diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2017-02-25 10:56:53 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-03-30 10:37:20 +0300 |
| commit | 19d436268dde95389c616bb3819da73f0a8b28a8 (patch) | |
| tree | bd08a3466744511ad2d07edd5e9be4161cfb56e2 /include | |
| parent | 70579a86e3c8eb2ce57999e594a73b4dfe095959 (diff) | |
| download | linux-19d436268dde95389c616bb3819da73f0a8b28a8.tar.xz | |
debug: Add _ONCE() logic to report_bug()
Josh suggested moving the _ONCE logic inside the trap handler, using a
bit in the bug_entry::flags field, avoiding the need for the extra
variable.
Sadly this only works for WARN_ON_ONCE(), since the others have
printk() statements prior to triggering the trap.
Still, this saves a fair amount of text and some data:
text data filename
10682460 4530992 defconfig-build/vmlinux.orig
10665111 4530096 defconfig-build/vmlinux.patched
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-generic/bug.h | 18 | ||||
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 5 | ||||
| -rw-r--r-- | include/linux/bug.h | 2 |
3 files changed, 20 insertions, 5 deletions
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index 6f96247226a4..5fe9f39cec44 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -5,6 +5,8 @@ #ifdef CONFIG_GENERIC_BUG #define BUGFLAG_WARNING (1 << 0) +#define BUGFLAG_ONCE (1 << 1) +#define BUGFLAG_DONE (1 << 2) #define BUGFLAG_TAINT(taint) (BUGFLAG_WARNING | ((taint) << 8)) #define BUG_GET_TAINT(bug) ((bug)->flags >> 8) #endif @@ -55,6 +57,18 @@ struct bug_entry { #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) #endif +#ifdef __WARN_FLAGS +#define __WARN_TAINT(taint) __WARN_FLAGS(BUGFLAG_TAINT(taint)) +#define __WARN_ONCE_TAINT(taint) __WARN_FLAGS(BUGFLAG_ONCE|BUGFLAG_TAINT(taint)) + +#define WARN_ON_ONCE(condition) ({ \ + int __ret_warn_on = !!(condition); \ + if (unlikely(__ret_warn_on)) \ + __WARN_ONCE_TAINT(TAINT_WARN); \ + unlikely(__ret_warn_on); \ +}) +#endif + /* * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report * significant issues that need prompt attention if they should ever @@ -97,7 +111,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint, #endif #ifndef WARN -#define WARN(condition, format...) ({ \ +#define WARN(condition, format...) ({ \ int __ret_warn_on = !!(condition); \ if (unlikely(__ret_warn_on)) \ __WARN_printf(format); \ @@ -112,6 +126,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint, unlikely(__ret_warn_on); \ }) +#ifndef WARN_ON_ONCE #define WARN_ON_ONCE(condition) ({ \ static bool __section(.data.unlikely) __warned; \ int __ret_warn_once = !!(condition); \ @@ -122,6 +137,7 @@ void __warn(const char *file, int line, void *caller, unsigned taint, } \ unlikely(__ret_warn_once); \ }) +#endif #define WARN_ONCE(condition, format...) ({ \ static bool __section(.data.unlikely) __warned; \ diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 0968d13b3885..51c8dbe8e8d9 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -286,8 +286,6 @@ *(.rodata1) \ } \ \ - BUG_TABLE \ - \ /* PCI quirks */ \ .pci_fixup : AT(ADDR(.pci_fixup) - LOAD_OFFSET) { \ VMLINUX_SYMBOL(__start_pci_fixups_early) = .; \ @@ -855,7 +853,8 @@ READ_MOSTLY_DATA(cacheline) \ DATA_DATA \ CONSTRUCTORS \ - } + } \ + BUG_TABLE #define INIT_TEXT_SECTION(inittext_align) \ . = ALIGN(inittext_align); \ diff --git a/include/linux/bug.h b/include/linux/bug.h index 5828489309bb..687b557fc5eb 100644 --- a/include/linux/bug.h +++ b/include/linux/bug.h @@ -105,7 +105,7 @@ static inline int is_warning_bug(const struct bug_entry *bug) return bug->flags & BUGFLAG_WARNING; } -const struct bug_entry *find_bug(unsigned long bugaddr); +struct bug_entry *find_bug(unsigned long bugaddr); enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs); |