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[IA64] Handle debug traps in fsys mode 

We need to handle debug traps in fsys mode non-fatally.  They can
happen now that we have fsyscalls which contain probe instructions.

Signed-off-by: Jason Uhlenkott <jasonuhl@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Jason Uhlenkott 2005-12-30 02:27:01 -08:00 committed by Tony Luck
parent 6d6e420005
commit 15029285dc
2 changed files with 22 additions and 8 deletions
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26
arch/ia64/kernel/traps.c
View File

@ -530,12 +530,15 @@ ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
if (fsys_mode(current, &regs)) {
extern char __kernel_syscall_via_break[];
/*
* Got a trap in fsys-mode: Taken Branch Trap and Single Step trap
* need special handling; Debug trap is not supposed to happen.
* Got a trap in fsys-mode: Taken Branch Trap
* and Single Step trap need special handling;
* Debug trap is ignored (we disable it here
* and re-enable it in the lower-privilege trap).
*/
if (unlikely(vector == 29)) {
die("Got debug trap in fsys-mode---not supposed to happen!",
&regs, 0);
set_thread_flag(TIF_DB_DISABLED);
ia64_psr(&regs)->db = 0;
ia64_psr(&regs)->lp = 1;
return;
}
/* re-do the system call via break 0x100000: */
@ -589,10 +592,19 @@ ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
case 34:
if (isr & 0x2) {
/* Lower-Privilege Transfer Trap */
/* If we disabled debug traps during an fsyscall,
* re-enable them here.
*/
if (test_thread_flag(TIF_DB_DISABLED)) {
clear_thread_flag(TIF_DB_DISABLED);
ia64_psr(&regs)->db = 1;
}
/*
* Just clear PSR.lp and then return immediately: all the
* interesting work (e.g., signal delivery is done in the kernel
* exit path).
* Just clear PSR.lp and then return immediately:
* all the interesting work (e.g., signal delivery)
* is done in the kernel exit path.
*/
ia64_psr(&regs)->lp = 0;
return;

4
include/asm-ia64/thread_info.h
View File

@ -93,6 +93,7 @@ struct thread_info {
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 17
#define TIF_MCA_INIT 18 /* this task is processing MCA or INIT */
#define TIF_DB_DISABLED 19 /* debug trap disabled for fsyscall */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
@ -100,9 +101,10 @@ struct thread_info {
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
#define _TIF_SIGDELAYED (1 << TIF_SIGDELAYED)
#define _TIF_SIGDELAYED (1 << TIF_SIGDELAYED)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_MCA_INIT (1 << TIF_MCA_INIT)
#define _TIF_DB_DISABLED (1 << TIF_DB_DISABLED)
/* "work to do on user-return" bits */
#define TIF_ALLWORK_MASK (_TIF_NOTIFY_RESUME|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SIGDELAYED)