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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_BUG_H
#define _ASM_X86_BUG_H
#include <linux/stringify.h>
/*
* Since some emulators terminate on UD2, we cannot use it for WARN.
* Since various instruction decoders disagree on the length of UD1,
* we cannot use it either. So use UD0 for WARN.
*
* (binutils knows about "ud1" but {en,de}codes it as 2 bytes, whereas
* our kernel decoder thinks it takes a ModRM byte, which seems consistent
* with various things like the Intel SDM instruction encoding rules)
*/
#define ASM_UD0 ".byte 0x0f, 0xff"
#define ASM_UD1 ".byte 0x0f, 0xb9" /* + ModRM */
#define ASM_UD2 ".byte 0x0f, 0x0b"
#define INSN_UD0 0xff0f
#define INSN_UD2 0x0b0f
#define LEN_UD0 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 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 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 { \
_BUG_FLAGS(ASM_UD2, 0); \
unreachable(); \
} while (0)
#define __WARN_FLAGS(flags) _BUG_FLAGS(ASM_UD0, BUGFLAG_WARNING|(flags))
#include <asm-generic/bug.h>
#endif /* _ASM_X86_BUG_H */
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