make CALLTRACE=1 to enable printing primitive calltraces upon panic.

This won't work with optimizations turned fully on.

Added protection against double panics.

sortix/Makefile

@@ -54,12 +54,17 @@ ifeq ($(JSSORTIX),1)
 endif
 ifeq ($(PANIC_SHORT),1)
     DEFINES:=$(DEFINES) -DPANIC_SHORT
-endif 
+endif
 ifeq ($(DISKWRITE),1)
     DEFINES:=$(DEFINES) -DENABLE_DISKWRITE=1
 else
     DEFINES:=$(DEFINES) -DENABLE_DISKWRITE=0
-endif 
+endif
+ifeq ($(CALLTRACE),1)
+    DEFINES:=$(DEFINES) -DENABLE_CALLTRACE=1
+else
+    DEFINES:=$(DEFINES) -DENABLE_CALLTRACE=0
+endif
 
 INCLUDES=-I../libmaxsi/preproc -I.. -I.
 CPPFLAGS=$(INCLUDES) $(DEFINES)
@@ -81,6 +86,8 @@ interrupt.o \
 time.o \
 log.o \
 utf8.o \
+calltrace.o \
+$(CPU)/calltrace.o \
 panic.o \
 keyboard.o \
 kb/ps2.o \

sortix/calltrace.cpp

@@ -0,0 +1,45 @@
+/*******************************************************************************
+
+	COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2012.
+
+	This file is part of Sortix.
+
+	Sortix is free software: you can redistribute it and/or modify it under the
+	terms of the GNU General Public License as published by the Free Software
+	Foundation, either version 3 of the License, or (at your option) any later
+	version.
+
+	Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
+	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+	FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+	details.
+
+	You should have received a copy of the GNU General Public License along with
+	Sortix. If not, see <http://www.gnu.org/licenses/>.
+
+	calltrace.cpp
+	Traverses the stack and prints the callstack, which aids debugging.
+
+*******************************************************************************/
+
+#include "platform.h"
+#include "calltrace.h"
+
+namespace Sortix {
+namespace Calltrace {
+
+extern "C" void calltrace();
+extern "C" void calltrace_print_function(size_t index, addr_t ip)
+{
+	Log::PrintF("%zu: 0x%zx\n", index, ip);
+}
+
+void Perform()
+{
+	Log::PrintF("Calltrace:\n");
+	calltrace();
+}
+
+} // namespace Calltrace
+} // namespace Sortix
+

sortix/calltrace.h

@@ -0,0 +1,35 @@
+/*******************************************************************************
+
+	COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2012.
+
+	This file is part of Sortix.
+
+	Sortix is free software: you can redistribute it and/or modify it under the
+	terms of the GNU General Public License as published by the Free Software
+	Foundation, either version 3 of the License, or (at your option) any later
+	version.
+
+	Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
+	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+	FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+	details.
+
+	You should have received a copy of the GNU General Public License along with
+	Sortix. If not, see <http://www.gnu.org/licenses/>.
+
+	calltrace.h
+	Traverses the stack and prints the callstack, which aids debugging.
+
+*******************************************************************************/
+
+#ifndef SORTIX_CALLTRACE_H
+#define SORTIX_CALLTRACE_H
+
+namespace Sortix {
+namespace Calltrace {
+void Perform();
+} // namespace Calltrace
+} // namespace Sortix
+
+#endif
+

sortix/panic.cpp

@@ -26,6 +26,7 @@
 #include <libmaxsi/string.h>
 #include <libmaxsi/memory.h>
 #include "log.h"
+#include "calltrace.h"
 #include "panic.h"
 
 using namespace Maxsi;
@@ -37,9 +38,17 @@ namespace Sortix
 #else
 	bool longpanic = true;
 #endif
+	bool panicing = false;
+	bool doublepanic = false;
 
 	void PanicInit()
 	{
+		if ( panicing )
+		{
+			Log::PrintF("Panic while panicing:\n");
+			doublepanic = true;
+			return;
+		}
 		if ( longpanic )
 		{
 			Log::Print("\e[m\e[31;40m\e[2J\e[H");
@@ -71,6 +80,19 @@ namespace Sortix
 			Log::Print("\e[m\e[31m\e[0J");
 			Log::Print("RED MAXSI OF DEATH\n");
 		}
+		panicing = true;
+	}
+
+	void PanicCalltrace()
+	{
+		Log::Print("\n");
+		Calltrace::Perform();
+	}
+
+	void PanicHooks()
+	{
+		if ( doublepanic ) { return; }
+		if ( ENABLE_CALLTRACE ) { PanicCalltrace(); }
 	}
 
 	void PanicHalt()
@@ -85,6 +107,7 @@ namespace Sortix
 	{
 		PanicInit();
 		Log::Print(Error);
+		PanicHooks();
 		PanicHalt();
 	}
 
@@ -95,6 +118,7 @@ namespace Sortix
 		va_start(list, Format);
 		Log::PrintFV(Format, list);
 		va_end(list);
+		PanicHooks();
 		PanicHalt();
 	}
 }

sortix/x64/calltrace.s

@@ -0,0 +1,50 @@
+/*******************************************************************************
+
+	COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2011, 2012.
+
+	This file is part of Sortix.
+
+	Sortix is free software: you can redistribute it and/or modify it under the
+	terms of the GNU General Public License as published by the Free Software
+	Foundation, either version 3 of the License, or (at your option) any later
+	version.
+
+	Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
+	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+	FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+	details.
+
+	You should have received a copy of the GNU General Public License along with
+	Sortix. If not, see <http://www.gnu.org/licenses/>.
+
+	x64/calltrace.s
+	Attempts to unwind the stack and prints the code locations where functions
+	were called. This greatly aids debugging.
+
+*******************************************************************************/
+
+.section .text
+
+.global calltrace
+.type calltrace, @function
+calltrace:
+	push %rbp
+	movq %rsp, %rbp
+	xorl %edi, %edi
+	movq %rbp, %rbx
+
+calltrace_unwind:
+	testq %rbx, %rbx
+	jz calltrace_done
+	movq 8(%rbx), %rsi # Previous RIP
+	movq 0(%rbx), %rbx # Previous RBP
+	pushq %rdi
+	call calltrace_print_function
+	popq %rdi
+	incq %rdi
+	jmp calltrace_unwind
+
+calltrace_done:
+	popq %rbp
+	retq
+

sortix/x86/calltrace.s

@@ -0,0 +1,52 @@
+/*******************************************************************************
+
+	COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2011, 2012.
+
+	This file is part of Sortix.
+
+	Sortix is free software: you can redistribute it and/or modify it under the
+	terms of the GNU General Public License as published by the Free Software
+	Foundation, either version 3 of the License, or (at your option) any later
+	version.
+
+	Sortix is distributed in the hope that it will be useful, but WITHOUT ANY
+	WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+	FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+	details.
+
+	You should have received a copy of the GNU General Public License along with
+	Sortix. If not, see <http://www.gnu.org/licenses/>.
+
+	x86/calltrace.s
+	Attempts to unwind the stack and prints the code locations where functions
+	were called. This greatly aids debugging.
+
+*******************************************************************************/
+
+.section .text
+
+.global calltrace
+.type calltrace, @function
+calltrace:
+	push %ebp
+	movl %esp, %ebp
+	xorl %edi, %edi
+	movl %ebp, %ebx
+
+calltrace_unwind:
+	testl %ebx, %ebx
+	jz calltrace_done
+	movl 4(%ebx), %esi # Previous EIP
+	movl 0(%ebx), %ebx # Previous EBP
+	pushl %esi
+	pushl %edi
+	call calltrace_print_function
+	popl %edi
+	addl $4, %esp
+	incl %edi
+	jmp calltrace_unwind
+
+calltrace_done:
+	popl %ebp
+	retl
+