Date: Tue, 30 Jan 2024 17:11:26 GMT From: Kyle Evans <kevans@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 984128ce2d5e - stable/13 - kern: pts: do not special case closed slave side Message-ID: <202401301711.40UHBQHr093606@gitrepo.freebsd.org>
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The branch stable/13 has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=984128ce2d5eb7d3374dd4b245d443ec2f5d96b2 commit 984128ce2d5eb7d3374dd4b245d443ec2f5d96b2 Author: Kyle Evans <kevans@FreeBSD.org> AuthorDate: 2024-01-16 02:55:59 +0000 Commit: Kyle Evans <kevans@FreeBSD.org> CommitDate: 2024-01-30 17:11:10 +0000 kern: pts: do not special case closed slave side This would previously return 1 if the slave side of the pts was closed to force an application to read() from it and observe the EOF, but it's not clear why and this is inconsistent both with how we handle devices with similar mechanics (like pipes) and also with other kernels, such as OpenBSD/NetBSD and Linux. PR: 239604 Reviewed by: kib (cherry picked from commit 30189156d325fbcc9d1997d791daedc9fa3bed20) --- sys/kern/tty_pts.c | 7 +----- tests/sys/kern/Makefile | 3 +++ tests/sys/kern/tty_pts.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 68 insertions(+), 6 deletions(-) diff --git a/sys/kern/tty_pts.c b/sys/kern/tty_pts.c index 5e35c52b9038..1351560ba05a 100644 --- a/sys/kern/tty_pts.c +++ b/sys/kern/tty_pts.c @@ -271,12 +271,7 @@ ptsdev_ioctl(struct file *fp, u_long cmd, void *data, return (0); case FIONREAD: tty_lock(tp); - if (psc->pts_flags & PTS_FINISHED) { - /* Force read() to be called. */ - *(int *)data = 1; - } else { - *(int *)data = ttydisc_getc_poll(tp); - } + *(int *)data = ttydisc_getc_poll(tp); tty_unlock(tp); return (0); case FIODGNAME: diff --git a/tests/sys/kern/Makefile b/tests/sys/kern/Makefile index 16faeeb40421..74c987e55734 100644 --- a/tests/sys/kern/Makefile +++ b/tests/sys/kern/Makefile @@ -34,6 +34,7 @@ ATF_TESTS_C+= subr_physmem_test PLAIN_TESTS_C+= subr_unit_test ATF_TESTS_C+= sysctl_kern_proc ATF_TESTS_C+= sys_getrandom +ATF_TESTS_C+= tty_pts ATF_TESTS_C+= unix_passfd_test ATF_TESTS_C+= unix_seqpacket_test TEST_METADATA.unix_seqpacket_test+= timeout="15" @@ -77,6 +78,8 @@ NETBSD_ATF_TESTS_C+= sysv_test CFLAGS.mqueue_test+= -I${SRCTOP}/tests LIBADD.mqueue_test+= rt +LIBADD.tty_pts+= atf_c util + ATF_TESTS_C+= libkern_crc32 SRCS.libkern_crc32+= libkern_crc32.c .PATH: ${SRCTOP}/sys/libkern diff --git a/tests/sys/kern/tty_pts.c b/tests/sys/kern/tty_pts.c new file mode 100644 index 000000000000..241cb085a5a7 --- /dev/null +++ b/tests/sys/kern/tty_pts.c @@ -0,0 +1,64 @@ +/*- + * Copyright (c) 2024 Kyle Evans <kevans@FreeBSD.org> + * + * SPDX-License-Identifier: BSD-2-Clause + */ + +#include <sys/types.h> +#include <sys/ioctl.h> + +#include <termios.h> + +#include <atf-c.h> +#include <libutil.h> + +/* Just a little more concise. */ +#define newpty(masterp, slavep) openpty((masterp), (slavep), NULL, NULL, NULL) + +ATF_TC_WITHOUT_HEAD(fionread); +ATF_TC_BODY(fionread, tc) +{ + char rbuf[32]; + char buf[] = "Hello"; + int master, slave; + int bytes; + + ATF_REQUIRE_EQ(0, newpty(&master, &slave)); + + /* Should be empty to begin with. */ + ATF_REQUIRE_EQ(0, ioctl(master, FIONREAD, &bytes)); + ATF_REQUIRE_EQ(0, bytes); + + ATF_REQUIRE_EQ(sizeof(buf) - 1, write(slave, buf, sizeof(buf) - 1)); + ATF_REQUIRE_EQ(0, ioctl(master, FIONREAD, &bytes)); + ATF_REQUIRE_EQ(sizeof(buf) - 1, bytes); + + /* Drain what we have available, should result in 0 bytes again. */ + ATF_REQUIRE_EQ(sizeof(buf) - 1, read(master, rbuf, sizeof(rbuf))); + ATF_REQUIRE_EQ(0, ioctl(master, FIONREAD, &bytes)); + ATF_REQUIRE_EQ(0, bytes); + + /* + * Write once more, then close the slave side with data still in the + * buffer. + */ + ATF_REQUIRE_EQ(sizeof(buf) - 1, write(slave, buf, sizeof(buf) - 1)); + ATF_REQUIRE_EQ(0, ioctl(master, FIONREAD, &bytes)); + ATF_REQUIRE_EQ(sizeof(buf) - 1, bytes); + + ATF_REQUIRE_EQ(0, close(slave)); + + /* + * The tty's output queue is discarded upon close, so we shouldn't have + * anything else to read(). + */ + ATF_REQUIRE_EQ(0, ioctl(master, FIONREAD, &bytes)); + ATF_REQUIRE_EQ(0, bytes); + ATF_REQUIRE_EQ(0, read(master, rbuf, sizeof(rbuf))); +} + +ATF_TP_ADD_TCS(tp) +{ + ATF_TP_ADD_TC(tp, fionread); + return (atf_no_error()); +}
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