From 9e4930dbf17c1eba72631cd52a0c621da3d1a816 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 2 Oct 2010 22:57:30 -0400 Subject: [PATCH] m68k: Simplify the singlestepping handling in signals Instead of checking the return value of do_signal() we can just do the work (raise SIGTRAP and clear SR.T1) directly in handle_signal(), when setting the sigframe up. Simplifies the assembler glue and is closer to the way we do it on other targets. Note that do_delayed_trace does *not* disappear; it's still needed to deal with single-stepping through syscall, since 68040 doesn't raise the trace exception at all if the trap exception is pending. We hit it after returning from sys_...() if TIF_DELAYED_TRACE is set; all that has changed is that we don't reuse it for "single-step into the handler" codepath. As the result, do_signal() doesn't need to return anything anymore. Signed-off-by: Al Viro Signed-off-by: Geert Uytterhoeven --- arch/m68k/kernel/entry.S | 6 +----- arch/m68k/kernel/signal.c | 11 +++++++---- 2 files changed, 8 insertions(+), 9 deletions(-) diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S index 3a15a03297a7..4e49f5777696 100644 --- a/arch/m68k/kernel/entry.S +++ b/arch/m68k/kernel/entry.S @@ -178,11 +178,7 @@ do_signal_return: addql #4,%sp RESTORE_SWITCH_STACK addql #4,%sp - tstl %d0 - jeq resume_userspace - | when single stepping into handler stop at the first insn - btst #6,%curptr@(TASK_INFO+TINFO_FLAGS+2) - jeq resume_userspace + jbra resume_userspace do_delayed_trace: bclr #7,%sp@(PT_OFF_SR) | clear trace bit in SR diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c index fa8200d03de2..a18b251fe593 100644 --- a/arch/m68k/kernel/signal.c +++ b/arch/m68k/kernel/signal.c @@ -978,6 +978,11 @@ handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info, if (!(ka->sa.sa_flags & SA_NODEFER)) sigaddset(¤t->blocked,sig); recalc_sigpending(); + + if (test_thread_flag(TIF_DELAYED_TRACE)) { + regs->sr &= ~0x8000; + send_sig(SIGTRAP, current, 1); + } } /* @@ -985,7 +990,7 @@ handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info, * want to handle. Thus you cannot kill init even with a SIGKILL even by * mistake. */ -asmlinkage int do_signal(struct pt_regs *regs) +asmlinkage void do_signal(struct pt_regs *regs) { siginfo_t info; struct k_sigaction ka; @@ -1004,7 +1009,7 @@ asmlinkage int do_signal(struct pt_regs *regs) /* Whee! Actually deliver the signal. */ handle_signal(signr, &ka, &info, oldset, regs); clear_thread_flag(TIF_RESTORE_SIGMASK); - return 1; + return; } /* Did we come from a system call? */ @@ -1017,6 +1022,4 @@ asmlinkage int do_signal(struct pt_regs *regs) clear_thread_flag(TIF_RESTORE_SIGMASK); sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); } - - return 0; }