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 73a6dec80e2acedaef3ca603d4b5799049f6e9f8 upstream.
Move the efi32_entry() routine out of head_64.S and into efi-mixed.S, which reduces clutter in the complicated startup routines. It also permits linkage of some symbols used by code to be made local.
Signed-off-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Borislav Petkov bp@suse.de Link: https://lore.kernel.org/r/20221122161017.2426828-6-ardb@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/boot/compressed/efi_mixed.S | 57 ++++++++++++++++++++++++++++------- arch/x86/boot/compressed/head_64.S | 45 --------------------------- 2 files changed, 47 insertions(+), 55 deletions(-)
--- a/arch/x86/boot/compressed/efi_mixed.S +++ b/arch/x86/boot/compressed/efi_mixed.S @@ -105,7 +105,7 @@ SYM_FUNC_START(__efi64_thunk) /* * Switch to IDT and GDT with 32-bit segments. This is the firmware GDT * and IDT that was installed when the kernel started executing. The - * pointers were saved at the EFI stub entry point in head_64.S. + * pointers were saved by the efi32_entry() routine below. * * Pass the saved DS selector to the 32-bit code, and use far return to * restore the saved CS selector. @@ -217,22 +217,59 @@ SYM_FUNC_START_LOCAL(efi_enter32) lret SYM_FUNC_END(efi_enter32)
+/* + * This is the common EFI stub entry point for mixed mode. + * + * Arguments: %ecx image handle + * %edx EFI system table pointer + * %esi struct bootparams pointer (or NULL when not using + * the EFI handover protocol) + * + * Since this is the point of no return for ordinary execution, no registers + * are considered live except for the function parameters. [Note that the EFI + * stub may still exit and return to the firmware using the Exit() EFI boot + * service.] + */ +SYM_FUNC_START(efi32_entry) + call 1f +1: pop %ebx + + /* Save firmware GDTR and code/data selectors */ + sgdtl (efi32_boot_gdt - 1b)(%ebx) + movw %cs, (efi32_boot_cs - 1b)(%ebx) + movw %ds, (efi32_boot_ds - 1b)(%ebx) + + /* Store firmware IDT descriptor */ + sidtl (efi32_boot_idt - 1b)(%ebx) + + /* Store boot arguments */ + leal (efi32_boot_args - 1b)(%ebx), %ebx + movl %ecx, 0(%ebx) + movl %edx, 4(%ebx) + movl %esi, 8(%ebx) + movb $0x0, 12(%ebx) // efi_is64 + + /* Disable paging */ + movl %cr0, %eax + btrl $X86_CR0_PG_BIT, %eax + movl %eax, %cr0 + + jmp startup_32 +SYM_FUNC_END(efi32_entry) + .data .balign 8 -SYM_DATA_START(efi32_boot_gdt) +SYM_DATA_START_LOCAL(efi32_boot_gdt) .word 0 .quad 0 SYM_DATA_END(efi32_boot_gdt)
-SYM_DATA_START(efi32_boot_idt) +SYM_DATA_START_LOCAL(efi32_boot_idt) .word 0 .quad 0 SYM_DATA_END(efi32_boot_idt)
-SYM_DATA_START(efi32_boot_cs) - .word 0 -SYM_DATA_END(efi32_boot_cs) - -SYM_DATA_START(efi32_boot_ds) - .word 0 -SYM_DATA_END(efi32_boot_ds) +SYM_DATA_LOCAL(efi32_boot_cs, .word 0) +SYM_DATA_LOCAL(efi32_boot_ds, .word 0) +SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0, 0) +SYM_DATA(efi_is64, .byte 1) --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -289,48 +289,6 @@ SYM_FUNC_START(efi32_stub_entry) popl %esi jmp efi32_entry SYM_FUNC_END(efi32_stub_entry) - - .text -/* - * This is the common EFI stub entry point for mixed mode. - * - * Arguments: %ecx image handle - * %edx EFI system table pointer - * %esi struct bootparams pointer (or NULL when not using - * the EFI handover protocol) - * - * Since this is the point of no return for ordinary execution, no registers - * are considered live except for the function parameters. [Note that the EFI - * stub may still exit and return to the firmware using the Exit() EFI boot - * service.] - */ -SYM_FUNC_START_LOCAL(efi32_entry) - call 1f -1: pop %ebx - - /* Save firmware GDTR and code/data selectors */ - sgdtl (efi32_boot_gdt - 1b)(%ebx) - movw %cs, (efi32_boot_cs - 1b)(%ebx) - movw %ds, (efi32_boot_ds - 1b)(%ebx) - - /* Store firmware IDT descriptor */ - sidtl (efi32_boot_idt - 1b)(%ebx) - - /* Store boot arguments */ - leal (efi32_boot_args - 1b)(%ebx), %ebx - movl %ecx, 0(%ebx) - movl %edx, 4(%ebx) - movl %esi, 8(%ebx) - movb $0x0, 12(%ebx) // efi_is64 - - /* Disable paging */ - movl %cr0, %eax - btrl $X86_CR0_PG_BIT, %eax - movl %eax, %cr0 - - jmp startup_32 -SYM_FUNC_END(efi32_entry) - __HEAD #endif
.code64 @@ -779,9 +737,6 @@ SYM_DATA_END_LABEL(boot32_idt, SYM_L_GLO SYM_DATA(image_offset, .long 0) #endif #ifdef CONFIG_EFI_MIXED -SYM_DATA(efi32_boot_args, .long 0, 0, 0) -SYM_DATA(efi_is64, .byte 1) - #define ST32_boottime 60 // offsetof(efi_system_table_32_t, boottime) #define BS32_handle_protocol 88 // offsetof(efi_boot_services_32_t, handle_protocol) #define LI32_image_base 32 // offsetof(efi_loaded_image_32_t, image_base)