From b6b38fa73b9e0810c68a19dcb3ade2974db20f8c Mon Sep 17 00:00:00 2001
From: "Dmitry V. Levin" <ldv@altlinux.org>
Date: Tue, 15 Dec 2015 15:26:29 +0000
Subject: [PATCH] tests/times.test: workaround libc bug on x32

As glibc times wrapper on x32 is known to wrongly truncate and then sign
extend the syscall return value, invoke the syscall directly on x32.

* tests/times.c (main) [__NR_times && __x86_64__ && __ILP32__]:
Invoke times syscall using inline asm.
---
 tests/times.c | 33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

diff --git a/tests/times.c b/tests/times.c
index f0e7086b..c34a9a32 100644
--- a/tests/times.c
+++ b/tests/times.c
@@ -69,9 +69,29 @@ main (void)
 	 * prefer direct times syscall over libc's times function because
 	 * the latter is more prone to return value truncation.
 	 */
-#if !defined __NR_times \
- || defined LINUX_MIPSN32 \
- || defined __x86_64__ && defined __ILP32__
+#undef USE_LIBC_SYSCALL
+#if defined __NR_times && \
+   !defined(LINUX_MIPSN32) && \
+   !(defined __x86_64__ && defined __ILP32__)
+# define USE_LIBC_SYSCALL 1
+#endif
+
+#if defined USE_LIBC_SYSCALL
+	long res = syscall(__NR_times, &tbuf);
+
+	if (-1L == res)
+		return 77;
+	else
+		llres = (unsigned long) res;
+#elif defined __NR_times && defined __x86_64__ && defined __ILP32__
+	register long arg asm("rdi") = (long) &tbuf;
+	asm volatile("syscall\n\t"
+		     : "=a"(llres)
+		     : "0"(__NR_times), "r"(arg)
+		     : "memory", "cc", "r11", "cx");
+	if (llres > 0xfffffffffffff000)
+		return 77;
+#else
 	clock_t res = times(&tbuf);
 
 	if ((clock_t) -1 == res)
@@ -80,13 +100,6 @@ main (void)
 		llres = (unsigned long) res;
 	else
 		llres = res;
-#else
-	long res = syscall(__NR_times, &tbuf);
-
-	if (-1L == res)
-		return 77;
-	else
-		llres = (unsigned long) res;
 #endif
 
 	printf("times({tms_utime=%llu, tms_stime=%llu, ",
-- 
2.40.0