mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-22 11:58:21 +07:00
19d436268d
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>
84 lines
2.2 KiB
C
84 lines
2.2 KiB
C
#ifndef _ASM_X86_BUG_H
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#define _ASM_X86_BUG_H
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#include <linux/stringify.h>
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/*
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* Since some emulators terminate on UD2, we cannot use it for WARN.
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* Since various instruction decoders disagree on the length of UD1,
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* we cannot use it either. So use UD0 for WARN.
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*
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* (binutils knows about "ud1" but {en,de}codes it as 2 bytes, whereas
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* our kernel decoder thinks it takes a ModRM byte, which seems consistent
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* with various things like the Intel SDM instruction encoding rules)
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*/
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#define ASM_UD0 ".byte 0x0f, 0xff"
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#define ASM_UD1 ".byte 0x0f, 0xb9" /* + ModRM */
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#define ASM_UD2 ".byte 0x0f, 0x0b"
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#define INSN_UD0 0xff0f
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#define INSN_UD2 0x0b0f
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#define LEN_UD0 2
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#ifdef CONFIG_GENERIC_BUG
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#ifdef CONFIG_X86_32
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# define __BUG_REL(val) ".long " __stringify(val)
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#else
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# define __BUG_REL(val) ".long " __stringify(val) " - 2b"
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#endif
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#ifdef CONFIG_DEBUG_BUGVERBOSE
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#define _BUG_FLAGS(ins, flags) \
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do { \
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asm volatile("1:\t" ins "\n" \
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".pushsection __bug_table,\"a\"\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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#define _BUG_FLAGS(ins, flags) \
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do { \
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asm volatile("1:\t" ins "\n" \
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".pushsection __bug_table,\"a\"\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))); \
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} 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)
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#endif /* CONFIG_GENERIC_BUG */
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#define HAVE_ARCH_BUG
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#define BUG() \
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do { \
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_BUG_FLAGS(ASM_UD2, 0); \
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unreachable(); \
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} while (0)
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#define __WARN_FLAGS(flags) _BUG_FLAGS(ASM_UD0, BUGFLAG_WARNING|(flags))
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#include <asm-generic/bug.h>
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#endif /* _ASM_X86_BUG_H */
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