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Fix dlmalloc horror bug - mman_map overwrites application code

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This commit is contained in:
Kamil Kowalczyk
2025-09-14 19:07:00 +02:00
parent e6891b39cc
commit 26ff717b50
18 changed files with 197 additions and 137 deletions
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27
kernel/hal/x86_64/gdt.c
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@ -4,17 +4,12 @@
#include "hal/hal.h"
#include "gdt.h"
#define GDT_SIZE 5
#define GDT_PRESENT 0x80
#define GDT_TSS 0x89
#define KSTACK 8192
ALIGNED(16) static uint8_t kernelstack[KSTACK];
#define ISTS 7
#define ISTACK 4096
ALIGNED(16) static uint8_t iststacks[ISTS][ISTACK];
typedef struct {
uint16_t limitlow;
uint16_t baselow;
@ -35,19 +30,7 @@ typedef struct {
GdtEntry tsshigh;
} PACKED ExtendedGdt;
typedef struct {
uint32_t resv0;
uint64_t rsp0;
uint64_t rsp1;
uint64_t rsp2;
uint64_t resv1;
uint64_t ist[ISTS];
uint64_t resv2;
uint16_t resv3;
uint16_t iopb_off;
} PACKED Tss;
ALIGNED(16) static Tss tss = {0};
ALIGNED(16) Tss tss = {0};
ALIGNED(16) static ExtendedGdt gdt = {0};
void gdt_setentry(GdtEntry *ent, uint32_t base, uint32_t limit, uint8_t acc, uint8_t gran) {
@ -65,18 +48,14 @@ void gdt_init(void) {
tss.rsp0 = (uint64_t)(kernelstack + sizeof(kernelstack));
for (size_t i = 0; i < ISTS; i++) {
tss.ist[i] = (uint64_t)(iststacks[i] + sizeof(iststacks[i]));
}
uint64_t tss_base = (uint64_t)&tss;
uint32_t tss_limit = sizeof(tss) - 1;
gdt_setentry(&gdt.old[0], 0, 0, 0, 0);
gdt_setentry(&gdt.old[1], 0, 0xFFFFF, 0x9a, 0xA0);
gdt_setentry(&gdt.old[2], 0, 0xFFFFF, 0x92, 0xA0);
gdt_setentry(&gdt.old[2], 0, 0xFFFFF, 0x92, 0xC0);
gdt_setentry(&gdt.old[3], 0, 0xFFFFF, 0xfa, 0xA0);
gdt_setentry(&gdt.old[4], 0, 0xFFFFF, 0xf2, 0xA0);
gdt_setentry(&gdt.old[4], 0, 0xFFFFF, 0xf2, 0xC0);
gdt_setentry(&gdt.tsslow, tss_base & 0xFFFFFFFF, tss_limit, GDT_PRESENT | GDT_TSS, 0x0);