[xtensa-cvscommit] linux/arch/xtensa/kernel signal.c,1.7,1.8

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

Update of /cvsroot/xtensa/linux/arch/xtensa/kernel
In directory sc8-pr-cvs1:/tmp/cvs-serv27015/arch/xtensa/kernel

Modified Files:
	signal.c 
Log Message:
Clear all CP and EXTRA state before transfering control to a signal handler.



Index: signal.c
===================================================================
RCS file: /cvsroot/xtensa/linux/arch/xtensa/kernel/signal.c,v
retrieving revision 1.7
retrieving revision 1.8
diff -C2 -d -r1.7 -r1.8
*** signal.c	23 Apr 2003 23:19:55 -0000	1.7
--- signal.c	29 Apr 2003 18:30:33 -0000	1.8
***************
*** 303,309 ****
  			xthal_validate_cp(i);
  			xthal_save_cpregs(tsk->thread.cpregs_ptr[i], i);
  			xthal_invalidate_cp(i);
! 			/* I think this is unnecessary; we're not switching owners. */
! 			/* coproc_owners[i] = 0; */
  		}
  	}
--- 303,313 ----
  			xthal_validate_cp(i);
  			xthal_save_cpregs(tsk->thread.cpregs_ptr[i], i);
+ 
+ 			/* Invalidate and "disown" the cp to allow
+ 			 * callers the chance to reset cp state in the
+ 			 * task_struct. */
+ 
  			xthal_invalidate_cp(i);
! 			coproc_owners[i] = 0;
  		}
  	}
***************
*** 323,338 ****
  
  	/* XTFIXME: If a task has never used a coprocessor, there is
! 	   no need to save and restore anything.  Tracking this
! 	   information would allow us to optimize this section.
! 	   Perhaps we can use current->used_math or (current->flags &
! 	   PF_USEDFPU) or define a new field in the thread
! 	   structure. */
  
  	struct task_struct *tsk = current;
  	flush_my_cpstate(tsk);
  	/* Note that we just copy everything: 'extra' and 'cp' state together. */
! 	if (__copy_to_user(buf, tsk->thread.cpextra, TOTAL_CPEXTRA_SIZE))
! 		return -1;
! 	return 1;
  #endif
  }
--- 327,358 ----
  
  	/* XTFIXME: If a task has never used a coprocessor, there is
! 	 * no need to save and restore anything.  Tracking this
! 	 * information would allow us to optimize this section.
! 	 * Perhaps we can use current->used_math or (current->flags &
! 	 * PF_USEDFPU) or define a new field in the thread
! 	 * structure. */
! 
! 	/* We flush any live, task-owned cp state to the task_struct,
! 	 * then copy it all to the sigframe.  Then we clear all
! 	 * cp/extra state in the task_struct, effectively
! 	 * clearing/resetting all cp/extra state for the signal
! 	 * handler (cp-exception handling will load these new values
! 	 * into the cp/extra registers.)  This step is important for
! 	 * things like a floating-point cp, where the OS must reset
! 	 * the FCR to the default rounding mode. */
  
+ 	int err = 0;
  	struct task_struct *tsk = current;
+ 
  	flush_my_cpstate(tsk);
  	/* Note that we just copy everything: 'extra' and 'cp' state together. */
! 	err |= __copy_to_user(buf, tsk->thread.cpextra, TOTAL_CPEXTRA_SIZE);
! 	memset(tsk->thread.cpextra, 0, TOTAL_CPEXTRA_SIZE);
! 
! #if (TOTAL_CPEXTRA_SIZE == 0)
! #error Sanity check on memset above, cpextra_size should not be zero.
! #endif
! 
! 	return err ? -1 : 1;
  #endif
  }