system/serenity
system/serenity
1
0
Fork 0
mirror of https://github.com/SerenityOS/serenity synced 2024-10-01 21:53:54 +00:00
Code Issues Packages Projects Releases Wiki Activity

Kernel/x86_64: *Restore* interrupt flag in page fault handler

Browse source 
If a page fault occurs while interrupts are disabled, we were wrongly
enabling interrupts right away in the page fault handler.

Instead, we should only do this if interrupts were enabled when the
page fault occurred.
This commit is contained in:
Andreas Kling 2022-12-30 23:14:28 +01:00
parent e3b9f78eb9
commit 1b4baaed56
1 changed files with 6 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
Kernel/Arch/x86_64/Interrupts.cpp
View file

@ -177,13 +177,16 @@ void page_fault_handler(TrapFrame* trap)
{
clac();
// NOTE: Once we've extracted the faulting address from CR2,
// we can re-enable interrupts.
auto fault_address = read_cr2();
sti();
auto& regs = *trap->regs;
// NOTE: Once we've extracted the faulting address from CR2, we can re-enable interrupts.
// However, we only do this *if* they were enabled when the page fault occurred.
if (regs.flags() & 0x200) {
sti();
}
if constexpr (PAGE_FAULT_DEBUG) {
u32 fault_page_directory = read_cr3();
dbgln("CPU #{} ring {} {} page fault in PD={:#x}, {}{} {}",