kernel/linux.git/include/linux/compiler.h, branch v3.18.15

kernel: Change ASSIGN_ONCE(val, x) to WRITE_ONCE(x, val)

2015-04-27T20:48:19+00:00

[ Upstream commit 43239cbe79fc369f5d2160bd7f69e28b5c50a58c ] Feedback has shown that WRITE_ONCE(x, val) is easier to use than ASSIGN_ONCE(val,x). There are no in-tree users yet, so lets change it for 3.19. Signed-off-by: Christian Borntraeger Acked-by: Peter Zijlstra Acked-by: Davidlohr Bueso Acked-by: Paul E. McKenney Signed-off-by: Sasha Levin

kernel: Provide READ_ONCE and ASSIGN_ONCE

2015-04-27T03:02:56+00:00

[ Upstream commit 230fa253df6352af12ad0a16128760b5cb3f92df ] ACCESS_ONCE does not work reliably on non-scalar types. For example gcc 4.6 and 4.7 might remove the volatile tag for such accesses during the SRA (scalar replacement of aggregates) step https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145) Let's provide READ_ONCE/ASSIGN_ONCE that will do all accesses via scalar types as suggested by Linus Torvalds. Accesses larger than the machines word size cannot be guaranteed to be atomic. These macros will use memcpy and emit a build warning. Signed-off-by: Christian Borntraeger Signed-off-by: Sasha Levin

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-06-13T02:18:49+00:00

Pull more perf updates from Ingo Molnar: "A second round of perf updates: - wide reaching kprobes sanitization and robustization, with the hope of fixing all 'probe this function crashes the kernel' bugs, by Masami Hiramatsu. - uprobes updates from Oleg Nesterov: tmpfs support, corner case fixes and robustization work. - perf tooling updates and fixes from Jiri Olsa, Namhyung Ki, Arnaldo et al: * Add support to accumulate hist periods (Namhyung Kim) * various fixes, refactorings and enhancements" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits) perf: Differentiate exec() and non-exec() comm events perf: Fix perf_event_comm() vs. exec() assumption uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates perf/documentation: Add description for conditional branch filter perf/x86: Add conditional branch filtering support perf/tool: Add conditional branch filter 'cond' to perf record perf: Add new conditional branch filter 'PERF_SAMPLE_BRANCH_COND' uprobes: Teach copy_insn() to support tmpfs uprobes: Shift ->readpage check from __copy_insn() to uprobe_register() perf/x86: Use common PMU interrupt disabled code perf/ARM: Use common PMU interrupt disabled code perf: Disable sampled events if no PMU interrupt perf: Fix use after free in perf_remove_from_context() perf tools: Fix 'make help' message error perf record: Fix poll return value propagation perf tools: Move elide bool into perf_hpp_fmt struct perf tools: Remove elide setup for SORT_MODE__MEMORY mode perf tools: Fix "==" into "=" in ui_browser__warning assignment perf tools: Allow overriding sysfs and proc finding with env var perf tools: Consider header files outside perf directory in tags target ...

compiler.h: avoid sparse errors in __compiletime_error_fallback()

2014-06-04T23:54:14+00:00

Usually, BUG_ON and friends aren't even evaluated in sparse, but recently compiletime_assert_atomic_type() was added, and that now results in a sparse warning every time it is used. The reason turns out to be the temporary variable, after it sparse no longer considers the value to be a constant, and results in a warning and an error. The error is the more annoying part of this as it suppresses any further warnings in the same file, hiding other problems. Unfortunately the condition cannot be simply expanded out to avoid the temporary variable since it breaks compiletime_assert on old versions of GCC such as GCC 4.2.4 which the latest metag compiler is based on. Therefore #ifndef __CHECKER__ out the __compiletime_error_fallback which uses the potentially negative size array to trigger a conditional compiler error, so that sparse doesn't see it. Signed-off-by: James Hogan Cc: Johannes Berg Cc: Daniel Santos Cc: Luciano Coelho Cc: Peter Zijlstra Cc: Paul E. McKenney Acked-by: Johannes Berg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kprobes: Introduce NOKPROBE_SYMBOL() macro to maintain kprobes blacklist

2014-04-24T08:02:56+00:00

Introduce NOKPROBE_SYMBOL() macro which builds a kprobes blacklist at kernel build time. The usage of this macro is similar to EXPORT_SYMBOL(), placed after the function definition: NOKPROBE_SYMBOL(function); Since this macro will inhibit inlining of static/inline functions, this patch also introduces a nokprobe_inline macro for static/inline functions. In this case, we must use NOKPROBE_SYMBOL() for the inline function caller. When CONFIG_KPROBES=y, the macro stores the given function address in the "_kprobe_blacklist" section. Since the data structures are not fully initialized by the macro (because there is no "size" information), those are re-initialized at boot time by using kallsyms. Signed-off-by: Masami Hiramatsu Link: http://lkml.kernel.org/r/20140417081705.26341.96719.stgit@ltc230.yrl.intra.hitachi.co.jp Cc: Alok Kataria Cc: Ananth N Mavinakayanahalli Cc: Andrew Morton Cc: Anil S Keshavamurthy Cc: Arnd Bergmann Cc: Christopher Li Cc: Chris Wright Cc: David S. Miller Cc: Jan-Simon Möller Cc: Jeremy Fitzhardinge Cc: Linus Torvalds Cc: Randy Dunlap Cc: Rusty Russell Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-sparse@vger.kernel.org Cc: virtualization@lists.linux-foundation.org Signed-off-by: Ingo Molnar

LLVMLinux: Add support for clang to compiler.h and new compiler-clang.h

2014-04-09T20:44:35+00:00

Add a compiler-clang.h file to add specific macros needed for compiling the kernel with clang. Initially the only override required is the macro for silencing the compiler for a purposefully uninintialized variable. Author: Mark Charlebois Signed-off-by: Mark Charlebois Signed-off-by: Behan Webster

Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

2014-01-24T02:11:00+00:00

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 ...

arch: Introduce smp_load_acquire(), smp_store_release()

2014-01-12T09:37:17+00:00

A number of situations currently require the heavyweight smp_mb(), even though there is no need to order prior stores against later loads. Many architectures have much cheaper ways to handle these situations, but the Linux kernel currently has no portable way to make use of them. This commit therefore supplies smp_load_acquire() and smp_store_release() to remedy this situation. The new smp_load_acquire() primitive orders the specified load against any subsequent reads or writes, while the new smp_store_release() primitive orders the specifed store against any prior reads or writes. These primitives allow array-based circular FIFOs to be implemented without an smp_mb(), and also allow a theoretical hole in rcu_assign_pointer() to be closed at no additional expense on most architectures. In addition, the RCU experience transitioning from explicit smp_read_barrier_depends() and smp_wmb() to rcu_dereference() and rcu_assign_pointer(), respectively resulted in substantial improvements in readability. It therefore seems likely that replacing other explicit barriers with smp_load_acquire() and smp_store_release() will provide similar benefits. It appears that roughly half of the explicit barriers in core kernel code might be so replaced. [Changelog by PaulMck] Reviewed-by: "Paul E. McKenney" Signed-off-by: Peter Zijlstra Acked-by: Will Deacon Cc: Benjamin Herrenschmidt Cc: Frederic Weisbecker Cc: Mathieu Desnoyers Cc: Michael Ellerman Cc: Michael Neuling Cc: Russell King Cc: Geert Uytterhoeven Cc: Heiko Carstens Cc: Linus Torvalds Cc: Martin Schwidefsky Cc: Victor Kaplansky Cc: Tony Luck Cc: Oleg Nesterov Link: http://lkml.kernel.org/r/20131213150640.908486364@infradead.org Signed-off-by: Ingo Molnar

crypto: more robust crypto_memneq

2013-12-05T13:28:41+00:00

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 Acked-by: Daniel Borkmann Signed-off-by: Herbert Xu

kprobes: Move __kprobes definition into compiler.h

2013-04-08T15:28:34+00:00

Currently, __kprobes is defined in linux/kprobes.h which is too big to be included in small or basic headers that want to make use of this simple attribute. So move __kprobes definition into linux/compiler.h in which other compiler attributes are defined. Signed-off-by: Masami Hiramatsu Cc: Timo Juhani Lindfors Cc: Ananth N Mavinakayanahalli Cc: Pavel Emelyanov Cc: Jiri Kosina Cc: Nadia Yvette Chambers Cc: yrl.pp-manager.tt@hitachi.com Cc: David S. Miller Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20130404104049.21071.20908.stgit@mhiramat-M0-7522 [ Improved the attribute explanation a bit. ] Signed-off-by: Ingo Molnar