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Ingo Molnar
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Revert "x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs"
This reverts commit f81f8ad. See this commit for details about the revert: e769742 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"") Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Borislav Petkov <bp@alien8.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Juergen Gross <jgross@suse.com> Cc: Richard Biener <rguenther@suse.de> Cc: Kees Cook <keescook@chromium.org> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Nadav Amit <namit@vmware.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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‎arch/x86/include/asm/bug.h

Lines changed: 42 additions & 56 deletions
Original file line numberDiff line numberDiff line change
@@ -4,8 +4,6 @@
44

55
#include <linux/stringify.h>
66

7-
#ifndef __ASSEMBLY__
8-
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/*
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* Despite that some emulators terminate on UD2, we use it for WARN().
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*
@@ -22,15 +20,53 @@
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2321
#define LEN_UD2 2
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23+
#ifdef CONFIG_GENERIC_BUG
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#ifdef CONFIG_X86_32
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# define __BUG_REL(val) ".long " __stringify(val)
27+
#else
28+
# define __BUG_REL(val) ".long " __stringify(val) " - 2b"
29+
#endif
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#ifdef CONFIG_DEBUG_BUGVERBOSE
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#define _BUG_FLAGS(ins, flags) \
34+
do { \
35+
asm volatile("1:\t" ins "\n" \
36+
".pushsection __bug_table,\"aw\"\n" \
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"2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \
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"\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \
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"\t.word %c1" "\t# bug_entry::line\n" \
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"\t.word %c2" "\t# bug_entry::flags\n" \
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"\t.org 2b+%c3\n" \
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".popsection" \
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: : "i" (__FILE__), "i" (__LINE__), \
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"i" (flags), \
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"i" (sizeof(struct bug_entry))); \
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} while (0)
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#else /* !CONFIG_DEBUG_BUGVERBOSE */
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2550
#define _BUG_FLAGS(ins, flags) \
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do { \
27-
asm volatile("ASM_BUG ins=\"" ins "\" file=%c0 line=%c1 " \
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"flags=%c2 size=%c3" \
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: : "i" (__FILE__), "i" (__LINE__), \
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"i" (flags), \
52+
asm volatile("1:\t" ins "\n" \
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".pushsection __bug_table,\"aw\"\n" \
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"2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \
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"\t.word %c0" "\t# bug_entry::flags\n" \
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"\t.org 2b+%c1\n" \
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".popsection" \
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: : "i" (flags), \
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"i" (sizeof(struct bug_entry))); \
3260
} while (0)
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#endif /* CONFIG_DEBUG_BUGVERBOSE */
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#else
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#define _BUG_FLAGS(ins, flags) asm volatile(ins)
67+
68+
#endif /* CONFIG_GENERIC_BUG */
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#define HAVE_ARCH_BUG
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#define BUG() \
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do { \
@@ -46,54 +82,4 @@ do { \
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#include <asm-generic/bug.h>
4884

49-
#else /* __ASSEMBLY__ */
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#ifdef CONFIG_GENERIC_BUG
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#ifdef CONFIG_X86_32
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.macro __BUG_REL val:req
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.long \val
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.endm
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#else
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.macro __BUG_REL val:req
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.long \val - 2b
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.endm
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#endif
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#ifdef CONFIG_DEBUG_BUGVERBOSE
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.macro ASM_BUG ins:req file:req line:req flags:req size:req
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1: \ins
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.pushsection __bug_table,"aw"
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2: __BUG_REL val=1b # bug_entry::bug_addr
69-
__BUG_REL val=\file # bug_entry::file
70-
.word \line # bug_entry::line
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.word \flags # bug_entry::flags
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.org 2b+\size
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.popsection
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.endm
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#else /* !CONFIG_DEBUG_BUGVERBOSE */
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.macro ASM_BUG ins:req file:req line:req flags:req size:req
79-
1: \ins
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.pushsection __bug_table,"aw"
81-
2: __BUG_REL val=1b # bug_entry::bug_addr
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.word \flags # bug_entry::flags
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.org 2b+\size
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.popsection
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.endm
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#endif /* CONFIG_DEBUG_BUGVERBOSE */
88-
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#else /* CONFIG_GENERIC_BUG */
90-
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.macro ASM_BUG ins:req file:req line:req flags:req size:req
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\ins
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.endm
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#endif /* CONFIG_GENERIC_BUG */
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#endif /* __ASSEMBLY__ */
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9985
#endif /* _ASM_X86_BUG_H */

‎arch/x86/kernel/macros.S

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -9,4 +9,3 @@
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#include <linux/compiler.h>
1010
#include <asm/refcount.h>
1111
#include <asm/alternative-asm.h>
12-
#include <asm/bug.h>

‎include/asm-generic/bug.h

Lines changed: 4 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -17,8 +17,10 @@
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#ifndef __ASSEMBLY__
1818
#include <linux/kernel.h>
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20-
struct bug_entry {
20+
#ifdef CONFIG_BUG
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#ifdef CONFIG_GENERIC_BUG
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struct bug_entry {
2224
#ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS
2325
unsigned long bug_addr;
2426
#else
@@ -33,10 +35,8 @@ struct bug_entry {
3335
unsigned short line;
3436
#endif
3537
unsigned short flags;
36-
#endif /* CONFIG_GENERIC_BUG */
3738
};
38-
39-
#ifdef CONFIG_BUG
39+
#endif /* CONFIG_GENERIC_BUG */
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4141
/*
4242
* Don't use BUG() or BUG_ON() unless there's really no way out; one

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