[RFC patch 08/20] LTTng Kernel Trace Thread Flag ia64

Mathieu Desnoyers
2009-05-09T16:54:16Z

[-- Attachment #1: lttng-kernel-trace-thread-flag-ia64.patch --]
[-- Type: text/plain, Size: 3439 bytes --]

Add a thread flag to activate system-wide syscall tracing.

FIXME : Masami reported that enabling the KERNEL_TRACE thread flag did disable
the gate page for gettimeofday, falling back on a standard system call. More
work would be needed in this area and I don't have the architecture available.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Masami Hiramatsu <mhiramat@redhat.com>
---
arch/ia64/include/asm/thread_info.h | 10 +++++++---
arch/ia64/kernel/entry.S | 6 ++++--
2 files changed, 11 insertions(+), 5 deletions(-)

Index: linux-2.6-lttng/arch/ia64/include/asm/thread_info.h
===================================================================
--- linux-2.6-lttng.orig/arch/ia64/include/asm/thread_info.h 2009-04-23 14:56:15.000000000 -0400
+++ linux-2.6-lttng/arch/ia64/include/asm/thread_info.h 2009-04-23 14:56:30.000000000 -0400
@@ -100,6 +100,7 @@ struct thread_info {
#define TIF_SYSCALL_TRACE 2 /* syscall trace active */
#define TIF_SYSCALL_AUDIT 3 /* syscall auditing active */
#define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
+#define TIF_KERNEL_TRACE 5 /* kernel trace active */
#define TIF_NOTIFY_RESUME 6 /* resumption notification requested */
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 17
@@ -111,7 +112,9 @@ struct thread_info {
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
-#define _TIF_SYSCALL_TRACEAUDIT (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP)
+#define _TIF_KERNEL_TRACE (1 << TIF_KERNEL_TRACE)
+#define _TIF_SYSCALL_TRACEAUDIT (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|\
+ _TIF_SINGLESTEP|_TIF_KERNEL_TRACE)
#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
@@ -124,8 +127,9 @@ struct thread_info {
/* "work to do on user-return" bits */
#define TIF_ALLWORK_MASK (_TIF_SIGPENDING|_TIF_NOTIFY_RESUME|_TIF_SYSCALL_AUDIT|\
_TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE)
-/* like TIF_ALLWORK_BITS but sans TIF_SYSCALL_TRACE or TIF_SYSCALL_AUDIT */
-#define TIF_WORK_MASK (TIF_ALLWORK_MASK&~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT))
+/* like TIF_ALLWORK_BITS but sans TIF_SYSCALL_TRACE, TIF_KERNEL_TRACE or TIF_SYSCALL_AUDIT */
+#define TIF_WORK_MASK (TIF_ALLWORK_MASK&~(_TIF_SYSCALL_TRACE|_TIF_KERNEL_TRACE|\
+ _TIF_SYSCALL_AUDIT))

#define TS_POLLING 1 /* true if in idle loop and not sleeping */
#define TS_RESTORE_SIGMASK 2 /* restore signal mask in do_signal() */
Index: linux-2.6-lttng/arch/ia64/kernel/entry.S
===================================================================
--- linux-2.6-lttng.orig/arch/ia64/kernel/entry.S 2009-04-23 14:56:15.000000000 -0400
+++ linux-2.6-lttng/arch/ia64/kernel/entry.S 2009-04-23 14:56:30.000000000 -0400
@@ -635,9 +635,11 @@ GLOBAL_ENTRY(ia64_ret_from_clone)
;;
ld4 r2=[r2]
;;
+ movl r8=_TIF_SYSCALL_TRACEAUDIT
+ ;; // added stop bits to prevent r8 dependency
+ and r2=r8,r2
mov r8=0
- and r2=_TIF_SYSCALL_TRACEAUDIT,r2
- ;;
+ ;; // added stop bits to prevent r2 dependency
cmp.ne p6,p0=r2,r0
(p6) br.cond.spnt .strace_check_retval
;; // added stop bits to prevent r8 dependency