parisc: Add syscall tracepoint support

This patch adds support for the TIF_SYSCALL_TRACEPOINT on the parisc
architecture. Basically, it calls the appropriate tracepoints on syscall
entry and exit.
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/Kconfig

@@ -6,6 +6,7 @@ config PARISC
 	select HAVE_OPROFILE
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
+	select HAVE_SYSCALL_TRACEPOINTS
 	select ARCH_WANT_FRAME_POINTERS
 	select RTC_CLASS
 	select RTC_DRV_GENERIC

arch/parisc/include/asm/ftrace.h

@@ -6,6 +6,8 @@ extern void mcount(void);
 
 #define MCOUNT_INSN_SIZE 4
 
+extern unsigned long sys_call_table[];
+
 extern unsigned long return_address(unsigned int);
 
 #define ftrace_return_address(n) return_address(n)

arch/parisc/include/asm/syscall.h

@@ -8,6 +8,8 @@
 #include <linux/err.h>
 #include <asm/ptrace.h>
 
+#define NR_syscalls (__NR_Linux_syscalls)
+
 static inline long syscall_get_nr(struct task_struct *tsk,
 				  struct pt_regs *regs)
 {
@@ -33,12 +35,19 @@ static inline void syscall_get_arguments(struct task_struct *tsk,
 		args[1] = regs->gr[25];
 	case 1:
 		args[0] = regs->gr[26];
+	case 0:
 		break;
 	default:
 		BUG();
 	}
 }
 
+static inline long syscall_get_return_value(struct task_struct *task,
+						struct pt_regs *regs)
+{
+	return regs->gr[28];
+}
+
 static inline void syscall_set_return_value(struct task_struct *task,
 					    struct pt_regs *regs,
 					    int error, long val)

arch/parisc/include/asm/thread_info.h

@@ -55,6 +55,7 @@ struct thread_info {
 #define TIF_SINGLESTEP		9	/* single stepping? */
 #define TIF_BLOCKSTEP		10	/* branch stepping? */
 #define TIF_SECCOMP		11	/* secure computing */
+#define TIF_SYSCALL_TRACEPOINT	12	/* syscall tracepoint instrumentation */
 
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
@@ -66,12 +67,13 @@ struct thread_info {
 #define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
 #define _TIF_BLOCKSTEP		(1 << TIF_BLOCKSTEP)
 #define _TIF_SECCOMP		(1 << TIF_SECCOMP)
+#define _TIF_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)
 
 #define _TIF_USER_WORK_MASK     (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | \
                                  _TIF_NEED_RESCHED)
 #define _TIF_SYSCALL_TRACE_MASK (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP |	\
 				 _TIF_BLOCKSTEP | _TIF_SYSCALL_AUDIT | \
-				 _TIF_SECCOMP)
+				 _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT)
 
 #ifdef CONFIG_64BIT
 # ifdef CONFIG_COMPAT

arch/parisc/kernel/ptrace.c

@@ -30,6 +30,9 @@
 /* PSW bits we allow the debugger to modify */
 #define USER_PSW_BITS	(PSW_N | PSW_B | PSW_V | PSW_CB)
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
 /*
  * Called by kernel/ptrace.c when detaching..
  *
@@ -283,6 +286,10 @@ long do_syscall_trace_enter(struct pt_regs *regs)
 		regs->gr[20] = -1UL;
 		goto out;
 	}
+#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
+	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
+		trace_sys_enter(regs, regs->gr[20]);
+#endif
 
 #ifdef CONFIG_64BIT
 	if (!is_compat_task())
@@ -311,6 +318,11 @@ void do_syscall_trace_exit(struct pt_regs *regs)
 
 	audit_syscall_exit(regs);
 
+#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
+	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
+		trace_sys_exit(regs, regs->gr[20]);
+#endif
+
 	if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
 		tracehook_report_syscall_exit(regs, stepping);
 }

arch/parisc/kernel/syscall.S

@@ -912,6 +912,7 @@ END(lws_table)
 
 	.align 8
 ENTRY(sys_call_table)
+	.export sys_call_table,data
 #include "syscall_table.S"
 END(sys_call_table)