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authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>2011-03-16 19:04:54 -0400
committerMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>2011-03-16 19:04:54 -0400
commitd664b35b277bbba9d63d663312bd653bf62d6d93 (patch)
tree1da1fb5b831ba2b0cead187d26e86c076d714192 /arch/x86/include
parentdcb5e8e536372594bdca903a8bac794817716e24 (diff)
downloadlinux-linaro-android-d664b35b277bbba9d63d663312bd653bf62d6d93.tar.gz
lttng-instrumentation/lttng-kernel-trace-thread-flag-x86
LTTng Linux Kernel Trace Thread Flag x86 Add a thread flag to activate system-wide syscall tracing. Make x86 support TIF_SYSCALL_TRACE async flag set in entry_32.S/entry_64.S. x86_64 : When the flag is inactive upon syscall entry and concurrently activated before exit, we seem to reach a state where the top of stack is incorrect upon return to user space. Fix this by fixing the top of stack and jumping to int_ret_from_sys_call if we detect that thread flags has been modified. We make sure that the thread flag read is coherent between our new test and the ALLWORK_MASK test by first saving it in a register used for both comparisons. Note : Removed : # perform syscall exit tracing ALIGN syscall_exit_work: - testb $_TIF_WORK_SYSCALL_EXIT, %cl jz work_pending TRACE_IRQS_ON ENABLE_INTERRUPTS(CLBR_ANY) # could let syscall_trace_leave() call
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/thread_info.h9
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index f0b6e5dbc5a..58a37ae7565 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -82,6 +82,7 @@ struct thread_info {
#define TIF_SYSCALL_EMU 6 /* syscall emulation active */
#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
#define TIF_SECCOMP 8 /* secure computing */
+#define TIF_KERNEL_TRACE 9 /* kernel trace active */
#define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
#define TIF_NOTSC 16 /* TSC is not accessible in userland */
@@ -105,6 +106,7 @@ struct thread_info {
#define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
+#define _TIF_KERNEL_TRACE (1 << TIF_KERNEL_TRACE)
#define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY)
#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
#define _TIF_NOTSC (1 << TIF_NOTSC)
@@ -121,18 +123,19 @@ struct thread_info {
/* work to do in syscall_trace_enter() */
#define _TIF_WORK_SYSCALL_ENTRY \
(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | _TIF_SYSCALL_AUDIT | \
- _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT)
+ _TIF_SECCOMP | _TIF_SINGLESTEP | _TIF_SYSCALL_TRACEPOINT | \
+ _TIF_KERNEL_TRACE)
/* work to do in syscall_trace_leave() */
#define _TIF_WORK_SYSCALL_EXIT \
(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP | \
- _TIF_SYSCALL_TRACEPOINT)
+ _TIF_SYSCALL_TRACEPOINT | _TIF_KERNEL_TRACE)
/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK \
(0x0000FFFF & \
~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT| \
- _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU))
+ _TIF_SINGLESTEP|_TIF_SECCOMP|_TIF_SYSCALL_EMU|_TIF_KERNEL_TRACE))
/* work to do on any return to user space */
#define _TIF_ALLWORK_MASK \