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hw: prevent absolute addresses in x86_64 assembler 

Ref #2091
This commit is contained in:
Stefan Kalkowski 2017-08-21 10:00:50 +02:00 committed by Christian Helmuth
parent b8cd58e6a5
commit 500893e7ec
1 changed files with 23 additions and 31 deletions
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54
repos/base-hw/src/core/spec/x86_64/mode_transition.s
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@ -37,8 +37,6 @@
/* mtc virt addresses */
.set MT_BASE, 0xffff0000
.set MT_BUFFER, MT_BASE + (_mt_buffer - _mt_begin)
.set MT_MASTER, MT_BASE + (_mt_master_context_begin - _mt_begin)
.set MT_TSS, MT_BASE + (_mt_tss - _mt_begin)
.set MT_ISR, MT_BASE
.set MT_IRQ_STACK, MT_BASE + (_mt_kernel_interrupt_stack - _mt_begin)
@ -70,11 +68,15 @@
.word \addr & 0xffff
.word 0x0008
.word \flags
.word \addr >> 16
.word (\addr >> 16) & 0xffff
.long \addr >> 32
.long 0
.endm
.macro _load_address label reg
mov \label@GOTPCREL(%rip), %\reg
.endm
.section .text
/*
@ -148,14 +150,17 @@
_mt_kernel_entry_pic:
/* Copy client context RAX to buffer */
movabs %rax, MT_BUFFER
pushq %rax
/* Switch to kernel page tables */
movabs MT_MASTER+CR3_OFFSET, %rax
_load_address _mt_master_context_begin rax
mov CR3_OFFSET(%rax), %rax
mov %rax, %cr3
/* Save information on interrupt stack frame in client context */
mov _mt_client_context_ptr, %rax
_load_address _mt_client_context_ptr rax
mov (%rax), %rax
popq RAX_OFFSET(%rax)
popq TRAPNO_OFFSET(%rax)
popq ERRCODE_OFFSET(%rax)
popq (%rax)
@ -171,7 +176,7 @@
pushq %rdx
pushq %rcx
pushq %rbx
pushq _mt_buffer
sub $8, %rsp
pushq %r15
pushq %r14
pushq %r13
@ -181,34 +186,20 @@
pushq %r9
pushq %r8
/* Restore register values from kernel context */
mov $_mt_master_context_begin+R8_OFFSET, %rsp
popq %r8
popq %r9
popq %r10
popq %r11
popq %r12
popq %r13
popq %r14
popq %r15
popq %rax
popq %rbx
popq %rcx
popq %rdx
popq %rdi
popq %rsi
popq %rbp
/* Restore kernel stack and continue kernel execution */
mov _mt_master_context_begin+SP_OFFSET, %rsp
jmp *_mt_master_context_begin
_load_address _mt_master_context_begin rsp
mov (%rsp), %rax
mov SP_OFFSET(%rsp), %rsp
jmp *%rax
.global _mt_user_entry_pic
_mt_user_entry_pic:
/* Prepare stack frame in mt buffer (Intel SDM Vol. 3A, figure 6-8) */
mov _mt_client_context_ptr, %rax
mov $_mt_buffer+BUFFER_SIZE, %rsp
_load_address _mt_client_context_ptr rax
mov (%rax), %rax
_load_address _mt_buffer rsp
add $BUFFER_SIZE, %rsp
pushq $0x23
pushq SP_OFFSET(%rax)
pushq FLAGS_OFFSET(%rax)
@ -218,6 +209,7 @@
/* Restore register values from client context */
lea R8_OFFSET(%rax), %rsp
_load_address _mt_buffer rbx
popq %r8
popq %r9
popq %r10
@ -226,7 +218,7 @@
popq %r13
popq %r14
popq %r15
popq _mt_buffer
popq (%rbx)
popq %rbx
popq %rcx
popq %rdx
@ -239,7 +231,7 @@
mov %rax, %cr3
/* Set stack back to mt buffer and restore client RAX */
movabs $MT_BUFFER, %rsp
_load_address _mt_buffer rsp
popq %rax
iretq