support SIGSEGV(page fault) and SIGILL(general protection error)

arch/x86/kernel/cpu.c

@@ -373,12 +373,15 @@ void handle_interrupt(int vector, struct x86_regs *regs)
 	}
 }
 
+void sigill(void *);
+
 void gpe_handler(struct x86_regs *regs)
 {
 	kprintf("General protection fault (err: %lx, %lx:%lx)\n",
 	        regs->error, regs->cs, regs->rip);
 	arch_show_interrupt_context(regs);
-	panic("GPF");
+	sigill(regs);
+	// panic("GPF");
 }
 
 void x86_issue_ipi(unsigned int apicid, unsigned int low)

arch/x86/kernel/include/signal.h

@@ -16,3 +16,39 @@ struct sigaction {
 struct k_sigaction {
         struct sigaction sa;
 };
+
+#define SIGHUP           1
+#define SIGINT           2
+#define SIGQUIT          3
+#define SIGILL           4
+#define SIGTRAP          5
+#define SIGABRT          6
+#define SIGIOT           6
+#define SIGBUS           7
+#define SIGFPE           8
+#define SIGKILL          9
+#define SIGUSR1         10
+#define SIGSEGV         11
+#define SIGUSR2         12
+#define SIGPIPE         13
+#define SIGALRM         14
+#define SIGTERM         15
+#define SIGSTKFLT       16
+#define SIGCHLD         17
+#define SIGCONT         18
+#define SIGSTOP         19
+#define SIGTSTP         20
+#define SIGTTIN         21
+#define SIGTTOU         22
+#define SIGURG          23
+#define SIGXCPU         24
+#define SIGXFSZ         25
+#define SIGVTALRM       26
+#define SIGPROF         27
+#define SIGWINCH        28
+#define SIGIO           29
+#define SIGPOLL         SIGIO
+#define SIGPWR          30
+#define SIGSYS          31
+#define SIGUNUSED       31
+#define SIGRTMIN        32

arch/x86/kernel/syscall.c

@@ -6,6 +6,10 @@
 #include <ihk/debug.h>
 #include <cls.h>
 #include <syscall.h>
+#include <process.h>
+#include <string.h>
+
+void terminate(int, int, ihk_mc_user_context_t *);
 
 //#define DEBUG_PRINT_SC
 
@@ -67,3 +71,80 @@ int obtain_clone_cpuid() {
     ihk_mc_spinlock_unlock_noirq(&cpuid_head_lock);
     return cpuid;
 }
+
+SYSCALL_DECLARE(rt_sigreturn)
+{
+        struct process *proc = cpu_local_var(current);
+        char *kspbottom;
+        asm volatile ("movq %%gs:132,%0" : "=r" (kspbottom));
+        memcpy(kspbottom - 120, proc->sigstack, 120);
+
+        return proc->sigrc;
+}
+
+void
+check_signal(unsigned long rc, unsigned long *regs)
+{
+	struct process *proc = cpu_local_var(current);
+	struct k_sigaction *k;
+	int	sig = proc->signal;
+
+	proc->signal = 0;
+	if(sig){
+		if(regs == NULL){ /* call from syscall */
+			asm volatile ("movq %%gs:132,%0" : "=r" (regs));
+			regs -= 16;
+		}
+		else{
+			rc = regs[9]; /* rax */
+		}
+
+		k = proc->sighandler->action + sig - 1;
+
+		if(k->sa.sa_handler == (void *)1){
+			return;
+		}
+		else if(k->sa.sa_handler){
+			unsigned long *usp; /* user stack */
+			long	w;
+
+			usp = (void *)regs[14];
+			memcpy(proc->sigstack, regs, 128);
+			proc->sigrc = rc;
+			usp--;
+			*usp = (unsigned long)k->sa.sa_restorer;
+			w = 56 + 3;
+			asm volatile ("pushq %0" :: "r" (w));
+			asm volatile ("pushq %0" :: "r" (usp));
+			w = 1 << 9;
+			asm volatile ("pushq %0" :: "r" (w));
+			w = 48 + 3;
+			asm volatile ("pushq %0" :: "r" (w));
+			asm volatile ("pushq %0" :: "r" (k->sa.sa_handler));
+			asm volatile ("iretq");
+		}
+		else{
+			if(sig == SIGCHLD || sig == SIGURG)
+				return;
+			terminate(0, sig, (ihk_mc_user_context_t *)regs[14]);
+		}
+	}
+}
+
+void
+sigsegv(unsigned long *regs)
+{
+	struct process *proc = cpu_local_var(current);
+
+	proc->signal = SIGSEGV;
+	check_signal(0, regs);
+}
+
+void
+sigill(unsigned long *regs)
+{
+	struct process *proc = cpu_local_var(current);
+
+	proc->signal = SIGILL;
+	check_signal(0, regs);
+}