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authorJason Uhlenkott <jasonuhl@sgi.com>2005-12-30 02:27:01 -0800
committerTony Luck <tony.luck@intel.com>2006-01-13 14:16:08 -0800
commit15029285dc977a392e74eacb7625984b71d4f605 (patch)
tree0fed8aac81f7b4491121550b3670b4a8aeabcff9
parent6d6e420005f3753392b608a614eee8475bdc16f7 (diff)
[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>
-rw-r--r--arch/ia64/kernel/traps.c26
-rw-r--r--include/asm-ia64/thread_info.h4
2 files changed, 22 insertions, 8 deletions
diff --git a/arch/ia64/kernel/traps.c b/arch/ia64/kernel/traps.c
index d3e0ecb56d6..55391901b01 100644
--- a/arch/ia64/kernel/traps.c
+++ b/arch/ia64/kernel/traps.c
@@ -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;
diff --git a/include/asm-ia64/thread_info.h b/include/asm-ia64/thread_info.h
index 653bb7f9a75..1d6518fe1f0 100644
--- a/include/asm-ia64/thread_info.h
+++ b/include/asm-ia64/thread_info.h
@@ -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)