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* grub-core/lib/i386/xen/relocator.S: Fix hypercall ABI violation.

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GRUB relied on %ebx being preserved across hypercall which isn't true.
This commit is contained in:
Vladimir Serbinenko 2013-12-17 13:40:52 +01:00
parent d16ff5897f
commit 2c384f1e6e
2 changed files with 28 additions and 18 deletions
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6
ChangeLog
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@ -1,3 +1,9 @@
2013-12-17 Vladimir Serbinenko <phcoder@gmail.com>
* grub-core/lib/i386/xen/relocator.S: Fix hypercall ABI violation.
GRUB relied on %ebx being preserved across hypercall which isn't true.
2013-12-17 Vladimir Serbinenko <phcoder@gmail.com> 2013-12-17 Vladimir Serbinenko <phcoder@gmail.com>
* grub-core/lib/x86_64/xen/relocator.S: Fix hypercall ABI violation. * grub-core/lib/x86_64/xen/relocator.S: Fix hypercall ABI violation.

40
grub-core/lib/i386/xen/relocator.S
View file

@ -38,35 +38,36 @@ VARIABLE(grub_relocator_xen_remapper_map)
VARIABLE(grub_relocator_xen_remapper_map_high) VARIABLE(grub_relocator_xen_remapper_map_high)
.long 0 .long 0
movl %ebx, %ebp
movl $2, %esi movl $2, %esi
movl $__HYPERVISOR_update_va_mapping, %eax movl $__HYPERVISOR_update_va_mapping, %eax
int $0x82 int $0x82
movl %ebp, %ebx
addl $(LOCAL(cont) - LOCAL(base)), %ebx addl $(LOCAL(cont) - LOCAL(base)), %ebx
jmp *%ebx jmp *%ebx
LOCAL(cont): LOCAL(cont):
xorl %eax, %eax
/* mov imm32, %ecx */ movl %eax, %ebp
.byte 0xb9 1:
VARIABLE(grub_relocator_xen_paging_size)
.long 0
/* mov imm32, %ebx */
.byte 0xbb
VARIABLE(grub_relocator_xen_paging_start)
.long 0
/* mov imm32, %eax */ /* mov imm32, %eax */
.byte 0xb8 .byte 0xb8
VARIABLE(grub_relocator_xen_mfn_list) VARIABLE(grub_relocator_xen_mfn_list)
.long 0 .long 0
movl %eax, %edi movl %eax, %edi
1: movl %ebp, %eax
movl %ecx, %ebp movl 0(%edi, %eax, 4), %ecx
movl 0(%edi), %ecx
/* mov imm32, %ebx */
.byte 0xbb
VARIABLE(grub_relocator_xen_paging_start)
.long 0
shll $12, %eax
addl %eax, %ebx
movl %ecx, %edx movl %ecx, %edx
shll $12, %ecx shll $12, %ecx
shrl $20, %edx shrl $20, %edx
@ -75,11 +76,14 @@ VARIABLE(grub_relocator_xen_mfn_list)
movl $__HYPERVISOR_update_va_mapping, %eax movl $__HYPERVISOR_update_va_mapping, %eax
int $0x82 int $0x82
movl %ebp, %ecx incl %ebp
addl $4, %edi /* mov imm32, %ecx */
addl $4096, %ebx .byte 0xb9
VARIABLE(grub_relocator_xen_paging_size)
.long 0
cmpl %ebp, %ecx
loop 1b ja 1b
/* mov imm32, %ebx */ /* mov imm32, %ebx */
.byte 0xbb .byte 0xbb