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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
[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>
authored by Jason Uhlenkott and committed by Tony Luck 15029285 6d6e4200
+19
-7
arch/ia64/kernel/traps.c
+19
-7
arch/ia64/kernel/traps.c
···
530
if (fsys_mode(current, ®s)) {
531
extern char __kernel_syscall_via_break[];
532
/*
533
-
* Got a trap in fsys-mode: Taken Branch Trap and Single Step trap
534
-
* need special handling; Debug trap is not supposed to happen.
535
*/
536
if (unlikely(vector == 29)) {
537
-
die("Got debug trap in fsys-mode---not supposed to happen!",
538
-
®s, 0);
539
return;
540
}
541
/* re-do the system call via break 0x100000: */
···
592
case 34:
593
if (isr & 0x2) {
594
/* Lower-Privilege Transfer Trap */
595
/*
596
-
* Just clear PSR.lp and then return immediately: all the
597
-
* interesting work (e.g., signal delivery is done in the kernel
598
-
* exit path).
599
*/
600
ia64_psr(®s)->lp = 0;
601
return;
···
530
if (fsys_mode(current, ®s)) {
531
extern char __kernel_syscall_via_break[];
532
/*
533
+
* Got a trap in fsys-mode: Taken Branch Trap
534
+
* and Single Step trap need special handling;
535
+
* Debug trap is ignored (we disable it here
536
+
* and re-enable it in the lower-privilege trap).
537
*/
538
if (unlikely(vector == 29)) {
539
+
set_thread_flag(TIF_DB_DISABLED);
540
+
ia64_psr(®s)->db = 0;
541
+
ia64_psr(®s)->lp = 1;
542
return;
543
}
544
/* re-do the system call via break 0x100000: */
···
589
case 34:
590
if (isr & 0x2) {
591
/* Lower-Privilege Transfer Trap */
592
+
593
+
/* If we disabled debug traps during an fsyscall,
594
+
* re-enable them here.
595
+
*/
596
+
if (test_thread_flag(TIF_DB_DISABLED)) {
597
+
clear_thread_flag(TIF_DB_DISABLED);
598
+
ia64_psr(®s)->db = 1;
599
+
}
600
+
601
/*
602
+
* Just clear PSR.lp and then return immediately:
603
+
* all the interesting work (e.g., signal delivery)
604
+
* is done in the kernel exit path.
605
*/
606
ia64_psr(®s)->lp = 0;
607
return;
+3
-1
include/asm-ia64/thread_info.h
+3
-1
include/asm-ia64/thread_info.h
···
93
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
94
#define TIF_MEMDIE 17
95
#define TIF_MCA_INIT 18 /* this task is processing MCA or INIT */
96
97
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
98
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
···
101
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
102
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
103
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
104
-
#define _TIF_SIGDELAYED (1 << TIF_SIGDELAYED)
105
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
106
#define _TIF_MCA_INIT (1 << TIF_MCA_INIT)
107
108
/* "work to do on user-return" bits */
109
#define TIF_ALLWORK_MASK (_TIF_NOTIFY_RESUME|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SIGDELAYED)
···
93
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
94
#define TIF_MEMDIE 17
95
#define TIF_MCA_INIT 18 /* this task is processing MCA or INIT */
96
+
#define TIF_DB_DISABLED 19 /* debug trap disabled for fsyscall */
97
98
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
99
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
···
100
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
101
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
102
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
103
+
#define _TIF_SIGDELAYED (1 << TIF_SIGDELAYED)
104
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
105
#define _TIF_MCA_INIT (1 << TIF_MCA_INIT)
106
+
#define _TIF_DB_DISABLED (1 << TIF_DB_DISABLED)
107
108
/* "work to do on user-return" bits */
109
#define TIF_ALLWORK_MASK (_TIF_NOTIFY_RESUME|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SIGDELAYED)