powerpc/ptrace: Combine SYSCALL_EMU & SYSCALL_TRACE handling (8dbdec0b) · Commits · 戴 / test

arch/powerpc/kernel/ptrace.c

+31 −23

Original line number	Diff line number	Diff line
		@@ -3263,32 +3263,40 @@ static inline int do_seccomp(struct pt_regs *regs) { return 0; }
		*/
		long do_syscall_trace_enter(struct pt_regs *regs)
		{
		u32 flags;

		user_exit();

		if (test_thread_flag(TIF_SYSCALL_EMU)) {
		flags = READ_ONCE(current_thread_info()->flags) &
		(_TIF_SYSCALL_EMU \| _TIF_SYSCALL_TRACE);

		if (flags) {
		int rc = tracehook_report_syscall_entry(regs);

		if (unlikely(flags & _TIF_SYSCALL_EMU)) {
		/*
		* A nonzero return code from tracehook_report_syscall_entry()
		* tells us to prevent the syscall execution, but we are not
		* going to execute it anyway.
		* A nonzero return code from
		* tracehook_report_syscall_entry() tells us to prevent
		* the syscall execution, but we are not going to
		* execute it anyway.
		*
		* Returning -1 will skip the syscall execution. We want to
		* avoid clobbering any register also, thus, not 'gotoing'
		* skip label.
		* Returning -1 will skip the syscall execution. We want
		* to avoid clobbering any registers, so we don't goto
		* the skip label below.
		*/
		if (tracehook_report_syscall_entry(regs))
		;
		return -1;
		}

		if (rc) {
		/*
		* The tracer may decide to abort the syscall, if so tracehook
		* will return !0. Note that the tracer may also just change
		* regs->gpr[0] to an invalid syscall number, that is handled
		* below on the exit path.
		* The tracer decided to abort the syscall. Note that
		* the tracer may also just change regs->gpr[0] to an
		* invalid syscall number, that is handled below on the
		* exit path.
		*/
		if (test_thread_flag(TIF_SYSCALL_TRACE) &&
		tracehook_report_syscall_entry(regs))
		goto skip;
		}
		}

		/* Run seccomp after ptrace; allow it to set gpr[3]. */
		if (do_seccomp(regs))

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