summaryrefslogtreecommitdiff
path: root/include/linux/compiler-intel.h
AgeCommit message (Collapse)AuthorFilesLines
2015-06-26compiler-intel: fix wrong compiler barrier() macroDaniel Borkmann1-0/+2
Cleanup commit 73679e508201 ("compiler-intel.h: Remove duplicate definition") removed the double definition of __memory_barrier() intrinsics. However, in doing so, it also removed the preceding #undef barrier by accident, meaning, the actual barrier() macro from compiler-gcc.h with inline asm is still in place as __GNUC__ is provided. Subsequently, barrier() can never be defined as __memory_barrier() from compiler.h since it already has a definition in place and if we trust the comment in compiler-intel.h, ecc doesn't support gcc specific asm statements. I don't have an ecc at hand (unsure if that's still used in the field?) and only found this by accident during code review, a revert of that cleanup would be simplest option. Fixes: 73679e508201 ("compiler-intel.h: Remove duplicate definition") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com> Cc: Pranith Kumar <bobby.prani@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: mancha security <mancha1@zoho.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-04lib: make memzero_explicit more robust against dead store eliminationDaniel Borkmann1-0/+3
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>
2014-04-15compiler-intel.h: Remove duplicate definitionPranith Kumar1-3/+0
barrier is already defined as __memory_barrier in compiler.h Remove this unnecessary redefinition. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> Link: http://lkml.kernel.org/r/CAJhHMCAnYPy0%2BqD-1KBnJPLt3XgAjdR12j%2BySSnPgmZcpbE7HQ@mail.gmail.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-01-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds1-0/+7
Pull crypto update from Herbert Xu: "Here is the crypto update for 3.14: - Improved crypto_memneq helper - Use cyprto_memneq in arch-specific crypto code - Replaced orphaned DCP driver with Freescale MXS DCP driver - Added AVX/AVX2 version of AESNI-GCM encode and decode - Added AMD Cryptographic Coprocessor (CCP) driver - Misc fixes" * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (41 commits) crypto: aesni - fix build on x86 (32bit) crypto: mxs - Fix sparse non static symbol warning crypto: ccp - CCP device enabled/disabled changes crypto: ccp - Cleanup hash invocation calls crypto: ccp - Change data length declarations to u64 crypto: ccp - Check for caller result area before using it crypto: ccp - Cleanup scatterlist usage crypto: ccp - Apply appropriate gfp_t type to memory allocations crypto: drivers - Sort drivers/crypto/Makefile ARM: mxs: dts: Enable DCP for MXS crypto: mxs - Add Freescale MXS DCP driver crypto: mxs - Remove the old DCP driver crypto: ahash - Fully restore ahash request before completing crypto: aesni - fix build on x86 (32bit) crypto: talitos - Remove redundant dev_set_drvdata crypto: ccp - Remove redundant dev_set_drvdata crypto: crypto4xx - Remove redundant dev_set_drvdata crypto: caam - simplify and harden key parsing crypto: omap-sham - Fix Polling mode for larger blocks crypto: tcrypt - Added speed tests for AEAD crypto alogrithms in tcrypt test suite ...
2013-12-11x86, build, icc: Remove uninitialized_var() from compiler-intel.hH. Peter Anvin1-2/+0
When compiling with icc, <linux/compiler-gcc.h> ends up included because the icc environment defines __GNUC__. Thus, we neither need nor want to have this macro defined in both compiler-gcc.h and compiler-intel.h, and the fact that they are inconsistent just makes the compiler spew warnings. Reported-by: Sunil K. Pandey <sunil.k.pandey@intel.com> Cc: Kevin B. Smith <kevin.b.smith@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/n/tip-0mbwou1zt7pafij09b897lg3@git.kernel.org Cc: <stable@vger.kernel.org>
2013-12-05crypto: more robust crypto_memneqCesar Eduardo Barros1-0/+7
Disabling compiler optimizations can be fragile, since a new optimization could be added to -O0 or -Os that breaks the assumptions the code is making. Instead of disabling compiler optimizations, use a dummy inline assembly (based on RELOC_HIDE) to block the problematic kinds of optimization, while still allowing other optimizations to be applied to the code. The dummy inline assembly is added after every OR, and has the accumulator variable as its input and output. The compiler is forced to assume that the dummy inline assembly could both depend on the accumulator variable and change the accumulator variable, so it is forced to compute the value correctly before the inline assembly, and cannot assume anything about its value after the inline assembly. This change should be enough to make crypto_memneq work correctly (with data-independent timing) even if it is inlined at its call sites. That can be done later in a followup patch. Compile-tested on x86_64. Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.eti.br> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2012-12-06byteorder: allow arch to opt to use GCC intrinsics for byteswappingDavid Woodhouse1-0/+7
Since GCC 4.4, there have been __builtin_bswap32() and __builtin_bswap16() intrinsics. A __builtin_bswap16() came a little later (4.6 for PowerPC, 48 for other platforms). By using these instead of the inline assembler that most architectures have in their __arch_swabXX() macros, we let the compiler see what's actually happening. The resulting code should be at least as good, and much *better* in the cases where it can be combined with a nearby load or store, using a load-and-byteswap or store-and-byteswap instruction (e.g. lwbrx/stwbrx on PowerPC, movbe on Atom). When GCC is sufficiently recent *and* the architecture opts in to using the intrinsics by setting CONFIG_ARCH_USE_BUILTIN_BSWAP, they will be used in preference to the __arch_swabXX() macros. An architecture which does not set ARCH_USE_BUILTIN_BSWAP will continue to use its own hand-crafted macros. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Acked-by: H. Peter Anvin <hpa@linux.intel.com>
2007-10-17Force erroneous inclusions of compiler-*.h files to be errorsRobert P. J. Day1-1/+3
Replace worthless comments with actual preprocessor errors when including the wrong versions of the compiler.h files. [akpm@linux-foundation.org: make it work] Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07ARRAY_SIZE: check for typeRusty Russell1-0/+3
We can use a gcc extension to ensure that ARRAY_SIZE() is handed an array, not a pointer. This is especially important when code is changed from a fixed array to a pointer. I assume the Intel compiler doesn't support __builtin_types_compatible_p. [jdike@addtoit.com: uml: update UML definition of ARRAY_SIZE] Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07Add unitialized_var() macro for suppressing gcc warningsBorislav Petkov1-0/+2
Introduce a macro for suppressing gcc from generating a warning about a probable uninitialized state of a variable. Example: - spinlock_t *ptl; + spinlock_t *uninitialized_var(ptl); Not a happy solution, but those warnings are obnoxious. - Using the usual pointlessly-set-it-to-zero approach wastes several bytes of text. - Using a macro means we can (hopefully) do something else if gcc changes cause the `x = x' hack to stop working - Using a macro means that people who are worried about hiding true bugs can easily turn it off. Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2005-04-17Linux-2.6.12-rc2Linus Torvalds1-0/+24
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!