linux/arch/um/include
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
..
skas uml: speed page fault path 2007-05-07 12:13:04 -07:00
sysdep-i386 fix file specification in comments 2007-05-09 08:58:16 +02:00
sysdep-ia64
sysdep-ppc Remove all inclusions of <linux/config.h> 2006-10-04 03:38:54 -04:00
sysdep-x86_64 fix uml-x86_64 2007-05-15 18:56:37 -07:00
tt uml: tidy process.c 2007-05-07 12:13:02 -07:00
aio.h [PATCH] uml: revert block driver use of host AIO 2005-10-12 08:22:26 -07:00
arch.h uml: tidy fault code 2007-05-07 12:13:02 -07:00
as-layout.h uml: create as-layout.h 2007-05-07 12:13:01 -07:00
chan_kern.h uml: handle errors on opening host side of consoles 2007-07-16 09:05:38 -07:00
chan_user.h uml: SIGIO support cleanup 2007-07-16 09:05:38 -07:00
choose-mode.h [PATCH] uml: better diagnostics for broken configs 2006-01-06 08:33:47 -08:00
common-offsets.h uml: Eliminate kernel allocator wrappers 2007-07-16 09:05:38 -07:00
elf_user.h
frame_kern.h
init.h [PATCH] uml: fix ((unused)) attribute 2006-02-24 14:31:37 -08:00
initrd.h
irq_kern.h IRQ: Use the new typedef for interrupt handler function pointers 2006-10-09 12:19:47 +01:00
irq_user.h [PATCH] uml: remove spinlock wrapper functions 2006-07-10 13:24:23 -07:00
kern.h [PATCH] uml: fix declaration of exit() 2006-03-27 08:44:37 -08:00
kern_util.h uml: fix irqstack crash 2007-09-19 11:24:18 -07:00
line.h [PATCH] uml: fix previous console locking 2007-02-11 10:51:22 -08:00
longjmp.h [PATCH] uml: make UML_SETJMP always safe 2006-10-11 11:14:20 -07:00
mconsole.h [PATCH] uml: fix compilation problems 2007-03-29 08:22:25 -07:00
mconsole_kern.h [PATCH] uml: console whitespace and comment tidying 2007-02-11 10:51:21 -08:00
mem.h [PATCH] uml: inline mk_pte and various friends 2005-09-10 12:00:18 -07:00
mem_kern.h
mem_user.h [PATCH] UML: Hotplug memory, take 2 2006-03-31 12:18:50 -08:00
misc_constants.h [PATCH] uml: move libc-dependent irq code to os-Linux 2006-03-27 08:44:37 -08:00
mode.h
mode_kern.h Remove all inclusions of <linux/config.h> 2006-10-04 03:38:54 -04:00
net_kern.h uml: Replace one-element array with zero-element array 2007-05-07 12:13:02 -07:00
net_user.h uml: network interface hotplug error handling 2007-05-07 12:13:00 -07:00
os.h uml: simplify helper stack handling 2007-07-16 09:05:38 -07:00
process.h
ptrace_user.h
registers.h [PATCH] uml: stack usage reduction 2006-09-26 08:49:09 -07:00
sigcontext.h
sigio.h [PATCH] uml: SIGIO formatting fixes 2007-02-11 10:51:23 -08:00
signal_kern.h
skas_ptrace.h [PATCH] uml: header and code cleanup 2005-05-05 16:36:39 -07:00
skas_ptregs.h [PATCH] uml makefiles sanitized 2005-09-29 08:46:26 -07:00
syscall.h [PATCH] uml: system call path cleanup 2005-09-05 00:06:23 -07:00
sysrq.h [PATCH] uml: stack dump fix 2005-05-28 16:46:13 -07:00
task.h [PATCH] uml makefiles sanitized 2005-09-29 08:46:26 -07:00
tempfile.h [PATCH] uml: locking comments in memory and tempfile code 2007-02-11 10:51:23 -08:00
tlb.h uml: more page fault path trimming 2007-05-07 12:13:04 -07:00
ubd_user.h
um_malloc.h uml: Eliminate kernel allocator wrappers 2007-07-16 09:05:38 -07:00
um_mmu.h
um_uaccess.h Remove all inclusions of <linux/config.h> 2006-10-04 03:38:54 -04:00
uml_uaccess.h [PATCH] uml: separate libc-dependent uaccess code 2005-11-07 07:53:31 -08:00
user.h uml: fix prototypes 2007-05-07 12:13:04 -07:00