[PATCH 2/3] ARM: add TRACEHOOK support

[stevenrwalter@gmail.com (Steven Walter)]

Add calls to tracehook_report_syscall_{entry,exit} and tracehook_signal_handler

Signed-off-by: Steven Walter <stevenrwalter@gmail.com>
---
 arch/arm/Kconfig              |    1 +
 arch/arm/include/asm/ptrace.h |    5 +++++
 arch/arm/kernel/ptrace.c      |   21 +++++++--------------
 arch/arm/kernel/signal.c      |    2 ++
 4 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b65b910..0a93d76 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -10,6 +10,7 @@ config ARM
 	select GENERIC_ATOMIC64 if (CPU_V6 || !CPU_32v6K || !AEABI)
 	select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
 	select HAVE_ARCH_KGDB
+	select HAVE_ARCH_TRACEHOOK
 	select HAVE_KPROBES if (!XIP_KERNEL && !THUMB2_KERNEL)
 	select HAVE_KRETPROBES if (HAVE_KPROBES)
 	select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h
index 312d108..98ea76d 100644
--- a/arch/arm/include/asm/ptrace.h
+++ b/arch/arm/include/asm/ptrace.h
@@ -235,6 +235,11 @@ static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
 	return regs->ARM_sp;
 }
 
+static inline unsigned long user_stack_pointer(struct pt_regs *regs)
+{
+	return regs->ARM_sp;
+}
+
 #endif /* __KERNEL__ */
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 9726006..1411848 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -22,6 +22,7 @@
 #include <linux/perf_event.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/regset.h>
+#include <linux/tracehook.h>
 
 #include <asm/pgtable.h>
 #include <asm/system.h>
@@ -928,8 +929,6 @@ asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
 
 	if (!test_thread_flag(TIF_SYSCALL_TRACE))
 		return scno;
-	if (!(current->ptrace & PT_PTRACED))
-		return scno;
 
 	/*
 	 * Save IP.  IP is used to denote syscall entry/exit:
@@ -940,19 +939,13 @@ asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
 
 	current_thread_info()->syscall = scno;
 
-	/* the 0x80 provides a way for the tracing parent to distinguish
-	   between a syscall stop and SIGTRAP delivery */
-	ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
-				 ? 0x80 : 0));
-	/*
-	 * this isn't the same as continuing with a signal, but it will do
-	 * for normal use.  strace only continues with a signal if the
-	 * stopping signal is not SIGTRAP.  -brl
-	 */
-	if (current->exit_code) {
-		send_sig(current->exit_code, current, 1);
-		current->exit_code = 0;
+	if (why == 0) {
+		if (tracehook_report_syscall_entry(regs))
+			current_thread_info()->syscall = -1;
+	} else {
+		tracehook_report_syscall_exit(regs, 0);
 	}
+
 	regs->ARM_ip = ip;
 
 	return current_thread_info()->syscall;
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 0340224..26c26f5 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -645,6 +645,8 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 	recalc_sigpending();
 	spin_unlock_irq(&tsk->sighand->siglock);
 
+	tracehook_signal_handler(sig, info, ka, regs, 0);
+
 	return 0;
 }
 
-- 
1.7.5.4.2.g81f75