ioctl: use finfo as hints for resolving overlapping ioctl commands

Such an overlapping can be observed, e.g. when running vi under strace:

  ioctl(0, SNDCTL_TMR_START or TCSETS, {B38400 ...

After this change, when the file descriptor corresponds to a terminal
device, strace would be able to resolve the collision between ioctl
commands from different subsystems:

  ioctl(0, TCSETS, {B38400 ...

* src/defs.h (term_ioctl_decode_command_number): New function
declaration.
* src/ioctl.c (ioctl_decode_command_number): Add a new argument
for passing finfo that can be used as hints for decoding ioctl commands.
Handle the code `T'.
(SYS_FUNC(ioctl)): Pass finfo as hints to ioctl_decode_command_number.
* src/term.c: Include "xlat/term_cmds_overlapping.h".
(term_ioctl_decode_command_number): Decode the command in
this earlier stage if the corresponding file descriptor corresponds
to a terminal device.
* src/xlat/term_cmds_overlapping.in: New file listing overlapping
tty ioctl commands.
* tests/ioctl_termios.c (main): Extend cmds[] in checks[].
(main::checks::cmds): Add new member "pass_invalid_fd".
Omit " or ..." substring in case of TCSETS, TCSETSW, and TCSETSF for
a valid tty descriptor.
Add test commands for invalid descriptors.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@strace.io>

1 files changed, 9 insertions, 0 deletions

diff --git a/src/xlat/term_cmds_overlapping.in b/src/xlat/term_cmds_overlapping.in
new file mode 100644
index 000000000..6b0e00338
--- /dev/null
+++ b/src/xlat/term_cmds_overlapping.in
@@ -0,0 +1,9 @@
+/* 0x5401 .. 0x5408 */
+TCGETS
+TCSETS
+TCSETSW
+TCSETSF
+TCGETA
+TCSETA
+TCSETAW
+TCSETAF