linux-toradex.git/arch/alpha/kernel/signal.c, branch v4.0.7

all arches, signal: move restart_block to struct task_struct

2015-02-13T02:54:12+00:00

If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target.  This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski 
Cc: Thomas Gleixner 
Cc: Al Viro 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Kees Cook 
Cc: David Miller 
Acked-by: Richard Weinberger 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Vineet Gupta 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Haavard Skinnemoen 
Cc: Hans-Christian Egtvedt 
Cc: Steven Miao 
Cc: Mark Salter 
Cc: Aurelien Jacquiot 
Cc: Mikael Starvik 
Cc: Jesper Nilsson 
Cc: David Howells 
Cc: Richard Kuo 
Cc: "Luck, Tony" 
Cc: Geert Uytterhoeven 
Cc: Michal Simek 
Cc: Ralf Baechle 
Cc: Jonas Bonn 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Acked-by: Michael Ellerman  (powerpc)
Tested-by: Michael Ellerman  (powerpc)
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Chen Liqin 
Cc: Lennox Wu 
Cc: Chris Metcalf 
Cc: Guan Xuetao 
Cc: Chris Zankel 
Cc: Max Filippov 
Cc: Oleg Nesterov 
Cc: Guenter Roeck 
Signed-off-by: James Hogan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

alpha: pass k_sigaction and siginfo_t using ksignal pointer

2013-02-14T14:21:16+00:00

... and use the new helpers

Signed-off-by: Al Viro

alpha: switch to generic old sigsuspend

2013-02-03T23:15:46+00:00

Signed-off-by: Al Viro

alpha: switch to generic sigaltstack

2012-12-19T23:07:42+00:00

Signed-off-by: Al Viro

alpha: don't pass useless arguments to do_{,rt_},sigreturn()

2012-11-29T02:49:04+00:00

Signed-off-by: Al Viro

alpha: get rid of switch_stack argument of do_work_pending()

2012-10-12T01:40:13+00:00

... and now the asm glue side of that.

Signed-off-by: Al Viro

alpha: don't bother passing switch_stack separately from regs

2012-10-12T01:39:28+00:00

It's needed only in setup_sigcontext() and it's always reg - ;
no point passing it all way down through the call chain.  This is just
the signal.c side of that stuff; next will come the asm glue one...

Signed-off-by: Al Viro

alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c

2012-10-12T01:39:27+00:00

Turn the slow side of work_pending into C function, including all
the looping.  What we get out of that:
	* we do _not_ call get_signal_to_deliver() with IRQs disabled
anymore
	* no need to save/restore volatiles on each pass if there
turns to be more than one (unlikely, but still)
	* all double-restart prevention is in C now.
	* glue gets simpler.

Signed-off-by: Al Viro

new helper: signal_delivered()

2012-06-01T16:58:52+00:00

Does block_sigmask() + tracehook_signal_handler();  called when
sigframe has been successfully built.  All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).

I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).

Signed-off-by: Al Viro

most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set

2012-06-01T16:58:51+00:00

Only 3 out of 63 do not.  Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.

Signed-off-by: Al Viro