summaryrefslogtreecommitdiff
path: root/include/asm-generic
diff options
context:
space:
mode:
authorPeter Zijlstra <peterz@infradead.org>2017-02-25 10:56:53 +0300
committerIngo Molnar <mingo@kernel.org>2017-03-30 10:37:20 +0300
commit19d436268dde95389c616bb3819da73f0a8b28a8 (patch)
treebd08a3466744511ad2d07edd5e9be4161cfb56e2 /include/asm-generic
parent70579a86e3c8eb2ce57999e594a73b4dfe095959 (diff)
downloadlinux-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/asm-generic')
-rw-r--r--include/asm-generic/bug.h18
-rw-r--r--include/asm-generic/vmlinux.lds.h5
2 files changed, 19 insertions, 4 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); \