From: Dmitry V. Levin <ldv@altlinux.org>
Date: Fri, 18 Sep 2015 01:54:59 +0000 (+0000)
Subject: Add is_erestart helper function
X-Git-Tag: v4.11~180
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9af94a2f486064a62cce5439fd417a992e591eae;p=strace

Add is_erestart helper function

* defs.h (is_erestart): New prototype.
* syscall.c (is_erestart): New function.
* time.c (sys_nanosleep): Use is_erestart,
temporarily_clear_syserror, and restore_cleared_syserror.
---

diff --git a/defs.h b/defs.h
index 119f9b44..b7e00806 100644
--- a/defs.h
+++ b/defs.h
@@ -538,6 +538,7 @@ extern void get_regs(pid_t pid);
 extern int get_scno(struct tcb *tcp);
 extern const char *syscall_name(long scno);
 
+extern bool is_erestart(struct tcb *);
 extern void temporarily_clear_syserror(struct tcb *);
 extern void restore_cleared_syserror(struct tcb *);
 
diff --git a/syscall.c b/syscall.c
index aaa44ead..d4599e40 100644
--- a/syscall.c
+++ b/syscall.c
@@ -1131,6 +1131,20 @@ trace_syscall(struct tcb *tcp)
 		trace_syscall_exiting(tcp) : trace_syscall_entering(tcp);
 }
 
+bool
+is_erestart(struct tcb *tcp)
+{
+	switch (tcp->u_error) {
+		case ERESTARTSYS:
+		case ERESTARTNOINTR:
+		case ERESTARTNOHAND:
+		case ERESTART_RESTARTBLOCK:
+			return true;
+		default:
+			return false;
+	}
+}
+
 static int saved_u_error;
 
 void
diff --git a/time.c b/time.c
index e37f26e0..47023c59 100644
--- a/time.c
+++ b/time.c
@@ -203,22 +203,19 @@ SYS_FUNC(nanosleep)
 		print_timespec(tcp, tcp->u_arg[0]);
 		tprints(", ");
 	} else {
-		/* Second (returned) timespec is only significant
-		 * if syscall was interrupted. On success, we print
-		 * only its address, since kernel doesn't modify it,
+
+		/*
+		 * Second (returned) timespec is only significant if syscall
+		 * was interrupted.  On success and in case of other errors we
+		 * print only its address, since kernel doesn't modify it,
 		 * and printing the value may show uninitialized data.
 		 */
-		switch (tcp->u_error) {
-		default:
-			/* Not interrupted (slept entire interval) */
-			printaddr(tcp->u_arg[1]);
-			break;
-		case ERESTARTSYS:
-		case ERESTARTNOINTR:
-		case ERESTARTNOHAND:
-		case ERESTART_RESTARTBLOCK:
-			/* Interrupted */
+		if (is_erestart(tcp)) {
+			temporarily_clear_syserror(tcp);
 			print_timespec(tcp, tcp->u_arg[1]);
+			restore_cleared_syserror(tcp);
+		} else {
+			printaddr(tcp->u_arg[1]);
 		}
 	}
 	return 0;