2019-10-21 10:10:34

by Thomas Gleixner

Subject: [PATCH] lib/vdso: Make clock_getres() POSIX compliant again

A recent commit removed the NULL pointer check from the clock_getres()
implementation causing a test case to fault.

POSIX requires an explicit NULL pointer check for clock_getres() aside of
the validity check of the clock_id argument for obscure reasons.

Add it back for both 32bit and 64bit.

Note, this is only a partial revert of the offending commit which does not
bring back the broken fallback invocation in the the 32bit compat
implementations of clock_getres() and clock_gettime().

Fixes: a9446a906f52 ("lib/vdso/32: Remove inconsistent NULL pointer checks")
Reported-by: Andreas Schwab <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
---
lib/vdso/gettimeofday.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -214,9 +214,10 @@ int __cvdso_clock_getres_common(clockid_
return -1;
}

- res->tv_sec = 0;
- res->tv_nsec = ns;
-
+ if (likely(res)) {
+ res->tv_sec = 0;
+ res->tv_nsec = ns;
+ }
return 0;
}

@@ -245,7 +246,7 @@ static __maybe_unused int
ret = clock_getres_fallback(clock, &ts);
#endif

- if (likely(!ret)) {
+ if (likely(!ret && res)) {
res->tv_sec = ts.tv_sec;
res->tv_nsec = ts.tv_nsec;
}

2019-10-21 15:24:18

by Christophe Leroy

Subject: Re: [PATCH] lib/vdso: Make clock_getres() POSIX compliant again

Le 21/10/2019 à 12:07, Thomas Gleixner a écrit :
> A recent commit removed the NULL pointer check from the clock_getres()
> implementation causing a test case to fault.
>
> POSIX requires an explicit NULL pointer check for clock_getres() aside of
> the validity check of the clock_id argument for obscure reasons.
>
> Add it back for both 32bit and 64bit.
>
> Note, this is only a partial revert of the offending commit which does not
> bring back the broken fallback invocation in the the 32bit compat
> implementations of clock_getres() and clock_gettime().
>
> Fixes: a9446a906f52 ("lib/vdso/32: Remove inconsistent NULL pointer checks")
> Reported-by: Andreas Schwab <[email protected]>
> Signed-off-by: Thomas Gleixner <[email protected]>

Tested-by: Christophe Leroy <[email protected]>

> Cc: [email protected]
> ---
> lib/vdso/gettimeofday.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> --- a/lib/vdso/gettimeofday.c
> +++ b/lib/vdso/gettimeofday.c
> @@ -214,9 +214,10 @@ int __cvdso_clock_getres_common(clockid_
> return -1;
> }
>
> - res->tv_sec = 0;
> - res->tv_nsec = ns;
> -
> + if (likely(res)) {
> + res->tv_sec = 0;
> + res->tv_nsec = ns;
> + }
> return 0;
> }
>
> @@ -245,7 +246,7 @@ static __maybe_unused int
> ret = clock_getres_fallback(clock, &ts);
> #endif
>
> - if (likely(!ret)) {
> + if (likely(!ret && res)) {
> res->tv_sec = ts.tv_sec;
> res->tv_nsec = ts.tv_nsec;
> }
>

2019-10-23 17:43:02

by tip-bot2 for Alexey Makhalov

Subject: [tip: timers/urgent] lib/vdso: Make clock_getres() POSIX compliant again

The following commit has been merged into the timers/urgent branch of tip:

Commit-ID: 1638b8f096ca165965189b9626564c933c79fe63
Gitweb: https://git.kernel.org/tip/1638b8f096ca165965189b9626564c933c79fe63
Author: Thomas Gleixner <[email protected]>
AuthorDate: Mon, 21 Oct 2019 12:07:15 +02:00
Committer: Thomas Gleixner <[email protected]>
CommitterDate: Wed, 23 Oct 2019 14:48:23 +02:00

lib/vdso: Make clock_getres() POSIX compliant again

A recent commit removed the NULL pointer check from the clock_getres()
implementation causing a test case to fault.

POSIX requires an explicit NULL pointer check for clock_getres() aside of
the validity check of the clock_id argument for obscure reasons.

Add it back for both 32bit and 64bit.

Note, this is only a partial revert of the offending commit which does not
bring back the broken fallback invocation in the the 32bit compat
implementations of clock_getres() and clock_gettime().

Fixes: a9446a906f52 ("lib/vdso/32: Remove inconsistent NULL pointer checks")
Reported-by: Andreas Schwab <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Christophe Leroy <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

---
lib/vdso/gettimeofday.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index e630e7f..45f57fd 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -214,9 +214,10 @@ int __cvdso_clock_getres_common(clockid_t clock, struct __kernel_timespec *res)
return -1;
}

- res->tv_sec = 0;
- res->tv_nsec = ns;
-
+ if (likely(res)) {
+ res->tv_sec = 0;
+ res->tv_nsec = ns;
+ }
return 0;
}

@@ -245,7 +246,7 @@ __cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res)
ret = clock_getres_fallback(clock, &ts);
#endif

- if (likely(!ret)) {
+ if (likely(!ret && res)) {
res->tv_sec = ts.tv_sec;
res->tv_nsec = ts.tv_nsec;
}