sh64: fix tracing of signals.

This follows the parisc change to ensure that tracehook_signal_handler()
is aware of when we are single-stepping in order to ptrace_notify()
appropriately. While this was implemented for 32-bit SH, sh64 neglected
to make use of TIF_SINGLESTEP when it was folded in with the 32-bit code,
resulting in ptrace_notify() never being called.

As sh64 uses all of the other abstractions already, this simply plugs in
the thread flag in the appropriate enable/disable paths and fixes up the
tracehook notification accordingly. With this in place, sh64 is brought
in line with what 32-bit is already doing.

Reported-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 9 insertions, 2 deletions

diff --git a/arch/sh/kernel/ptrace_64.c b/arch/sh/kernel/ptrace_64.c
index 873ebdc4f98e..b063eb8b18e3 100644
--- a/arch/sh/kernel/ptrace_64.c
+++ b/arch/sh/kernel/ptrace_64.c
@@ -133,6 +133,8 @@ void user_enable_single_step(struct task_struct *child)
         struct pt_regs *regs = child->thread.uregs;
 
         regs->sr |= SR_SSTEP;   /* auto-resetting upon exception */
+
+        set_tsk_thread_flag(child, TIF_SINGLESTEP);
 }
 
 void user_disable_single_step(struct task_struct *child)
@@ -140,6 +142,8 @@ void user_disable_single_step(struct task_struct *child)
         struct pt_regs *regs = child->thread.uregs;
 
         regs->sr &= ~SR_SSTEP;
+
+        clear_tsk_thread_flag(child, TIF_SINGLESTEP);
 }
 
 static int genregs_get(struct task_struct *target,
@@ -454,6 +458,8 @@ asmlinkage long long do_syscall_trace_enter(struct pt_regs *regs)
 
 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
 {
+        int step;
+
         if (unlikely(current->audit_context))
                 audit_syscall_exit(AUDITSC_RESULT(regs->regs[9]),
                                    regs->regs[9]);
@@ -461,8 +467,9 @@ asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
                 trace_sys_exit(regs, regs->regs[9]);
 
-        if (test_thread_flag(TIF_SYSCALL_TRACE))
-                tracehook_report_syscall_exit(regs, 0);
+        step = test_thread_flag(TIF_SINGLESTEP);
+        if (step || test_thread_flag(TIF_SYSCALL_TRACE))
+                tracehook_report_syscall_exit(regs, step);
 }
 
 /* Called with interrupts disabled */