unwind: move stacktrace capturing and mmap cache invalidating to trace_syscall_entering

Instead of handling stacktrace capturing and mmap cache invalidating in
sys_* functions, handle them uniformly in trace_syscall_entering using
new flags introduced by previous two commits.

The patch is simpler than its older version(v3).  The value of
hide_log_until_execve is just ignored.  I found the value is nothing
to do with this patch.  unwind_cache_invalidate is mentioned only
once in trace_syscall_exiting.
Both are suggested by Dmitry Levin.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

3 files changed, 14 insertions, 40 deletions

diff --git a/mem.c b/mem.c
index 180e37006..6ecd363c8 100644
--- a/mem.c
+++ b/mem.c
@@ -60,13 +60,6 @@ static int
 print_mmap(struct tcb *tcp, long *u_arg, unsigned long long offset)
 {
 	if (entering(tcp)) {
-#ifdef USE_LIBUNWIND
-		if (stack_trace_enabled) {
-			unwind_capture_stacktrace(tcp);
-			unwind_cache_invalidate(tcp);
-		}
-#endif
-
 		/* addr */
 		if (!u_arg[0])
 			tprints("NULL, ");
@@ -195,17 +188,7 @@ sys_munmap(struct tcb *tcp)
 	if (entering(tcp)) {
 		tprintf("%#lx, %lu",
 			tcp->u_arg[0], tcp->u_arg[1]);
-#ifdef USE_LIBUNWIND
-		if (stack_trace_enabled)
-			unwind_capture_stacktrace(tcp);
-#endif
-	}
-#ifdef USE_LIBUNWIND
-	else {
-		if (stack_trace_enabled)
-			unwind_cache_invalidate(tcp);
 	}
-#endif
 	return 0;
 }
 
@@ -216,17 +199,7 @@ sys_mprotect(struct tcb *tcp)
 		tprintf("%#lx, %lu, ",
 			tcp->u_arg[0], tcp->u_arg[1]);
 		printflags(mmap_prot, tcp->u_arg[2], "PROT_???");
-#ifdef USE_LIBUNWIND
-		if (stack_trace_enabled)
-			unwind_capture_stacktrace(tcp);
-#endif
 	}
-#ifdef USE_LIBUNWIND
-	else {
-		if (stack_trace_enabled)
-			unwind_cache_invalidate(tcp);
-	}
-#endif
 	return 0;
 }
 
diff --git a/process.c b/process.c
index ec9e1b4ed..a880f9e36 100644
--- a/process.c
+++ b/process.c
@@ -798,20 +798,7 @@ sys_execve(struct tcb *tcp)
 			printargv(tcp, tcp->u_arg[2]);
 			tprints("]");
 		}
-#ifdef USE_LIBUNWIND
-		if (stack_trace_enabled) {
-			unwind_capture_stacktrace(tcp);
-		}
-#endif
 	}
-#ifdef USE_LIBUNWIND
-	else {
-		if (stack_trace_enabled) {
-			unwind_cache_invalidate(tcp);
-		}
-	}
-#endif
-
 	return 0;
 }
 
diff --git a/syscall.c b/syscall.c
index f81655102..c95eb6c88 100644
--- a/syscall.c
+++ b/syscall.c
@@ -2040,6 +2040,13 @@ trace_syscall_entering(struct tcb *tcp)
 		goto ret;
 	}
 
+#ifdef USE_LIBUNWIND
+	if (stack_trace_enabled) {
+		if (tcp->s_ent->sys_flags & STACKTRACE_CAPTURE_ON_ENTER)
+			unwind_capture_stacktrace(tcp);
+	}
+#endif
+
 	printleader(tcp);
 	if (tcp->qual_flg & UNDEFINED_SCNO)
 		tprintf("%s(", undefined_scno_name(tcp));
@@ -2513,6 +2520,13 @@ trace_syscall_exiting(struct tcb *tcp)
 	if (Tflag || cflag)
 		gettimeofday(&tv, NULL);
 
+#ifdef USE_LIBUNWIND
+	if (stack_trace_enabled) {
+		if (tcp->s_ent->sys_flags & STACKTRACE_INVALIDATE_CACHE)
+			unwind_cache_invalidate(tcp);
+	}
+#endif
+
 #if SUPPORTED_PERSONALITIES > 1
 	update_personality(tcp, tcp->currpers);
 #endif