6.1-stable review patch. If anyone has any objections, please let me know.
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From: Ard Biesheuvel ardb@kernel.org
commit 30c9ca16a5271ba6f8ad9c86507ff1c789c94677 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/boot/compressed/head_64.S | 5 +++-- arch/x86/boot/compressed/mem_encrypt.S | 10 ---------- 2 files changed, 3 insertions(+), 12 deletions(-)
--- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -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 */ --- a/arch/x86/boot/compressed/mem_encrypt.S +++ b/arch/x86/boot/compressed/mem_encrypt.S @@ -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)