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 <[e-mail]>

arch/parisc/Kconfig

···
 	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

···
 
 #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

···
 #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)
 {
···
 		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,

arch/parisc/include/asm/thread_info.h

···
 #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)
···
 #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

···
 /* 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..
  *
···
 		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())
···
 		test_thread_flag(TIF_BLOCKSTEP);
 
 	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

···
 
 	.align 8
 ENTRY(sys_call_table)
+	.export sys_call_table,data
 #include "syscall_table.S"
 END(sys_call_table)