[LTP] [PATCH V8] syscalls: clock_settime: Add test around y2038 vulnerability

[Viresh Kumar]

On 05-08-20, 17:11, Cyril Hrubis wrote:
> Hi!
> > This adds a test around the y2038 vulnerability, it sets the system time
> > to just before y2038 time (i.e. max value that can be stored in s32),
> > and adds a timer to expire just after crossing it.
> > 
> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> > ---
> > V8:
> > - Check compatibility issues for TST_KERN_OLD_TIMESPEC and not the new
> >   timespec.
> > - s/TFAIL/TCONF/ in setup()
> > - Use kernel_timer_t
> > - rearrange code and don't expect timer to fire before.
> > 
> >  runtest/syscalls                                   |   1 +
> >  testcases/kernel/syscalls/clock_settime/.gitignore |   1 +
> >  .../syscalls/clock_settime/clock_settime03.c       | 123 +++++++++++++++++++++
> >  3 files changed, 125 insertions(+)
> >  create mode 100644 testcases/kernel/syscalls/clock_settime/clock_settime03.c
> > 
> > diff --git a/runtest/syscalls b/runtest/syscalls
> > index 3c6e78a4c6d0..3c2f5f6c0b37 100644
> > --- a/runtest/syscalls
> > +++ b/runtest/syscalls
> > @@ -99,6 +99,7 @@ leapsec01 leapsec01
> >  
> >  clock_settime01 clock_settime01
> >  clock_settime02 clock_settime02
> > +clock_settime03 clock_settime03
> >  
> >  clone01 clone01
> >  clone02 clone02
> > diff --git a/testcases/kernel/syscalls/clock_settime/.gitignore b/testcases/kernel/syscalls/clock_settime/.gitignore
> > index 28121755006b..b66169b3eb7b 100644
> > --- a/testcases/kernel/syscalls/clock_settime/.gitignore
> > +++ b/testcases/kernel/syscalls/clock_settime/.gitignore
> > @@ -1,2 +1,3 @@
> >  clock_settime01
> >  clock_settime02
> > +clock_settime03
> > diff --git a/testcases/kernel/syscalls/clock_settime/clock_settime03.c b/testcases/kernel/syscalls/clock_settime/clock_settime03.c
> > new file mode 100644
> > index 000000000000..da062a8d0333
> > --- /dev/null
> > +++ b/testcases/kernel/syscalls/clock_settime/clock_settime03.c
> > @@ -0,0 +1,123 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * Copyright (c) 2020 Linaro Limited. All rights reserved.
> > + * Author: Viresh Kumar<viresh.kumar@linaro.org>
> > + *
> > + * Check Year 2038 related vulnerabilities.
> > + */
> > +
> > +#include <signal.h>
> > +#include "config.h"
> > +#include "tst_timer.h"
> > +#include "tst_safe_clocks.h"
> > +
> > +#define TIMER_DELTA	3
> > +#define ALLOWED_DELTA	(50 * 1000) /* 50 ms */
> > +
> > +static struct tst_ts start, end;
> > +static struct tst_its its;
> > +
> > +static struct test_variants {
> > +	int (*clock_gettime)(clockid_t clk_id, void *ts);
> > +	int (*clock_settime)(clockid_t clk_id, void *ts);
> > +	int (*timer_settime)(kernel_timer_t timerid, int flags, void *its,
> > +			     void *old_its);
> > +	enum tst_ts_type type;
> > +	char *desc;
> > +} variants[] = {
> > +#if (__NR_clock_settime != __LTP__NR_INVALID_SYSCALL)
> > +	{ .clock_gettime = sys_clock_gettime, .clock_settime = sys_clock_settime, .timer_settime = sys_timer_settime, .type = TST_KERN_OLD_TIMESPEC, .desc = "syscall with old kernel spec"},
> > +#endif
> > +
> > +#if (__NR_clock_settime64 != __LTP__NR_INVALID_SYSCALL)
> > +	{ .clock_gettime = sys_clock_gettime64, .clock_settime = sys_clock_settime64, .timer_settime = sys_timer_settime64, .type = TST_KERN_TIMESPEC, .desc = "syscall time64 with kernel spec"},
> > +#endif
> > +};
> > +
> > +static void setup(void)
> > +{
> > +	struct test_variants *tv = &variants[tst_variant];
> > +
> > +	tst_res(TINFO, "Testing variant: %s", tv->desc);
> > +	start.type = end.type = its.type = tv->type;
> > +
> > +	/* Check if the kernel is y2038 safe */
> > +	if (tv->type == TST_KERN_OLD_TIMESPEC &&
> > +	    sizeof(start.ts.kern_old_ts) == 8)
> > +		tst_brk(TCONF, "Not Y2038 safe to run test");
> 
> Thinking of this again, it may be safer to assert the size of the
> kernel_old_ts.tv_sec, since the compiler is technically allowed to padd
> the structure. So what about sizeof(start.ts.kernel_old_ts.tv_sec) == 4?
> 
> > +}
> > +
> > +static void run(void)
> > +{
> > +	struct test_variants *tv = &variants[tst_variant];
> > +	unsigned long long time = 0x7FFFFFFE; /* Time just before y2038 */
> > +	struct sigevent ev = {
> > +		.sigev_notify = SIGEV_SIGNAL,
> > +		.sigev_signo = SIGABRT,
> > +	};
> > +	long long diff;
> > +	kernel_timer_t timer;
> > +	sigset_t set;
> > +	int sig, ret;
> > +
> > +	if (sigemptyset(&set) == -1)
> > +		tst_brk(TBROK, "sigemptyset() failed");
> > +
> > +	if (sigaddset(&set, SIGABRT) == -1)
> > +		tst_brk(TBROK, "sigaddset() failed");
> 
> We do have a safe macros for these two now.
> 
> 
> Other than that these the code looks good. I can fix these two before
> applying if you agree.

Sure. Thanks.

-- 
viresh