Changeset 610 for trunk/kernel/syscalls/sys_getcwd.c

Timestamp:

Dec 27, 2018, 7:38:58 PM (6 years ago)

Author:

alain

Message:

Fix several bugs in VFS to support the following
ksh commandis : cp, mv, rm, mkdir, cd, pwd

File:

• trunk/kernel/syscalls/sys_getcwd.c (modified) (6 diffs)

trunk/kernel/syscalls/sys_getcwd.c

@@ -1 +1 @@
 /*
- * sys_getcwd.c - get process current work directory
+ * sys_getcwd.c - kernel function implementing the "getcwd" syscall.
  * 
  * Author    Alain Greiner (2016,2017,2018)
@@ -35 +35 @@
 #include <syscalls.h>
 
-/* TODO: user page(s) need to be locked  [AG] */
-
-////////////////////////////////
-int sys_getcwd ( char     * buf, 
+///////////////////////////////////
+int sys_getcwd ( char     * buffer,
                  uint32_t   nbytes )
 {
-        error_t    error;
-    vseg_t   * vseg;
-    char       kbuf[CONFIG_VFS_MAX_PATH_LENGTH];
-  
+        error_t       error;
+    vseg_t      * vseg;
+    char        * first;                   // first character valid in buffer
+
+    char          kbuf[CONFIG_VFS_MAX_PATH_LENGTH]; 
+
         thread_t  * this    = CURRENT_THREAD;
     process_t * process = this->process;
+
+#if (DEBUG_SYS_GETCWD || CONFIG_INSTRUMENTATION_SYSCALLS)
+uint64_t     tm_start = hal_get_cycles();
+#endif
 
     // check buffer size
@@ -53 +57 @@
 
 #if DEBUG_SYSCALLS_ERROR
-printk("\n[ERROR] in %s : buffer too small / thread %x / process %x\n",
-__FUNCTION__ , this->trdid , process->pid );
+printk("\n[ERROR] in %s : buffer too small for thread %x,%x]\n",
+__FUNCTION__ , process->pid, this->trdid );
 #endif
                 this->errno = EINVAL;
@@ -61 +65 @@
 
     // check buffer in user space
-    error = vmm_get_vseg( process, (intptr_t)buf , &vseg );
+    error = vmm_get_vseg( process, (intptr_t)buffer , &vseg );
 
         if( error )
@@ -67 +71 @@
 
 #if DEBUG_SYSCALLS_ERROR
-printk("\n[ERROR] in %s : user buffer unmapped %x / thread %x / process %x\n",
-__FUNCTION__ , (intptr_t)buf , this->trdid , process->pid );
+printk("\n[ERROR] in %s : user buffer unmapped %x for thread[%x,%x]\n",
+__FUNCTION__ , (intptr_t)buffer , process->pid, this->trdid );
 #endif
                 this->errno = EINVAL;
@@ -74 +78 @@
         }
 
-    // get reference process cluster and local pointer
+#if DEBUG_SYS_GETCWD
+if( DEBUG_SYS_GETCWD < tm_start )
+printk("\n[%s] thread[%x,%x] enter / cycle %d\n",
+__FUNCTION__, process->pid, this->trdid, (uint32_t)tm_start );
+#endif
+
+    // get extended pointer on CWD inode from the reference process
     xptr_t      ref_xp  = process->ref_xp;
+    process_t * ref_ptr = GET_PTR( ref_xp );
     cxy_t       ref_cxy = GET_CXY( ref_xp );
-    process_t * ref_ptr = (process_t *)GET_PTR( ref_xp );
-
-    // get CWD lock in read mode
-        remote_rwlock_rd_acquire( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
+    xptr_t      cwd_xp  = hal_remote_l64( XPTR( ref_cxy , &ref_ptr->cwd_xp ) );
 
     // call relevant VFS function
-        error = vfs_get_path( XPTR( ref_cxy , &ref_ptr->vfs_cwd_xp ) ,
-                          kbuf , CONFIG_VFS_MAX_PATH_LENGTH );
-
-    // release CWD lock in read mode
-        remote_rwlock_rd_release( XPTR( ref_cxy , &ref_ptr->cwd_lock ) );
+        error = vfs_get_path( cwd_xp,
+                          kbuf, 
+                          &first, 
+                          CONFIG_VFS_MAX_PATH_LENGTH );
 
     // copy kernel buffer to user space
-    hal_copy_to_uspace( buf , kbuf , CONFIG_VFS_MAX_PATH_LENGTH );
+    hal_strcpy_to_uspace( buffer , first , CONFIG_VFS_MAX_PATH_LENGTH );
 
     hal_fence();
+
+#if (DEBUG_SYS_GETCWD || CONFIG_INSTRUMENTATION_SYSCALLS)
+uint64_t     tm_end = hal_get_cycles();
+#endif
+
+#if DEBUG_SYS_GETCWD
+if( DEBUG_SYS_GETCWD < tm_end )
+printk("\n[%s] thread[%x,%x] exit / cycle %d\n",
+__FUNCTION__, process->pid, this->trdid, (uint32_t)tm_end );
+#endif
+ 
+#if CONFIG_INSTRUMENTATION_SYSCALLS
+hal_atomic_add( &syscalls_cumul_cost[SYS_GETCWD] , tm_end - tm_start );
+hal_atomic_add( &syscalls_occurences[SYS_GETCWD] , 1 );
+#endif
 
         return 0;