target/linux/uml/patches-5.15/001-um-fix-default-console-kernel-parameter.patch

   1 From 53b5c5f559cc95fc676cb4cc9e5a8d9f0cb8f58c Mon Sep 17 00:00:00 2001
   2 Message-Id: <53b5c5f559cc95fc676cb4cc9e5a8d9f0cb8f58c.1659815468.git.chunkeey@gmail.com>
   3 From: Christian Lamparter <chunkeey@gmail.com>
   4 Date: Sat, 6 Aug 2022 21:22:01 +0200
   5 Subject: [PATCH v1 1/2] um: fix default console kernel parameter
   6 To: linux-um@lists.infradead.org
   7 Cc: Richard Weinberger <richard@nod.at>,
   8     Anton Ivanov <anton.ivanov@cambridgegreys.com>,
   9     Johannes Berg <johannes@sipsolutions.net>
  10
  11 OpenWrt's UML with 5.15 was producing odd errors/warnings during preinit
  12 part of the early userspace portion:
  13
  14 |[    0.000000] Kernel command line: ubd0=root.img root=98:0 console=tty
  15 |[...]
  16 |[    0.440000] random: jshn: uninitialized urandom read (4 bytes read)
  17 |[    0.460000] random: jshn: uninitialized urandom read (4 bytes read)
  18 |/etc/preinit: line 47: can't create /dev/tty: No such device or address
  19 |/etc/preinit: line 48: can't create /dev/tty: No such device or address
  20 |/etc/preinit: line 58: can't open /dev/tty: No such device or address
  21 |[...] repeated many times
  22
  23 That "/dev/tty" came from the command line (which is automatically
  24 added if no console= parameter was specified for the uml binary).
  25
  26 The TLDP project tells the following about the /dev/tty:
  27 <https://tldp.org/HOWTO/Text-Terminal-HOWTO-7.html#ss7.3>
  28 | /dev/tty stands for the controlling terminal (if any) for the current
  29 | process.[...]
  30 | /dev/tty is something like a link to the actually terminal device[..]
  31
  32 The "(if any)" is important here, since it's possible for processes to
  33 not have a controlling terminal.
  34
  35 I think this was a simple typo and the author wanted tty0 there.
  36
  37 CC: Thomas Meyer <thomas@m3y3r.de>
  38 Fixes: d7ffac33631b ("um: stdio_console: Make preferred console")
  39 Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
  40 ---
  41  arch/um/kernel/um_arch.c | 2 +-
  42  1 file changed, 1 insertion(+), 1 deletion(-)
  43
  44 --- a/arch/um/kernel/um_arch.c
  45 +++ b/arch/um/kernel/um_arch.c
  46 @@ -31,7 +31,7 @@
  47  #include <os.h>
  48
  49  #define DEFAULT_COMMAND_LINE_ROOT "root=98:0"
  50 -#define DEFAULT_COMMAND_LINE_CONSOLE "console=tty"
  51 +#define DEFAULT_COMMAND_LINE_CONSOLE "console=tty0"
  52
  53  /* Changed in add_arg and setup_arch, which run before SMP is started */
  54  static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };