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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_BUG_H
#define _ASM_X86_BUG_H
#include <linux/stringify.h>
#include <linux/instrumentation.h>
/*
* Despite that some emulators terminate on UD2, we use it for WARN().
*
* Since various instruction decoders/specs disagree on the encoding of
* UD0/UD1.
*/
#define ASM_UD0 ".byte 0x0f, 0xff" /* + ModRM (for Intel) */
#define ASM_UD1 ".byte 0x0f, 0xb9" /* + ModRM */
#define ASM_UD2 ".byte 0x0f, 0x0b"
#define INSN_UD0 0xff0f
#define INSN_UD2 0x0b0f
#define LEN_UD2 2
#ifdef CONFIG_GENERIC_BUG
#ifdef CONFIG_X86_32
# define __BUG_REL(val) ".long " __stringify(val)
#else
# define __BUG_REL(val) ".long " __stringify(val) " - 2b"
#endif
#ifdef CONFIG_DEBUG_BUGVERBOSE
#define _BUG_FLAGS(ins, flags) \
do { \
asm_inline volatile("1:\t" ins "\n" \
".pushsection __bug_table,\"aw\"\n" \
"2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \
"\t" __BUG_REL(%c0) "\t# bug_entry::file\n" \
"\t.word %c1" "\t# bug_entry::line\n" \
"\t.word %c2" "\t# bug_entry::flags\n" \
"\t.org 2b+%c3\n" \
".popsection" \
: : "i" (__FILE__), "i" (__LINE__), \
"i" (flags), \
"i" (sizeof(struct bug_entry))); \
} while (0)
#else /* !CONFIG_DEBUG_BUGVERBOSE */
#define _BUG_FLAGS(ins, flags) \
do { \
asm_inline volatile("1:\t" ins "\n" \
".pushsection __bug_table,\"aw\"\n" \
"2:\t" __BUG_REL(1b) "\t# bug_entry::bug_addr\n" \
"\t.word %c0" "\t# bug_entry::flags\n" \
"\t.org 2b+%c1\n" \
".popsection" \
: : "i" (flags), \
"i" (sizeof(struct bug_entry))); \
} while (0)
#endif /* CONFIG_DEBUG_BUGVERBOSE */
#else
#define _BUG_FLAGS(ins, flags) asm volatile(ins)
#endif /* CONFIG_GENERIC_BUG */
#define HAVE_ARCH_BUG
#define BUG() \
do { \
instrumentation_begin(); \
_BUG_FLAGS(ASM_UD2, 0); \
unreachable(); \
} while (0)
/*
* This instrumentation_begin() is strictly speaking incorrect; but it
* suppresses the complaints from WARN()s in noinstr code. If such a WARN()
* were to trigger, we'd rather wreck the machine in an attempt to get the
* message out than not know about it.
*/
#define __WARN_FLAGS(flags) \
do { \
instrumentation_begin(); \
_BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
annotate_reachable(); \
instrumentation_end(); \
} while (0)
#include <asm-generic/bug.h>
#endif /* _ASM_X86_BUG_H */
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