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Kernel: Move kernel region checks from x86 page fault handler to MM

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Ideally the x86 fault handler would only do x86 specific things and
delegate the rest of the work to MemoryManager. This patch moves some of
the address checks to a more generic place.
This commit is contained in:
Andreas Kling 2022-01-28 15:04:34 +01:00
parent 5092813a45
commit a12e19c015
Notes: sideshowbarker 2024-07-18 03:23:00 +09:00
2 changed files with 17 additions and 16 deletions
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16
Kernel/Arch/x86/common/Interrupts.cpp
View file

@ -327,22 +327,6 @@ void page_fault_handler(TrapFrame* trap)
return handle_crash(regs, "Bad stack on page fault", SIGSEGV);
}
if (fault_address >= (FlatPtr)&start_of_ro_after_init && fault_address < (FlatPtr)&end_of_ro_after_init) {
dump(regs);
PANIC("Attempt to write into READONLY_AFTER_INIT section");
}
if (fault_address >= (FlatPtr)&start_of_unmap_after_init && fault_address < (FlatPtr)&end_of_unmap_after_init) {
dump(regs);
auto sym = symbolicate_kernel_address(fault_address);
PANIC("Attempt to access UNMAP_AFTER_INIT section ({:p}: {})", fault_address, sym ? sym->name : "(Unknown)");
}
if (fault_address >= (FlatPtr)&start_of_kernel_ksyms && fault_address < (FlatPtr)&end_of_kernel_ksyms) {
dump(regs);
PANIC("Attempt to access KSYMS section");
}
PageFault fault { regs.exception_code, VirtualAddress { fault_address } };
auto response = MM.handle_page_fault(fault);

17
Kernel/Memory/MemoryManager.cpp
View file

@ -12,6 +12,7 @@
#include <Kernel/CMOS.h>
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/Heap/kmalloc.h>
#include <Kernel/KSyms.h>
#include <Kernel/Memory/AnonymousVMObject.h>
#include <Kernel/Memory/MemoryManager.h>
#include <Kernel/Memory/PageDirectory.h>
@ -720,6 +721,22 @@ Region* MemoryManager::find_region_from_vaddr(VirtualAddress vaddr)
PageFaultResponse MemoryManager::handle_page_fault(PageFault const& fault)
{
VERIFY_INTERRUPTS_DISABLED();
auto faulted_in_range = [&fault](auto const* start, auto const* end) {
return fault.vaddr() >= VirtualAddress { start } && fault.vaddr() < VirtualAddress { end };
};
if (faulted_in_range(&start_of_ro_after_init, &end_of_ro_after_init))
PANIC("Attempt to write into READONLY_AFTER_INIT section");
if (faulted_in_range(&start_of_unmap_after_init, &end_of_unmap_after_init)) {
auto const* kernel_symbol = symbolicate_kernel_address(fault.vaddr().get());
PANIC("Attempt to access UNMAP_AFTER_INIT section ({:p}: {})", fault.vaddr(), kernel_symbol ? kernel_symbol->name : "(Unknown)");
}
if (faulted_in_range(&start_of_kernel_ksyms, &end_of_kernel_ksyms))
PANIC("Attempt to access KSYMS section");
if (Processor::current_in_irq()) {
dbgln("CPU[{}] BUG! Page fault while handling IRQ! code={}, vaddr={}, irq level: {}",
Processor::current_id(), fault.code(), fault.vaddr(), Processor::current_in_irq());