From f475850f314e7e99bfb08a24c182da5ced517759 Mon Sep 17 00:00:00 2001
From: hinus <hinus@163.com>
Date: Wed, 11 Aug 2021 17:10:09 +0800
Subject: [PATCH] Title: System call 'umask' Issue:
 https://gitee.com/hinus/linux_kernel_011/issues/I44ZQO Description: System
 call 'umask'

---
 include/linux/sys.h | 4 ++--
 include/unistd.h    | 1 +
 kernel/sys.c        | 7 +++++++
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/linux/sys.h b/include/linux/sys.h
index 8c92ab3..532b87b 100644
--- a/include/linux/sys.h
+++ b/include/linux/sys.h
@@ -58,7 +58,7 @@ extern int sys_mpx();
 //extern int sys_setpgid();
 extern int sys_ulimit();
 extern int sys_uname();
-//extern int sys_umask();
+extern int sys_umask();
 extern int sys_chroot();
 //extern int sys_ustat();
 //extern int sys_dup2();
@@ -156,7 +156,7 @@ fn_ptr sys_call_table[] = {
     sys_ulimit,
 
     sys_uname,
-    0, //    sys_umask,
+    sys_umask,
     sys_chroot,
     0, //    sys_ustat,
     0, //    sys_dup2,
diff --git a/include/unistd.h b/include/unistd.h
index f180a18..f2436f2 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -168,6 +168,7 @@ int lseek(int fildes, off_t offset, int origin);
 int rmdir(const char* pathname);
 
 time_t time(time_t * tloc);
+mode_t umask(mode_t mask);
 int uname(struct utsname * name);
 
 #endif
diff --git a/kernel/sys.c b/kernel/sys.c
index e114595..6e29cda 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -102,3 +102,10 @@ int sys_uname(struct utsname * name) {
     return 0;
 }
 
+int sys_umask(int mask) {
+    int old = current->umask;
+
+    current->umask = mask & 0777;
+    return (old);
+}
+
-- 
Gitee