syscalls: umask

kernel-src/arch/x86-64/syscall.asm

@@ -32,6 +32,7 @@ extern syscall_linkat
 extern syscall_readlinkat
 extern syscall_fchmod
 extern syscall_fchmodat
+extern syscall_umask
 syscalltab:
 dq syscall_print
 dq syscall_mmap
@@ -66,7 +67,8 @@ dq syscall_linkat
 dq syscall_readlinkat
 dq syscall_fchmod
 dq syscall_fchmodat
-syscallcount equ 33
+dq syscall_umask
+syscallcount equ 34
 section .text
 global arch_syscall_entry
 ; on entry:

kernel-src/arch/x86-64/syscalllog.c

@@ -4,7 +4,7 @@
 
 #ifdef SYSCALL_LOGGING
 
-#define SYSCALL_COUNT 33
+#define SYSCALL_COUNT 34
 #define LOGSTR(x) arch_e9_puts(x)
 
 static char *name[] = {
@@ -40,7 +40,8 @@ static char *name[] = {
 	"linkat",
 	"readlinkat",
 	"fchmod",
-	"fchmodat"
+	"fchmodat",
+	"umask"
 };
 
 static char *args[] = {
@@ -76,7 +77,8 @@ static char *args[] = {
 	"olddirfd %d oldpath %s newdirfd %d oldpath %s flags %d type %d", // linkat
 	"dirfd %d path %s buffer %p buffer length %lu", // readlinkat
 	"fd %d mode %o", // fchmod
-	"dirfd %d path %s mode %o flags %d" // fchmodat
+	"dirfd %d path %s mode %o flags %d", // fchmodat
+	"mode %o" // umask
 };
 
 #endif

kernel-src/include/kernel/scheduler.h

@@ -67,6 +67,8 @@ typedef struct proc_t {
 
 #include <arch/cpu.h>
 
+#define UMASK(mode) ((mode) & ~_cpu()->thread->proc->umask)
+
 extern proc_t *sched_initproc;
 
 void sched_init();

kernel-src/sys/syscalls/chmod.c

@@ -11,7 +11,7 @@ static int dochmod(vnode_t *node, mode_t mode) {
 	if (e)
 		return e;
 
-	attr.mode = mode;
+	attr.mode = UMASK(mode);
 
 	return VOP_SETATTR(node, &attr, cred);
 }

kernel-src/sys/syscalls/linkat.c

@@ -40,7 +40,8 @@ syscallret_t syscall_linkat(context_t *, int olddirfd, const char *uoldpath, int
 
 	vattr_t attr = {
 		.gid = _cpu()->thread->proc->cred.gid,
-		.uid = _cpu()->thread->proc->cred.uid
+		.uid = _cpu()->thread->proc->cred.uid,
+		.mode = UMASK(0777)
 	};
 
 	ret.errno = vfs_link(olddirnode, oldpath, newdirnode, newpath, type == 0 ? V_TYPE_REGULAR : V_TYPE_LINK, &attr);

kernel-src/sys/syscalls/mkdirat.c

@@ -26,7 +26,7 @@ syscallret_t syscall_mkdirat(context_t *, int dirfd, const char *upath, mode_t m
 		goto cleanup;
 
 	vattr_t attr = {
-		.mode = mode,
+		.mode = UMASK(mode),
 		.gid = _cpu()->thread->proc->cred.gid,
 		.uid = _cpu()->thread->proc->cred.uid
 	};

kernel-src/sys/syscalls/open.c

@@ -35,7 +35,7 @@ syscallret_t syscall_openat(context_t *context, int dirfd, const char *path, int
 
 	if (ret.errno == ENOENT && (flags & O_CREAT)) {
 		vattr_t attr = {
-			.mode = mode,
+			.mode = UMASK(mode),
 			.gid = _cpu()->thread->proc->cred.gid,
 			.uid = _cpu()->thread->proc->cred.uid
 		};

kernel-src/sys/syscalls/umask.c

@@ -0,0 +1,14 @@
+#include <kernel/syscalls.h>
+#include <arch/cpu.h>
+
+syscallret_t syscall_umask(context_t *, mode_t mode) {
+	syscallret_t ret = {
+		.errno = 0
+	};
+
+	mode &= 0777;
+
+	ret.ret = __atomic_exchange_n(&_cpu()->thread->proc->umask, mode, __ATOMIC_SEQ_CST);
+
+	return ret;
+}