From patchwork Mon Oct 28 16:59:25 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukasz Majewski X-Patchwork-Id: 35399 Received: (qmail 53336 invoked by alias); 28 Oct 2019 16:59:49 -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 Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 53318 invoked by uid 89); 28 Oct 2019 16:59:49 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-20.0 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 spammy=5.1, Moreover, facilitate X-HELO: mail-out.m-online.net From: Lukasz Majewski To: Joseph Myers , Paul Eggert Cc: Alistair Francis , Alistair Francis , GNU C Library , Adhemerval Zanella , Florian Weimer , Florian Weimer , Zack Weinberg , Lukasz Majewski Subject: [PATCH 1/2] y2038: linux: Provide __utimensat64 implementation Date: Mon, 28 Oct 2019 17:59:25 +0100 Message-Id: <20191028165926.10351-1-lukma@denx.de> MIME-Version: 1.0 This patch provides new __utimensat64 explicit 64 bit function for setting access and modification time of a file. Moreover, a 32 bit version - __utimensat has been refactored to internally use __utimensat64. The __utimensat is now supposed to be used on systems still supporting 32 bit time (__TIMESIZE != 64) - hence the necessary conversions to 64 bit struct __timespec64. When pointer to struct __timespec64 is NULL - the file access and modification time is set to the current one and no conversions from struct timespec to __timespec64 are performed. The new utimensat_time64 syscall available from Linux 5.1+ has been used, when applicable. The new helper function - __utimensat64_helper - has been introduced to facilitate code re-usage on function providing futimens syscall handling. It also checks if passed nanoseconds are in the valid range as well as if one of two special values - UTIME_NOW and UTIME_OMIT were not passed. Moreover, when utimensat syscall on systems supporting 32 bit time ABI is used, the check is performed if passed data fits into 32 bit time_t range. Build tests: - The code has been tested on x86_64/x86 (native compilation): make PARALLELMFLAGS="-j8" && make xcheck PARALLELMFLAGS="-j8" - The glibc has been build tested (make PARALLELMFLAGS="-j8") for x86 (i386), x86_64-x32, and armv7 Run-time tests: - Run specific tests on ARM/x86 32bit systems (qemu): https://github.com/lmajewski/meta-y2038 and run tests: https://github.com/lmajewski/y2038-tests/commits/master - Use of cross-test-ssh.sh for ARM (armv7): make PARALLELMFLAGS="-j8" test-wrapper='./cross-test-ssh.sh root@192.168.7.2' xcheck Linux kernel, headers and minimal kernel version for glibc build test matrix: - Linux v5.1 (with utimensat_time64) and glibc build with v5.1 as minimal kernel version (--enable-kernel="5.1.0") The __ASSUME_TIME64_SYSCALLS flag defined. - Linux v5.1 and default minimal kernel version The __ASSUME_TIME64_SYSCALLS not defined, but kernel supports utimensat_time64 syscall. - Linux v4.19 (no utimensat_time64 support) with default minimal kernel version for contemporary glibc This kernel doesn't support utimensat_time64 syscall, so the fallback to utimensat is tested. The above tests were performed with Y2038 redirection applied as well as without (so the __TIMESIZE != 64 execution path is checked as well). No regressions were observed. --- include/time.h | 12 +++++ sysdeps/unix/sysv/linux/utimensat.c | 76 +++++++++++++++++++++++++++-- 2 files changed, 84 insertions(+), 4 deletions(-) diff --git a/include/time.h b/include/time.h index de660f7f57..432489ae29 100644 --- a/include/time.h +++ b/include/time.h @@ -141,6 +141,18 @@ extern int __clock_getres64 (clockid_t clock_id, libc_hidden_proto (__clock_getres64); #endif +#if __TIMESIZE == 64 +# define __utimensat64 __utimensat +#else +extern int __utimensat64 (int fd, const char *file, + const struct __timespec64 tsp[2], int flags); +libc_hidden_proto (__utimensat64); +#endif + +extern int __utimensat64_helper (int fd, const char *file, + const struct __timespec64 tsp[2], int flags); +libc_hidden_proto (__utimensat64_helper); + /* Compute the `struct tm' representation of T, offset OFFSET seconds east of UTC, and store year, yday, mon, mday, wday, hour, min, sec into *TP. diff --git a/sysdeps/unix/sysv/linux/utimensat.c b/sysdeps/unix/sysv/linux/utimensat.c index 3bffa7d22a..d4b9679d99 100644 --- a/sysdeps/unix/sysv/linux/utimensat.c +++ b/sysdeps/unix/sysv/linux/utimensat.c @@ -19,18 +19,86 @@ #include #include #include +#include +#include +/* Helper function defined for easy reusage of the code which calls utimensat + and utimensat_time64 syscall. */ +int +__utimensat64_helper (int fd, const char *file, + const struct __timespec64 tsp64[2], int flags) +{ + if (tsp64 && (! valid_nanoseconds(tsp64[0].tv_nsec) + || ! valid_nanoseconds(tsp64[1].tv_nsec))) + { + if (tsp64[0].tv_nsec != UTIME_NOW && tsp64[0].tv_nsec != UTIME_OMIT + && tsp64[1].tv_nsec != UTIME_NOW && tsp64[1].tv_nsec != UTIME_OMIT) + { + __set_errno (EINVAL); + return -1; + } + } + +#ifdef __ASSUME_TIME64_SYSCALLS +# ifndef __NR_utimensat_time64 +# define __NR_utimensat_time64 __NR_utimensat +# endif + return INLINE_SYSCALL (utimensat_time64, 4, fd, file, &tsp64[0], flags); +#else +# ifdef __NR_utimensat_time64 + int ret = INLINE_SYSCALL (utimensat_time64, 4, fd, file, &tsp64[0], flags); + if (ret == 0 || errno != ENOSYS) + return ret; +# endif + if (tsp64 + && (! in_time_t_range (tsp64[0].tv_sec) + || ! in_time_t_range (tsp64[1].tv_sec))) + { + __set_errno (EOVERFLOW); + return -1; + } + + struct timespec tsp32[2]; + if (tsp64) + { + tsp32[0] = valid_timespec64_to_timespec (tsp64[0]); + tsp32[1] = valid_timespec64_to_timespec (tsp64[1]); + } + + return INLINE_SYSCALL (utimensat, 4, fd, file, tsp64 ? &tsp32[0] : NULL, + flags); +#endif + +} +libc_hidden_def (__utimensat64_helper) /* Change the access time of FILE to TSP[0] and the modification time of FILE to TSP[1]. Starting with 2.6.22 the Linux kernel has the utimensat syscall. */ int -utimensat (int fd, const char *file, const struct timespec tsp[2], - int flags) +__utimensat64 (int fd, const char *file, const struct __timespec64 tsp64[2], + int flags) { if (file == NULL) return INLINE_SYSCALL_ERROR_RETURN_VALUE (EINVAL); - /* Avoid implicit array coercion in syscall macros. */ - return INLINE_SYSCALL (utimensat, 4, fd, file, &tsp[0], flags); + + return __utimensat64_helper (fd, file, &tsp64[0], flags); +} + +#if __TIMESIZE != 64 +int +__utimensat (int fd, const char *file, const struct timespec tsp[2], + int flags) +{ + struct __timespec64 tsp64[2]; + if (tsp) + { + tsp64[0] = valid_timespec_to_timespec64 (tsp[0]); + tsp64[1] = valid_timespec_to_timespec64 (tsp[1]); + } + + return __utimensat64 (fd, file, tsp ? &tsp64[0] : NULL, flags); } +#endif +weak_alias (__utimensat, utimensat)