arch/tile: Call tracehook_report_syscall_{entry,exit} in syscall trace

Call tracehook functions for syscall tracing.

The check for TIF_SYSCALL_TRACE was removed, because the same check is
done right before in the assembly file.
Signed-off-by: Simon Marchi <simon.marchi@polymtl.ca>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> [with ptrace.h fixup]

arch/tile/include/asm/ptrace.h

@@ -44,7 +44,8 @@ typedef unsigned long pt_reg_t;
 struct pt_regs *get_pt_regs(struct pt_regs *);
 
 /* Trace the current syscall. */
-extern void do_syscall_trace(void);
+extern int do_syscall_trace_enter(struct pt_regs *regs);
+extern void do_syscall_trace_exit(struct pt_regs *regs);
 
 #define arch_has_single_step()	(1)
 

arch/tile/kernel/intvec_32.S

@@ -1201,7 +1201,10 @@ handle_syscall:
 	lw	r30, r31
 	andi    r30, r30, _TIF_SYSCALL_TRACE
 	bzt	r30, .Lrestore_syscall_regs
-	jal	do_syscall_trace
+	{
+	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
+	 jal    do_syscall_trace_enter
+	}
 	FEEDBACK_REENTER(handle_syscall)
 
 	/*
@@ -1252,7 +1255,10 @@ handle_syscall:
 	lw	r30, r31
 	andi    r30, r30, _TIF_SYSCALL_TRACE
 	bzt     r30, 1f
-	jal	do_syscall_trace
+	{
+	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
+	 jal    do_syscall_trace_exit
+	}
 	FEEDBACK_REENTER(handle_syscall)
 1:	{
 	 movei  r30, 0               /* not an NMI */

arch/tile/kernel/intvec_64.S

@@ -1006,7 +1006,10 @@ handle_syscall:
 	 addi   r30, r31, THREAD_INFO_STATUS_OFFSET - THREAD_INFO_FLAGS_OFFSET
 	 beqzt	r30, .Lrestore_syscall_regs
 	}
-	jal	do_syscall_trace
+	{
+	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
+	 jal    do_syscall_trace_enter
+	}
 	FEEDBACK_REENTER(handle_syscall)
 
 	/*
@@ -1077,7 +1080,10 @@ handle_syscall:
 	 andi    r0, r30, _TIF_SINGLESTEP
 	 beqzt   r0, 1f
 	}
-	jal	do_syscall_trace
+	{
+	 PTREGS_PTR(r0, PTREGS_OFFSET_BASE)
+	 jal    do_syscall_trace_exit
+	}
 	FEEDBACK_REENTER(handle_syscall)
 	andi    r0, r30, _TIF_SINGLESTEP
 

arch/tile/kernel/ptrace.c

@@ -21,6 +21,7 @@
 #include <linux/uaccess.h>
 #include <linux/regset.h>
 #include <linux/elf.h>
+#include <linux/tracehook.h>
 #include <asm/traps.h>
 #include <arch/chip.h>
 
@@ -246,29 +247,18 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
 }
 #endif
 
-void do_syscall_trace(void)
+int do_syscall_trace_enter(struct pt_regs *regs)
 {
-	if (!test_thread_flag(TIF_SYSCALL_TRACE))
-		return;
-
-	if (!(current->ptrace & PT_PTRACED))
-		return;
+	if (tracehook_report_syscall_entry(regs)) {
+		regs->regs[TREG_SYSCALL_NR] = -1;
+	}
 
-	/*
-	 * 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));
+	return regs->regs[TREG_SYSCALL_NR];
+}
 
-	/*
-	 * 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;
-	}
+void do_syscall_trace_exit(struct pt_regs *regs)
+{
+	tracehook_report_syscall_exit(regs, 0);
 }
 
 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)