From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 0194A1F454 for ; Fri, 8 Nov 2019 12:54:49 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-type; q=dns; s=default; b=WiUzl 4UtVXEQYmXEDvo7ALguzdg/4yH5jCMDOkZx86kepvaRSgKGdd0Olv4DsCHAYvnkV 6fB2z/22AElTgXyT9Fz4AN8m5qxp7bvaBfQkpBIkLvg2FICzqgfuVBIgPbl4BlSu Wkt13rmdkslOMO5wQIU5aPW4sVsq7Sod4e3yJU= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-type; s=default; bh=flujz3XiDuS dmLZzvbfDvxvVkoI=; b=XfvTPFBvT7qzrJ4mTuzip3UEmAktuo+KA9G2kilHeT9 L+dL4/2rGD9jQgSfCuXaP76Q/we4wuoXioPnd9pGb7yQNQBoFBxxKGdxJfKzWkZX TTow1U8CQyO7cc1gOLoZ9DVPYYEl+R+786zhOsALp1NZsDS9kgIiD8q1DQUnJF6Y = Received: (qmail 124000 invoked by alias); 8 Nov 2019 12:54:47 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 123988 invoked by uid 89); 8 Nov 2019 12:54:47 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mail-out.m-online.net Date: Fri, 8 Nov 2019 13:54:32 +0100 From: Lukasz Majewski To: Alistair Francis Cc: libc-alpha@sourceware.org, alistair23@gmail.com, Paul Eggert , Joseph Myers Subject: Re: [PATCH v5] sysdeps/clock_nanosleep: Use clock_nanosleep_time64 if avaliable Message-ID: <20191108135432.06b5ff95@jawa> In-Reply-To: <20191107181142.1048-1-alistair.francis@wdc.com> References: <20191107181142.1048-1-alistair.francis@wdc.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; boundary="Sig_/hkR87t6lml8Z092Hq5zzQ97"; protocol="application/pgp-signature" --Sig_/hkR87t6lml8Z092Hq5zzQ97 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Hi Alistair, Please find my comments regarding checking of NULL pointers. > The clock_nanosleep syscall is not supported on newer 32-bit > platforms (such as RV32). To fix this issue let's use > clock_nanosleep_time64 if it is avaliable. > --- > This was patch was runtime tested with RV32 and RV64 > It was build tested using the ./scripts/build-many-glibcs.py script. >=20 > I also ran: > $ make ; make install ; make check > tests on native ARM (32-bit) with the following three confiugrations: > - 4.19 Kernel and 4.19 Headers > - 5.2 Kernel and 4.19 Headers > - 5.2 Kernel and 5.2 Headers > and didn't see any regressions >=20 > v5: > - Fix clock_nanosleep syscall > - Rebase on master >=20 > v4: > - Rebase on master > - Use __clock_nanosleep to avoid duplicate implementations > - Fix the error handling when a syscall fails > v2: > - Explicitly include `#include ` >=20 > include/time.h | 20 +++++++ > sysdeps/unix/sysv/linux/clock_nanosleep.c | 66 > +++++++++++++++++++++-- 2 files changed, 81 insertions(+), 5 > deletions(-) >=20 > diff --git a/include/time.h b/include/time.h > index b3e635395db..03389bda290 100644 > --- a/include/time.h > +++ b/include/time.h > @@ -209,6 +209,26 @@ libc_hidden_proto (__difftime64) > =20 > extern double __difftime (time_t time1, time_t time0); > =20 > +#if __TIMESIZE =3D=3D 64 > +# define __thrd_sleep_time64 thrd_sleep > +# define __clock_nanosleep_time64 __clock_nanosleep > +# define __nanosleep_time64 __nanosleep > +# define __nanosleep_nocancel_time64 __nanosleep_nocancel > +#else > +extern int __thrd_sleep_time64 (const struct __timespec64* > time_point, > + struct __timespec64* remaining); > +libc_hidden_proto (__thrd_sleep_time64) > +extern int __clock_nanosleep_time64 (clockid_t clock_id, > + int flags, const struct > __timespec64 *req, > + struct __timespec64 *rem); > +libc_hidden_proto (__clock_nanosleep_time64) > +extern int __nanosleep_time64 (const struct __timespec64 > *requested_time, > + struct __timespec64 *remaining); > +libc_hidden_proto (__nanosleep_time64) > +extern int __nanosleep_nocancel_time64 (const struct __timespec64 > *requested_time, > + struct __timespec64 > *remaining); +libc_hidden_proto (__nanosleep_nocancel_time64) > +#endif > =20 > /* Use in the clock_* functions. Size of the field representing the > actual clock ID. */ > diff --git a/sysdeps/unix/sysv/linux/clock_nanosleep.c > b/sysdeps/unix/sysv/linux/clock_nanosleep.c index > f3c6fd2d5f7..7212dcf9c6d 100644 --- > a/sysdeps/unix/sysv/linux/clock_nanosleep.c +++ > b/sysdeps/unix/sysv/linux/clock_nanosleep.c @@ -16,6 +16,7 @@ > . */ > =20 > #include > +#include > #include > =20 > #include > @@ -26,9 +27,11 @@ > /* We can simply use the syscall. The CPU clocks are not supported > with this function. */ > int > -__clock_nanosleep (clockid_t clock_id, int flags, const struct > timespec *req, > - struct timespec *rem) > +__clock_nanosleep_time64 (clockid_t clock_id, int flags, const > struct __timespec64 *req, > + struct __timespec64 *rem) > { > + int r; > + > if (clock_id =3D=3D CLOCK_THREAD_CPUTIME_ID) > return EINVAL; > if (clock_id =3D=3D CLOCK_PROCESS_CPUTIME_ID) > @@ -37,11 +40,64 @@ __clock_nanosleep (clockid_t clock_id, int flags, > const struct timespec *req, /* If the call is interrupted by a signal > handler or encounters an error, it returns a positive value similar > to errno. */ INTERNAL_SYSCALL_DECL (err); > - int r =3D INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, > flags, > - req, rem); > + > +#ifdef __ASSUME_TIME64_SYSCALLS > +# ifndef __NR_clock_nanosleep_time64 > +# define __NR_clock_nanosleep_time64 __NR_clock_nanosleep > +# endif > + r =3D INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id, > + flags, req, rem); > +#else > +# ifdef __NR_clock_nanosleep_time64 > + r =3D INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id, > + flags, req, rem); > + > + if (r =3D=3D 0 || errno !=3D ENOSYS) > + { > + return (INTERNAL_SYSCALL_ERROR_P (r, err) > + ? INTERNAL_SYSCALL_ERRNO (r, err) : 0); > + } > +# endif /* __NR_clock_nanosleep_time64 */ > + struct timespec ts32, tr32; > + > + if (! in_time_t_range (req->tv_sec)) > + { > + __set_errno (EOVERFLOW); > + return -1; > + } > + > + ts32 =3D valid_timespec64_to_timespec (*req); Here we don't need to check req =3D=3D NULL, as we will go into this piece of code only for 32 bit systems (and kernel < 5.1) with glibc's local copy of struct __timespec64. > + r =3D INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, > flags, > + &ts32, &tr32); > + > + if ((r =3D=3D 0 || errno !=3D ENOSYS) && rem) > + *rem =3D valid_timespec_to_timespec64 (tr32); > +#endif /* __ASSUME_TIME64_SYSCALLS */ > + > return (INTERNAL_SYSCALL_ERROR_P (r, err) > - ? INTERNAL_SYSCALL_ERRNO (r, err) : 0); > + ? INTERNAL_SYSCALL_ERRNO (r, err) : 0); > } > + > +#if __TIMESIZE !=3D 64 > +int > +__clock_nanosleep (clockid_t clock_id, int flags, const struct > timespec *req, > + struct timespec *rem) > +{ > + int r; > + struct __timespec64 treq64, trem64; > + ^^^^^^^^^^^^ - [*] > + treq64 =3D valid_timespec_to_timespec64 (*req); The above line would cause regression. Please find below explanation: The check on *rqtp (in Linux kernel's clock_nanosleep syscall handling): https://elixir.bootlin.com/linux/v5.4-rc5/source/kernel/time/posix-timers.c= #L1220 When compiling test program with clock_nanosleep() passing *request [1] as NULL [3] - the clock_nanosleep returns 14, which corresponds to=20 #define EFAULT 14 [2] (which matches [1]). Hence we should have following code in [*]: if (req =3D=3D NULL) { __set_errno(EFAULT) returm 1; } Otherwise we will break in glibc before we enter the clock_nanosleep syscall (which would then return with proper error code). Links: [1] - http://man7.org/linux/man-pages/man2/clock_nanosleep.2.html [2] - cpp -dM /usr/include/errno.h | grep 'define E' | sort -n -k 3 [3] - test program: int main(int argc, char **argv) { int result; result =3D clock_nanosleep(CLOCK_REALTIME, 0 /* relative */, NULL, NULL); if (result) printf("clock_nanosleep: %d\n", result); return 0; } > + r =3D __clock_nanosleep_time64 (clock_id, flags, &treq64, &trem64); > + > + if (r =3D=3D 0 || errno !=3D ENOSYS) > + { > + if (rem) > + *rem =3D valid_timespec64_to_timespec (trem64); > + } > + > + return r; > +} > +#endif > libc_hidden_def (__clock_nanosleep) > versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, > GLIBC_2_17); /* clock_nanosleep moved to libc in version 2.17; Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de --Sig_/hkR87t6lml8Z092Hq5zzQ97 Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEgAyFJ+N6uu6+XupJAR8vZIA0zr0FAl3FZYgACgkQAR8vZIA0 zr2OaAf+JICJbDGqkhGKbl69m0mwfmBFN9vHAm5Spq6+VtAGHAYPvcxGxiQCPY5h gzN7kXZboGBue3gcxBb7fmKo/KGk+OFFaHY1AN6LlTQOYhide+7mTCbytr4CZ3O1 xd4cwa4QebSabtU5G/tt+iLVLSTmnjJjS62RZh2nzPA+Iji4AG2qipnp9RpBGBn7 qC+exFeFbojPecOBQalxRG0UKNNH6HbPX4LTdAvtZfP5U3Qs3WI6opyKJ5Xhxdzj IgL4nFuycDro+r6NUq2VlGW/xYstJmdM9UwKL0EsvO//f1JjK18YvN9o8mj9PLKe xCBlI6cHoiscNjC0KZGE3FtN2ey5Nw== =XXUa -----END PGP SIGNATURE----- --Sig_/hkR87t6lml8Z092Hq5zzQ97--