#include <lunaix/mm/region.h>
#include <lunaix/mm/vmm.h>
#include <lunaix/sched.h>
+#include <lunaix/signal.h>
#include <lunaix/status.h>
#include <lunaix/syslog.h>
+#include <klibc/string.h>
+
+static u32_t
+get_ptattr(struct mm_region* vmr)
+{
+ u32_t vmr_attr = vmr->attr;
+ u32_t ptattr = PG_PRESENT | PG_ALLOW_USER;
+
+ if ((vmr_attr & PROT_WRITE)) {
+ ptattr |= PG_WRITE;
+ }
+
+ return ptattr & 0xfff;
+}
+
static void
kprintf(const char* fmt, ...)
{
va_end(args);
}
+#define COW_MASK (REGION_RSHARED | REGION_READ | REGION_WRITE)
+
extern void
__print_panic_msg(const char* msg, const isr_param* param);
-extern void __kernel_heap_start;
-
void
intr_routine_page_fault(const isr_param* param)
{
- uintptr_t ptr = cpu_rcr2();
+ uint32_t errcode = param->execp->err_code;
+ ptr_t ptr = cpu_rcr2();
if (!ptr) {
goto segv_term;
}
goto segv_term;
}
- if (!SEL_RPL(param->cs)) {
- // 如果是内核页错误……
- if (do_kernel(&mapping)) {
- return;
- }
- goto segv_term;
+ if (!SEL_RPL(param->execp->cs)) {
+ // TODO if kernel pfault
}
- struct mm_region* hit_region = region_get(__current, ptr);
+ vm_regions_t* vmr = (vm_regions_t*)&__current->mm.regions;
+ struct mm_region* hit_region = region_get(vmr, ptr);
if (!hit_region) {
- // Into the void...
+ // 当你凝视深渊时……
goto segv_term;
}
- x86_pte_t* pte = PTE_MOUNTED(PD_REFERENCED, ptr >> 12);
- if (*pte & PG_PRESENT) {
- if ((hit_region->attr & REGION_PERM_MASK) ==
- (REGION_RSHARED | REGION_READ)) {
+ volatile x86_pte_t* pte = &PTE_MOUNTED(VMS_SELF, ptr >> 12);
+ if (PG_IS_PRESENT(*pte)) {
+ if (((errcode ^ mapping.flags) & PG_ALLOW_USER)) {
+ // invalid access
+ kprintf(KDEBUG "invalid user access. (%p->%p, attr:0x%x)\n",
+ mapping.va,
+ mapping.pa,
+ mapping.flags);
+ goto segv_term;
+ }
+ if ((hit_region->attr & COW_MASK) == COW_MASK) {
// normal page fault, do COW
- cpu_invplg(pte);
- uintptr_t pa =
- (uintptr_t)vmm_dup_page(__current->pid, PG_ENTRY_ADDR(*pte));
+ cpu_invplg((ptr_t)pte);
+
+ ptr_t pa = (ptr_t)vmm_dup_page(__current->pid, PG_ENTRY_ADDR(*pte));
+
pmm_free_page(__current->pid, *pte & ~0xFFF);
- *pte = (*pte & 0xFFF) | pa | PG_WRITE;
- return;
+ *pte = (*pte & 0xFFF & ~PG_DIRTY) | pa | PG_WRITE;
+
+ goto resolved;
}
// impossible cases or accessing privileged page
goto segv_term;
}
- if (!(*pte)) {
- // Invalid location
+ // an anonymous page and not present
+ // -> a new page need to be alloc
+ if ((hit_region->attr & REGION_ANON)) {
+ if (!PG_IS_PRESENT(*pte)) {
+ cpu_invplg((ptr_t)pte);
+
+ ptr_t pa = pmm_alloc_page(__current->pid, 0);
+ if (!pa) {
+ goto oom;
+ }
+
+ *pte = *pte | pa | get_ptattr(hit_region);
+ memset((void*)PG_ALIGN(ptr), 0, PG_SIZE);
+ goto resolved;
+ }
+ // permission denied on anon page (e.g., write on readonly page)
goto segv_term;
}
- uintptr_t loc = *pte & ~0xfff;
- // a writable page, not present, pte attr is not null
- // and no indication of cached page -> a new page need to be alloc
- if ((hit_region->attr & REGION_WRITE) && (*pte & 0xfff) && !loc) {
- cpu_invplg(pte);
- uintptr_t pa = pmm_alloc_page(__current->pid, 0);
- *pte = *pte | pa | PG_PRESENT;
- return;
+
+ // if mfile is set (Non-anonymous), then it is a mem map
+ if (hit_region->mfile && !PG_IS_PRESENT(*pte)) {
+ struct v_file* file = hit_region->mfile;
+
+ ptr = PG_ALIGN(ptr);
+
+ u32_t mseg_off = (ptr - hit_region->start);
+ u32_t mfile_off = mseg_off + hit_region->foff;
+ ptr_t pa = pmm_alloc_page(__current->pid, 0);
+
+ if (!pa) {
+ goto oom;
+ }
+
+ cpu_invplg((ptr_t)pte);
+ *pte = (*pte & 0xFFF) | pa | get_ptattr(hit_region);
+
+ memset((void*)ptr, 0, PG_SIZE);
+
+ int errno = 0;
+ if (mseg_off < hit_region->flen) {
+ errno =
+ file->ops->read_page(file->inode, (void*)ptr, PG_SIZE, mfile_off);
+ }
+
+ if (errno < 0) {
+ kprintf(KERROR "fail to populate page (%d)\n", errno);
+ goto segv_term;
+ }
+
+ *pte &= ~PG_DIRTY;
+
+ goto resolved;
}
- // page not present, bring it from disk or somewhere else
+
+ // page not present, might be a chance to introduce swap file?
__print_panic_msg("WIP page fault route", param);
while (1)
;
+oom:
+ kprintf(KERROR "out of memory\n");
+
segv_term:
- kprintf(KERROR "(pid: %d) Segmentation fault on %p (%p:%p)\n",
+ kprintf(KERROR "(pid: %d) Segmentation fault on %p (%p:%p,e=0x%x)\n",
__current->pid,
ptr,
- param->cs,
- param->eip);
- terminate_proc(LXSEGFAULT);
- // should not reach
-}
+ param->execp->cs,
+ param->execp->eip,
+ param->execp->err_code);
-int
-do_kernel(v_mapping* mapping)
-{
- uintptr_t addr = mapping->va;
- if (addr >= &__kernel_heap_start && addr < L2_BASE_VADDR) {
- // This is kernel heap page
- uintptr_t pa = pmm_alloc_page(KERNEL_PID, 0);
- *mapping->pte = (*mapping->pte & 0xfff) | pa | PG_PRESENT;
- cpu_invplg(mapping->pte);
- cpu_invplg(addr);
- goto done;
- }
+ sigset_add(__current->sigctx.sig_pending, _SIGSEGV);
+
+ schedule();
+ // should not reach
+ while (1)
+ ;
- return 0;
-done:
- return 1;
+resolved:
+ cpu_invplg(ptr);
+ return;
}
\ No newline at end of file
git://scm.lunaixsky.com / lunaix-os.git / blobdiff