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Commit bd53147d authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Thomas Gleixner
Browse files

x86: Fix boot protocol KEEP_SEGMENTS check. 



The kernel only ever supports 1 version of the boot protocol
so there is no need to check the boot protocol revision to
see if a feature is supported.

Both x86 and x86_64 support the same boot protocol so we need
to implement the KEEP_SEGMENTS on x86_64 as well.  It isn't
just paravirt bootloaders that could use this functionality.

Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@suse.de>
Acked-by: default avatarH. Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 0cca1ca6

arch/x86/boot/compressed/head_32.S

+4 −8
Original line number Diff line number Diff line
@@ -33,24 +33,20 @@ 
	.globl startup_32



startup_32:

	/* check to see if KEEP_SEGMENTS flag is meaningful */

	cmpw $0x207, BP_version(%esi)

	jb 1f



	cld

	/* test KEEP_SEGMENTS flag to see if the bootloader is asking

	 * us to not reload segments */

	testb $(1<<6), BP_loadflags(%esi)

	jnz 2f

	jnz 1f



1:	cli

	cli

	movl $(__BOOT_DS),%eax

	movl %eax,%ds

	movl %eax,%es

	movl %eax,%fs

	movl %eax,%gs

	movl %eax,%ss



2:	cld

1:



/* Calculate the delta between where we were compiled to run

 * at and where we were actually loaded at.  This can only be done

arch/x86/boot/compressed/head_64.S

+7 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include <asm/pgtable.h>

#include <asm/page.h>

#include <asm/msr.h>

#include <asm/asm-offsets.h>



.section ".text.head"

	.code32
@@ -36,11 +37,17 @@ 


startup_32:

	cld

	/* test KEEP_SEGMENTS flag to see if the bootloader is asking

	 * us to not reload segments */

	testb $(1<<6), BP_loadflags(%esi)

	jnz 1f



	cli

	movl	$(__KERNEL_DS), %eax

	movl	%eax, %ds

	movl	%eax, %es

	movl	%eax, %ss

1:



/* Calculate the delta between where we were compiled to run

 * at and where we were actually loaded at.  This can only be done

arch/x86/kernel/asm-offsets_64.c

+10 −0
Original line number Diff line number Diff line
@@ -15,12 +15,16 @@ 
#include <asm/segment.h>

#include <asm/thread_info.h>

#include <asm/ia32.h>

#include <asm/bootparam.h>



#define DEFINE(sym, val) \

        asm volatile("\n->" #sym " %0 " #val : : "i" (val))



#define BLANK() asm volatile("\n->" : : )



#define OFFSET(sym, str, mem) \

	DEFINE(sym, offsetof(struct str, mem))



#define __NO_STUBS 1

#undef __SYSCALL

#undef _ASM_X86_64_UNISTD_H_
@@ -109,5 +113,11 @@ int main(void) 
	DEFINE(crypto_tfm_ctx_offset, offsetof(struct crypto_tfm, __crt_ctx));

	BLANK();

	DEFINE(__NR_syscall_max, sizeof(syscalls) - 1);



	BLANK();

	OFFSET(BP_scratch, boot_params, scratch);

	OFFSET(BP_loadflags, boot_params, hdr.loadflags);

	OFFSET(BP_hardware_subarch, boot_params, hdr.hardware_subarch);

	OFFSET(BP_version, boot_params, hdr.version);

	return 0;

}