syscalls: setpriority

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

@@ -103,6 +103,7 @@ extern syscall_fstatvfs
 extern syscall_fstatvfsat
 extern syscall_getsockopt
 extern syscall_clock_getres
+extern syscall_setpriority
 syscalltab:
 dq syscall_print
 dq syscall_mmap
@@ -208,7 +209,8 @@ dq syscall_fstatvfs
 dq syscall_fstatvfsat
 dq syscall_getsockopt
 dq syscall_clock_getres
-syscallcount equ 104
+dq syscall_setpriority
+syscallcount equ 105
 section .text
 global arch_syscall_entry
 ; on entry:

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

@@ -9,7 +9,7 @@
 void arch_interrupt_disable();
 void arch_interrupt_enable();
 
-#define SYSCALL_COUNT 104
+#define SYSCALL_COUNT 105
 #define LOGSTR(x) arch_e9_puts(x)
 
 static char *name[] = {
@@ -117,6 +117,7 @@ static char *name[] = {
 	"fstatvfsat",
 	"getsockopt",
 	"clock_getres",
+	"setpriority",
 };
 
 static char *args[] = {
@@ -224,6 +225,7 @@ static char *args[] = {
 	"dirfd %d path %s ustat %p flags %d", // fstatvfsat
 	"fd %d level %d optname %d optval %p optlen %p", // getsockopt
 	"clockid %d timespec %p", // clock_getres
+	"which %d who %d prio %d", // setpriority
 };
 
 #endif

kernel-src/sys/syscalls/setpriority.c

@@ -0,0 +1,29 @@
+#include <kernel/syscalls.h>
+#include <kernel/thread.h>
+#include <kernel/auth.h>
+#include <arch/cpu.h>
+
+syscallret_t syscall_setpriority(context_t *, int which, int who, int priority) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	if (which != 0) {
+		ret.errno = EINVAL;
+		return ret;
+	}
+
+	if (who) {
+		ret.errno = ESRCH;
+		return ret;
+	}
+
+	ret.errno = priority < current_thread()->proc->nice ? auth_process_check(&current_thread()->proc->cred, AUTH_ACTIONS_PROCESS_NICE, NULL) : 0;
+	if (ret.errno)
+		return ret;
+
+	current_thread()->proc->nice = max(min(priority, SCHED_NICE_MAX), SCHED_NICE_MIN);
+
+	ret.ret = 0;
+	return ret;
+}