diff options
| author | Arvind Sankar <nivedita@alum.mit.edu> | 2020-03-08 09:08:43 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-03-08 09:58:17 +0100 |
| commit | 8acf63efa1712fa5495425a4224378bb3e1231e0 (patch) | |
| tree | 357541e3062049db304f4b612d01abc7cb44bddd /arch/x86 | |
| parent | 3fab43318f0565ffb45925bea5903bc400ce2864 (diff) | |
efi/x86: Avoid using code32_start
code32_start is meant for 16-bit real-mode bootloaders to inform the
kernel where the 32-bit protected mode code starts. Nothing in the
protected mode kernel except the EFI stub uses it.
efi_main() currently returns boot_params, with code32_start set inside it
to tell efi_stub_entry() where startup_32 is located. Since it was invoked
by efi_stub_entry() in the first place, boot_params is already known.
Return the address of startup_32 instead.
This will allow a 64-bit kernel to live above 4Gb, for example, and it's
cleaner as well.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200301230436.2246909-5-nivedita@alum.mit.edu
Link: https://lore.kernel.org/r/20200308080859.21568-13-ardb@kernel.org
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/boot/compressed/head_32.S | 3 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/head_64.S | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/asm-offsets.c | 1 |
3 files changed, 3 insertions, 5 deletions
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 2f8138b71ea9..e013bdc1237b 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -156,9 +156,8 @@ SYM_FUNC_END(startup_32) SYM_FUNC_START(efi32_stub_entry) SYM_FUNC_START_ALIAS(efi_stub_entry) add $0x4, %esp + movl 8(%esp), %esi /* save boot_params pointer */ call efi_main - movl %eax, %esi - movl BP_code32_start(%esi), %eax leal startup_32(%eax), %eax jmp *%eax SYM_FUNC_END(efi32_stub_entry) diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index fabbd4c2e9f2..6a4ff919008c 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -472,9 +472,9 @@ SYM_CODE_END(startup_64) SYM_FUNC_START(efi64_stub_entry) SYM_FUNC_START_ALIAS(efi_stub_entry) and $~0xf, %rsp /* realign the stack */ + movq %rdx, %rbx /* save boot_params pointer */ call efi_main - movq %rax,%rsi - movl BP_code32_start(%esi), %eax + movq %rbx,%rsi leaq startup_64(%rax), %rax jmp *%rax SYM_FUNC_END(efi64_stub_entry) diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index 5c7ee3df4d0b..3ca07ad552ae 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -88,7 +88,6 @@ static void __used common(void) OFFSET(BP_kernel_alignment, boot_params, hdr.kernel_alignment); OFFSET(BP_init_size, boot_params, hdr.init_size); OFFSET(BP_pref_address, boot_params, hdr.pref_address); - OFFSET(BP_code32_start, boot_params, hdr.code32_start); BLANK(); DEFINE(PTREGS_SIZE, sizeof(struct pt_regs)); |