Commit 0e232921 authored by Paolo \'Blaisorblade\' Giarrusso's avatar Paolo \'Blaisorblade\' Giarrusso Committed by Linus Torvalds

[PATCH] uml: Adds LEGACY_PTY config option

The second adds the LEGACY_PTY config option. Without it, with late 2.6 kernels
/dev/ptyxx won't work. In fact, with those kernels, root_fs_toms does not
work, because it's "unable to allocate TTY pair". And removes the dead option 
"UNIX98_PTY_COUNT" (just commented out for now).
Signed-off-by: default avatarPaolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 67663831
...@@ -108,11 +108,60 @@ config SSL_CHAN ...@@ -108,11 +108,60 @@ config SSL_CHAN
config UNIX98_PTYS config UNIX98_PTYS
bool "Unix98 PTY support" bool "Unix98 PTY support"
---help---
config UNIX98_PTY_COUNT A pseudo terminal (PTY) is a software device consisting of two
int "Maximum number of Unix98 PTYs in use (0-2048)" halves: a master and a slave. The slave device behaves identical to
depends on UNIX98_PTYS a physical terminal; the master device is used by a process to
read data from and write data to the slave, thereby emulating a
terminal. Typical programs for the master side are telnet servers
and xterms.
Linux has traditionally used the BSD-like names /dev/ptyxx for
masters and /dev/ttyxx for slaves of pseudo terminals. This scheme
has a number of problems. The GNU C library glibc 2.1 and later,
however, supports the Unix98 naming standard: in order to acquire a
pseudo terminal, a process opens /dev/ptmx; the number of the pseudo
terminal is then made available to the process and the pseudo
terminal slave can be accessed as /dev/pts/<number>. What was
traditionally /dev/ttyp2 will then be /dev/pts/2, for example.
All modern Linux systems use the Unix98 ptys. Say Y unless
you're on an embedded system and want to conserve memory.
config LEGACY_PTYS
bool "Legacy (BSD) PTY support"
default y
---help---
A pseudo terminal (PTY) is a software device consisting of two
halves: a master and a slave. The slave device behaves identical to
a physical terminal; the master device is used by a process to
read data from and write data to the slave, thereby emulating a
terminal. Typical programs for the master side are telnet servers
and xterms.
Linux has traditionally used the BSD-like names /dev/ptyxx
for masters and /dev/ttyxx for slaves of pseudo
terminals. This scheme has a number of problems, including
security. This option enables these legacy devices; on most
systems, it is safe to say N.
config LEGACY_PTY_COUNT
int "Maximum number of legacy PTY in use"
depends on LEGACY_PTYS
default "256" default "256"
---help---
The maximum number of legacy PTYs that can be used at any one time.
The default is 256, and should be more than enough. Embedded
systems may want to reduce this to save memory.
When not in use, each legacy PTY occupies 12 bytes on 32-bit
architectures and 24 bytes on 64-bit architectures.
#config UNIX98_PTY_COUNT
# int "Maximum number of Unix98 PTYs in use (0-2048)"
# depends on UNIX98_PTYS
# default "256"
config WATCHDOG config WATCHDOG
bool "Watchdog Timer Support" bool "Watchdog Timer Support"
......
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