bug fixes

5 files changed, 27 insertions, 25 deletions

diff --git a/kernel/arch/i386/mmu.c b/kernel/arch/i386/mmu.c
index 7147c74..53b2156 100644
--- a/kernel/arch/i386/mmu.c
+++ b/kernel/arch/i386/mmu.c
@@ -8,7 +8,6 @@
 
 #define INDEX_FROM_BIT(a) (a / (32))
 #define OFFSET_FROM_BIT(a) (a % (32))
-#define PAGE_SIZE ((uintptr_t)0x1000)
 
 #define PAGE_ALLOCATE 1
 #define PAGE_NO_ALLOCATE 0
@@ -107,6 +106,7 @@ Page *get_page(void *ptr, PageDirectory *directory, int create_new_page,
   Page *p = &directory->tables[table_index]->pages[address % 1024];
   if (create_new_page) {
     p->present = 0;
+    p->user = set_user;
   }
   return &directory->tables[table_index]->pages[address % 1024];
 }
@@ -120,19 +120,6 @@ void mmu_free_pages(void *a, u32 n) {
   }
 }
 
-void *next_page(void *ptr) {
-  uintptr_t a = (uintptr_t)ptr;
-  return (void *)(a + (PAGE_SIZE - ((u32)a & (PAGE_SIZE - 1))));
-}
-
-void *align_page(void *a) {
-  if ((uintptr_t)a & (PAGE_SIZE - 1)) {
-    return next_page(a);
-  }
-
-  return a;
-}
-
 u32 first_free_frame(void) {
   u32 i = 1;
   for (; i < INDEX_FROM_BIT(num_array_frames * 32); i++) {
@@ -329,7 +316,13 @@ int mmu_allocate_region(void *ptr, size_t n, mmu_flags flags,
   pd = (pd) ? pd : get_active_pagedirectory();
   size_t num_pages = n / 0x1000;
   for (size_t i = 0; i <= num_pages; i++) {
-    Page *p = get_page((void *)(ptr + i * 0x1000), pd, PAGE_ALLOCATE, 1);
+    Page *p = get_page((void *)(ptr + i * 0x1000), pd, 0, 0);
+    if (p && p->present) {
+      p->rw = (flags & MMU_FLAG_RW);
+      p->user = !(flags & MMU_FLAG_KERNEL);
+      continue;
+    }
+    p = get_page((void *)(ptr + i * 0x1000), pd, PAGE_ALLOCATE, 1);
     assert(p);
     int rw = (flags & MMU_FLAG_RW);
     int kernel = (flags & MMU_FLAG_KERNEL);
@@ -338,6 +331,7 @@ int mmu_allocate_region(void *ptr, size_t n, mmu_flags flags,
       return 0;
     }
   }
+  flush_tlb();
   return 1;
 }
 
diff --git a/kernel/cpu/syscall.c b/kernel/cpu/syscall.c
index 6789628..d3da640 100644
--- a/kernel/cpu/syscall.c
+++ b/kernel/cpu/syscall.c
@@ -110,8 +110,6 @@ int syscall_getpid(void) {
   return current_task->pid;
 }
 
-void *align_page(void *a);
-
 int syscall_brk(void *addr) {
   void *end = current_task->data_segment_end;
   if (!mmu_allocate_region(end, addr - end, MMU_FLAG_RW, NULL)) {
diff --git a/kernel/fs/ext2.c b/kernel/fs/ext2.c
index e815e79..9a3560f 100644
--- a/kernel/fs/ext2.c
+++ b/kernel/fs/ext2.c
@@ -1,6 +1,7 @@
 #include <assert.h>
 #include <fs/ext2.h>
 #include <fs/vfs.h>
+#include <math.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <typedefs.h>
@@ -251,8 +252,8 @@ int ext2_read_dir(int dir_inode, u8 *buffer, size_t len, size_t offset) {
     u8 *p = (u8 *)&tmp_entry;
     size_t l = sizeof(struct dirent);
 
-    l = (len < l) ? len : l;
-    memcpy(buffer, p, l);
+    l = min(len - rc, l);
+    memcpy(buffer + rc, p, l);
     len -= l;
     rc += l;
   }
diff --git a/kernel/fs/shm.c b/kernel/fs/shm.c
index 7eec825..2a2995b 100644
--- a/kernel/fs/shm.c
+++ b/kernel/fs/shm.c
@@ -54,9 +54,17 @@ vfs_vm_object_t *shm_get_vm_object(u64 length, u64 offset, vfs_fd_t *fd) {
 
 int shm_ftruncate(vfs_fd_t *fd, size_t length) {
   vfs_vm_object_t *p = fd->inode->internal_object;
+  if (p->real_pointer) {
+    u8 *mem_region = p->real_pointer;
+    mmu_free_address_range(mem_region, align_page(p->size), NULL);
+  }
+
+  p->real_pointer = mmu_find_unallocated_virtual_range(NULL, length);
+  mmu_allocate_region(p->real_pointer, length, MMU_FLAG_RW, NULL);
   p->size = length;
-  p->real_pointer = krealloc(p->real_pointer, length + 0x2000);
-  p->virtual_object = align_page(p->real_pointer);
+
+  p->virtual_object = p->real_pointer;
+
   int n = (uintptr_t)align_page((void *)(u32)length) / 0x1000;
   p->object = krealloc(p->object, sizeof(void *) * n);
   for (int i = 0; i < n; i++) {
@@ -72,8 +80,6 @@ int shm_open(const char *name, int oflag, mode_t mode) {
   vfs_vm_object_t *internal_object =
       hashmap_get_entry(shared_memory_objects, name);
   if (!internal_object) {
-    //    if (!(oflag & O_CREAT))
-    //      return -EMFILE;
     internal_object = kcalloc(1, sizeof(vfs_vm_object_t));
     hashmap_add_entry(shared_memory_objects, name, internal_object, NULL, 0);
   }
diff --git a/kernel/includes/mmu.h b/kernel/includes/mmu.h
index 9a27c5b..43814d5 100644
--- a/kernel/includes/mmu.h
+++ b/kernel/includes/mmu.h
@@ -9,8 +9,11 @@ typedef u8 mmu_flags;
 #define MMU_FLAG_RW (1 << 0)
 #define MMU_FLAG_KERNEL (1 << 1)
 
-void *next_page(void *a);
-void *align_page(void *a);
+#define PAGE_SIZE ((uintptr_t)0x1000)
+#define next_page(_ptr)                                                        \
+  ((_ptr) + (PAGE_SIZE - (((uintptr_t)_ptr) & (PAGE_SIZE - 1))))
+#define align_page(_ptr)                                                       \
+  (((((uintptr_t)_ptr) & (PAGE_SIZE - 1)) > 0) ? next_page((_ptr)) : (_ptr))
 
 typedef struct Page {
   u32 present : 1;