From 35e080ae319d25c1df82855cda3a1bb014e90ba6 Mon Sep 17 00:00:00 2001

From: "Dmitry V. Levin" <ldv@altlinux.org>

Date: Wed, 8 Jan 2020 00:41:58 +0000

Subject: [PATCH] syscall: do not capture stack trace while the tracee executes

 strace code

* syscall.c (syscall_entering_trace) [ENABLE_STACKTRACE]: Do not capture

stack trace when TCB_CHECK_EXEC_SYSCALL flag is set.

---

 syscall.c | 9 +++++----

 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/syscall.c b/syscall.c

index fadd3b5..a8fb4f1 100644

--- a/syscall.c

+++ b/syscall.c

@@ -620,7 +620,7 @@ syscall_entering_trace(struct tcb *tcp, unsigned int *sig)

 	if (hide_log(tcp)) {

 		/*

 		 * Restrain from fault injection

-		 * while the trace executes strace code.

+		 * while the tracee executes strace code.

 		 */

 		tcp->qual_flg &= ~QUAL_INJECT;

@@ -655,9 +655,10 @@ syscall_entering_trace(struct tcb *tcp, unsigned int *sig)

 	}

 #ifdef ENABLE_STACKTRACE

-	if (stack_trace_enabled) {

-		if (tcp_sysent(tcp)->sys_flags & STACKTRACE_CAPTURE_ON_ENTER)

-			unwind_tcb_capture(tcp);

+	if (stack_trace_enabled &&

+	    !check_exec_syscall(tcp) &&

+	    tcp_sysent(tcp)->sys_flags & STACKTRACE_CAPTURE_ON_ENTER) {

+		unwind_tcb_capture(tcp);

 	}

 #endif

-- 

2.1.4