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2026-02-25 15:20:06 +01:00
parent 8b271e2470
commit 23b453dac8
3 changed files with 37 additions and 10 deletions
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41
kernel/interrupt/handlers.cc
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@@ -9,6 +9,8 @@
#include "../device/ps2controller.h" #include "../device/ps2controller.h"
#include "./epilogues.h" #include "./epilogues.h"
#include "./guard.h" #include "./guard.h"
#include "../memory/pagetable.h"
#include "../memory/pageframealloc.h"
static void printContext(const InterruptContext *context) { static void printContext(const InterruptContext *context) {
DBG << "ip: " << hex << context->cs << ':' << context->ip DBG << "ip: " << hex << context->cs << ':' << context->ip
@@ -49,14 +51,39 @@ static void printContext(const InterruptContext *context) {
#include "syscall/skeleton.h" #include "syscall/skeleton.h"
[[gnu::interrupt]] static void handle_page_fault(InterruptContext *context, [[gnu::interrupt]] static void handle_page_fault(InterruptContext *context,
uint64_t error) { uint64_t error) {
DBG << "Page fault encountered at linear address " << hex DBG << "Page fault encountered at linear address " << hex
<< Core::CR<2>::read() << endl << Core::CR<2>::read() << endl
<< PageFaultError(error) << endl; << PageFaultError(error) << endl;
printContext(context); four_lvl_paging_t* paging_tree = Guard::enter().vault().scheduler.active()->paging_tree ;
asm volatile("mov %%cr3, %0" : "=r"(paging_tree));
Syscall::Skeleton::exit(Guard::enter().vault()); uintptr_t virt = 0;
//kernelpanic("Page fault!"); asm volatile("mov %%cr2, %0" : "=r"(virt));
if (PageFaultError(error).present && PageFaultError(error).write) {
uintptr_t pf =isMapped(virt, paging_tree);
uint64_t pf_number = uint64_t (pf >> 12 );
if(PageFrameAllocator::PageFrames[pf_number].ref_count==1){
setMapping(virt, (void*) pf , paging_tree, 1);
}else{
uintptr_t page = (uintptr_t) PageFrameAllocator::alloc(false);
//Syscall::Skeleton::map(page, 4096);
setMapping(virt, (void*) page , paging_tree, 1);
memcpy( (void*)page, (void*)virt, 4096);
Syscall::Skeleton::invlpg(virt);
}
}
Syscall::Skeleton::exit(Guard::enter().vault());
//kernelpanic("Page fault!");
} }
/*! \brief Assembly interrupt handler for the keyboard. /*! \brief Assembly interrupt handler for the keyboard.

4
kernel/memory/pagetable.cc
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@@ -160,7 +160,7 @@ void* getFreeVirtSpace(four_lvl_paging_t* search_table, uint8_t num_pages){
} }
void setMapping(uintptr_t vaddr, void* frame, four_lvl_paging_t* flpt){ void setMapping(uintptr_t vaddr, void* frame, four_lvl_paging_t* flpt, uint8_t writeable){
uint16_t l4Index = (vaddr>>39) & 0x1FF; uint16_t l4Index = (vaddr>>39) & 0x1FF;
uint16_t l3Index = (vaddr>>30) & 0x1FF; uint16_t l3Index = (vaddr>>30) & 0x1FF;
uint16_t l2Index = (vaddr>>21) & 0x1FF; uint16_t l2Index = (vaddr>>21) & 0x1FF;
@@ -207,7 +207,7 @@ void setMapping(uintptr_t vaddr, void* frame, four_lvl_paging_t* flpt){
assert(!(lvl1->entries[l1Index].present)); // should not be present, bc its a new mapping assert(!(lvl1->entries[l1Index].present)); // should not be present, bc its a new mapping
lvl1->entries[l1Index] = { lvl1->entries[l1Index] = {
.present = 1, .present = 1,
.write = 1, .write = writeable,
.user = 1, .user = 1,
.address = (uintptr_t)frame >> 12 .address = (uintptr_t)frame >> 12
}; };

2
kernel/memory/pagetable.h
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@@ -50,7 +50,7 @@ typedef struct {
void write_identity_map(pagetable_t* identity_table, uint64_t size); void write_identity_map(pagetable_t* identity_table, uint64_t size);
void create_basic_page_table(four_lvl_paging_t* table, pagetable_t* kernel_identity); void create_basic_page_table(four_lvl_paging_t* table, pagetable_t* kernel_identity);
void load_cr3(void* cr3_value); void load_cr3(void* cr3_value);
void setMapping(uintptr_t vaddr, void* frame, four_lvl_paging_t* flpt); void setMapping(uintptr_t vaddr, void* frame, four_lvl_paging_t* flpt, uint8_t writeable =1);
uintptr_t isMapped(uintptr_t vaddr, four_lvl_paging_t* flpt); uintptr_t isMapped(uintptr_t vaddr, four_lvl_paging_t* flpt);
void* getFreeVirtSpace(four_lvl_paging_t* search_table, uint8_t num_pages); void* getFreeVirtSpace(four_lvl_paging_t* search_table, uint8_t num_pages);
void copy_pagetable(four_lvl_paging_t* parent_table, four_lvl_paging_t* child_table); void copy_pagetable(four_lvl_paging_t* parent_table, four_lvl_paging_t* child_table);