparse non static symbol warning ...
| * lib: memzero_explicit: add comment for its usageDaniel Borkmann2015-01-081-0/+5
| | | | | | | | | | | | | | | | | | | | | | Lets improve the comment to add a note on when to use memzero_explicit() for those not digging through the git logs. We don't want people to pollute places with memzero_explicit() where it's not really necessary. Reference: https://lkml.org/lkml/2015/1/4/190 Suggested-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* | lib/string.c: improve strrchr()Rasmus Villemoes2015-02-131-6/+6
| | | | | | | | | | | | | | | | | | | | | | Instead of potentially passing over the string twice in case c is not found, just keep track of the last occurrence. According to bloat-o-meter, this also cuts the generated code by a third (54 vs 36 bytes). Oh, and we get rid of those 7-space indented lines. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib/string.c: remove strnicmp()Rasmus Villemoes2015-02-121-8/+0
|/ | | | | | | | | | | Now that all in-tree users of strnicmp have been converted to strncasecmp, the wrapper can be removed. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: David Howells <dhowells@redhat.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'random_for_linus' of ↵Linus Torvalds2014-10-241-0/+16
|\ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random Pull /dev/random updates from Ted Ts'o: "This adds a memzero_explicit() call which is guaranteed not to be optimized away by GCC. This is important when we are wiping cryptographically sensitive material" * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: crypto: memzero_explicit - make sure to clear out sensitive data random: add and use memzero_explicit() for clearing data
| * random: add and use memzero_explicit() for clearing dataDaniel Borkmann2014-10-171-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | zatimend has reported that in his environment (3.16/gcc4.8.3/corei7) memset() calls which clear out sensitive data in extract_{buf,entropy, entropy_user}() in random driver are being optimized away by gcc. Add a helper memzero_explicit() (similarly as explicit_bzero() variants) that can be used in such cases where a variable with sensitive data is being cleared out in the end. Other use cases might also be in crypto code. [ I have put this into lib/string.c though, as it's always built-in and doesn't need any dependencies then. ] Fixes kernel bugzilla: 82041 Reported-by: zatimend@hotmail.co.uk Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
* | lib: string: Make all calls to strnicmp into calls to strncasecmpRasmus Villemoes2014-10-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | The previous patch made strnicmp into a wrapper for strncasecmp. This patch makes all in-tree users of strnicmp call strncasecmp directly, while still making sure that the strnicmp symbol can be used by out-of-tree modules. It should be considered a temporary hack until all in-tree callers have been converted. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | lib/string.c: remove duplicated functionRasmus Villemoes2014-10-141-17/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | lib/string.c contains two functions, strnicmp and strncasecmp, which do roughly the same thing, namely compare two strings case-insensitively up to a given bound. They have slightly different implementations, but the only important difference is that strncasecmp doesn't handle len==0 appropriately; it effectively becomes strcasecmp in that case. strnicmp correctly says that two strings are always equal in their first 0 characters. strncasecmp is the POSIX name for this functionality. So rename the non-broken function to the standard name. To minimize the impact on the rest of the kernel (and since both are exported to modules), make strnicmp a wrapper for strncasecmp. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Grant Likely <grant.likely@linaro.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: "H. Peter Anvin" <hpa@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Make ARCH_HAS_FAST_MULTIPLIER a real config variableLinus Torvalds2014-09-131-2/+2
|/ | | | | | | | | | | | | | | | | | | | | It used to be an ad-hoc hack defined by the x86 version of <asm/bitops.h> that enabled a couple of library routines to know whether an integer multiply is faster than repeated shifts and additions. This just makes it use the real Kconfig system instead, and makes x86 (which was the only architecture that did this) select the option. NOTE! Even for x86, this really is kind of wrong. If we cared, we would probably not enable this for builds optimized for netburst (P4), where shifts-and-adds are generally faster than multiplies. This patch does *not* change that kind of logic, though, it is purely a syntactic change with no code changes. This was triggered by the fact that we have other places that really want to know "do I want to expand multiples by constants by hand or not", particularly the hash generation code. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/string.c: use the name "C-string" in commentsDan Carpenter2014-06-041-4/+4
| | | | | | | | | | | | | For strncpy() and friends the source string may or may not have an actual NUL character at the end. The documentation is confusing in this because it specifically mentions that you are passing a "NUL-terminated" string. Wikipedia says that "C-string" is an alternative name we can use instead. http://en.wikipedia.org/wiki/Null-terminated_string Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: add glibc style strchrnul() variantGrant Likely2014-05-231-0/+18
| | | | | | | | | | The strchrnul() variant helpfully returns a the end of the string instead of a NULL if the requested character is not found. This can simplify string parsing code since it doesn't need to expicitly check for a NULL return. If a valid string pointer is passed in, then a valid null terminated string will always come back out. Signed-off-by: Grant Likely <grant.likely@linaro.org>
* asmlinkage Make __stack_chk_failed and memcmp visibleAndi Kleen2014-02-131-1/+1
| | | | | | | | | | | | | | | In LTO symbols implicitely referenced by the compiler need to be visible. Earlier these symbols were visible implicitely from being exported, but we disabled implicit visibility fo EXPORTs when modules are disabled to improve code size. So now these symbols have to be marked visible explicitely. Do this for __stack_chk_fail (with stack protector) and memcmp. Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1391845930-28580-10-git-send-email-ak@linux.intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* Merge tag 'module-for-3.4' of ↵Linus Torvalds2012-03-241-1/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull cleanup of fs/ and lib/ users of module.h from Paul Gortmaker: "Fix up files in fs/ and lib/ dirs to only use module.h if they really need it. These are trivial in scope vs the work done previously. We now have things where any few remaining cleanups can be farmed out to arch or subsystem maintainers, and I have done so when possible. What is remaining here represents the bits that don't clearly lie within a single arch/subsystem boundary, like the fs dir and the lib dir. Some duplicate includes arising from overlapping fixes from independent subsystem maintainer submissions are also quashed." Fix up trivial conflicts due to clashes with other include file cleanups (including some due to the previous bug.h cleanup pull). * tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: lib: reduce the use of module.h wherever possible fs: reduce the use of module.h wherever possible includecheck: delete any duplicate instances of module.h
| * lib: reduce the use of module.h wherever possiblePaul Gortmaker2012-03-071-1/+4
| | | | | | | | | | | | | | | | | | | | For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | Merge tag 'bug-for-3.4' of ↵Linus Torvalds2012-03-241-0/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull <linux/bug.h> cleanup from Paul Gortmaker: "The changes shown here are to unify linux's BUG support under the one <linux/bug.h> file. Due to historical reasons, we have some BUG code in bug.h and some in kernel.h -- i.e. the support for BUILD_BUG in linux/kernel.h predates the addition of linux/bug.h, but old code in kernel.h wasn't moved to bug.h at that time. As a band-aid, kernel.h was including <asm/bug.h> to pseudo link them. This has caused confusion[1] and general yuck/WTF[2] reactions. Here is an example that violates the principle of least surprise: CC lib/string.o lib/string.c: In function 'strlcat': lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON' make[2]: *** [lib/string.o] Error 1 $ $ grep linux/bug.h lib/string.c #include <linux/bug.h> $ We've included <linux/bug.h> for the BUG infrastructure and yet we still get a compile fail! [We've not kernel.h for BUILD_BUG_ON.] Ugh - very confusing for someone who is new to kernel development. With the above in mind, the goals of this changeset are: 1) find and fix any include/*.h files that were relying on the implicit presence of BUG code. 2) find and fix any C files that were consuming kernel.h and hence relying on implicitly getting some/all BUG code. 3) Move the BUG related code living in kernel.h to <linux/bug.h> 4) remove the asm/bug.h from kernel.h to finally break the chain. During development, the order was more like 3-4, build-test, 1-2. But to ensure that git history for bisect doesn't get needless build failures introduced, the commits have been reorderd to fix the problem areas in advance. [1] https://lkml.org/lkml/2012/1/3/90 [2] https://lkml.org/lkml/2012/1/17/414" Fix up conflicts (new radeon file, reiserfs header cleanups) as per Paul and linux-next. * tag 'bug-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: kernel.h: doesn't explicitly use bug.h, so don't include it. bug: consolidate BUILD_BUG_ON with other bug code BUG: headers with BUG/BUG_ON etc. need linux/bug.h bug.h: add include of it to various implicit C users lib: fix implicit users of kernel.h for TAINT_WARN spinlock: macroize assert_spin_locked to avoid bug.h dependency x86: relocate get/set debugreg fcns to include/asm/debugreg.
| * | bug.h: add include of it to various implicit C usersPaul Gortmaker2012-02-291-0/+1
| |/ | | | | | | | | | | | | | | | | With bug.h currently living right in linux/kernel.h there are files that use BUG_ON and friends but are not including the header explicitly. Fix them up so we can remove the presence in kernel.h file. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* / string: memchr_inv() speed improvementsAkinobu Mita2012-03-231-4/+16
|/ | | | | | | | | | | | | | | | | | | | | | | - Generate a 64-bit pattern more efficiently memchr_inv needs to generate a 64-bit pattern filled with a target character. The operation can be done by more efficient way. - Don't call the slow check_bytes() if the memory area is 64-bit aligned memchr_inv compares contiguous 64-bit words with the 64-bit pattern as much as possible. The outside of the region is checked by check_bytes() that scans for each byte. Unfortunately, the first 64-bit word is unexpectedly scanned by check_bytes() even if the memory area is aligned to a 64-bit boundary. Both changes were originally suggested by Eric Dumazet. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/string.c: fix strim() semantics for strings that have only blanksMichael Holzheu2011-10-311-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 84c95c9acf0 ("string: on strstrip(), first remove leading spaces before running over str") improved the performance of the strim() function. Unfortunately this changed the semantics of strim() and broke my code. Before the patch it was possible to use strim() without using the return value for removing trailing spaces from strings that had either only blanks or only trailing blanks. Now this does not work any longer for strings that *only* have blanks. Before patch: " " -> "" (empty string) After patch: " " -> " " (no change) I think we should remove your patch to restore the old behavior. The description (lib/string.c): * Note that the first trailing whitespace is replaced with a %NUL-terminator => The first trailing whitespace of a string that only has whitespace characters is the first whitespace The patch restores the old strim() semantics. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: Andre Goddard Rosa <andre.goddard@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/string.c: introduce memchr_inv()Akinobu Mita2011-10-311-0/+54
| | | | | | | | | | | | | | | | | | memchr_inv() is mainly used to check whether the whole buffer is filled with just a specified byte. The function name and prototype are stolen from logfs and the implementation is from SLUB. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Christoph Lameter <cl@linux-foundation.org> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Matt Mackall <mpm@selenic.com> Acked-by: Joern Engel <joern@logfs.org> Cc: Marcin Slusarz <marcin.slusarz@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add a strtobool function matching semantics of existing in kernel equivalentsJonathan Cameron2011-05-191-0/+29
| | | | | | | | This is a rename of the usr_strtobool proposal, which was a renamed, relocated and fixed version of previous kstrtobool RFC Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* lib/string.c: simplify strnstr()André Goddard Rosa2010-03-061-3/+3
| | | | | | | | | Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Joe Perches <joe@perches.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/string.c: simplify stricmp()André Goddard Rosa2010-03-061-19/+15
| | | | | | | | | | | | | Removes 32 bytes on core2 with gcc 4.4.1: text data bss dec hex filename 3196 0 0 3196 c7c lib/string-BEFORE.o 3164 0 0 3164 c5c lib/string-AFTER.o Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: Introduce strnstr()Li Zefan2010-01-141-1/+26
| | | | | | | | | | It differs strstr() in that it limits the length to be searched in the first string. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4B4E8743.6030805@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* lib/string.c: fix kernel-doc warningsRandy Dunlap2009-12-221-3/+3
| | | | | | | | | | | Fix kernel-doc warnings (@arg name) in string.c::skip_spaces(). Warning(lib/string.c:347): No description found for parameter 'str' Warning(lib/string.c:347): Excess function parameter 's' description in 'skip_spaces' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Subject: Re: [PATCH] strstrip incorrectly marked __must_checkKOSAKI Motohiro2009-12-151-3/+3
| | | | | | | | | | | | | | | | | Recently, We marked strstrip() as must_check. because it was frequently misused and it should be checked. However, we found one exception. scsi/ipr.c intentionally ignore return value of strstrip. Because it wishes to keep the whitespace at the beginning. Thus we need to keep with and without checked whitespace trim function. This patch adds a new strim() and changes ipr.c to use it. [akpm@linux-foundation.org: coding-style fixes] Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* string: on strstrip(), first remove leading spaces before running over strAndré Goddard Rosa2009-12-151-2/+2
| | | | | | | | | ... so that strlen() iterates over a smaller string comprising of the remaining characters only. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* string: factorize skip_spaces and export it to be generally availableAndré Goddard Rosa2009-12-151-4/+15
| | | | | | | | | | | | | | | | | | | | On the following sentence: while (*s && isspace(*s)) s++; If *s == 0, isspace() evaluates to ((_ctype[*s] & 0x20) != 0), which evaluates to ((0x08 & 0x20) != 0) which equals to 0 as well. If *s == 1, we depend on isspace() result anyway. In other words, "a char equals zero is never a space", so remove this check. Also, *s != 0 is most common case (non-null string). Fixed const return as noticed by Jan Engelhardt and James Bottomley. Fixed unnecessary extra cast on strstrip() as noticed by Jan Engelhardt. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* strcmp: fix overflow and possibly signedness errorLinus Torvalds2009-11-181-6/+14
| | | | | | | | | | | | | | | | | | Doing the strcmp return value as signed char __res = *cs - *ct; is wrong for two reasons. The subtraction can overflow because __res doesn't use a type big enough. Moreover the compared bytes should be interpreted as unsigned char as specified by POSIX. The same problem is fixed in strncmp. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Michael Buesch <mb@bu3sch.de> Cc: Andreas Schwab <schwab@linux-m68k.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add a new sysfs_streq() string comparison functionDavid Brownell2008-05-011-0/+27
| | | | | | | | | | | | | | | | | | Add a new sysfs_streq() string comparison function, which ignores the trailing newlines found in sysfs inputs. By example: sysfs_streq("a", "b") ==> false sysfs_streq("a", "a") ==> true sysfs_streq("a", "a\n") ==> true sysfs_streq("a\n", "a") ==> true This is intended to simplify parsing of sysfs inputs, letting them avoid the need to manually strip off newlines from inputs. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [STRING]: Move strcasecmp/strncasecmp to lib/string.cDavid S. Miller2007-04-261-0/+28
| | | | | | | We have several platforms using local copies of identical code. Signed-off-by: David S. Miller <davem@davemloft.net>
* [PATCH] Numerous fixes to kernel-doc info in source files.Robert P. J. Day2007-02-111-5/+3
| | | | | | | | | | | | | | | A variety of (mostly) innocuous fixes to the embedded kernel-doc content in source files, including: * make multi-line initial descriptions single line * denote some function names, constants and structs as such * change erroneous opening '/*' to '/**' in a few places * reword some text for clarity Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] strstrip remove last blank fixMichael Holzheu2006-10-281-1/+1
| | | | | | | | | | | | | | | | | | | | strstrip() does not remove the last blank from strings which only consist of blanks. Example: char string[] = " "; strstrip(string); results in " ", but should produce an empty string! The following patch solves this problem: Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@de.ibm.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by Joern Engel <joern@wh.fh-wedel.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] strstrip() APIPekka Enberg2006-06-231-0/+30
| | | | | | | | | | | | | | Add a new strstrip() function to lib/string.c for removing leading and trailing whitespace from a string. Cc: Michael Holzheu <holzheu@de.ibm.com> Acked-by: Ingo Oeser <ioe-lkml@rameria.de> Acked-by: Joern Engel <joern@wohnheim.fh-wedel.de> Cc: Corey Minyard <minyard@acm.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Michael Holzheu <HOLZHEU@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Silence a const vs non-const warningJan-Benedict Glaw2006-04-111-1/+1
| | | | | | | | | | lib/string.c: In function 'memcpy': lib/string.c:470: warning: initialization discards qualifiers from pointer = target type Signed-off-by: Jan-Benedict Glaw <jbglaw@lug-owl.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Clean up arch-overrides in linux/string.hKyle McMartin2006-04-111-0/+2
| | | | | | | | | | | | | | Some string functions were safely overrideable in lib/string.c, but their corresponding declarations in linux/string.h were not. Correct this, and make strcspn overrideable. Odds of someone wanting to do optimized assembly of these are small, but for the sake of cleanliness, might as well bring them into line with the rest of the file. Signed-off-by: Kyle McMartin <kyle@parisc-linux.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] No arch-specific strpbrk implementationsKyle McMartin2006-04-111-0/+1
| | | | | | | | | | | | | | | While cleaning up parisc_ksyms.c earlier, I noticed that strpbrk wasn't being exported from lib/string.c. Investigating further, I noticed a changeset that removed its export and added it to _ksyms.c on a few more architectures. The justification was that "other arches do it." I think this is wrong, since no architecture currently defines __HAVE_ARCH_STRPBRK, there's no reason for any of them to be exporting it themselves. Therefore, consolidate the export to lib/string.c. Signed-off-by: Kyle McMartin <kyle@parisc-linux.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] multiple exports of strpbrkAndrew Morton2006-03-221-1/+0
| | | | | | | | | | | | | | | Sam's tree includes a new check, which found that we're exporting strpbrk() multiple times. It seems that the convention is that this is exported from the arch files, so reove the lib/string.c export. Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: David Howells <dhowells@redhat.com> Cc: Greg Ungerer <gerg@uclinux.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lib/string.c cleanup: restore useful memmove constPaul Jackson2005-10-301-1/+2
| | | | | | | | | | | | | | | A couple of (char *) casts removed in a previous cleanup patch in lib/string.c:memmove() were actually useful, as they suppressed a couple of warnings: assignment discards qualifiers from pointer target type Fix by declaring the local variable const in the first place, so casts aren't needed to strip the const qualifier. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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