From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1792) id 4ED4B3858D1E; Sun, 12 Feb 2023 14:50:48 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 4ED4B3858D1E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1676213448; bh=NnA+/kQqQeMSJflI4lmHGSWfGNCe4NyglQjO0tFbwFw=; h=From:To:Subject:Date:From; b=OqvZrauY/1N1he/qhVUOJQihepCifg3QpEtLRVSQFC4UTAkJFoFsrMg1zVf3/Ac4/ 1vRk+aX4TVSBpoprOk2xlx/+VGY++My8/BI30NhhoVccxsiIXcjv2xsD6uuS20VeM9 5HsAZ52cgq2DaiknirEc4mVy1aEEyTALOOJv2ofA= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Samuel Thibault To: glibc-cvs@sourceware.org Subject: [glibc] hurd: Refactor readlinkat() X-Act-Checkin: glibc X-Git-Author: Sergey Bugaev X-Git-Refname: refs/heads/master X-Git-Oldrev: e42ec822190056895e55e5140ce2304e67e34445 X-Git-Newrev: 8a86e7b6a67f21294ada5bf67f3484ae3e134848 Message-Id: <20230212145048.4ED4B3858D1E@sourceware.org> Date: Sun, 12 Feb 2023 14:50:48 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=8a86e7b6a67f21294ada5bf67f3484ae3e134848 commit 8a86e7b6a67f21294ada5bf67f3484ae3e134848 Author: Sergey Bugaev Date: Sun Feb 12 14:10:32 2023 +0300 hurd: Refactor readlinkat() Make the code flow more linear using early returns where possible. This makes it so much easier to reason about what runs on error / successful code paths. Signed-off-by: Sergey Bugaev Message-Id: <20230212111044.610942-2-bugaevc@gmail.com> Diff: --- sysdeps/mach/hurd/readlinkat.c | 55 ++++++++++++++++++++++++------------------ 1 file changed, 32 insertions(+), 23 deletions(-) diff --git a/sysdeps/mach/hurd/readlinkat.c b/sysdeps/mach/hurd/readlinkat.c index 1efb09cae2..dabdbb3713 100644 --- a/sysdeps/mach/hurd/readlinkat.c +++ b/sysdeps/mach/hurd/readlinkat.c @@ -31,38 +31,47 @@ __readlinkat (int fd, const char *file_name, char *buf, size_t len) error_t err; file_t file_stat; struct stat64 st; + enum retry_type doretry; + char retryname[1024]; + file_t file; + char *rbuf = buf; file_stat = __file_name_lookup_at (fd, 0, file_name, O_NOLINK, 0); if (file_stat == MACH_PORT_NULL) return -1; err = __io_stat (file_stat, &st); - if (! err) - if (S_ISLNK (st.st_mode)) - { - enum retry_type doretry; - char retryname[1024]; - file_t file; - char *rbuf = buf; + if (err) + goto out; + if (!S_ISLNK (st.st_mode)) + { + err = EINVAL; + goto out; + } - err = __dir_lookup (file_stat, "", O_READ | O_NOLINK, 0, &doretry, retryname, &file); - if (! err && (doretry != FS_RETRY_NORMAL || retryname[0] != '\0')) - err = EGRATUITOUS; - if (! err) - { - err = __io_read (file, &rbuf, &len, 0, len); - if (!err && rbuf != buf) - { - memcpy (buf, rbuf, len); - __vm_deallocate (__mach_task_self (), (vm_address_t)rbuf, len); - } + err = __dir_lookup (file_stat, "", O_READ | O_NOLINK, + 0, &doretry, retryname, &file); + if (err) + goto out; + if (doretry != FS_RETRY_NORMAL || retryname[0] != '\0') + { + err = EGRATUITOUS; + goto out; + } + + err = __io_read (file, &rbuf, &len, 0, len); + __mach_port_deallocate (__mach_task_self (), file); + if (err) + goto out; + + if (rbuf != buf) + { + memcpy (buf, rbuf, len); + __vm_deallocate (__mach_task_self (), (vm_address_t) rbuf, len); + } - __mach_port_deallocate (__mach_task_self (), file); - } - } - else - err = EINVAL; + out: __mach_port_deallocate (__mach_task_self (), file_stat); return err ? __hurd_fail (err) : len;