microblaze: Support ptrace syscall tracing.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>

1 files changed, 62 insertions, 0 deletions

diff --git a/arch/microblaze/kernel/ptrace.c b/arch/microblaze/kernel/ptrace.c
index 53ff39a..4b3ac32 100644
--- a/arch/microblaze/kernel/ptrace.c
+++ b/arch/microblaze/kernel/ptrace.c
@@ -29,6 +29,10 @@
 #include <linux/sched.h>
 #include <linux/ptrace.h>
 #include <linux/signal.h>
+#include <linux/elf.h>
+#include <linux/audit.h>
+#include <linux/seccomp.h>
+#include <linux/tracehook.h>
 
 #include <linux/errno.h>
 #include <asm/processor.h>
@@ -174,6 +178,64 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 	return rval;
 }
 
+asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
+{
+	long ret = 0;
+
+	secure_computing(regs->r12);
+
+	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
+	    tracehook_report_syscall_entry(regs))
+		/*
+		 * Tracing decided this syscall should not happen.
+		 * We'll return a bogus call number to get an ENOSYS
+		 * error, but leave the original number in regs->regs[0].
+		 */
+		ret = -1L;
+
+	if (unlikely(current->audit_context))
+		audit_syscall_entry(EM_XILINX_MICROBLAZE, regs->r12,
+				    regs->r5, regs->r6,
+				    regs->r7, regs->r8);
+
+	return ret ?: regs->r12;
+}
+
+asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
+{
+	int step;
+
+	if (unlikely(current->audit_context))
+		audit_syscall_exit(AUDITSC_RESULT(regs->r3), regs->r3);
+
+	step = test_thread_flag(TIF_SINGLESTEP);
+	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
+		tracehook_report_syscall_exit(regs, step);
+}
+
+#if 0
+static asmlinkage void syscall_trace(void)
+{
+	if (!test_thread_flag(TIF_SYSCALL_TRACE))
+		return;
+	if (!(current->ptrace & PT_PTRACED))
+		return;
+	/* 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));
+	/*
+	 * 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;
+	}
+}
+#endif
+
 void ptrace_disable(struct task_struct *child)
 {
 	/* nothing to do */