From: Matthias Kruk <m@m10k.eu>
Date: Thu, 2 Jan 2020 07:41:15 +0000 (+0900)
Subject: Deliver signals to processes causing exceptions, panic only if the kernel itself... 
X-Git-Url: https://git.corax.cc/?a=commitdiff_plain;h=338db41350385f4c0791472c2d4fc1eb04325d95;p=corax

Deliver signals to processes causing exceptions, panic only if the kernel itself causes an exception
---

diff --git a/kernel/arch/interrupt.c b/kernel/arch/interrupt.c
index 1ad7d04..53ff677 100644
--- a/kernel/arch/interrupt.c
+++ b/kernel/arch/interrupt.c
@@ -22,6 +22,7 @@
 #include <arch.h>
 #include <debug.h>
 #include <process.h>
+#include <signal.h>
 #include "cpu.h"
 #include "defs.h"
 
@@ -94,36 +95,10 @@ void _int_handle(stack_frame_t ctx)
     */
 /*    PANIC("Unhandled interrupt"); */
 
-	switch(ctx.intn) {
-	case INT_KEYBOARD: {
-#if FEATURE(DEBUG)
-        extern struct cpu _cpu[CONFIG_SMP_CPUS];
-#endif /* FEATURE(DEBUG) */
-
-        dbg_printf("Keyboard interrupt\n");
-
-#if FEATURE(DEBUG)
-		/* hacky reboot: clear IDT entries for
-		 * #DF and #GP, then cause a #GP */
-		_cpu[CPU_ID].cpu_idt[EXC_DOUBLEFAULT].sd_low = 0;
-		_cpu[CPU_ID].cpu_idt[EXC_DOUBLEFAULT].sd_high = 0;
-		_cpu[CPU_ID].cpu_idt[EXC_PROTECTION].sd_low = 0;
-		_cpu[CPU_ID].cpu_idt[EXC_PROTECTION].sd_high = 0;
-
-		/* this is such a retarded thing to do, I don't see how this
-		 * could not cause a triple fault */
-		asm volatile("ljmp $0x30, $0xfee00020"); /* LEEROY JENKINS!!! */
-#endif /* FEATURE(DEBUG) */
-		break;
-	}
-
-	case INT_TIMER:
+	if(ctx.intn == INT_TIMER) {
 		sched_tick();
-		break;
-
-	default:
-		dbg_printf("Interrupt %u occurred\n", ctx.intn);
-		break;
+	} else {
+		/* FIXME: handle interrupt */
 	}
 
     return;
@@ -135,23 +110,71 @@ void _exc_handle(stack_frame_t ctx)
 
 	cproc = process_get_current();
 
-    dbg_printf("Exception %u [%s] occurred. Error code 0x%08x.\n", ctx.intn, ctx.intn < EXC_MAX ? _exc_name[ctx.intn] : 0, ctx.error);
-	dbg_printf("In context %p [pid %u]\n", cproc, process_get_id(cproc));
-    dbg_printf("Fault in 0x%02x:%08x; EFLAGS = 0x%08x\n", ctx.cs, ctx.eip, ctx.eflags);
+	if(ctx.cs == KERNEL_CODE) {
+		/* kernel bug */
+
+		dbg_printf("Exception %u [%s] occurred. Error code 0x%08x.\n",
+				   ctx.intn, ctx.intn < EXC_MAX ? _exc_name[ctx.intn] : 0, ctx.error);
+		dbg_printf("In context %p [pid %u]\n", cproc, process_get_id(cproc));
+		dbg_printf("Fault in 0x%02x:%08x; EFLAGS = 0x%08x\n", ctx.cs, ctx.eip, ctx.eflags);
 
-    if(ctx.intn == EXC_PAGEFAULT) {
-        u32_t cr2;
-		pg_dir_t *pd;
+		if(ctx.intn == EXC_PAGEFAULT) {
+			u32_t cr2;
+			pg_dir_t *pd;
 
-        asm volatile("movl %%cr2, %%eax; movl %%eax, %0" : "=r"(cr2));
-        dbg_printf("Page fault address: 0x%08x\n", cr2);
+			asm volatile("movl %%cr2, %%eax; movl %%eax, %0" : "=r"(cr2));
+			dbg_printf("Page fault address: 0x%08x\n", cr2);
 
-		if(process_get_pagedir(cproc, &pd) == 0) {
-			pg_fault_debug(pd, (void*)cr2);
+			if(process_get_pagedir(cproc, &pd) == 0) {
+				pg_fault_debug(pd, (void*)cr2);
+			}
 		}
-    }
 
-    PANIC("Unhandled exception");
+		PANIC("Unhandled exception");
+
+	} else {
+		/* deliver exception to causing process */
+
+		int sig;
+
+		switch(ctx.intn) {
+		default:
+		case EXC_DEBUG:
+		case EXC_NMI:
+		case EXC_BREAKPOINT:
+		case EXC_OVERFLOW:
+		case EXC_BOUNDRANGE:
+		case EXC_DEVNOTAVAIL:
+		case EXC_DOUBLEFAULT:
+		case EXC_COPROCSEGM:
+		case EXC_INVALIDTSS:
+		case EXC_SEGMNOTPRES:
+		case EXC_STACKFAULT:
+		case EXC_PROTECTION:
+		case EXC_PAGEFAULT:
+		case EXC_ALIGNMENT:
+		case EXC_MACHINECHECK:
+		case EXC_VIRTUALIZATION:
+			sig = SIGSEGV;
+			break;
+
+		case EXC_INVALOPCODE:
+			sig = SIGILL;
+			break;
+
+		case EXC_DIVERR:
+		case EXC_FPUERROR:
+		case EXC_SIMD:
+			sig = SIGFPE;
+			break;
+		}
+
+		/*
+		 * Deliver the signal to the current process. The process_signal_deliver()
+		 * function will make sure that the signal is handled by the current task.
+		 */
+		process_signal_deliver(cproc, sig);
+	}
 
     return;
 }