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x86/entry_32: Convert X86_INVD_BUG to ALTERNATIVE macro 

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>
This commit is contained in:
Borislav Petkov 2015-01-18 12:35:55 +01:00
parent 669f8a9001
commit 8e65f6e03a
1 changed files with 3 additions and 9 deletions
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12
arch/x86/kernel/entry_32.S
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@ -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