[xtensa-cvscommit] linux/arch/xtensa/kernel handlers.S,1.11,1.12

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

Update of /cvsroot/xtensa/linux/arch/xtensa/kernel
In directory sc8-pr-cvs1:/tmp/cvs-serv18526

Modified Files:
	handlers.S 
Log Message:
Add kernel exception stack checking.  To be conditionalized once
things are a bit more stable and we tune for efficiency.
Without this, looping exceptions can be difficult to diagnose.



Index: handlers.S
===================================================================
RCS file: /cvsroot/xtensa/linux/arch/xtensa/kernel/handlers.S,v
retrieving revision 1.11
retrieving revision 1.12
diff -C2 -d -r1.11 -r1.12
*** handlers.S	7 Feb 2003 02:03:35 -0000	1.11
--- handlers.S	11 Feb 2003 07:24:35 -0000	1.12
***************
*** 12,16 ****
   * for more details.
   *
!  * Copyright (C) 2001 - 2002 Tensilica Inc.
   *
   * Authors:	Marc Gauthier <ma...@te...> <ma...@al...>
--- 12,16 ----
   * for more details.
   *
!  * Copyright (C) 2001 - 2003 Tensilica Inc.
   *
   * Authors:	Marc Gauthier <ma...@te...> <ma...@al...>
***************
*** 427,430 ****
--- 427,431 ----
  
  
+ 
  /* First-level exit handler for unhandled-late kernel exceptions.
   *
***************
*** 1239,1242 ****
--- 1240,1261 ----
  	///* slot */
  	//s32i	a2, a1, PT_CPENABLE
+ 
+ #if 1
+ 	/*  Stack overflow check, for debugging:  */
+ 	_GET_CURRENT a2
+ 	movi	a3, TASK_STRUCT_SIZE + PT_SIZE	// (could add sizeof(elf_fpregset_t) as well...
+ 	add	a3, a2, a3			// a3 = stack overflow check boundary
+ 	bgeu	a1, a3, 1f			// stack ptr in seemingly reasonable distance?
+ 	movi	a4, panic			// too close to task struct for comfort, panic
+ 	movi	a6, kern_stk_overflow_msg
+ 	mov	a7, a1				// sp
+ 	mov	a8, a3				// boundary
+ 	callx4	a4				// call panic(msg,sp,boundary)
+ 	j	1f				// normally doesn't get here, but just in case...
+ 	//.rodata
+ kern_stk_overflow_msg:	.asciz	"kernel stack overflow (sp=0x%X boundary=0x%X)"
+ 	.text
+ 1:
+ #endif