[tip: x86/boot] x86/boot: Grab kernel_info offset from zoffset header directly

[tip-bot2 for Ard Biesheuvel]

The following commit has been merged into the x86/boot branch of tip:

Commit-ID:     2e765c02dcbfc2a8a4527c621a84b9502f6b9bd2
Gitweb:        https://git.kernel.org/tip/2e765c02dcbfc2a8a4527c621a84b9502f6b9bd2
Author:        Ard Biesheuvel <ardb@xxxxxxxxxx>
AuthorDate:    Fri, 15 Sep 2023 17:16:25 
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Sun, 17 Sep 2023 19:48:42 +02:00

x86/boot: Grab kernel_info offset from zoffset header directly

Instead of parsing zoffset.h and poking the kernel_info offset value
into the header from the build tool, just grab the value directly in the
asm file that describes this header.

This change has no impact on the resulting bzImage binary.

Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230915171623.655440-11-ardb@xxxxxxxxxx
---
 arch/x86/boot/header.S      | 2 +-
 arch/x86/boot/tools/build.c | 4 ----
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 6059f87..5575d0f 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -526,7 +526,7 @@ pref_address:		.quad LOAD_PHYSICAL_ADDR	# preferred load addr
 
 init_size:		.long INIT_SIZE		# kernel initialization size
 handover_offset:	.long 0			# Filled in by build.c
-kernel_info_offset:	.long 0			# Filled in by build.c
+kernel_info_offset:	.long ZO_kernel_info
 
 # End of setup header #####################################################
 
diff --git a/arch/x86/boot/tools/build.c b/arch/x86/boot/tools/build.c
index 10b0207..14ef13f 100644
--- a/arch/x86/boot/tools/build.c
+++ b/arch/x86/boot/tools/build.c
@@ -59,7 +59,6 @@ static unsigned long efi32_stub_entry;
 static unsigned long efi64_stub_entry;
 static unsigned long efi_pe_entry;
 static unsigned long efi32_pe_entry;
-static unsigned long kernel_info;
 static unsigned long _end;
 
 /*----------------------------------------------------------------------*/
@@ -337,7 +336,6 @@ static void parse_zoffset(char *fname)
 		PARSE_ZOFS(p, efi64_stub_entry);
 		PARSE_ZOFS(p, efi_pe_entry);
 		PARSE_ZOFS(p, efi32_pe_entry);
-		PARSE_ZOFS(p, kernel_info);
 		PARSE_ZOFS(p, _end);
 
 		p = strchr(p, '\n');
@@ -419,8 +417,6 @@ int main(int argc, char ** argv)
 	update_pecoff_text(setup_sectors * 512, i + (sys_size * 16));
 
 	efi_stub_entry_update();
-	/* Update kernel_info offset. */
-	put_unaligned_le32(kernel_info, &buf[0x268]);
 
 	crc = partial_crc32(buf, i, crc);
 	if (fwrite(buf, 1, i, dest) != i)