android_kernel_xiaomi_sm8350/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
sysdep-x86_64 fix uml-x86_64 2007-05-15 18:56:37 -07:00
tt
aio.h
arch.h
as-layout.h
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
common-offsets.h uml: Eliminate kernel allocator wrappers 2007-07-16 09:05:38 -07:00
elf_user.h
frame_kern.h
init.h
initrd.h
irq_kern.h
irq_user.h
kern_util.h uml: fix irqstack crash 2007-09-19 11:24:18 -07:00
kern.h
line.h
longjmp.h
mconsole_kern.h
mconsole.h
mem_kern.h
mem_user.h
mem.h
misc_constants.h
mode_kern.h
mode.h
net_kern.h
net_user.h
os.h uml: simplify helper stack handling 2007-07-16 09:05:38 -07:00
process.h
ptrace_user.h
registers.h
sigcontext.h
sigio.h
signal_kern.h
skas_ptrace.h
skas_ptregs.h
syscall.h
sysrq.h
task.h
tempfile.h
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
uml_uaccess.h
user.h uml: fix prototypes 2007-05-07 12:13:04 -07:00