From 9ae1e990f1ab522b98baefbfebf3cbac1a2cfac2 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 28 Oct 2020 09:11:23 +0100 Subject: perf tools: Remove broken __no_tail_call attribute MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Acked-by: Ard Biesheuvel Acked-by: Miguel Ojeda Cc: Alexei Starovoitov Cc: Arnd Bergmann Cc: Arvind Sankar Cc: Daniel Borkmann Cc: Geert Uytterhoeven Cc: Ian Rogers Cc: Josh Poimboeuf Cc: Kees Kook Cc: Martin Liška Cc: Nick Desaulniers Cc: Randy Dunlap Cc: Thomas Gleixner Link: http://lore.kernel.org/lkml/20201028081123.GT2628@hirez.programming.kicks-ass.net Signed-off-by: Arnaldo Carvalho de Melo --- tools/include/linux/compiler-gcc.h | 12 ------------ tools/include/linux/compiler.h | 3 --- 2 files changed, 15 deletions(-) (limited to 'tools/include/linux') diff --git a/tools/include/linux/compiler-gcc.h b/tools/include/linux/compiler-gcc.h index b9d4322e1e65..95c072b70d0e 100644 --- a/tools/include/linux/compiler-gcc.h +++ b/tools/include/linux/compiler-gcc.h @@ -27,18 +27,6 @@ #define __pure __attribute__((pure)) #endif #define noinline __attribute__((noinline)) -#ifdef __has_attribute -#if __has_attribute(disable_tail_calls) -#define __no_tail_call __attribute__((disable_tail_calls)) -#endif -#endif -#ifndef __no_tail_call -#if GCC_VERSION > 40201 -#define __no_tail_call __attribute__((optimize("no-optimize-sibling-calls"))) -#else -#define __no_tail_call -#endif -#endif #ifndef __packed #define __packed __attribute__((packed)) #endif diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index 2b3f7353e891..d22a974372c0 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -47,9 +47,6 @@ #ifndef noinline #define noinline #endif -#ifndef __no_tail_call -#define __no_tail_call -#endif /* Are two types/vars the same type (ignoring qualifiers)? */ #ifndef __same_type -- cgit From b3e453272d436aab8adbe810c6d7043670281487 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Thu, 26 Nov 2020 18:00:06 +0100 Subject: tools lib: Adopt memchr_inv() from kernel We'll use it to check for undefined/zero data. Signed-off-by: Jiri Olsa Suggested-by: Arnaldo Carvalho de Melo Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Budankov Cc: Andi Kleen Cc: Ian Rogers Cc: Mark Rutland Cc: Michael Petlan Cc: Peter Zijlstra Cc: Song Liu Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20201126170026.2619053-6-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/include/linux/string.h | 1 + tools/lib/string.c | 58 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+) (limited to 'tools/include/linux') diff --git a/tools/include/linux/string.h b/tools/include/linux/string.h index 5e9e781905ed..db5c99318c79 100644 --- a/tools/include/linux/string.h +++ b/tools/include/linux/string.h @@ -46,4 +46,5 @@ extern char * __must_check skip_spaces(const char *); extern char *strim(char *); +extern void *memchr_inv(const void *start, int c, size_t bytes); #endif /* _TOOLS_LINUX_STRING_H_ */ diff --git a/tools/lib/string.c b/tools/lib/string.c index f645343815de..8b6892f959ab 100644 --- a/tools/lib/string.c +++ b/tools/lib/string.c @@ -168,3 +168,61 @@ char *strreplace(char *s, char old, char new) *s = new; return s; } + +static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) +{ + while (bytes) { + if (*start != value) + return (void *)start; + start++; + bytes--; + } + return NULL; +} + +/** + * memchr_inv - Find an unmatching character in an area of memory. + * @start: The memory area + * @c: Find a character other than c + * @bytes: The size of the area. + * + * returns the address of the first character other than @c, or %NULL + * if the whole buffer contains just @c. + */ +void *memchr_inv(const void *start, int c, size_t bytes) +{ + u8 value = c; + u64 value64; + unsigned int words, prefix; + + if (bytes <= 16) + return check_bytes8(start, value, bytes); + + value64 = value; + value64 |= value64 << 8; + value64 |= value64 << 16; + value64 |= value64 << 32; + + prefix = (unsigned long)start % 8; + if (prefix) { + u8 *r; + + prefix = 8 - prefix; + r = check_bytes8(start, value, prefix); + if (r) + return r; + start += prefix; + bytes -= prefix; + } + + words = bytes / 8; + + while (words) { + if (*(u64 *)start != value64) + return check_bytes8(start, value, 8); + start += 8; + words--; + } + + return check_bytes8(start, value, bytes % 8); +} -- cgit From f289041ed4cf9a3f6e8a32068fef9ffb2acc5662 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Mon, 14 Dec 2020 19:13:45 -0800 Subject: mm, page_poison: remove CONFIG_PAGE_POISONING_ZERO CONFIG_PAGE_POISONING_ZERO uses the zero pattern instead of 0xAA. It was introduced by commit 1414c7f4f7d7 ("mm/page_poisoning.c: allow for zero poisoning"), noting that using zeroes retains the benefit of sanitizing content of freed pages, with the benefit of not having to zero them again on alloc, and the downside of making some forms of corruption (stray writes of NULLs) harder to detect than with the 0xAA pattern. Together with CONFIG_PAGE_POISONING_NO_SANITY it made possible to sanitize the contents on free without checking it back on alloc. These days we have the init_on_free() option to achieve sanitization with zeroes and to save clearing on alloc (and without checking on alloc). Arguably if someone does choose to check the poison for corruption on alloc, the savings of not clearing the page are secondary, and it makes sense to always use the 0xAA poison pattern. Thus, remove the CONFIG_PAGE_POISONING_ZERO option for being redundant. Link: https://lkml.kernel.org/r/20201113104033.22907-6-vbabka@suse.cz Signed-off-by: Vlastimil Babka Acked-by: David Hildenbrand Cc: Mike Rapoport Cc: Rafael J. Wysocki Cc: Alexander Potapenko Cc: Kees Cook Cc: Laura Abbott Cc: Mateusz Nosek Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/poison.h | 4 ---- mm/Kconfig.debug | 12 ------------ mm/page_alloc.c | 8 +------- tools/include/linux/poison.h | 6 +----- 4 files changed, 2 insertions(+), 28 deletions(-) (limited to 'tools/include/linux') diff --git a/include/linux/poison.h b/include/linux/poison.h index dc8ae5d8db03..aff1c9250c82 100644 --- a/include/linux/poison.h +++ b/include/linux/poison.h @@ -27,11 +27,7 @@ #define TIMER_ENTRY_STATIC ((void *) 0x300 + POISON_POINTER_DELTA) /********** mm/page_poison.c **********/ -#ifdef CONFIG_PAGE_POISONING_ZERO -#define PAGE_POISON 0x00 -#else #define PAGE_POISON 0xaa -#endif /********** mm/page_alloc.c ************/ diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 14e29fe5bfa6..1e73717802f8 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -80,18 +80,6 @@ config PAGE_POISONING If unsure, say N -config PAGE_POISONING_ZERO - bool "Use zero for poisoning instead of debugging value" - depends on PAGE_POISONING - help - Instead of using the existing poison value, fill the pages with - zeros. This makes it harder to detect when errors are occurring - due to sanitization but the zeroing at free means that it is - no longer necessary to write zeros when GFP_ZERO is used on - allocation. - - If unsure, say N - config DEBUG_PAGE_REF bool "Enable tracepoint to track down page reference manipulation" depends on DEBUG_KERNEL diff --git a/mm/page_alloc.c b/mm/page_alloc.c index efcd1baa35e4..918647ff6eef 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2228,12 +2228,6 @@ static inline int check_new_page(struct page *page) return 1; } -static inline bool free_pages_prezeroed(void) -{ - return (IS_ENABLED(CONFIG_PAGE_POISONING_ZERO) && - page_poisoning_enabled_static()) || want_init_on_free(); -} - #ifdef CONFIG_DEBUG_VM /* * With DEBUG_VM enabled, order-0 pages are checked for expected state when @@ -2296,7 +2290,7 @@ inline void post_alloc_hook(struct page *page, unsigned int order, kernel_unpoison_pages(page, 1 << order); set_page_owner(page, order, gfp_flags); - if (!free_pages_prezeroed() && want_init_on_alloc(gfp_flags)) + if (!want_init_on_free() && want_init_on_alloc(gfp_flags)) kernel_init_free_pages(page, 1 << order); } diff --git a/tools/include/linux/poison.h b/tools/include/linux/poison.h index d29725769107..2e6338ac5eed 100644 --- a/tools/include/linux/poison.h +++ b/tools/include/linux/poison.h @@ -35,12 +35,8 @@ */ #define TIMER_ENTRY_STATIC ((void *) 0x300 + POISON_POINTER_DELTA) -/********** mm/debug-pagealloc.c **********/ -#ifdef CONFIG_PAGE_POISONING_ZERO -#define PAGE_POISON 0x00 -#else +/********** mm/page_poison.c **********/ #define PAGE_POISON 0xaa -#endif /********** mm/page_alloc.c ************/ -- cgit From 4262f8c3efa1e79bd5950437a3eea58eeb4c1c70 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 14 Dec 2020 09:59:00 -0300 Subject: tools headers: Syncronize linux/build_bug.h with the kernel sources To pick up the changes in: 14dc3983b5dff513 ("kbuild: avoid static_assert for genksyms") And silence this perf build warning: Warning: Kernel ABI header at 'tools/include/linux/build_bug.h' differs from latest version at 'include/linux/build_bug.h' diff -u tools/include/linux/build_bug.h include/linux/build_bug.h Cc: Adrian Hunter Cc: Arnd Bergmann Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo --- tools/include/linux/build_bug.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'tools/include/linux') diff --git a/tools/include/linux/build_bug.h b/tools/include/linux/build_bug.h index cc7070c7439b..ce365d212768 100644 --- a/tools/include/linux/build_bug.h +++ b/tools/include/linux/build_bug.h @@ -79,4 +79,9 @@ #define __static_assert(expr, msg, ...) _Static_assert(expr, msg) #endif // static_assert +#ifdef __GENKSYMS__ +/* genksyms gets confused by _Static_assert */ +#define _Static_assert(expr, ...) +#endif + #endif /* _LINUX_BUILD_BUG_H */ -- cgit From 4bba4c4bb09ad4a2b70836725e08439c86d8f9e4 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 18 Dec 2020 09:59:05 -0300 Subject: tools headers: Get tools's linux/compiler.h closer to the kernel's We're cherry picking stuff from the kernel to allow for the other headers that we keep in sync via tools/perf/check-headers.sh to work, so introduce linux/compiler_types.h and from there get the compiler specific stuff. Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo --- tools/include/linux/compiler.h | 4 +--- tools/include/linux/compiler_types.h | 10 ++++++++++ 2 files changed, 11 insertions(+), 3 deletions(-) create mode 100644 tools/include/linux/compiler_types.h (limited to 'tools/include/linux') diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h index d22a974372c0..ff872dc2637c 100644 --- a/tools/include/linux/compiler.h +++ b/tools/include/linux/compiler.h @@ -2,9 +2,7 @@ #ifndef _TOOLS_LINUX_COMPILER_H_ #define _TOOLS_LINUX_COMPILER_H_ -#ifdef __GNUC__ -#include -#endif +#include #ifndef __compiletime_error # define __compiletime_error(message) diff --git a/tools/include/linux/compiler_types.h b/tools/include/linux/compiler_types.h new file mode 100644 index 000000000000..31fc2caa758a --- /dev/null +++ b/tools/include/linux/compiler_types.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_COMPILER_TYPES_H +#define __LINUX_COMPILER_TYPES_H + +/* Compiler specific macros. */ +#ifdef __GNUC__ +#include +#endif + +#endif /* __LINUX_COMPILER_TYPES_H */ -- cgit From ffb9beb13e8daf3fcb6bab470d07962b05d619b7 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 18 Dec 2020 10:16:08 -0300 Subject: tools headers: Add conditional __has_builtin() As it'll be used by the ctype.h sync with its kernel source original. Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo --- tools/include/linux/compiler_types.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'tools/include/linux') diff --git a/tools/include/linux/compiler_types.h b/tools/include/linux/compiler_types.h index 31fc2caa758a..feea09029f61 100644 --- a/tools/include/linux/compiler_types.h +++ b/tools/include/linux/compiler_types.h @@ -2,6 +2,17 @@ #ifndef __LINUX_COMPILER_TYPES_H #define __LINUX_COMPILER_TYPES_H +/* Builtins */ + +/* + * __has_builtin is supported on gcc >= 10, clang >= 3 and icc >= 21. + * In the meantime, to support gcc < 10, we implement __has_builtin + * by hand. + */ +#ifndef __has_builtin +#define __has_builtin(x) (0) +#endif + /* Compiler specific macros. */ #ifdef __GNUC__ #include -- cgit From 23cd9543a52b96ac75d666eee3576b47f1901248 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 17 Dec 2020 14:41:21 -0300 Subject: tools headers: Update linux/ctype.h with the kernel sources To pick up the changes in: caabdd0f59a9771e ("ctype.h: remove duplicate isdigit() helper") Addressing this perf build warning: Warning: Kernel ABI header at 'tools/include/linux/ctype.h' differs from latest version at 'include/linux/ctype.h' diff -u tools/include/linux/ctype.h include/linux/ctype.h And we need to continue using the combination of: inline __isdigit() #define isdigit() __isdigit When the __has_builtin() thing isn't available, as it is a builtin in older systems with it as a builtin but with compilers not hacinv __has_builtin(), rendering the __has_builtin() check useless otherwise. Cc: Adrian Hunter Cc: Arnd Bergmann Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo --- tools/include/linux/ctype.h | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'tools/include/linux') diff --git a/tools/include/linux/ctype.h b/tools/include/linux/ctype.h index 310090b4c474..29ed3fe94404 100644 --- a/tools/include/linux/ctype.h +++ b/tools/include/linux/ctype.h @@ -2,6 +2,8 @@ #ifndef _LINUX_CTYPE_H #define _LINUX_CTYPE_H +#include + /* * NOTE! This ctype does not handle EOF like the standard C * library is required to. @@ -23,11 +25,6 @@ extern const unsigned char _ctype[]; #define isalnum(c) ((__ismask(c)&(_U|_L|_D)) != 0) #define isalpha(c) ((__ismask(c)&(_U|_L)) != 0) #define iscntrl(c) ((__ismask(c)&(_C)) != 0) -static inline int __isdigit(int c) -{ - return '0' <= c && c <= '9'; -} -#define isdigit(c) __isdigit(c) #define isgraph(c) ((__ismask(c)&(_P|_U|_L|_D)) != 0) #define islower(c) ((__ismask(c)&(_L)) != 0) #define isprint(c) ((__ismask(c)&(_P|_U|_L|_D|_SP)) != 0) @@ -40,6 +37,16 @@ static inline int __isdigit(int c) #define isascii(c) (((unsigned char)(c))<=0x7f) #define toascii(c) (((unsigned char)(c))&0x7f) +#if __has_builtin(__builtin_isdigit) +#define isdigit(c) __builtin_isdigit(c) +#else +static inline int __isdigit(int c) +{ + return '0' <= c && c <= '9'; +} +#define isdigit(c) __isdigit(c) +#endif + static inline unsigned char __tolower(unsigned char c) { if (isupper(c)) -- cgit