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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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34
kernel/proc/proc.c
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@ -90,8 +90,10 @@ Proc *proc_spawnkern(void (*ent)(void), char *name) {
proc->kern = true;
uint8_t *sp = (uint8_t *)pmm_alloc(PROC_STACKBLOCKS) + PROC_STACKSIZE;
uint8_t *kstackp = (uint8_t *)pmm_alloc(PROC_STACKBLOCKS) + PROC_STACKSIZE;
proc->platformdata.kstack = kstackp;
proc->platformdata.pstack = sp;
proc->platformdata.kstack = sp;
hal_memset(&proc->platformdata.trapframe, 0, sizeof(proc->platformdata.trapframe));
proc->platformdata.trapframe.ss = 0x10;
@ -99,7 +101,7 @@ Proc *proc_spawnkern(void (*ent)(void), char *name) {
proc->platformdata.trapframe.rflags = 0x202;
proc->platformdata.trapframe.cs = 0x08;
proc->platformdata.trapframe.rip = (uint64_t)ent;
proc->platformdata.cr3 = hal_vmm_current_cr3();
proc->platformdata.cr3 = KERNEL_CR3;
proc->state = PROC_EMBRYO;
proc->pid = pids++;
spinlock_init(&proc->bcast_pipes.spinlock);
@ -145,21 +147,24 @@ Proc *proc_spawnuser(char *mountpoint, char *path) {
uint8_t *sp = (uint8_t *)pmm_alloc(PROC_STACKBLOCKS) + PROC_STACKSIZE;
uint8_t *spbase = sp - PROC_STACKSIZE;
uint8_t *kstackp = (uint8_t *)pmm_alloc(PROC_STACKBLOCKS) + PROC_STACKSIZE;
proc->platformdata.kstack = kstackp;
proc->platformdata.pstack = sp;
proc->platformdata.kstack = sp;
hal_memset(&proc->platformdata.trapframe, 0, sizeof(proc->platformdata.trapframe));
proc->platformdata.cr3 = hal_vmm_userproc_pml4(proc);
uint32_t flags = HAL_PG_RW | HAL_PG_USER | HAL_PG_PRESENT;
hal_vmm_map_range(VIRT(proc->platformdata.cr3), spbase, spbase, PROC_STACKSIZE, flags);
VasRange *range = dlmalloc(sizeof(*range));
range->virtstart = spbase;
range->physstart = spbase;
range->size = PROC_STACKSIZE;
range->pgflags = flags;
LL_APPEND(proc->vas, range);
ElfAuxval aux = proc_load_elf_segs(proc, data);
proc->platformdata.trapframe.ss = 0x20 | 0x3;
@ -216,15 +221,16 @@ void proc_reaper(void) {
}
}
for (size_t i = 0; i < PROC_PIPEHANDLES_MAX; i++) {
if (zombie->pipes[i] != NULL && zombie->pipes[i]->ownerpid == zombie->pid) {
dlfree(zombie->pipes[i]);
ipc_pipefree(zombie->pipes[i]);
zombie->pipes[i] = NULL;
}
}
/* for (size_t i = 0; i < PROC_PIPEHANDLES_MAX; i++) { */
/* if (zombie->pipes[i] != NULL && zombie->pipes[i]->ownerpid == zombie->pid) { */
/* dlfree(zombie->pipes[i]); */
/* ipc_pipefree(zombie->pipes[i]); */
/* zombie->pipes[i] = NULL; */
/* } */
/* } */
pmm_free((uintptr_t)(zombie->platformdata.kstack - PROC_STACKSIZE), PROC_STACKBLOCKS);
pmm_free((uintptr_t)(zombie->platformdata.pstack - PROC_STACKSIZE), PROC_STACKBLOCKS);
if (!zombie->kern) {
VasRange *vashead = zombie->vas;
@ -258,8 +264,6 @@ void proc_reaper(void) {
}
}
extern void hal_zombiespin(void);
void proc_sched(void *cpustate) {
hal_intr_disable();
sched_ticks++;
@ -274,6 +278,7 @@ void proc_sched(void *cpustate) {
proc_reaper();
}
tss.rsp0 = (uint64_t)VIRT(PROCS.current->platformdata.kstack);
hal_switchproc(&PROCS.current->platformdata.trapframe, (void *)PROCS.current->platformdata.cr3);
}
@ -331,5 +336,6 @@ void proc_init(void) {
proc_register(init);
init->state = PROC_READY;
tss.rsp0 = (uint64_t)VIRT(PROCS.current->platformdata.kstack);
hal_switchproc(&PROCS.current->platformdata.trapframe, (void *)PROCS.current->platformdata.cr3);
}

1
kernel/proc/proc.h
View File

@ -24,6 +24,7 @@
typedef struct {
IntrStackFrame trapframe;
uint8_t *kstack;
uint8_t *pstack;
PgTable *cr3;
} ProcPlatformData;