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Subject[PATCH v2 09/15] x86/entry_32: Convert X86_INVD_BUG to ALTERNATIVE macro
Date
From: Borislav Petkov <bp@suse.de>

Booting a 486 kernel on an AMD guest with this patch applied, says:

apply_alternatives: feat: 0*32+25, old: (c160a475, len: 5), repl: (c19557d4, len: 5)
c160a475: alt_insn: 68 10 35 00 c1
c19557d4: rpl_insn: 68 80 39 00 c1

which is:

old insn VA: 0xc160a475, CPU feat: X86_FEATURE_XMM, size: 5
simd_coprocessor_error:
c160a475: 68 10 35 00 c1 push $0xc1003510 <do_general_protection>
repl insn: 0xc19557d4, size: 5
c160a475: 68 80 39 00 c1 push $0xc1003980 <do_simd_coprocessor_error>

Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/entry_32.S | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index d23c9a1d40e1..b910577d1ff9 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -816,15 +816,9 @@ ENTRY(simd_coprocessor_error)
pushl_cfi $0
#ifdef CONFIG_X86_INVD_BUG
/* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
-661: pushl_cfi $do_general_protection
-662:
-.section .altinstructions,"a"
- altinstruction_entry 661b, 663f, X86_FEATURE_XMM, 662b-661b, 664f-663f, 0
-.previous
-.section .altinstr_replacement,"ax"
-663: pushl $do_simd_coprocessor_error
-664:
-.previous
+ ALTERNATIVE "pushl_cfi $do_general_protection", \
+ "pushl $do_simd_coprocessor_error", \
+ X86_FEATURE_XMM
#else
pushl_cfi $do_simd_coprocessor_error
#endif
--
2.2.0.33.gc18b867


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