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Mail Archives: djgpp-workers/1996/08/08/00:44:32

Message-Id: <s20a17f1.030@MAIL.TAIT.CO.NZ>
Date: Thu, 08 Aug 1996 16:38:56 +1200
From: Bill Currie <bill_currie AT MAIL DOT TAIT DOT CO DOT NZ>
To: djgpp-workers AT delorie DOT com
Subject: window sti/cli bug

I *THINK* i may have figured out why doing a cli under windows makes all further
interrupts masked when running under windows.  I was thinking that maybe windows
has a vmint disabled count rather than a flag, and there are insufficient sti's
to counteract the cli's (including implicit ones via int's).  I did a grep on
iret in src/libc (with context) and not all the hardware ISR's do a sti before
the iret (even though the dpmi spec says this should be done).  Here is a list of
all occurences of the iret instruction (including data for _go32...), to be
looked  over to determine which irets should have an sti before them.  Sorry
about the size, but I thought some lines of context would be helpfull.

Bill

----------------------------------
debug/common/dbgcom.c-166-	je	Lc31b							\n\
debug/common/dbgcom.c-167-	cmpw	$0x0205,%ax						\n\
debug/common/dbgcom.c-168-	je	Lc31d							\n\
debug/common/dbgcom.c-169-Lc31c:	.byte	0x2e							\n\
debug/common/dbgcom.c-170-	ljmp	_old_i31						\n\
debug/common/dbgcom.c:171:Lc31a:	iret								\n\
debug/common/dbgcom.c-172-Lc31b:	.byte	0x2e							\n\
debug/common/dbgcom.c-173-	cmpw	___djgpp_app_DS,%bx					\n\
debug/common/dbgcom.c-174-	jne	Lc31c							\n\
debug/common/dbgcom.c-175-	pushf								\n\
debug/common/dbgcom.c-176-	.byte	0x2e							\n\
--
libc/ansi/setjmp/longjmp.s-78-	popl	___djgpp_exception_state_ptr
libc/ansi/setjmp/longjmp.s-79-	popl	%ds
libc/ansi/setjmp/longjmp.s-80-	popl	%edi
libc/ansi/setjmp/longjmp.s-81-	popl	%esi
libc/ansi/setjmp/longjmp.s-82-
libc/ansi/setjmp/longjmp.s:83:	iret			/* actually jump to new cs:eip
loading flags */
--
npx handler
libc/go32/exceptn.s-279-	movb	$0x75,%al
libc/go32/exceptn.s-280-hw_to_excp:
libc/go32/exceptn.s-281-	call	___djgpp_hw_exception
libc/go32/exceptn.s-282-	popl	%eax
libc/go32/exceptn.s-283-	sti
libc/go32/exceptn.s:284:	iret
libc/go32/exceptn.s-285-
libc/go32/exceptn.s-286-	.align 4
libc/go32/exceptn.s-287-	.global	___djgpp_kbd_hdlr
libc/go32/exceptn.s-288-___djgpp_kbd_hdlr:
libc/go32/exceptn.s-289-	pushl	%eax
--
timer handler
libc/go32/exceptn.s-354-2:
libc/go32/exceptn.s-355-	pushl	%eax
libc/go32/exceptn.s-356-	movb	$0x20,%al			/* EOI the interrupt */
libc/go32/exceptn.s-357-	outb	%al,$0x020
libc/go32/exceptn.s-358-	popl	%eax
libc/go32/exceptn.s:359:	iret
libc/go32/exceptn.s-360-
libc/go32/exceptn.s-361-	/* On entry ES is the DS alias selector */
libc/go32/exceptn.s-362-	.align 4
libc/go32/exceptn.s-363-	.global	___djgpp_cbrk_hdlr		/* A RMCB handler for
0x1b */
libc/go32/exceptn.s-364-___djgpp_cbrk_hdlr:
--
control break handler
libc/go32/exceptn.s-373-   	.byte	0x2e				/* CS: */
libc/go32/exceptn.s-374-	testb	$2, ___djgpp_hwint_flags	/* Count, don't
kill */
libc/go32/exceptn.s-375-	jne	1f
libc/go32/exceptn.s-376-
libc/go32/exceptn.s-377-	call	___djgpp_hw_exception
libc/go32/exceptn.s:378:	iret
libc/go32/exceptn.s-379-1:
libc/go32/exceptn.s-380-	incl	%es:___djgpp_cbrk_count
libc/go32/exceptn.s:381:	iret
libc/go32/exceptn.s-382-
crit err, general
libc/go32/exceptn.s-383-	.global	___djgpp_i24			/* Int 24 handler if
needed */
libc/go32/exceptn.s:384:	.global	___djgpp_iret			/* Int 23 handler if
needed */
libc/go32/exceptn.s-385-___djgpp_i24:
libc/go32/exceptn.s-386-	movb	$3,%al
libc/go32/exceptn.s:387:___djgpp_iret:
libc/go32/exceptn.s:388:	iret
libc/go32/exceptn.s-389-
libc/go32/exceptn.s-390-/* Code to stop execution ASAP, EAX destroyed.  Make
DS/ES/SS invalid. 
libc/go32/exceptn.s-391-   Fake exception value is passed in AL and moved into
the "forced" variable.
libc/go32/exceptn.s-392-   This is used to convert a HW interrupt into something
we can transfer
libc/go32/exceptn.s-393-   control away from via longjmp or exit(), common with
SIGINT, SIGFPE, or
--
libc/go32/gopint.c-69-/* 4F */ 0x0f, 0xa1,			/*     pop fs                  
*/
libc/go32/gopint.c-70-/* 51 */ 0x07,				/*     pop es                  
*/
libc/go32/gopint.c-71-/* 52 */ 0x1f				/*     pop ds                  
*/
libc/go32/gopint.c-72-};
libc/go32/gopint.c-73-
libc/go32/gopint.c:74:static unsigned char wrapper_intiret[] = {
libc/go32/gopint.c:75:/* 53 */ 0xcf,				/*     iret                    
*/
libc/go32/gopint.c-76-};
libc/go32/gopint.c-77-
libc/go32/gopint.c-78-static unsigned char wrapper_intchain[] = {
libc/go32/gopint.c-79-/* 53 */ 0x2e, 0xff, 0x2d,		/*     jmp     cs: 		*/
libc/go32/gopint.c-80-/* 56 */ FILL, FILL, FILL, FILL,	/*     [_old_int+39]
		*/
libc/go32/gopint.c:81:/* 5A */ 0xcf,				/*     iret                    
*/
libc/go32/gopint.c-82-/* 5B */ FILL, FILL, FILL, FILL,	/*     old_address 		*/
libc/go32/gopint.c-83-/* 5F */ FILL, FILL,			/*     old_segment 		*/
libc/go32/gopint.c-84-};
libc/go32/gopint.c-85-
libc/go32/gopint.c-86-unsigned long _go32_interrupt_stack_size = 32256;
--
libc/go32/gormcb.c-66-/* 50 */ 0x26, 0x89, 0x47, 0x2a,	/*     mov es:[edi+42],eax 
    */
libc/go32/gormcb.c-67-};
libc/go32/gormcb.c-68-
libc/go32/gormcb.c-69-static unsigned char wrapper_retf[] = {
libc/go32/gormcb.c-70-         0x66, 0x26, 0x83, 0x47, 0x2e, 0x04,	/* add    
es:[edi+46],0x4 */
libc/go32/gormcb.c:71:         0xcf				    	/* iret                
   */
libc/go32/gormcb.c-72-};
libc/go32/gormcb.c-73-
libc/go32/gormcb.c:74:static unsigned char wrapper_iret[] = {
libc/go32/gormcb.c-75-         0x66, 0x8b, 0x46, 0x04,		/* mov     ax,[esi+4]  
   */
libc/go32/gormcb.c-76-         0x66, 0x26, 0x89, 0x47, 0x20,		/* mov    
es:[edi+32],ax  */
libc/go32/gormcb.c-77-         0x66, 0x26, 0x83, 0x47, 0x2e, 0x06,	/* add    
es:[edi+46],0x6 */
libc/go32/gormcb.c:78:         0xcf					/* iret                   
*/
libc/go32/gormcb.c-79-};
libc/go32/gormcb.c-80-
libc/go32/gormcb.c-81-unsigned long _go32_rmcb_stack_size = 32256;
libc/go32/gormcb.c-82-
libc/go32/gormcb.c-83-static int setup_rmcb(unsigned char *wrapper,
_go32_dpmi_seginfo *info,


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