drew/acadia
1
0
Fork 0
Code Issues 6 Pull requests Projects Releases Packages Wiki Activity Actions

Fix race condition in page fault handler.

Browse source 
We enabled interrupts before getting the value of cr2 in the handler.
If the handler was preempted, cr2 could have been overriden by a page
fault in a separate thread or process.
This commit is contained in:
Drew Galbraith 2023-06-07 22:24:50 -07:00
parent 3e1e37bf03
commit bd32e85164
2 changed files with 16 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

13
zion/interrupt/interrupt_enter.s
View file

@ -14,9 +14,12 @@
push %rcx # (Return Address)
push %rbx
push %rax
mov %cr2, %rax
push %rax
.endm
.macro interrupt_exit
add $8, %rsp
pop %rax
pop %rbx
pop %rcx
@ -26,11 +29,11 @@
pop %r8
pop %r9
pop %r10
pop %r10
pop %r10
pop %r10
pop %r10
pop %r10
pop %r11
pop %r12
pop %r13
pop %r14
pop %r15
pop %rbp
add $8, %rsp # Remove error code.