| Message ID | 20200304133515.15035-1-ardb@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | [efi-next] efi/x86: preserve %ebx correctly in efi_set_virtual_address_map() | expand |
diff --git a/arch/x86/platform/efi/efi_stub_32.S b/arch/x86/platform/efi/efi_stub_32.S index 09237236fb25..09ec84f6ef51 100644 --- a/arch/x86/platform/efi/efi_stub_32.S +++ b/arch/x86/platform/efi/efi_stub_32.S @@ -54,7 +54,7 @@ SYM_FUNC_START(efi_call_svam) orl $0x80000000, %edx movl %edx, %cr0 - pop %ebx + movl 16(%esp), %ebx leave ret SYM_FUNC_END(efi_call_svam)
Commit 59f2a619a2db8611 ("efi: Add 'runtime' pointer to struct efi") modified the assembler routine called by efi_set_virtual_address_map(), to grab the 'runtime' EFI service pointer while running with paging disabled (which is tricky to do in C code) After the change, register %ebx is not restored correctly, resulting in all kinds of weird behavior, so fix that. Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/x86/platform/efi/efi_stub_32.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)