linux/arch
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
..
alpha alpha: -Werror fixes for sys_titan.c 2007-08-11 15:47:42 -07:00
arm [ARM] 4567/1: Fix 'Oops - undefined instruction' when CONFIG_VFP=y on non VFP device 2007-09-13 15:10:27 +01:00
avr32 [AVR32] Wire up i2c-gpio on the ATNGW100 board 2007-08-15 16:36:55 +02:00
blackfin Blackfin arch: Update/Fix PM support add new pm_ops valid 2007-08-27 17:29:10 +08:00
cris ide: fix hidden dependencies on CONFIG_IDE_GENERIC 2007-08-20 22:42:54 +02:00
frv FRV: connect up fallocate 2007-08-11 15:47:40 -07:00
h8300 H8/300: Fix misnamed "CONFIG_BLKDEV_RESERVE_ADDRESS" Kconfig variable 2007-09-11 17:21:20 -07:00
i386 xen: don't bother trying to set cr4 2007-09-19 11:24:18 -07:00
ia64 Fix spurious syscall tracing after PTRACE_DETACH + PTRACE_ATTACH 2007-09-10 18:57:47 -07:00
m32r m32r: Rename STI/CLI macros 2007-09-06 11:10:56 +09:00
m68k m68k(nommu): add missing syscalls 2007-09-11 17:21:20 -07:00
m68knommu m68k(nommu): add missing syscalls 2007-09-11 17:21:20 -07:00
mips [MIPS] 20Kc: Disable use of WAIT instruction. 2007-09-14 19:08:43 +01:00
parisc [PARISC] Add NOTES section 2007-08-27 00:29:25 -04:00
powerpc Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc 2007-09-12 12:23:51 -07:00
ppc [PPC] 8xx: Fix r3 trashing due to 8MB TLB page instantiation 2007-09-10 16:01:22 -05:00
s390 [S390] kprobes: fix instruction length calculation 2007-08-22 13:51:49 +02:00
sh sh: missing symbol fix for sh4-202 2007-08-22 13:32:07 +09:00
sh64 sh64: arch/sh64/kernel/setup.c: duplicate include removal. 2007-08-12 12:18:54 +09:00
sparc [SPARC32]: Kill unused vars and macros from prom/console.c 2007-08-26 18:49:10 -07:00
sparc64 [SPARC64]: Warn user if cpu is ignored. 2007-09-16 14:45:06 -07:00
um uml: fix irqstack crash 2007-09-19 11:24:18 -07:00
v850 PTRACE_POKEDATA consolidation 2007-07-17 10:23:03 -07:00
x86_64 x86_64: Add missing mask operation to vdso 2007-09-12 09:28:06 -07:00
xtensa xtensa process.c must #include <linux/fs.h> 2007-08-30 09:58:22 -07:00