[tip:,x86/boot] x86/boot/compressed: Adhere to calling convention in get_sev_encryption_bit()
Commit Message
The following commit has been merged into the x86/boot branch of tip:
Commit-ID: 30c9ca16a5271ba6f8ad9c86507ff1c789c94677
Gitweb: https://git.kernel.org/tip/30c9ca16a5271ba6f8ad9c86507ff1c789c94677
Author: Ard Biesheuvel <ardb@kernel.org>
AuthorDate: Tue, 22 Nov 2022 17:10:15 +01:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Thu, 24 Nov 2022 08:57:41 +01:00
x86/boot/compressed: Adhere to calling convention in get_sev_encryption_bit()
Make get_sev_encryption_bit() follow the ordinary i386 calling
convention, and only call it if CONFIG_AMD_MEM_ENCRYPT is actually
enabled. This clarifies the calling code, and makes it more
maintainable.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20221122161017.2426828-16-ardb@kernel.org
---
arch/x86/boot/compressed/head_64.S | 5 +++--
arch/x86/boot/compressed/mem_encrypt.S | 10 ----------
2 files changed, 3 insertions(+), 12 deletions(-)
@@ -180,12 +180,13 @@ SYM_FUNC_START(startup_32)
*/
/*
* If SEV is active then set the encryption mask in the page tables.
- * This will insure that when the kernel is copied and decompressed
+ * This will ensure that when the kernel is copied and decompressed
* it will be done so encrypted.
*/
- call get_sev_encryption_bit
xorl %edx, %edx
#ifdef CONFIG_AMD_MEM_ENCRYPT
+ call get_sev_encryption_bit
+ xorl %edx, %edx
testl %eax, %eax
jz 1f
subl $32, %eax /* Encryption bit is always above bit 31 */
@@ -18,12 +18,7 @@
.text
.code32
SYM_FUNC_START(get_sev_encryption_bit)
- xor %eax, %eax
-
-#ifdef CONFIG_AMD_MEM_ENCRYPT
push %ebx
- push %ecx
- push %edx
movl $0x80000000, %eax /* CPUID to check the highest leaf */
cpuid
@@ -54,12 +49,7 @@ SYM_FUNC_START(get_sev_encryption_bit)
xor %eax, %eax
.Lsev_exit:
- pop %edx
- pop %ecx
pop %ebx
-
-#endif /* CONFIG_AMD_MEM_ENCRYPT */
-
RET
SYM_FUNC_END(get_sev_encryption_bit)