From 6823b5e244a5748032130574ae3a25a0a36bbbf5 Mon Sep 17 00:00:00 2001 From: Michael Pratt Date: Tue, 4 Feb 2020 13:05:30 -0800 Subject: timer_create(2) should return 0 on success The timer ID is copied out to the argument. Fixes #1738 PiperOrigin-RevId: 293210801 --- pkg/sentry/syscalls/linux/sys_timer.go | 2 +- test/syscalls/linux/timers.cc | 18 +++++++++++++++++- 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/pkg/sentry/syscalls/linux/sys_timer.go b/pkg/sentry/syscalls/linux/sys_timer.go index 432351917..a4c400f87 100644 --- a/pkg/sentry/syscalls/linux/sys_timer.go +++ b/pkg/sentry/syscalls/linux/sys_timer.go @@ -146,7 +146,7 @@ func TimerCreate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.S return 0, nil, err } - return uintptr(id), nil, nil + return 0, nil, nil } // TimerSettime implements linux syscall timer_settime(2). diff --git a/test/syscalls/linux/timers.cc b/test/syscalls/linux/timers.cc index 3db18d7ac..2f92c27da 100644 --- a/test/syscalls/linux/timers.cc +++ b/test/syscalls/linux/timers.cc @@ -297,9 +297,13 @@ class IntervalTimer { PosixErrorOr TimerCreate(clockid_t clockid, const struct sigevent& sev) { int timerid; - if (syscall(SYS_timer_create, clockid, &sev, &timerid) < 0) { + int ret = syscall(SYS_timer_create, clockid, &sev, &timerid); + if (ret < 0) { return PosixError(errno, "timer_create"); } + if (ret > 0) { + return PosixError(EINVAL, "timer_create should never return positive"); + } MaybeSave(); return IntervalTimer(timerid); } @@ -317,6 +321,18 @@ TEST(IntervalTimerTest, IsInitiallyStopped) { EXPECT_EQ(0, its.it_value.tv_nsec); } +// Kernel can create multiple timers without issue. +// +// Regression test for gvisor.dev/issue/1738. +TEST(IntervalTimerTest, MultipleTimers) { + struct sigevent sev = {}; + sev.sigev_notify = SIGEV_NONE; + const auto timer1 = + ASSERT_NO_ERRNO_AND_VALUE(TimerCreate(CLOCK_MONOTONIC, sev)); + const auto timer2 = + ASSERT_NO_ERRNO_AND_VALUE(TimerCreate(CLOCK_MONOTONIC, sev)); +} + TEST(IntervalTimerTest, SingleShotSilent) { struct sigevent sev = {}; sev.sigev_notify = SIGEV_NONE; -- cgit v1.2.3