linux-hardened/arch/um
Jeff Dike 508a92741a uml: fix irqstack crash
This patch fixes a crash caused by an interrupt coming in when an IRQ stack
is being torn down.  When this happens, handle_signal will loop, setting up
the IRQ stack again because the tearing down had finished, and handling
whatever signals had come in.

However, to_irq_stack returns a mask of pending signals to be handled, plus
bit zero is set if the IRQ stack was already active, and thus shouldn't be
torn down.  This causes a problem because when handle_signal goes around
the loop, sig will be zero, and to_irq_stack will duly set bit zero in the
returned mask, faking handle_signal into believing that it shouldn't tear
down the IRQ stack and return thread_info pointers back to their original
values.

This will eventually cause a crash, as the IRQ stack thread_info will
continue pointing to the original task_struct and an interrupt will look
into it after it has been freed.

The fix is to stop passing a signal number into to_irq_stack.  Rather, the
pending signals mask is initialized beforehand with the bit for sig already
set.  References to sig in to_irq_stack can be replaced with references to
the mask.

[akpm@linux-foundation.org: use UL]
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-19 11:24:18 -07:00
..
drivers uml: fix previous request size limit fix 2007-08-22 19:52:46 -07:00
include uml: fix irqstack crash 2007-09-19 11:24:18 -07:00
kernel uml: fix irqstack crash 2007-09-19 11:24:18 -07:00
os-Linux uml: fix irqstack crash 2007-09-19 11:24:18 -07:00
scripts [PATCH] (uml) sparse flags for userland glue are missing $(CF) 2007-03-14 15:27:48 -07:00
sys-i386 uml: fix string exporting on UML/i386 2007-07-24 12:24:58 -07:00
sys-ia64 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sys-ppc uml: remove user_util.h 2007-05-07 12:13:01 -07:00
sys-x86_64 uml: fix x86_64 core dump crash 2007-08-31 01:42:22 -07:00
defconfig i386: Allow KVM on i386 nonpae 2007-07-19 14:37:05 -07:00
Kconfig uml: fix kernel stack size on x86_64 2007-06-08 17:23:33 -07:00
Kconfig.char [PATCH] uml: enable RAW 2007-03-01 14:53:38 -08:00
Kconfig.debug Add generic exit-time stack-depth checking to CONFIG_DEBUG_STACK_USAGE 2007-07-16 09:05:38 -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.x86_64 [PATCH] um: fix undefined reference to hweight32 2006-03-26 08:57:09 -08:00
Makefile fallout from kbuild changes 2007-07-19 18:37:54 -07:00
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