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>

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index d23c9a1d40e1a178a464df1f4d8a5c10ce440583..b910577d1ff9df98b683eb56e0661299de037a0d 100644 (file)
--- 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