Commit Graph

21 Commits

Author SHA1 Message Date
Richard Weinberger
fa41b1c7df arch: Remove exec_domain from remaining archs
Signed-off-by: Richard Weinberger <richard@nod.at>
2015-04-12 21:03:30 +02:00
Andy Lutomirski
f56141e3e2 all arches, signal: move restart_block to struct task_struct
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 <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Richard Weinberger
8e2beafa2f openrisc: Use sigsp()
Use sigsp() instead of the open coded variant.

Signed-off-by: Richard Weinberger <richard@nod.at>
2014-08-06 13:04:31 +02:00
Richard Weinberger
548dafe880 openrisc: Use get_signal() signal_setup_done()
Use the more generic functions get_signal() signal_setup_done()
for signal delivery.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
2014-01-09 10:57:21 +01:00
Jonas Bonn
10f67dbf6a openrisc: Rework signal handling
The mainline signal handling code for OpenRISC has been buggy since day
one with respect to syscall restart.  This patch significantly reworks
the signal handling code:

i)   Move the "work pending" loop to C code (borrowed from ARM arch)

ii)  Allow a tracer to muck about with the IP and skip syscall restart
     in that case (again, borrowed from ARM)

iii) Make signal handling WRT syscall restart actually work

v)   Make the signal handling code look more like that of other
     architectures so that it's easier for others to follow

Reported-by: Anders Nystrom <anders@southpole.se>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
2014-01-09 10:57:21 +01:00
Al Viro
faec5a96a0 openrisc: switch to generic sigaltstack
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-03 18:16:05 -05:00
Al Viro
d26654e5f9 openrisk: fix altstack switching on sigreturn
do_sigaltstack() expects _userland_ address, TYVM...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-11-28 21:46:11 -05:00
Al Viro
efee984c27 new helper: signal_delivered()
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 <viro@zeniv.linux.org.uk>
2012-06-01 12:58:52 -04:00
Al Viro
77097ae503 most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set
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 <viro@zeniv.linux.org.uk>
2012-06-01 12:58:51 -04:00
Al Viro
a610d6e672 pull clearing RESTORE_SIGMASK into block_sigmask()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:49 -04:00
Al Viro
39974d085d openrisc: tracehook_signal_handler() is supposed to be called on success
... not if sigframe couldn't have been built.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:48 -04:00
Al Viro
b7f9a11a6c new helper: sigmask_to_save()
replace boilerplate "should we use ->saved_sigmask or ->blocked?"
with calls of obvious inlined helper...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:48 -04:00
Al Viro
51a7b448d4 new helper: restore_saved_sigmask()
first fruits of ..._restore_sigmask() helpers: now we can take
boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK
and restore the blocked mask from ->saved_mask" into a common
helper.  Open-coded instances switched...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:47 -04:00
Al Viro
a42c6ded82 move key_repace_session_keyring() into tracehook_notify_resume()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-23 22:09:20 -04:00
Jonas Bonn
6cbe5e9526 openrisc: sanitize use of orig_gpr11
The pt_regs struct had both a 'syscallno' field and an 'orig_gpr11' field
and it wasn't really clear how these were supposed to be used.  This patch
removes the syscallno field altogether and makes orig_gpr11 work more
like other architectures: keep track of syscall number in progress or
hold -1 for non-syscall exceptions.

Signed-off-by: Jonas Bonn <jonas@southpole.se>
2012-03-06 10:37:00 +01:00
Matt Fleming
d8d4b20df4 OpenRISC: Use set_current_blocked() and block_sigmask()
As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check whether the signal we're about to block
is pending in the shared queue.

Also, use the new helper function introduced in commit 5e6292c0f2
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate
code across architectures. In the past some architectures got this
code wrong, so using this helper function should stop that from
happening again.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux@lists.openrisc.net
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
2012-02-17 09:55:25 +01:00
Matt Fleming
e933c70de0 OpenRISC: Don't mask signals if we fail to setup signal stack
setup_rt_frame() needs to return an indication of whether it succeeded
or failed in setting up the signal stack frame. If setup_rt_frame()
fails then we must not modify current->blocked.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux@lists.openrisc.net
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
2012-02-17 09:55:24 +01:00
Matt Fleming
b675eeb743 OpenRISC: No need to reset handler if SA_ONESHOT
get_signal_to_deliver() already resets the signal handler if
SA_ONESHOT is set in ka->sa.sa_flags, there's no need to do it again
in handle_signal(). Furthermore, because we were modifying
ka->sa.sa_handler (which is a copy of sighand->action[]) instead of
sighand->action[] the original code actually had no effect on signal
delivery.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux@lists.openrisc.net
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
2012-02-17 09:55:23 +01:00
Matt Fleming
4ca159f725 OpenRISC: Don't reimplement force_sigsegv()
Instead of open coding the sequence from force_sigsegv() just call
it. This also fixes a bug because we were modifying ka->sa.sa_handler
(which is a copy of sighand->action[]), whereas the intention of the
code was to modify sighand->action[] directly.

As the original code was working with a copy it had no effect on
signal delivery.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux@lists.openrisc.net
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
2012-02-17 09:55:23 +01:00
Jonas Bonn
d7cb666709 openrisc: don't use pt_regs in struct sigcontext
As it was decided not to export struct pt_regs to userspace, struct
sigcontext shouldn't be using it either.  The pt_regs struct for OpenRISC
is kernel internal and the layout of the registers may change in the
future.  The struct user_regs_struct is what is guaranteed to remain
stable, so struct sigcontext may use that instead.

This patch removes the usage of struct pt_regs in struct sigcontext and
makes according changes in signal.c to get the register layout right.

The usp field is removed from the sigcontext structure as this information
is already contained in the user_regs_struct.

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Emilio Cota <cota@braap.org>
2011-09-05 14:29:12 +02:00
Jonas Bonn
ac689eb7f9 OpenRISC: Signal handling
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2011-07-22 18:46:29 +02:00