From 191c47396747e54457510c7e126b6ba098fefbbd Mon Sep 17 00:00:00 2001
From: Minep <zelong56@gmail.com>
Date: Mon, 20 Jun 2022 17:19:11 +0100
Subject: [PATCH] feat: pause(2) support

---
 lunaix-os/includes/lunaix/lunistd.h |  2 ++
 lunaix-os/includes/lunaix/process.h |  3 +++
 lunaix-os/includes/lunaix/status.h  |  2 ++
 lunaix-os/includes/lunaix/syscall.h | 15 ++++++++++-----
 lunaix-os/kernel/asm/x86/syscall.S  |  1 +
 lunaix-os/kernel/lxinit.c           |  1 +
 lunaix-os/kernel/signal.c           | 15 +++++++++++++++
 7 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/lunaix-os/includes/lunaix/lunistd.h b/lunaix-os/includes/lunaix/lunistd.h
index 42c4320..7a1c368 100644
--- a/lunaix-os/includes/lunaix/lunistd.h
+++ b/lunaix-os/includes/lunaix/lunistd.h
@@ -18,4 +18,6 @@ __LXSYSCALL1(void, _exit, int, status)
 
 __LXSYSCALL1(unsigned int, sleep, unsigned int, seconds)
 
+__LXSYSCALL(int, pause)
+
 #endif /* __LUNAIX_UNISTD_H */
diff --git a/lunaix-os/includes/lunaix/process.h b/lunaix-os/includes/lunaix/process.h
index 7a5d502..2cd4330 100644
--- a/lunaix-os/includes/lunaix/process.h
+++ b/lunaix-os/includes/lunaix/process.h
@@ -21,6 +21,8 @@
 
 #define PROC_TERMMASK 0x6
 
+#define PROC_FINPAUSE 1
+
 struct proc_mm
 {
     heap_context_t u_heap;
@@ -64,6 +66,7 @@ struct proc_info
     int32_t k_status;
     sigset_t sig_pending;
     sigset_t sig_mask;
+    int flags;
     void* sig_handler[_SIG_NUM];
     pid_t pgid;
     struct lx_timer* timer;
diff --git a/lunaix-os/includes/lunaix/status.h b/lunaix-os/includes/lunaix/status.h
index f3309ab..aeef93e 100644
--- a/lunaix-os/includes/lunaix/status.h
+++ b/lunaix-os/includes/lunaix/status.h
@@ -9,4 +9,6 @@
 #define LXSEGFAULT -(5)
 #define LXINVL -(6)
 
+#define EINTR -(7)
+
 #endif /* __LUNAIX_CODE_H */
diff --git a/lunaix-os/includes/lunaix/syscall.h b/lunaix-os/includes/lunaix/syscall.h
index 3a6e2eb..f695cf7 100644
--- a/lunaix-os/includes/lunaix/syscall.h
+++ b/lunaix-os/includes/lunaix/syscall.h
@@ -33,11 +33,6 @@ syscall_install();
 #define __PARAM_MAP5(t1, p1, ...) t1 p1, __PARAM_MAP4(__VA_ARGS__)
 #define __PARAM_MAP6(t1, p1, ...) t1 p1, __PARAM_MAP5(__VA_ARGS__)
 
-#define ___DOINT33(callcode, rettype)                                          \
-    int v;                                                                     \
-    asm volatile("int %1\n" : "=a"(v) : "i"(LUNAIX_SYS_CALL), "a"(callcode));  \
-    return (rettype)v;
-
 #define __DEFINE_LXSYSCALL(rettype, name) asmlinkage rettype __lxsys_##name()
 
 #define __DEFINE_LXSYSCALL1(rettype, name, t1, p1)                             \
@@ -53,6 +48,16 @@ syscall_install();
     asmlinkage rettype __lxsys_##name(                                         \
       __PARAM_MAP4(t1, p1, t2, p2, t3, p3, t4, p4))
 
+#define __SYSCALL_INTERRUPTIBLE(code)                                          \
+    asm("sti");                                                                \
+    { code };                                                                  \
+    asm("cli");
+
+#define ___DOINT33(callcode, rettype)                                          \
+    int v;                                                                     \
+    asm volatile("int %1\n" : "=a"(v) : "i"(LUNAIX_SYS_CALL), "a"(callcode));  \
+    return (rettype)v;
+
 #define __LXSYSCALL(rettype, name)                                             \
     static rettype name()                                                      \
     {                                                                          \
diff --git a/lunaix-os/kernel/asm/x86/syscall.S b/lunaix-os/kernel/asm/x86/syscall.S
index e97cc6f..0922a96 100644
--- a/lunaix-os/kernel/asm/x86/syscall.S
+++ b/lunaix-os/kernel/asm/x86/syscall.S
@@ -21,6 +21,7 @@
         .long __lxsys_sigreturn
         .long __lxsys_sigprocmask
         .long __lxsys_signal
+        .long __lxsys_pause
         2:
         .rept __SYSCALL_MAX - (2b - 1b)/4
             .long 0
diff --git a/lunaix-os/kernel/lxinit.c b/lunaix-os/kernel/lxinit.c
index 1485c34..2de87c5 100644
--- a/lunaix-os/kernel/lxinit.c
+++ b/lunaix-os/kernel/lxinit.c
@@ -50,6 +50,7 @@ _lxinit_main()
         kprintf("I am child, I am about to terminated\n");
         _exit(1);
     }
+    pause();
     pid_t child = wait(&status);
     kprintf("I am parent, my child (%d) terminated normally with code: %d.\n",
             child,
diff --git a/lunaix-os/kernel/signal.c b/lunaix-os/kernel/signal.c
index 49f1e53..80a7098 100644
--- a/lunaix-os/kernel/signal.c
+++ b/lunaix-os/kernel/signal.c
@@ -1,6 +1,7 @@
 #include <lunaix/process.h>
 #include <lunaix/sched.h>
 #include <lunaix/signal.h>
+#include <lunaix/status.h>
 #include <lunaix/syscall.h>
 
 extern struct scheduler sched_ctx; /* kernel/sched.c */
@@ -62,6 +63,7 @@ __DEFINE_LXSYSCALL1(int, sigreturn, struct proc_sig, *sig_ctx)
 {
     __current->intr_ctx = sig_ctx->prev_context;
     __current->sig_mask &= ~__SIGNAL(sig_ctx->sig_num);
+    __current->flags &= ~PROC_FINPAUSE;
     schedule();
 }
 
@@ -101,4 +103,17 @@ __DEFINE_LXSYSCALL2(int, signal, int, signum, sighandler_t, handler)
     __current->sig_handler[signum] = (void*)handler;
 
     return 0;
+}
+
+__DEFINE_LXSYSCALL(int, pause)
+{
+    __current->flags |= PROC_FINPAUSE;
+
+    __SYSCALL_INTERRUPTIBLE({
+        while ((__current->flags & PROC_FINPAUSE)) {
+            sched_yield();
+        }
+    })
+    __current->k_status = EINTR;
+    return -1;
 }
\ No newline at end of file
-- 
2.27.0