[xtensa-cvscommit] linux/include/asm-xtensa ptrace.h,1.6,1.7

[<joe...@us...>]

Update of /cvsroot/xtensa/linux/include/asm-xtensa
In directory sc8-pr-cvs1:/tmp/cvs-serv30731/include/asm-xtensa

Modified Files:
	ptrace.h 
Log Message:

Fixed a bug that hangs the kernel.  We were improperly handling double exceptions that occurred during the handling of a window underflow exception.


Index: ptrace.h
===================================================================
RCS file: /cvsroot/xtensa/linux/include/asm-xtensa/ptrace.h,v
retrieving revision 1.6
retrieving revision 1.7
diff -C2 -d -r1.6 -r1.7
*** ptrace.h	28 Jan 2003 23:52:23 -0000	1.6
--- ptrace.h	30 Jan 2003 23:55:27 -0000	1.7
***************
*** 30,34 ****
  /*  3 x 64-entries x 4-byte tables follow from TABLE_OFS.  */
  
! /*  Exception causes/codes?:  */
  #define EXC_CODE_USER		0x000
  #define EXC_CODE_KERNEL		0x040
--- 30,34 ----
  /*  3 x 64-entries x 4-byte tables follow from TABLE_OFS.  */
  
! /*  Offsets within exception_handlers[] */
  #define EXC_CODE_USER		0x000
  #define EXC_CODE_KERNEL		0x040
***************
*** 36,49 ****
  #define EXC_CODE_UNHANDLED	0x100
  
! /*  Exception types:  */			/*unhandled quickspill*/
! #define EXCTYPE_USER			0	/*    0         0     */
! #define EXCTYPE_USER_UNHANDLED		1	/*    1         0     */
! #define EXCTYPE_KERNEL			2	/*    0         1     */
! #define EXCTYPE_KERNEL_UNHANDLED	3	/*    1         1     */
! #define EXCTYPE_DOUBLE_WIND_USER	4	/*    0         0     */
! #define EXCTYPE_DOUBLE_WIND_KERNEL	8	/*    0         0     */
  /*  Bits:  */
  #define EXCTYPE_UNHANDLED_SHIFT		0
  #define EXCTYPE_QUICKSPILL_SHIFT	1
  
  
--- 36,77 ----
  #define EXC_CODE_UNHANDLED	0x100
  
! /*  Exception types:  */
! 
! /* Double exceptions in window vectors need different treatment of
!    WINDOWBASE that double exceptions that occur outside of window
!    vectors.
! 
!    PS distinguishes between user and kernel, so we don't need to here.
!    However, we do so to simplify the determination of whether we need
!    to spill everything (user, quickspill=0) or not (kernel,
!    quickspill=1).
! 
!    XTFIXME: For safety, we don't distinguish between double exceptions
!    that occurred from user mode (i.e., PS.UM = 1, PS.EXCM = 1; e.g.,
!    window exceptions) and from kernel mode (i.e., PS.UM = 0, PS.EXCM =
!    1).  Since we don't switch stacks on kernel mode, I think it will
!    be safe to do a quick spill on the *_DOUBLE_KERNEL and
!    *_DOUBLE_WIND_KERNEL cases.  Try it.  :) You just need to set the
!    quickspill bits below...
! 
! 		unhandled exception		  -------+
! 		user or kernel exception	  -----+ |
! 		double exception		  ---+ | |
! 		double exception in window vector -+ | | |
! 						   | | | |
! 						   V V V V */
! #define EXCTYPE_USER			0	/* 0 0 0 0 */
! #define EXCTYPE_USER_UNHANDLED		1	/* 0 0 0 1 */
! #define EXCTYPE_KERNEL			2	/* 0 0 1 0 */
! #define EXCTYPE_KERNEL_UNHANDLED	3	/* 0 0 1 1 */
! #define EXCTYPE_DOUBLE_USER		4	/* 0 1 0 0 */
! #define EXCTYPE_DOUBLE_KERNEL		4	/* 0 1 0 0 */
! #define EXCTYPE_DOUBLE_WIND_USER	12	/* 1 1 0 0 */
! #define EXCTYPE_DOUBLE_WIND_KERNEL	12	/* 1 1 0 0 */
  /*  Bits:  */
  #define EXCTYPE_UNHANDLED_SHIFT		0
  #define EXCTYPE_QUICKSPILL_SHIFT	1
+ #define EXCTYPE_DOUBLE_SHIFT		2
+ #define EXCTYPE_DOUBLE_WIND_SHIFT	3
  
  
***************
*** 100,105 ****
  	unsigned vpri;
  	unsigned wmask;
! 	unsigned wb;		/* WINDOWBASE */
! 	unsigned ws;		/* WINDOWSTART */
  	unsigned reserved0;	/*??? cpenable ???*/
  	unsigned reserved1;
--- 128,133 ----
  	unsigned vpri;
  	unsigned wmask;
! 	unsigned wb;
! 	unsigned ws;
  	unsigned reserved0;	/*??? cpenable ???*/
  	unsigned reserved1;