linux_dsm_epyc7002/tools/include/linux/compiler-gcc.h
Peter Zijlstra 9ae1e990f1 perf tools: Remove broken __no_tail_call attribute
The GCC specific __attribute__((optimize)) attribute does not what is
commonly expected and is explicitly recommended against using in
production code by the GCC people.

Unlike what is often expected, it doesn't add to the optimization flags,
but it fully replaces them, loosing any and all optimization flags
provided by the compiler commandline.

The only guaranteed upon means of inhibiting tail-calls is by placing a
volatile asm with side-effects after the call such that the tail-call simply
cannot be done.

Given the original commit wasn't specific on which calls were the problem, this
removal might re-introduce the problem, which can then be re-analyzed and cured
properly.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Kook <keescook@chromium.org>
Cc: Martin Liška <mliska@suse.cz>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20201028081123.GT2628@hirez.programming.kicks-ass.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-11-03 08:32:15 -03:00

45 lines
1.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _TOOLS_LINUX_COMPILER_H_
#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
#endif
/*
* Common definitions for all gcc versions go here.
*/
#ifndef GCC_VERSION
#define GCC_VERSION (__GNUC__ * 10000 \
+ __GNUC_MINOR__ * 100 \
+ __GNUC_PATCHLEVEL__)
#endif
#if GCC_VERSION >= 70000 && !defined(__CHECKER__)
# define __fallthrough __attribute__ ((fallthrough))
#endif
#if GCC_VERSION >= 40300
# define __compiletime_error(message) __attribute__((error(message)))
#endif /* GCC_VERSION >= 40300 */
/* &a[0] degrades to a pointer: a different type from an array */
#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
#ifndef __pure
#define __pure __attribute__((pure))
#endif
#define noinline __attribute__((noinline))
#ifndef __packed
#define __packed __attribute__((packed))
#endif
#ifndef __noreturn
#define __noreturn __attribute__((noreturn))
#endif
#ifndef __aligned
#define __aligned(x) __attribute__((aligned(x)))
#endif
#define __printf(a, b) __attribute__((format(printf, a, b)))
#define __scanf(a, b) __attribute__((format(scanf, a, b)))
#if GCC_VERSION >= 50100
#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
#endif