Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Thomas writes:
  "A single fix for the AMD memory encryption boot code so it does not
   read random garbage instead of the cached encryption bit when a kexec
   kernel is allocated above the 32bit address limit."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Fix kexec booting failure in the SEV bit detection code
This commit is contained in:
Greg Kroah-Hartman 2018-09-29 14:34:06 -07:00
commit e75417739b

View File

@ -25,20 +25,6 @@ ENTRY(get_sev_encryption_bit)
push %ebx
push %ecx
push %edx
push %edi
/*
* RIP-relative addressing is needed to access the encryption bit
* variable. Since we are running in 32-bit mode we need this call/pop
* sequence to get the proper relative addressing.
*/
call 1f
1: popl %edi
subl $1b, %edi
movl enc_bit(%edi), %eax
cmpl $0, %eax
jge .Lsev_exit
/* Check if running under a hypervisor */
movl $1, %eax
@ -69,15 +55,12 @@ ENTRY(get_sev_encryption_bit)
movl %ebx, %eax
andl $0x3f, %eax /* Return the encryption bit location */
movl %eax, enc_bit(%edi)
jmp .Lsev_exit
.Lno_sev:
xor %eax, %eax
movl %eax, enc_bit(%edi)
.Lsev_exit:
pop %edi
pop %edx
pop %ecx
pop %ebx
@ -113,8 +96,6 @@ ENTRY(set_sev_encryption_mask)
ENDPROC(set_sev_encryption_mask)
.data
enc_bit:
.int 0xffffffff
#ifdef CONFIG_AMD_MEM_ENCRYPT
.balign 8