kernel/linux.git/include/linux/tty.h, branch v4.6.3

Fix OpenSSH pty regression on close

2016-06-01T19:18:03+00:00

commit 0f40fbbcc34e093255a2b2d70b6b0fb48c3f39aa upstream. OpenSSH expects the (non-blocking) read() of pty master to return EAGAIN only if it has received all of the slave-side output after it has received SIGCHLD. This used to work on pre-3.12 kernels. This fix effectively forces non-blocking read() and poll() to block for parallel i/o to complete for all ttys. It also unwinds these changes: 1) f8747d4a466ab2cafe56112c51b3379f9fdb7a12 tty: Fix pty master read() after slave closes 2) 52bce7f8d4fc633c9a9d0646eef58ba6ae9a3b73 pty, n_tty: Simplify input processing on final close 3) 1a48632ffed61352a7810ce089dc5a8bcd505a60 pty: Fix input race when closing Inspired by analysis and patch from Marc Aurele La France Reported-by: Volth Reported-by: Marc Aurele La France BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=52 BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=2492 Signed-off-by: Brian Bloniarz Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Unify receive_buf() code paths

2016-01-28T22:13:44+00:00

Instead of two distinct code branches for receive_buf() handling, use tty_ldisc_receive_buf() as the single code path. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Fix GPF in flush_to_ldisc(), part 2

2016-01-28T22:13:44+00:00

commit 9ce119f318ba ("tty: Fix GPF in flush_to_ldisc()") fixed a GPF caused by a line discipline which does not define a receive_buf() method. However, the vt driver (and speakup driver also) pushes selection data directly to the line discipline receive_buf() method via tty_ldisc_receive_buf(). Fix the same problem in tty_ldisc_receive_buf(). Cc: Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: audit: Combine push functions

2016-01-28T00:41:04+00:00

tty_audit_push() and tty_audit_push_current() perform identical tasks; eliminate the tty_audit_push() implementation and the tty_audit_push_current() name. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: audit: Ignore current association for audit push

2016-01-28T00:41:04+00:00

In canonical read mode, each line read and logged is pushed separately with tty_audit_push(). For all single-threaded processes and multi-threaded processes reading from only one tty, this patch has no effect; the last line read will still be the entry pushed to the audit log because the tty association cannot have changed between tty_audit_add_data() and tty_audit_push(). For multi-threaded processes reading from different ttys concurrently, the audit log will have mixed log entries anyway. Consider two ttys audited concurrently: CPU0 CPU1 ---------- ------------ tty_audit_add_data(ttyA) tty_audit_add_data(ttyB) tty_audit_push() tty_audit_add_data(ttyB) tty_audit_push() This patch will now cause the ttyB output to be split into separate audit log entries. However, this possibility is equally likely without this patch: CPU0 CPU1 ---------- ------------ tty_audit_add_data(ttyB) tty_audit_add_data(ttyA) tty_audit_push() tty_audit_add_data(ttyB) tty_audit_push() Mixed canonical and non-canonical reads have similar races. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: audit: Remove icanon mode from call chain

2016-01-28T00:41:04+00:00

The tty termios bits cannot change while n_tty_read() is in the i/o loop; the termios_rwsem ensures mutual exclusion with termios changes in n_tty_set_termios(). Check L_ICANON() directly and eliminate icanon parameter. NB: tty_audit_add_data() => tty_audit_buf_get() => tty_audit_buf_alloc() is a single path; ie., tty_audit_buf_get() and tty_audit_buf_alloc() have no other callers. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Make tty_files_lock per-tty

2016-01-27T23:13:28+00:00

Access to tty->tty_files list is always per-tty, never for all ttys simultaneously. Replace global tty_files_lock spinlock with per-tty ->files_lock. Initialize when the ->tty_files list is inited, in alloc_tty_struct(). Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Remove unreferenced tty flags macro TTY_DEBUG

2016-01-27T23:13:28+00:00

The TTY_DEBUG macro is not used; remove. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Move tty_check_change() helper

2016-01-27T23:13:28+00:00

Move is_ignored() to drivers/tty/tty_io.c and re-declare in file scope. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Remove declarations to non-existent functions

2016-01-27T23:13:28+00:00

tty_read_raw_data() and tty_signal() no longer exist; remove declarations. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman