feat: nearly complete POSIX.1-2008 compliant terminal interface implementation

[lunaix-os.git] / lunaix-os / kernel / mm / mmap.c

diff --git a/lunaix-os/kernel/mm/mmap.c b/lunaix-os/kernel/mm/mmap.c
index 77e1264d2926661d78ea1ff335e030a250f5ccc5..fa71016adc828e4792e47c5bf69796bb6f5a10cd 100644 (file)
--- a/lunaix-os/kernel/mm/mmap.c
+++ b/lunaix-os/kernel/mm/mmap.c
@@ -7,8 +7,10 @@
 #include <lunaix/syscall.h>
 #include <lunaix/syscall_utils.h>
 
+#include <sys/mm/mempart.h>
+
 // any size beyond this is bullshit
-#define BS_SIZE (KERNEL_MM_BASE - UMMAP_START)
+#define BS_SIZE (KERNEL_EXEC - USR_MMAP)
 
 int
 mem_has_overlap(vm_regions_t* regions, ptr_t start, ptr_t end)
@@ -64,7 +66,7 @@ mem_map(void** addr_out,
 {
     assert_msg(addr, "addr can not be NULL");
 
-    ptr_t last_end = USER_START, found_loc = addr;
+    ptr_t last_end = USR_EXEC, found_loc = addr;
     struct mm_region *pos, *n;
 
     vm_regions_t* vm_regions = &param->pvms->regions;
@@ -92,7 +94,7 @@ mem_map(void** addr_out,
             if (pos->start > found_loc && avail_space > param->mlen) {
                 goto found;
             }
-            found_loc = pos->end + PG_SIZE;
+            found_loc = pos->end + MEM_PAGE;
         }
 
         last_end = pos->end;
@@ -101,7 +103,7 @@ mem_map(void** addr_out,
     return ENOMEM;
 
 found:
-    if (found_loc >= KERNEL_MM_BASE || found_loc < USER_START) {
+    if (found_loc >= KERNEL_EXEC || found_loc < USR_EXEC) {
         return ENOMEM;
     }
 
@@ -112,7 +114,6 @@ found:
 
     region->mfile = file;
     region->foff = param->offset;
-    region->flen = param->flen;
     region->proc_vms = param->pvms;
 
     region_add(vm_regions, region);
@@ -172,8 +173,7 @@ mem_sync_pages(ptr_t mnt,
             size_t offset = mapping.va - region->start + region->foff;
             struct v_inode* inode = region->mfile->inode;
 
-            region->mfile->ops->write_page(
-              inode, (void*)mapping.va, PG_SIZE, offset);
+            region->mfile->ops->write_page(inode, (void*)mapping.va, offset);
 
             *mapping.pte &= ~PG_DIRTY;
 
@@ -237,6 +237,91 @@ mem_unmap_region(ptr_t mnt, struct mm_region* region)
     region_release(region);
 }
 
+// Case: head inseted, tail inseted
+#define CASE_HITI(vmr, addr, len)                                              \
+    ((vmr)->start <= (addr) && ((addr) + (len)) <= (vmr)->end)
+
+// Case: head inseted, tail extruded
+#define CASE_HITE(vmr, addr, len)                                              \
+    ((vmr)->start <= (addr) && ((addr) + (len)) > (vmr)->end)
+
+// Case: head extruded, tail inseted
+#define CASE_HETI(vmr, addr, len)                                              \
+    ((vmr)->start > (addr) && ((addr) + (len)) <= (vmr)->end)
+
+// Case: head extruded, tail extruded
+#define CASE_HETE(vmr, addr, len)                                              \
+    ((vmr)->start > (addr) && ((addr) + (len)) > (vmr)->end)
+
+static void
+__unmap_overlapped_cases(ptr_t mnt,
+                         struct mm_region* vmr,
+                         ptr_t* addr,
+                         size_t* length)
+{
+    // seg start, umapped segement start
+    ptr_t seg_start = *addr, umps_start = 0;
+
+    // seg len, umapped segement len
+    size_t seg_len = *length, umps_len = 0;
+
+    size_t displ = 0, shrink = 0;
+
+    if (CASE_HITI(vmr, seg_start, seg_len)) {
+        size_t new_start = seg_start + seg_len;
+
+        // Require a split
+        if (new_start < vmr->end) {
+            struct mm_region* region = region_dup(vmr);
+            if (region->mfile) {
+                size_t f_shifted = new_start - region->start;
+                region->foff += f_shifted;
+            }
+            region->start = new_start;
+            llist_insert_after(&vmr->head, &region->head);
+        }
+
+        shrink = vmr->end - seg_start;
+        umps_len = shrink;
+        umps_start = seg_start;
+    } else if (CASE_HITE(vmr, seg_start, seg_len)) {
+        shrink = vmr->end - seg_start;
+        umps_len = shrink;
+        umps_start = seg_start;
+    } else if (CASE_HETI(vmr, seg_start, seg_len)) {
+        displ = seg_len - (vmr->start - seg_start);
+        umps_len = displ;
+        umps_start = vmr->start;
+    } else if (CASE_HETE(vmr, seg_start, seg_len)) {
+        shrink = vmr->end - vmr->start;
+        umps_len = shrink;
+        umps_start = vmr->start;
+    }
+
+    mem_sync_pages(mnt, vmr, vmr->start, umps_len, 0);
+    for (size_t i = 0; i < umps_len; i += PG_SIZE) {
+        ptr_t pa = vmm_del_mapping(mnt, vmr->start + i);
+        if (pa) {
+            pmm_free_page(vmr->proc_vms->pid, pa);
+        }
+    }
+
+    vmr->start += displ;
+    vmr->end -= shrink;
+
+    if (vmr->start >= vmr->end) {
+        llist_delete(&vmr->head);
+        region_release(vmr);
+    } else if (vmr->mfile) {
+        vmr->foff += displ;
+    }
+
+    *addr = umps_start + umps_len;
+
+    size_t ump_len = *addr - seg_start;
+    *length = MAX(seg_len, ump_len) - ump_len;
+}
+
 int
 mem_unmap(ptr_t mnt, vm_regions_t* regions, ptr_t addr, size_t length)
 {
@@ -246,42 +331,17 @@ mem_unmap(ptr_t mnt, vm_regions_t* regions, ptr_t addr, size_t length)
 
     llist_for_each(pos, n, regions, head)
     {
-        if (pos->start <= cur_addr && pos->end >= cur_addr) {
+        u32_t l = pos->start - cur_addr;
+        if ((pos->start <= cur_addr && cur_addr < pos->end) || l <= length) {
             break;
         }
     }
 
-    while (&pos->head != regions && cur_addr >= pos->start) {
-        u32_t l = pos->end - cur_addr;
-        pos->end = cur_addr;
-
-        if (l > length) {
-            // unmap cause discontinunity in a memory region -  do split
-            struct mm_region* region = valloc(sizeof(struct mm_region));
-            *region = *pos;
-            region->start = cur_addr + length;
-            llist_insert_after(&pos->head, &region->head);
-            l = length;
-        }
-
-        mem_sync_pages(mnt, pos, cur_addr, l, 0);
-
-        for (size_t i = 0; i < l; i += PG_SIZE) {
-            ptr_t pa = vmm_del_mapping(mnt, cur_addr + i);
-            if (pa) {
-                pmm_free_page(pos->proc_vms->pid, pa);
-            }
-        }
-
+    while (&pos->head != regions && length) {
         n = container_of(pos->head.next, typeof(*pos), head);
-        if (pos->end == pos->start) {
-            llist_delete(&pos->head);
-            region_release(pos);
-        }
+        __unmap_overlapped_cases(mnt, pos, &cur_addr, &length);
 
         pos = n;
-        length -= l;
-        cur_addr += length;
     }
 
     return 0;
@@ -304,8 +364,8 @@ __DEFINE_LXSYSCALL3(void*, sys_mmap, void*, addr, size_t, length, va_list, lst)
     }
 
     if (!addr_ptr) {
-        addr_ptr = UMMAP_START;
-    } else if (addr_ptr < UMMAP_START || addr_ptr + length >= UMMAP_END) {
+        addr_ptr = USR_MMAP;
+    } else if (addr_ptr < USR_MMAP || addr_ptr + length >= USR_MMAP_END) {
         if (!(options & (MAP_FIXED | MAP_FIXED_NOREPLACE))) {
             errno = ENOMEM;
             goto done;
@@ -329,6 +389,7 @@ __DEFINE_LXSYSCALL3(void*, sys_mmap, void*, addr, size_t, length, va_list, lst)
 
     struct mmap_param param = { .flags = options,
                                 .mlen = ROUNDUP(length, PG_SIZE),
+                                .flen = length,
                                 .offset = offset,
                                 .type = REGION_TYPE_GENERAL,
                                 .proct = proct,