linux-sg2042/arch/um
Jeff Dike 838e56a11c [PATCH] uml: fix 2.6.20 hang
A previous cleanup misused need_poll, which had a fairly broken interface.
It implemented a growable array, changing the used elements count itself,
but leaving it up to the caller to fill in the actual elements, including
the entire array if the array had to be reallocated.  This worked because
the previous users were switching between two such structures, and the
elements were copied from the inactive array to the active array after
making sure the active array had enough room.

maybe_sigio_broken was made to use need_poll, but it was operating on a
single array, so when the buffer was reallocated, the previous contents
were lost.

This patch makes need_poll implement more sane semantics.  It merely
assures that the array is of the proper size and that the contents are
preserved.  It is up to the caller to adjust the used elements count and to
ensure that the proper elements are resent.

This manifested itself as a hang in 2.6.20 as the uninitialized buffer
convinced UML that one of its own file descriptors didn't support SIGIO and
needed to be watched by poll in a separate thread.  The result was an
interrupt flood as control traffic over this descriptor sparked interrupts,
which resulted in more control traffic, ad nauseum.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:56 -08:00
..
drivers [PATCH] mark struct file_operations const 2 2007-02-12 09:48:44 -08:00
include [PATCH] Dynamic kernel command-line: fixups 2007-02-12 09:48:39 -08:00
kernel [PATCH] Dynamic kernel command-line: fixups 2007-02-12 09:48:39 -08:00
os-Linux [PATCH] uml: fix 2.6.20 hang 2007-02-16 08:13:56 -08:00
scripts kbuild: fix ia64 breakage after introducing make -rR 2006-07-01 09:58:02 +02:00
sys-i386 [PATCH] uml: fix signal frame alignment 2007-01-30 16:01:35 -08:00
sys-ia64 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sys-ppc Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
sys-x86_64 [PATCH] uml: x86_64 ptrace fixes 2007-02-11 10:51:24 -08:00
Kconfig [PATCH] sort the devres mess out 2007-02-11 11:18:07 -08:00
Kconfig.char [PATCH] uml: kconfig - silence warning 2006-10-20 10:26:36 -07:00
Kconfig.debug [PATCH] uml: remove syscall debugging 2006-07-10 13:24:24 -07:00
Kconfig.i386 [PATCH] fix indentation-related breakage in Kconfig.i386 2007-01-30 08:39:21 -08:00
Kconfig.net [PATCH] uml: Rename Kconfig files to be like the other arches 2005-09-05 00:06:19 -07:00
Kconfig.scsi [PATCH] uml: Rename Kconfig files to be like the other arches 2005-09-05 00:06:19 -07:00
Kconfig.x86_64 [PATCH] um: fix undefined reference to hweight32 2006-03-26 08:57:09 -08:00
Makefile [PATCH] uml: fix compilation options for USER_OBJS 2006-10-30 12:08:41 -08:00
Makefile-i386 [PATCH] uml: fix compilation options for USER_OBJS 2006-10-30 12:08:41 -08:00
Makefile-ia64 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile-os-Linux Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile-ppc Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile-skas [PATCH] uml makefiles sanitized 2005-09-29 08:46:26 -07:00
Makefile-tt Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile-x86_64 [PATCH] uml: fix compilation options for USER_OBJS 2006-10-30 12:08:41 -08:00
config.release Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
defconfig [PATCH] uml: remove syscall debugging 2006-07-10 13:24:24 -07:00