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=-2.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FORGED_GMAIL_RCVD, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,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 14C621F454 for ; Fri, 8 Nov 2019 17:08:26 +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:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-type; q=dns; s=default; b=xY6X wzVAkxh1HFwvih9tFeaNMoWznpP+HcktvrG2BOuv7ra4cQT8MTHy/PzIZ8VRtISs aM0X6L6C5de16CapAQYHUiUDHBFl4h2yIyzwxMtt5QUiwbugMiXXapoE8TxF9R+i iIiD6WV8w7zctTQP0nLSFA316G3eYL+pxHjhWls= 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:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-type; s=default; bh=T/GsXVuTV/ HsInpOxptj8MS7q/c=; b=MoavVbxGBOUCD92fRCBJ1NVXzLdHbYR8zFiNxEdWe3 IRiiyZBifQstLo2tpMG9iv/0xFRcnCdwxFh3dIq2eF0GDMgmPkq7+tKzX+PfZdqU chjQNi0VX7VVtBqh9pk2AXFetyy+qP5de3MOPo717KBofRtCpehbaD1+JRVl//0q 4= Received: (qmail 75514 invoked by alias); 8 Nov 2019 17:08:23 -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 75502 invoked by uid 89); 8 Nov 2019 17:08:23 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mail-lj1-f194.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=WCYzeG65PGza0vxbWmzge2RKZiiYKWDyhDKsshEzzOc=; b=BeA9LVNljvR4zonnLMXUYcGyP3NaGSdB/nYtoPMwHfCOXWcDsAsfcu3ZZb1kL00o4H JKz5ejWNp9AeteUQxpmPxkA5SLP5A1yHgVN7rmOxJav25gmIsf4Lbvx/2EY3jsAegQNv Soj6rOjH9hIl1pIrCeoXegaHiff5aGEpQJ0wFE+G73nycKjfkhqlYf7ykqLlS8LfSS5y SnoH05zS41i6VXyk+QhMizLvkL44sRG6KlYti9Aq+jqfxDRWIDZIqoMJ1ZRTUR3vkh4s G+UkNCoGXRz3YVNJgwHIx+KFFLfysHW8MMrEpDf4iFEUWdlUDdiDVt9+NQ9cx5UjM5Ia awVA== MIME-Version: 1.0 References: <20191107181142.1048-1-alistair.francis@wdc.com> <20191108135432.06b5ff95@jawa> In-Reply-To: From: Alistair Francis Date: Fri, 8 Nov 2019 09:07:52 -0800 Message-ID: Subject: Re: [PATCH v5] sysdeps/clock_nanosleep: Use clock_nanosleep_time64 if avaliable To: Lukasz Majewski Cc: Alistair Francis , GNU C Library , Paul Eggert , Joseph Myers Content-Type: text/plain; charset="UTF-8" On Fri, Nov 8, 2019 at 8:56 AM Alistair Francis wrote: > > On Fri, Nov 8, 2019 at 4:54 AM Lukasz Majewski wrote: > > > > 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. > > > > > > 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 > > > > > > v5: > > > - Fix clock_nanosleep syscall > > > - Rebase on master > > > > > > v4: > > > - Rebase on master > > > - Use __clock_nanosleep to avoid duplicate implementations > > > - Fix the error handling when a syscall fails > > > v2: > > > - Explicitly include `#include ` > > > > > > include/time.h | 20 +++++++ > > > sysdeps/unix/sysv/linux/clock_nanosleep.c | 66 > > > +++++++++++++++++++++-- 2 files changed, 81 insertions(+), 5 > > > deletions(-) > > > > > > 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) > > > > > > extern double __difftime (time_t time1, time_t time0); > > > > > > +#if __TIMESIZE == 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 > > > > > > /* 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 @@ > > > . */ > > > > > > #include > > > +#include > > > #include > > > > > > #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 == CLOCK_THREAD_CPUTIME_ID) > > > return EINVAL; > > > if (clock_id == 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 = 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 = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id, > > > + flags, req, rem); > > > +#else > > > +# ifdef __NR_clock_nanosleep_time64 > > > + r = INTERNAL_SYSCALL_CANCEL (clock_nanosleep_time64, err, clock_id, > > > + flags, req, rem); > > > + > > > + if (r == 0 || errno != 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 = valid_timespec64_to_timespec (*req); > > > > Here we don't need to check req == 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 = INTERNAL_SYSCALL_CANCEL (clock_nanosleep, err, clock_id, > > > flags, > > > + &ts32, &tr32); > > > + > > > + if ((r == 0 || errno != ENOSYS) && rem) > > > + *rem = 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 != 64 > > > +int > > > +__clock_nanosleep (clockid_t clock_id, int flags, const struct > > > timespec *req, > > > + struct timespec *rem) > > > +{ > > > + int r; > > > + struct __timespec64 treq64, trem64; > > > + > > > > ^^^^^^^^^^^^ - [*] > > > > > + treq64 = 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 > > #define EFAULT 14 [2] (which matches [1]). > > > > Hence we should have following code in [*]: > > > > if (req == 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). > > I think you are right. I have updated the patch. As Joseph mentioned in another thread, glibc doesn't check for NULL pointers, so I have removed this. Alistair > > Alistair > > > > > > > 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 = clock_nanosleep(CLOCK_REALTIME, 0 /* relative */, > > NULL, NULL); > > > > if (result) > > printf("clock_nanosleep: %d\n", result); > > > > return 0; > > } > > > > > + r = __clock_nanosleep_time64 (clock_id, flags, &treq64, &trem64); > > > + > > > + if (r == 0 || errno != ENOSYS) > > > + { > > > + if (rem) > > > + *rem = 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