Lesson 10: 信号机制 Step 1

Implement signal handling framework

include/errno.h

@@ -0,0 +1,49 @@
+#ifndef _ERRNO_H
+#define _ERRNO_H
+
+// 错误号定义
+
+extern int errno;
+
+#define ERROR		99
+#define EPERM		 1
+#define ENOENT		 2
+#define ESRCH		 3
+#define EINTR		 4
+#define EIO		 5
+#define ENXIO		 6
+#define E2BIG		 7
+#define ENOEXEC		 8
+#define EBADF		 9
+#define ECHILD		10
+#define EAGAIN		11
+#define ENOMEM		12
+#define EACCES		13
+#define EFAULT		14
+#define ENOTBLK		15
+#define EBUSY		16
+#define EEXIST		17
+#define EXDEV		18
+#define ENODEV		19
+#define ENOTDIR		20
+#define EISDIR		21
+#define EINVAL		22
+#define ENFILE		23
+#define EMFILE		24
+#define ENOTTY		25
+#define ETXTBSY		26
+#define EFBIG		27
+#define ENOSPC		28
+#define ESPIPE		29
+#define EROFS		30
+#define EMLINK		31
+#define EPIPE		32
+#define EDOM		33
+#define ERANGE		34
+#define EDEADLK		35
+#define ENAMETOOLONG	36
+#define ENOLCK		37
+#define ENOSYS		38
+#define ENOTEMPTY	39
+
+#endif

include/linux/sys.h

@@ -7,6 +7,7 @@ extern int sys_fork();
 extern int sys_pause();
 extern int stub_syscall();
 extern int serial_debugstr(char *str);
+extern int sys_kill(int pid, int sig);
 
 // 目前除了少数syscall之外其余的syscall均为stub状态
 fn_ptr sys_call_table[] = {
@@ -47,7 +48,7 @@ fn_ptr sys_call_table[] = {
     stub_syscall,
     stub_syscall,
     stub_syscall,
-    stub_syscall,
+    sys_kill,
     stub_syscall,
     stub_syscall,
     stub_syscall, // 40

include/signal.h

@@ -1,6 +1,55 @@
 #ifndef _SIGNAL_H
 #define _SIGNAL_H
 
+#include <sys/types.h>
+
+typedef int sig_atomic_t;
+typedef unsigned int sigset_t;
+
+#define _NSIG 32		// 32种信号，所以下面的信号集也是32bit啦
+#define NSIG _NSIG
+
+// 定义信号宏
+
+#define SIGHUP 		1
+#define SIGINT 		2
+#define SIGQUIT 	3
+#define SIGILL 		4
+#define SIGTRAP 	5
+#define SIGABRT 	6
+#define SIGIOT 		6
+#define SIGUNUSED 	7
+#define SIGFPE 		8
+#define SIGKILL 	9
+#define SIGUSR1 	10
+#define SIGSEGV		11
+#define SIGUSR2		12
+#define SIGPIPE		13
+#define SIGALRM		14
+#define SIGSTKFLT	16
+#define SIGCHLD		17
+#define SIGCONT		18
+#define SIGSTOP		19
+#define SIGTSTP		20
+#define SIGTTIN		21
+#define SIGTTOU		22
+
+// 下面定义 sigaction 需要的结构
+#define SA_NOCLDSTOP 1
+#define SA_NOMASK 0x40000000		// 表示不阻止在某个信号的信号处理程序中再次收到该信号
+#define SA_ONESHOT 0x80000000		// 只调用一次信号处理句柄
+
+#define SIG_BLOCK 0
+#define SIG_UNBLOCK 1
+#define SIG_SETMASK 2
+
+#define SIG_DFL ((void(*) (int))0)		// 默认信号处理句柄
+#define SIG_IGN ((void(*) (int))1)		// 信号处理忽略句柄
+
+void (*signal(int _sig, void(*func)(int)))(int);
+int raise(int sig);						// 向自身发信号
+int kill(pid_t pid, int sig);			// 向某个进程发信号
+
 typedef unsigned int sigset_t;  // 32bit 信号集，一位表示一个信号，对于linux0.11已经够用了
 
 struct sigaction {
@@ -10,4 +59,17 @@ struct sigaction {
     void (*sa_restorer)(void);
 };
 
+// 对阻塞信号集的操作
+// Not implemented in sigaction
+int sigaddset(sigset_t *mask, int signo);
+int sigdelset(sigset_t *mask, int signo);
+int sigemptyset(sigset_t *mask);
+int sigfillset(sigset_t *mask);
+int sigismember(sigset_t *mask, int signo);
+
+int sigpending(sigset_t *set);
+int sigprocmask(int how, sigset_t *set, sigset_t *oldset);
+// 改变对于某个信号sig的处理过程
+int sigaction(int sig, struct sigaction *act, struct sigaction *oldact);
+
 #endif

include/sys/types.h

@@ -0,0 +1,47 @@
+#ifndef _SYS_TYPES_H
+#define _SYS_TYPES_H
+
+#ifndef _SIZE_T
+#define _SIZE_T
+typedef unsigned int size_t;
+#endif
+
+#ifndef _TIME_T
+#define _TIME_T
+typedef long time_t;
+#endif
+
+#ifndef _PTRDIFF_T
+#define _PTRDIFF_T
+typedef long ptrdiff_t;
+#endif
+
+#ifndef NULL
+#define NULL ((void *) 0)
+#endif
+
+typedef int pid_t;
+typedef unsigned short uid_t;
+typedef unsigned char gid_t;
+typedef unsigned short dev_t;
+typedef unsigned short ino_t;
+typedef unsigned short mode_t;
+typedef unsigned short umode_t;
+typedef unsigned char nlink_t;
+typedef int daddr_t;
+typedef long off_t;
+typedef unsigned char u_char;
+typedef unsigned short ushort;
+
+typedef struct { int quot,rem; } div_t;
+typedef struct { long quot,rem; } ldiv_t;
+
+struct ustat {
+	daddr_t f_tfree;
+	ino_t f_tinode;
+	char f_fname[6];
+	char f_fpack[6];
+};
+
+#endif
+

include/unistd.h

@@ -0,0 +1,67 @@
+#ifndef _UNISTD_H
+#define _UNISTD_H
+
+#ifdef __LIBRARY__
+
+#define __NR_fork 2
+#define __NR_pause 29
+#define __NR_kill 37
+#define __NR_sys_debug 72
+
+#define _syscall0(type, name)  \
+type name(void) \
+{ \
+    long __res; \
+    __asm__ volatile("int $0x80\n\t" \
+            : "=a" (__res)          \
+            : "0" (__NR_##name)); \
+    if (__res >= 0) \
+        return (type) __res; \
+    /*errno = -__res;*/ \
+    return  -1;\
+}
+
+#define _syscall1(type, name, atype, a) \
+type name(atype a) \
+{ \
+    long __res; \
+    __asm__ volatile("int $0x80\n\t" \
+            : "=a" (__res) \
+            : "0" (__NR_##name), "b" ((long) a)); \
+    if (__res >= 0) \
+        return (type) __res; \
+    /*errno = -__res;*/ \
+    return -1; \
+}
+
+#define _syscall2(type, name, atype, a, btype, b) \
+type name(atype a, btype b) \
+{ \
+    long __res; \
+    __asm__ volatile("int $0x80\n\t" \
+            : "=a" (__res) \
+            : "0" (__NR_##name), "b" ((long) a), "c" ((long) b)); \
+    if (__res >= 0) \
+        return (type) __res; \
+    /*errno = -__res;*/ \
+    return -1; \
+}
+
+#define _syscall3(type, name, atype, a, btype, b, ctype, c) \
+type name(atype a, btype b, ctype c) \
+{ \
+    long __res; \
+    __asm__ volatile("int $0x80\n\t" \
+            : "=a" (res) \
+            : "0" (__NR_##name), "b" ((long) a), "c" ((long) c), "d" ((long) c)); \
+    if (__res >= 0) \
+        return (type) __res; \
+    /* errno = -__res;*/ \
+    return -1; \
+}
+
+#endif
+
+static int pause(void);
+
+#endif

init/main.c

@@ -7,7 +7,7 @@
 
 #include <linux/kernel.h>
 #include <linux/sched.h>
-#include <linux/unistd.h>
+#include <unistd.h>
 #include <asm/system.h>
 #include <asm/io.h>
 // Use to debug serial
@@ -23,28 +23,9 @@ void init();
 
 static inline int fork(void) __attribute__((always_inline));
 static inline int pause(void) __attribute__((always_inline));
-static inline int sys_debug(char *str) __attribute__((always_inline));
-//static inline _syscall0(int, fork);
-
-static inline int fork(void) {
-    long __res;
-    __asm__ volatile("int $0x80\n\t"
-            :"=a" (__res)
-            :"0" (__NR_fork));
-    if( __res >= 0)
-        return (int) __res;
-    return -1;
-}
-
-static inline int sys_debug(char *str) {
-    long __res;
-    __asm__ volatile("int $0x80\n\t"
-            :"=a" (__res)
-            :"0" (__NR_sys_debug), "b" ((long)(str)));
-   if (__res >= 0)
-       return (int) __res;
-   return -1;
-}
+static inline int sys_debug(char *str);
+static inline _syscall0(int,fork)
+static inline _syscall1(int, sys_debug, char *, str)
 
 static inline int pause(void) {
     long __res;
@@ -72,9 +53,7 @@ static inline int pause(void) {
             :::"ax");
 
 int memtest_main(void);
-
-typedef unsigned long size_t;
-int snprintf(char *str, size_t size, const char *fmt, ...);
+void signal_demo_main(void);
 
 int main() {
     video_init();
@@ -91,13 +70,18 @@ int main() {
     // now user process can execute!
     // but why cannot schedule!
     if(!fork()) {
-        init();
+        if(!fork()) {
+            sched_abcd_demo();
+        } else {
+            signal_demo_main();
+        }
+        while(1);
     }
     // while(1);
     //     sys_debug("B");
 }
 
-void init() {
+void sched_abcd_demo() {
     // Here init process (pid = 1) will
     // print AABB randomly
     if(!fork()) {

kernel/Makefile

@@ -1,6 +1,7 @@
 include ../Makefile.header
 
-OBJS = printk.o panic.o traps.o asm.o sched.o system_call.o sys.o fork.o serial_debug.o
+OBJS = printk.o panic.o traps.o asm.o sched.o system_call.o sys.o fork.o \
+	   serial_debug.o signal.o signal_demo.o exit.o
 
 LDFLAGS	+= -r
 CFLAGS += -I../include