kernel: stuff

8 files changed, 49 insertions, 16 deletions

diff --git a/kernel/cpu/syscall.c b/kernel/cpu/syscall.c
index d31835d..aad0284 100644
--- a/kernel/cpu/syscall.c
+++ b/kernel/cpu/syscall.c
@@ -362,6 +362,13 @@ int syscall_shm_open(SYS_SHM_OPEN_PARAMS *args) {
   return shm_open(args->name, args->oflag, args->mode);
 }
 
+int syscall_shm_unlink(const char *name) {
+  if (!mmu_is_valid_user_c_string(name, NULL)) {
+    return -EPERM; // TODO: Is this correct?
+  }
+  return shm_unlink(name);
+}
+
 int syscall_sigaction(int sig, const struct sigaction *restrict act,
                       struct sigaction *restrict oact) {
   set_signal_handler(sig, act->sa_handler);
@@ -692,6 +699,7 @@ int (*syscall_functions[])() = {
     (void(*))syscall_queue_mod_entries,
     (void(*))syscall_queue_wait,
     (void(*))syscall_sendfile,
+    (void(*))syscall_shm_unlink,
 };
 
 void int_syscall(reg_t *r);
diff --git a/kernel/fs/shm.c b/kernel/fs/shm.c
index 57ec3c5..5e44b97 100644
--- a/kernel/fs/shm.c
+++ b/kernel/fs/shm.c
@@ -78,6 +78,12 @@ int shm_ftruncate(vfs_fd_t *fd, size_t length) {
   return 0;
 }
 
+void shm_close(vfs_fd_t *fd) {
+  vfs_vm_object_t *internal_object = fd->inode->internal_object;
+  assert(internal_object->num_of_references > 0);
+  internal_object->num_of_references--;
+}
+
 int shm_open(const char *name, int oflag, mode_t mode) {
   // Try to find or create a new shared memory object.
   vfs_vm_object_t *internal_object =
@@ -90,10 +96,11 @@ int shm_open(const char *name, int oflag, mode_t mode) {
     hashmap_add_entry(shared_memory_objects, name, internal_object, NULL, 0);
   }
 
+  internal_object->num_of_references++;
   vfs_inode_t *inode = vfs_create_inode(
       0 /*inode_num*/, 0 /*type*/, NULL, NULL, 1 /*is_open*/, 0,
       internal_object, 0 /*file_size*/, NULL /*open*/, NULL /*create_file*/,
-      shm_read, shm_write, NULL /*close*/, NULL /*create_directory*/,
+      shm_read, shm_write, shm_close, NULL /*create_directory*/,
       shm_get_vm_object, shm_ftruncate, NULL /*stat*/, NULL /*send_signal*/,
       NULL /*connect*/);
 
@@ -107,6 +114,19 @@ int shm_open(const char *name, int oflag, mode_t mode) {
 }
 
 int shm_unlink(const char *name) {
-  (void)name;
+  vfs_vm_object_t *p = hashmap_get_entry(shared_memory_objects, name);
+  if (!p) {
+    return -ENOENT;
+  }
+  if (0 != p->num_of_references) {
+    p->num_of_references--;
+  }
+  if (0 == p->num_of_references && p->real_pointer) {
+    u8 *mem_region = p->real_pointer;
+    mmu_free_address_range(mem_region, align_page(p->size), NULL);
+    p->real_pointer = NULL;
+    p->size = 0;
+  }
+  assert(hashmap_delete_entry(shared_memory_objects, name));
   return 0;
 }
diff --git a/kernel/fs/vfs.h b/kernel/fs/vfs.h
index 640cfbb..396802b 100644
--- a/kernel/fs/vfs.h
+++ b/kernel/fs/vfs.h
@@ -25,6 +25,7 @@ struct vfs_vm_object {
   void *virtual_object;
   void **object;
   u64 size;
+  u32 num_of_references;
 };
 
 struct vfs_mounts {
diff --git a/kernel/network/udp.c b/kernel/network/udp.c
index c0a5237..6b40c1a 100644
--- a/kernel/network/udp.c
+++ b/kernel/network/udp.c
@@ -16,12 +16,11 @@ void send_udp_packet(struct sockaddr_in *src, const struct sockaddr_in *dst,
   header[2] = htons(payload_length + 8);
 
   u16 packet_length = sizeof(header) + payload_length;
-  u8 *packet = kmalloc(packet_length);
+  u8 packet[0x1000];
   memcpy(packet, header, sizeof(header));
   memcpy(packet + sizeof(header), payload, payload_length);
   send_ipv4_packet((ipv4_t){.d = dst->sin_addr.s_addr}, 0x11, packet,
                    packet_length);
-  kfree(packet);
 }
 
 void handle_udp(ipv4_t src_ip, ipv4_t dst_ip, const u8 *payload,
diff --git a/kernel/sched/scheduler.c b/kernel/sched/scheduler.c
index 1285d26..9fec2b7 100644
--- a/kernel/sched/scheduler.c
+++ b/kernel/sched/scheduler.c
@@ -28,14 +28,6 @@ u32 next_pid = 0;
 
 extern u32 read_eip(void);
 
-process_t *get_current_task(void) {
-  return current_task;
-}
-
-process_t *get_ready_queue(void) {
-  return ready_queue;
-}
-
 void process_push_restore_context(process_t *p, reg_t r) {
   if (!p) {
     p = current_task;
@@ -535,20 +527,27 @@ process_t *next_task(process_t *s) {
 
 void signal_process(process_t *p, int sig) {
   assert(sig < 32);
-  kprintf("sending signal to: %x\n", p);
+  int talking_to_itself = (p == current_task);
   if (!p->signal_handlers[sig]) {
     if (SIGTERM == sig) {
       kprintf("HAS NO SIGTERM\n");
       exit_process(p, 1 /*TODO: what should the status be?*/);
-      ASSERT_NOT_REACHED;
+      if (talking_to_itself) {
+        ASSERT_NOT_REACHED;
+      }
     } else if (SIGSEGV == sig) {
       kprintf("HAS NO SIGSEGV\n");
       exit_process(p, 1 /*TODO: what should the status be?*/);
-      ASSERT_NOT_REACHED;
+      if (talking_to_itself) {
+        ASSERT_NOT_REACHED;
+      }
     } else {
       // TODO: Should also exit proess(I think)
-      ASSERT_NOT_REACHED;
+      if (talking_to_itself) {
+        ASSERT_NOT_REACHED;
+      }
     }
+    return;
   }
   signal_t signal = {.handler_ip = (uintptr_t)p->signal_handlers[sig]};
   process_push_signal(p, signal);
diff --git a/userland/libc/include/stdio.h b/userland/libc/include/stdio.h
index aebf086..ac49a67 100644
--- a/userland/libc/include/stdio.h
+++ b/userland/libc/include/stdio.h
@@ -76,6 +76,7 @@ int wait(int *stat_loc);
 void exit(int status);
 void *memcpy(void *dest, const void *src, uint32_t n);
 int shm_open(const char *name, int oflag, mode_t mode);
+int shm_unlink(const char *name);
 int dprintf(int fd, const char *format, ...);
 int vdprintf(int fd, const char *format, va_list ap);
 int vprintf(const char *format, va_list ap);
diff --git a/userland/libc/include/syscall.h b/userland/libc/include/syscall.h
index dda4b82..a0303f4 100644
--- a/userland/libc/include/syscall.h
+++ b/userland/libc/include/syscall.h
@@ -52,6 +52,7 @@
 #define SYS_QUEUE_MOD_ENTRIES 44
 #define SYS_QUEUE_WAIT 45
 #define SYS_SENDFILE 46
+#define SYS_SHM_UNLINK 47
 
 int syscall(uint32_t eax, uint32_t ebx, uint32_t ecx, uint32_t edx,
             uint32_t esi, uint32_t edi);
diff --git a/userland/libc/libc.c b/userland/libc/libc.c
index decd002..f1b6bdf 100644
--- a/userland/libc/libc.c
+++ b/userland/libc/libc.c
@@ -272,3 +272,7 @@ int shm_open(const char *name, int oflag, mode_t mode) {
   };
   RC_ERRNO(syscall(SYS_SHM_OPEN, (u32)&args, 0, 0, 0, 0));
 }
+
+int shm_unlink(const char *name) {
+  RC_ERRNO(syscall(SYS_SHM_UNLINK, (u32)name, 0, 0, 0, 0));
+}