ARM: 7374/1: add TRACEHOOK support

Add calls to tracehook_report_syscall_{entry,exit} and tracehook_signal_handler
Signed-off-by: Steven Walter <stevenrwalter@gmail.com>
Signed-off-by: Wade Farnsworth <wade_farnsworth@mentor.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/Kconfig

@@ -11,6 +11,7 @@ config ARM
 	select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
 	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL
 	select HAVE_ARCH_KGDB
+	select HAVE_ARCH_TRACEHOOK
 	select HAVE_KPROBES if !XIP_KERNEL
 	select HAVE_KRETPROBES if (HAVE_KPROBES)
 	select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)

arch/arm/include/asm/ptrace.h

@@ -249,6 +249,11 @@ 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__ */

arch/arm/kernel/ptrace.c

@@ -24,6 +24,7 @@
 #include <linux/hw_breakpoint.h>
 #include <linux/regset.h>
 #include <linux/audit.h>
+#include <linux/tracehook.h>
 
 #include <asm/pgtable.h>
 #include <asm/traps.h>
@@ -931,24 +932,14 @@ 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;
 
 	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)
+		tracehook_report_syscall_exit(regs, 0);
+	else if (tracehook_report_syscall_entry(regs))
+		current_thread_info()->syscall = -1;
+
 	regs->ARM_ip = ip;
 
 	return current_thread_info()->syscall;

arch/arm/kernel/signal.c

@@ -636,6 +636,8 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 	 */
 	block_sigmask(ka, sig);
 
+	tracehook_signal_handler(sig, info, ka, regs, 0);
+
 	return 0;
 }