Commit-ID: f4dee0bb65752a1b5c9f7912bea8216f03667209
Gitweb: http://git.kernel.org/tip/f4dee0bb65752a1b5c9f7912bea8216f03667209
Author: Jiri Slaby <jslaby@xxxxxxx>
AuthorDate: Thu, 24 Aug 2017 09:33:26 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 29 Aug 2017 13:23:29 +0200
x86/boot/32: Extract efi_pe_entry() from startup_32()
The efi_pe_entry() body is somehow squashed into startup_32(). In the old days,
we forced startup_32() to start at offset 0x00 and efi_pe_entry() to start
at 0x10.
But this requirement was removed long time ago, in:
99f857db8857 ("x86, build: Dynamically find entry points in compressed startup code")
The way it is now makes the code less readable and illogical. Given
we can now safely extract the inlined efi_pe_entry() body from
startup_32() into a separate function, we do so and we separate it to two
functions as they are marked already: efi_pe_entry() + efi32_stub_entry().
We also annotate the functions appropriatelly by ENTRY+ENDPROC.
ABI offset is preserved:
0000 128 FUNC GLOBAL DEFAULT 6 startup_32
0080 60 FUNC GLOBAL DEFAULT 6 efi_pe_entry
00bc 68 FUNC GLOBAL DEFAULT 6 efi32_stub_entry
On the top-level, it looked like this:
ENTRY(startup_32)
#ifdef CONFIG_EFI_STUB ; start of inlined
jmp preferred_addr
ENTRY(efi_pe_entry)
... ; a lot of assembly (efi_pe_entry)
ENTRY(efi32_stub_entry)
... ; a lot of assembly (efi32_stub_entry)
leal preferred_addr(%eax), %eax
jmp *%eax
preferred_addr:
#endif ; end of inlined
... ; a lot of assembly (startup_32)
ENDPROC(startup_32)
And it is now converted into:
ENTRY(startup_32)
... ; a lot of assembly (startup_32)
ENDPROC(startup_32)
#ifdef CONFIG_EFI_STUB
ENTRY(efi_pe_entry)
... ; a lot of assembly (efi_pe_entry)
ENDPROC(efi_pe_entry)
ENTRY(efi32_stub_entry)
... ; a lot of assembly (efi32_stub_entry)
leal startup_32(%eax), %eax
jmp *%eax
ENDPROC(efi32_stub_entry)
#endif
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: ard.biesheuvel@xxxxxxxxxx
Cc: linux-efi@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20170824073327.4129-1-jslaby@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/boot/compressed/head_32.S | 129 ++++++++++++++++++-------------------
1 file changed, 64 insertions(+), 65 deletions(-)
diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S
index d85b962..11c68cf 100644
--- a/arch/x86/boot/compressed/head_32.S
+++ b/arch/x86/boot/compressed/head_32.S
@@ -61,71 +61,6 @@
__HEAD
ENTRY(startup_32)
-#ifdef CONFIG_EFI_STUB
- jmp preferred_addr
-
- /*
- * We don't need the return address, so set up the stack so
- * efi_main() can find its arguments.
- */
-ENTRY(efi_pe_entry)
- add $0x4, %esp
-
- call 1f
-1: popl %esi
- subl $1b, %esi
-
- popl %ecx
- movl %ecx, efi32_config(%esi) /* Handle */
- popl %ecx
- movl %ecx, efi32_config+8(%esi) /* EFI System table pointer */
-
- /* Relocate efi_config->call() */
- leal efi32_config(%esi), %eax
- add %esi, 40(%eax)
- pushl %eax
-
- call make_boot_params
- cmpl $0, %eax
- je fail
- movl %esi, BP_code32_start(%eax)
- popl %ecx
- pushl %eax
- pushl %ecx
- jmp 2f /* Skip efi_config initialization */
-
-ENTRY(efi32_stub_entry)
- add $0x4, %esp
- popl %ecx
- popl %edx
-
- call 1f
-1: popl %esi
- subl $1b, %esi
-
- movl %ecx, efi32_config(%esi) /* Handle */
- movl %edx, efi32_config+8(%esi) /* EFI System table pointer */
-
- /* Relocate efi_config->call() */
- leal efi32_config(%esi), %eax
- add %esi, 40(%eax)
- pushl %eax
-2:
- call efi_main
- cmpl $0, %eax
- movl %eax, %esi
- jne 2f
-fail:
- /* EFI init failed, so hang. */
- hlt
- jmp fail
-2:
- movl BP_code32_start(%esi), %eax
- leal preferred_addr(%eax), %eax
- jmp *%eax
-
-preferred_addr:
-#endif
cld
/*
* Test KEEP_SEGMENTS flag to see if the bootloader is asking
@@ -208,6 +143,70 @@ preferred_addr:
jmp *%eax
ENDPROC(startup_32)
+#ifdef CONFIG_EFI_STUB
+/*
+ * We don't need the return address, so set up the stack so efi_main() can find
+ * its arguments.
+ */
+ENTRY(efi_pe_entry)
+ add $0x4, %esp
+
+ call 1f
+1: popl %esi
+ subl $1b, %esi
+
+ popl %ecx
+ movl %ecx, efi32_config(%esi) /* Handle */
+ popl %ecx
+ movl %ecx, efi32_config+8(%esi) /* EFI System table pointer */
+
+ /* Relocate efi_config->call() */
+ leal efi32_config(%esi), %eax
+ add %esi, 40(%eax)
+ pushl %eax
+
+ call make_boot_params
+ cmpl $0, %eax
+ je fail
+ movl %esi, BP_code32_start(%eax)
+ popl %ecx
+ pushl %eax
+ pushl %ecx
+ jmp 2f /* Skip efi_config initialization */
+ENDPROC(efi_pe_entry)
+
+ENTRY(efi32_stub_entry)
+ add $0x4, %esp
+ popl %ecx
+ popl %edx
+
+ call 1f
+1: popl %esi
+ subl $1b, %esi
+
+ movl %ecx, efi32_config(%esi) /* Handle */
+ movl %edx, efi32_config+8(%esi) /* EFI System table pointer */
+
+ /* Relocate efi_config->call() */
+ leal efi32_config(%esi), %eax
+ add %esi, 40(%eax)
+ pushl %eax
+2:
+ call efi_main
+ cmpl $0, %eax
+ movl %eax, %esi
+ jne 2f
+fail:
+ /* EFI init failed, so hang. */
+ hlt
+ jmp fail
+2:
+ movl BP_code32_start(%esi), %eax
+ leal startup_32(%eax), %eax
+ jmp *%eax
+ENDPROC(efi32_stub_entry)
+#endif
+
.text
relocated:
--
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