[patch-early-RFC 01/10] LTTng - ARM instrumentation

From: Mathieu Desnoyers
Date: Wed Dec 05 2007 - 22:02:58 EST


Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
---
arch/arm/kernel/entry-common.S | 8 ++++----
arch/arm/kernel/process.c | 6 +++++-
arch/arm/kernel/ptrace.c | 6 ++++++
arch/arm/kernel/sys_arm.c | 2 ++
arch/arm/kernel/traps.c | 7 +++++++
5 files changed, 24 insertions(+), 5 deletions(-)

Index: linux-2.6-lttng/arch/arm/kernel/entry-common.S
===================================================================
--- linux-2.6-lttng.orig/arch/arm/kernel/entry-common.S 2007-10-11 11:44:13.000000000 -0400
+++ linux-2.6-lttng/arch/arm/kernel/entry-common.S 2007-10-11 11:44:57.000000000 -0400
@@ -85,8 +85,8 @@ ENTRY(ret_from_fork)
get_thread_info tsk
ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing
mov why, #1
- tst r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
- beq ret_slow_syscall
+ tst r1, #_TIF_SYSCALL_TRACE | _TIF_KERNEL_TRACE
+ beq ret_slow_syscall @ are we tracing syscalls?
mov r1, sp
mov r0, #1 @ trace exit [IP = 1]
bl syscall_trace
@@ -205,8 +205,8 @@ ENTRY(vector_swi)
#endif

stmdb sp!, {r4, r5} @ push fifth and sixth args
- tst ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
- bne __sys_trace
+ tst ip, #_TIF_SYSCALL_TRACE | _TIF_KERNEL_TRACE
+ bne __sys_trace @ are we tracing syscalls?

cmp scno, #NR_syscalls @ check upper syscall limit
adr lr, ret_fast_syscall @ return address
Index: linux-2.6-lttng/arch/arm/kernel/process.c
===================================================================
--- linux-2.6-lttng.orig/arch/arm/kernel/process.c 2007-10-11 11:44:13.000000000 -0400
+++ linux-2.6-lttng/arch/arm/kernel/process.c 2007-10-11 14:46:50.000000000 -0400
@@ -418,6 +418,7 @@ asm( ".section .text\n"
pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
{
struct pt_regs regs;
+ long pid;

memset(&regs, 0, sizeof(regs));

@@ -427,7 +428,10 @@ pid_t kernel_thread(int (*fn)(void *), v
regs.ARM_pc = (unsigned long)kernel_thread_helper;
regs.ARM_cpsr = SVC_MODE;

- return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
+ pid = do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
+
+ trace_mark(kernel_arch_kthread_create, "pid %ld fn %p", pid, fn);
+ return pid;
}
EXPORT_SYMBOL(kernel_thread);

Index: linux-2.6-lttng/arch/arm/kernel/ptrace.c
===================================================================
--- linux-2.6-lttng.orig/arch/arm/kernel/ptrace.c 2007-10-11 11:44:13.000000000 -0400
+++ linux-2.6-lttng/arch/arm/kernel/ptrace.c 2007-10-11 14:48:21.000000000 -0400
@@ -789,6 +789,12 @@ asmlinkage int syscall_trace(int why, st
{
unsigned long ip;

+ if (!why)
+ trace_mark(kernel_arch_syscall_entry, "syscall_id %d ip #p%ld",
+ scno, instruction_pointer(regs));
+ else
+ trace_mark(kernel_arch_syscall_exit, MARK_NOARGS);
+
if (!test_thread_flag(TIF_SYSCALL_TRACE))
return scno;
if (!(current->ptrace & PT_PTRACED))
Index: linux-2.6-lttng/arch/arm/kernel/sys_arm.c
===================================================================
--- linux-2.6-lttng.orig/arch/arm/kernel/sys_arm.c 2007-10-11 11:44:13.000000000 -0400
+++ linux-2.6-lttng/arch/arm/kernel/sys_arm.c 2007-10-11 14:47:23.000000000 -0400
@@ -161,6 +161,8 @@ asmlinkage int sys_ipc(uint call, int fi
version = call >> 16; /* hack for backward compatibility */
call &= 0xffff;

+ trace_mark(kernel_arch_ipc_call, "call %u first %d", call, first);
+
switch (call) {
case SEMOP:
return sys_semtimedop (first, (struct sembuf __user *)ptr, second, NULL);
Index: linux-2.6-lttng/arch/arm/kernel/traps.c
===================================================================
--- linux-2.6-lttng.orig/arch/arm/kernel/traps.c 2007-10-11 11:44:13.000000000 -0400
+++ linux-2.6-lttng/arch/arm/kernel/traps.c 2007-10-11 14:48:11.000000000 -0400
@@ -269,7 +269,14 @@ void arm_notify_die(const char *str, str
current->thread.error_code = err;
current->thread.trap_no = trap;

+ trace_mark(kernel_arch_trap_entry, "trap_id %ld ip #p%ld",
+ current->thread.trap_no,
+ instruction_pointer(regs));
+
force_sig_info(info->si_signo, info, current);
+
+ trace_mark(kernel_arch_trap_exit, MARK_NOARGS);
+
} else {
die(str, regs, err);
}

--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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