[xtensa-cvscommit] linux/arch/xtensa/kernel setup.c,1.5,1.6

[<ma...@us...>]

Update of /cvsroot/xtensa/linux/arch/xtensa/kernel
In directory sc8-pr-cvs1:/tmp/cvs-serv17715

Modified Files:
	setup.c 
Log Message:
Make kernel traceback on panic more robust against corrupt/unclean stacks.



Index: setup.c
===================================================================
RCS file: /cvsroot/xtensa/linux/arch/xtensa/kernel/setup.c,v
retrieving revision 1.5
retrieving revision 1.6
diff -C2 -d -r1.5 -r1.6
*** setup.c	7 Feb 2003 02:03:35 -0000	1.5
--- setup.c	11 Feb 2003 07:20:50 -0000	1.6
***************
*** 247,258 ****
  	register unsigned current_retpc asm ("a0");	/* return address */
  	register unsigned *current_sp asm ("a1");	/* current stack pointer */
! 	unsigned retpc, next_retpc, *sp;
  	int i;
  
  	printk( "Call traceback:\n" );
  	xthal_window_spill();	/* save any live caller windows to stack */
  	sp = current_sp;	/* start with current stack frame */
  	retpc = current_retpc;	/* and current return address */
  	for( i = 0; i < MAX_TRACEBACK; i++ ) {
  	    next_retpc = sp[-4];	/* a0 of caller */
  	    sp = (unsigned*) sp[-3];	/* a1 of caller -- go to next caller */
--- 247,265 ----
  	register unsigned current_retpc asm ("a0");	/* return address */
  	register unsigned *current_sp asm ("a1");	/* current stack pointer */
! 	unsigned retpc, next_retpc, upperpc, *sp, *prevsp;
  	int i;
  
  	printk( "Call traceback:\n" );
  	xthal_window_spill();	/* save any live caller windows to stack */
+ 	upperpc = ((unsigned)&xtensa_panic_event) & 0xC0000000;	/* upper 2 bits of PC */
  	sp = current_sp;	/* start with current stack frame */
+ 	prevsp = sp - 1;
  	retpc = current_retpc;	/* and current return address */
  	for( i = 0; i < MAX_TRACEBACK; i++ ) {
+ 	    if( ((unsigned)sp & 3) != 0 || sp <= prevsp || sp > __KSTK_TOS(current) ) {
+ 		printk( "   (stack pointer out of range or unaligned)\n" );
+ 		break;
+ 	    }
+ 	    prevsp = sp;
  	    next_retpc = sp[-4];	/* a0 of caller */
  	    sp = (unsigned*) sp[-3];	/* a1 of caller -- go to next caller */
***************
*** 261,265 ****
  		break;
  	    }
! 	    printk( "   SP=%08X PC=%08X\n", (unsigned) sp, retpc );
  	    retpc = next_retpc;
  	}
--- 268,273 ----
  		break;
  	    }
! 	    printk( "   SP=%08X PC=%08X\n",
! 		    (unsigned) sp, ((retpc & 0x3FFFFFFF) | upperpc) );
  	    retpc = next_retpc;
  	}