Kernel, libc: Add O_EXCL

kernel/include/sys/Syscall.h

@@ -1,6 +1,7 @@
 #pragma once
 #include "interrupts/Context.h"
 #include <stddef.h>
+#include <sys/types.h>
 
 #define SYS_exit 0
 #define SYS_yield 1
@@ -45,7 +46,7 @@ void sys_paint(Context* context, uint64_t x, uint64_t y, uint64_t w, uint64_t h,
 void sys_getprocid(Context* context, int field);
 void sys_mmap(Context* context, void* address, size_t size, int prot);
 void sys_munmap(Context* context, void* address, size_t size);
-void sys_open(Context* context, const char* filename, int flags);
+void sys_open(Context* context, const char* filename, int flags, mode_t mode);
 void sys_read(Context* context, int fd, size_t size, char* buffer);
 void sys_close(Context* context, int fd);
 void sys_seek(Context* context, int fd, long offset, int whence);

kernel/src/sys/Syscall.cpp

@@ -19,7 +19,7 @@ void Syscall::entry(Context* context)
     case SYS_getprocid: sys_getprocid(context, (int)context->rdi); break;
     case SYS_mmap: sys_mmap(context, (void*)context->rdi, context->rsi, (int)context->rdx); break;
     case SYS_munmap: sys_munmap(context, (void*)context->rdi, context->rsi); break;
-    case SYS_open: sys_open(context, (const char*)context->rdi, (int)context->rsi); break;
+    case SYS_open: sys_open(context, (const char*)context->rdi, (int)context->rsi, (mode_t)context->rdx); break;
     case SYS_read: sys_read(context, (int)context->rdi, context->rsi, (char*)context->rdx); break;
     case SYS_close: sys_close(context, (int)context->rdi); break;
     case SYS_seek: sys_seek(context, (int)context->rdi, (long)context->rsi, (int)context->rdx); break;

kernel/src/sys/stdio.cpp

@@ -11,6 +11,7 @@
 #include "sys/UserMemory.h"
 #include "thread/Scheduler.h"
 #include "thread/Task.h"
+#include <sys/types.h>
 
 #define OPEN_READ 1
 #define OPEN_WRITE 2
@@ -20,6 +21,7 @@
 #define OPEN_TRUNCATED 32
 #define OPEN_CREATE 64
 #define OPEN_APPEND 128
+#define OPEN_EXCL 256
 
 #define SEEK_SET 0
 #define SEEK_CUR 1
@@ -137,7 +139,7 @@ void sys_write(Context* context, int fd, size_t size, const char* addr)
     return;
 }
 
-void sys_open(Context* context, const char* filename, int flags)
+void sys_open(Context* context, const char* filename, int flags, mode_t) // FIXME: mode is not used.
 {
     Task* current_task = Scheduler::current_task();
     int fd = current_task->alloc_fd();
@@ -163,6 +165,17 @@ void sys_open(Context* context, const char* filename, int flags)
         context->rax = -ENOENT;
         return;
     }
+    else
+    {
+        bool excl = (flags & OPEN_EXCL) > 0;
+
+        if (excl)
+        {
+            kfree(kfilename);
+            context->rax = -EEXIST;
+            return;
+        }
+    }
 
     bool can_read = (flags & OPEN_READ) > 0;
     bool can_write = (flags & OPEN_WRITE) > 0;

libs/libc/include/fcntl.h

@@ -19,6 +19,8 @@
 #define O_CREAT 64
 /* Open the file for appending. */
 #define O_APPEND 128
+/* Fail to open the file if it already exists. */
+#define O_EXCL 256
 
 /* Duplicate a file descriptor. */
 #define F_DUPFD 0
@@ -31,7 +33,7 @@ extern "C"
 #endif
 
     /* Opens the file specified by pathname. Returns a file descriptor on success, or -1 on error. */
-    int open(const char* pathname, int flags);
+    int open(const char* pathname, int flags, ...);
 
     /* Performs an operation on the file descriptor fd determined by cmd. */
     int fcntl(int fd, int cmd, ...);

libs/libc/include/time.h

@@ -21,6 +21,13 @@ struct tm
     const char* tm_zone;
 };
 
+// Captures elapsed time.
+struct timeval
+{
+    time_t tv_sec;
+    unsigned long tv_usec;
+};
+
 #define CLOCKS_PER_SEC 1000 // Number of clock_t per second.
 
 #ifdef __cplusplus

libs/libc/src/fcntl.cpp

@@ -6,9 +6,13 @@
 
 extern "C"
 {
-    int open(const char* pathname, int flags)
+    int open(const char* pathname, int flags, ...)
     {
-        return (int)syscall(SYS_open, pathname, flags);
+        va_list ap;
+        va_start(ap, flags);
+        long result = syscall(SYS_open, pathname, flags, va_arg(ap, unsigned int));
+        va_end(ap);
+        return (int)result;
     }
 
     int fcntl(int fd, int cmd, ...)

libs/libc/src/syscall.cpp

@@ -26,13 +26,13 @@ extern "C" long syscall(long number, ...)
     case SYS_fstat:
     case SYS_stat:
     case SYS_dup2:
-    case SYS_pstat:
+    case SYS_pstat: {
-    case SYS_open: {
         arg arg0 = va_arg(ap, arg);
         arg arg1 = va_arg(ap, arg);
         result = __luna_syscall2(number, arg0, arg1);
         break;
     }
+    case SYS_open:
     case SYS_getdents:
     case SYS_fcntl:
     case SYS_seek: