Commit graph

165 commits

Author SHA1 Message Date
Ingo Molnar
68db0cf106 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h>
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/task_stack.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:36 +01:00
Ingo Molnar
299300258d sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task.h>
We are going to split <linux/sched/task.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/task.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:35 +01:00
Ingo Molnar
b17b01533b sched/headers: Prepare for new header dependencies before moving code to <linux/sched/debug.h>
We are going to split <linux/sched/debug.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/debug.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:34 +01:00
Jason Cooper
c984cbf2e3 ARM: use simpler API for random address requests
Currently, all callers to randomize_range() set the length to 0 and
calculate end by adding a constant to the start address.  We can simplify
the API to remove a bunch of needless checks and variables.

Use the new randomize_addr(start, range) call to set the requested
address.

Link: http://lkml.kernel.org/r/20160803233913.32511-4-jason@lakedaemon.net
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Russell King - ARM Linux" <linux@arm.linux.org.uk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-11 15:06:32 -07:00
Russell King
e6978e4bf1 ARM: save and reset the address limit when entering an exception
When we enter an exception, the current address limit should not apply
to the exception context: if the exception context wishes to access
kernel space via the user accessors (eg, perf code), it must explicitly
request such access.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2016-07-07 16:01:01 +01:00
Russell King
5fa9da5043 ARM: get rid of horrible *(unsigned int *)(regs + 1)
Get rid of the horrible "*(unsigned int *)(regs + 1)" to get at the
parent context domain access register value, instead using the newly
introduced svc_pt_regs structure.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2016-06-22 19:55:05 +01:00
Michal Hocko
6904817607 vdso: make arch_setup_additional_pages wait for mmap_sem for write killable
most architectures are relying on mmap_sem for write in their
arch_setup_additional_pages.  If the waiting task gets killed by the oom
killer it would block oom_reaper from asynchronous address space reclaim
and reduce the chances of timely OOM resolving.  Wait for the lock in
the killable mode and return with EINTR if the task got killed while
waiting.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>	[x86 vdso]
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00
Jiri Slaby
e64646946e exit_thread: accept a task parameter to be exited
We need to call exit_thread from copy_process in a fail path.  So make it
accept task_struct as a parameter.

[v2]
* s390: exit_thread_runtime_instr doesn't make sense to be called for
  non-current tasks.
* arm: fix the comment in vfp_thread_copy
* change 'me' to 'tsk' for task_struct
* now we can change only archs that actually have exit_thread

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 17:58:30 -07:00
Russell King
77f1b959b0 ARM: report proper DACR value in oops dumps
When printing the DACR value, we print the domain register value.
This is incorrect, as with SW_PAN enabled, that is the current setting,
rather than the faulting context's setting.  Arrange to print the
faulting domain's saved DACR value instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-12-04 19:20:48 +00:00
Linus Torvalds
57e6bbcb4b Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM fixes from Russell King:
 "A number of fixes for the merge window, fixing a number of cases
  missed when testing the uaccess code, particularly cases which only
  show up with certain compiler versions"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8431/1: fix alignement of __bug_table section entries
  arm/xen: Enable user access to the kernel before issuing a privcmd call
  ARM: domains: add memory dependencies to get_domain/set_domain
  ARM: domains: thread_info.h no longer needs asm/domains.h
  ARM: uaccess: fix undefined instruction on ARMv7M/noMMU
  ARM: uaccess: remove unneeded uaccess_save_and_disable macro
  ARM: swpan: fix nwfpe for uaccess changes
  ARM: 8429/1: disable GCC SRA optimization
2015-09-14 12:24:10 -07:00
Russell King
af4cb25df9 ARM: uaccess: fix undefined instruction on ARMv7M/noMMU
The use of get_domain() in copy_thread() results in an oops on
ARMv7M/noMMU systems.  The thread cpu_domain value is only used when
CONFIG_CPU_USE_DOMAINS is enabled, so there's no need to save the
value in copy_thread() except when this is enabled, and this option
will never be enabled on these platforms.

Unhandled exception: IPSR = 00000006 LR = fffffff1
CPU: 0 PID: 0 Comm: swapper Not tainted 4.2.0-next-20150909-00001-gb8ec5ad #41
Hardware name: NXP LPC18xx/43xx (Device Tree)
task: 2823fbe0 ti: 2823c000 task.ti: 2823c000
PC is at copy_thread+0x18/0x92
LR is at copy_thread+0x19/0x92
pc : [<2800a46e>]    lr : [<2800a46f>]    psr: 4100000b
sp : 2823df00  ip : 00000000  fp : 287c81c0
r10: 00000000  r9 : 00800300  r8 : 287c8000
r7 : 287c8000  r6 : 2818908d  r5 : 00000000  r4 : 287ca000
r3 : 00000000  r2 : 00000000  r1 : fffffff0  r0 : 287ca048
xPSR: 4100000b

Reported-by: Ariel D'Alessandro <ariel@vanguardiasur.com.ar>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-09-09 23:26:44 +01:00
Russell King
40d3f02851 Merge branches 'cleanup', 'fixes', 'misc', 'omap-barrier' and 'uaccess' into for-linus 2015-09-03 15:28:37 +01:00
Russell King
a5e090acbf ARM: software-based priviledged-no-access support
Provide a software-based implementation of the priviledged no access
support found in ARMv8.1.

Userspace pages are mapped using a different domain number from the
kernel and IO mappings.  If we switch the user domain to "no access"
when we enter the kernel, we can prevent the kernel from touching
userspace.

However, the kernel needs to be able to access userspace via the
various user accessor functions.  With the wrapping in the previous
patch, we can temporarily enable access when the kernel needs user
access, and re-disable it afterwards.

This allows us to trap non-intended accesses to userspace, eg, caused
by an inadvertent dereference of the LIST_POISON* values, which, with
appropriate user mappings setup, can be made to succeed.  This in turn
can allow use-after-free bugs to be further exploited than would
otherwise be possible.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-08-26 20:34:24 +01:00
Stephen Boyd
9205b797db ARM: 8421/1: smp: Collapse arch_cpu_idle_dead() into cpu_die()
The only caller of cpu_die() on ARM is arch_cpu_idle_dead(), so
let's simplify the code by renaming cpu_die() to
arch_cpu_idle_dead(). While were here, drop the __ref annotation
because __cpuinit is gone nowadays.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-08-25 18:19:19 +01:00
Russell King
1eef5d2f1b ARM: domains: switch to keeping domain value in register
Rather than modifying both the domain access control register and our
per-thread copy, modify only the domain access control register, and
use the per-thread copy to save and restore the register over context
switches.  We can also avoid the explicit initialisation of the
init thread_info structure.

This allows us to avoid needing to gain access to the thread information
at the uaccess control sites.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-08-21 13:55:49 +01:00
Russell King
c848791f03 Merge branches 'misc', 'vdso' and 'fixes' into for-next
Conflicts:
	arch/arm/mm/proc-macros.S
2015-04-14 22:28:25 +01:00
Russell King
045ab94e10 ARM: move reboot code to arch/arm/kernel/reboot.c
Move shutdown and reboot related code to a separate file, out of
process.c.  This helps to avoid polluting process.c with non-process
related code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-04-02 09:50:45 +01:00
Russell King
767bf7e7a1 ARM: fix broken hibernation
Normally, when a CPU wants to clear a cache line to zero in the external
L2 cache, it would generate bus cycles to write each word as it would do
with any other data access.

However, a Cortex A9 connected to a L2C-310 has a specific feature where
the CPU can detect this operation, and signal that it wants to zero an
entire cache line.  This feature, known as Full Line of Zeros (FLZ),
involves a non-standard AXI signalling mechanism which only the L2C-310
can properly interpret.

There are separate enable bits in both the L2C-310 and the Cortex A9 -
the L2C-310 needs to be enabled and have the FLZ enable bit set in the
auxiliary control register before the Cortex A9 has this feature
enabled.

Unfortunately, the suspend code was not respecting this - it's not
obvious from the code:

swsusp_arch_suspend()
 cpu_suspend() /* saves the Cortex A9 auxiliary control register */
  arch_save_image()
  soft_restart() /* turns off FLZ in Cortex A9, and disables L2C */
   cpu_resume() /* restores the Cortex A9 registers, inc auxcr */

At this point, we end up with the L2C disabled, but the Cortex A9 with
FLZ enabled - which means any memset() or zeroing of a full cache line
will fail to take effect.

A similar issue exists in the resume path, but it's slightly more
complex:

swsusp_arch_suspend()
 cpu_suspend() /* saves the Cortex A9 auxiliary control register */
  arch_save_image() /* image with A9 auxcr saved */
...
swsusp_arch_resume()
 call_with_stack()
  arch_restore_image() /* restores image with A9 auxcr saved above */
  soft_restart() /* turns off FLZ in Cortex A9, and disables L2C */
   cpu_resume() /* restores the Cortex A9 registers, inc auxcr */

Again, here we end up with the L2C disabled, but Cortex A9 FLZ enabled.

There's no need to turn off the L2C in either of these two paths; there
are benefits from not doing so - for example, the page copies will be
faster with the L2C enabled.

Hence, fix this by providing a variant of soft_restart() which can be
used without turning the L2 cache controller off, and use it in both
of these paths to keep the L2C enabled across the respective resume
transitions.

Fixes: 8ef418c717 ("ARM: l2c: trial at enabling some Cortex-A9 optimisations")
Reported-by: Sean Cross <xobs@kosagi.com>
Tested-by: Sean Cross <xobs@kosagi.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-04-02 09:50:10 +01:00
Nathan Lynch
ecf99a4391 ARM: 8331/1: VDSO initialization, mapping, and synchronization
Initialize the VDSO page list at boot, install the VDSO mapping at
exec time, and update the data page during timer ticks.  This code is
not built if CONFIG_VDSO is not enabled.

Account for the VDSO length when randomizing the offset from the
stack.  The [vdso] and [vvar] pages are placed immediately following
the sigpage with separate _install_special_mapping calls.

We want to "penalize" systems lacking the arch timer as little
as possible.  Previous versions of this code installed the VDSO
unconditionally and unmodified, making it a measurably slower way for
glibc to invoke the real syscalls on such systems.  E.g. calling
gettimeofday via glibc goes from ~560ns to ~630ns on i.MX6Q.

If we can indicate to glibc that the time-related APIs in the VDSO are
not accelerated, glibc can continue to invoke the syscalls directly
instead of dispatching through the VDSO only to fall back to the slow
path.

Thus, if the architected timer is unusable for whatever reason, patch
the VDSO at boot time so that symbol lookups for gettimeofday and
clock_gettime return NULL.  (This is similar to what powerpc does and
borrows code from there.)  This allows glibc to perform the syscall
directly instead of passing control to the VDSO, which minimizes the
penalty.  In my measurements the time taken for a gettimeofday call
via glibc goes from ~560ns to ~580ns (again on i.MX6Q), and this is
solely due to adding a test and branch to glibc's gettimeofday syscall
wrapper.

An alternative to patching the VDSO at boot would be to not install
the VDSO at all when the arch timer isn't usable.  Another alternative
is to include a separate "dummy" vdso.so without gettimeofday and
clock_gettime, which would be selected at boot time.  Either of these
would get cumbersome if the VDSO were to gain support for an API such
as getcpu which is unrelated to arch timer support.

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-03-27 22:20:45 +00:00
Stephen Boyd
f3a04202c5 ARM: 8241/1: Update processor_modes for hyp and monitor mode
If the kernel is running in hypervisor mode or monitor mode we'll
print UK6_32 or UK10_32 if we call into __show_regs(). Let's
update these strings to indicate the new modes that didn't exist
when this code was written.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-12-03 16:00:07 +00:00
Linus Torvalds
93834c6419 Immutable branch with restart handler patches for v3.18
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJUJQ8/AAoJEMsfJm/On5mBMNgP+QEUHpRKJaOGU3jX/ftHH/t3
 EoNUx7lZt6Q0c9MB2ySAxILYpWUujc9N0tDkRDyW7mTWunF8gEGiRN+iKaSbzcUN
 Y4VffRAbxBasIaBqRtpDl08ycODh6Xu1t8sAao03DdhnMNLGNNO79s3UFHsubdTC
 cXx9mfYR/2SHV/0BXiFvKi8ovdqUspdp9cyZO/qc0PVFGbsADx3MNGGzkvWfgvcE
 6vXnKnUkZrNl5JPiG77kTKZnDsjEMXggmA9DGWKijFCJjGIbuLiuIDf63Zp+eQ52
 mJMRA+ViP/dDgAxY1dkWBcF5nOBT1vTYwLfy69jEoQeHzcomiHVoDKmCSBOpeAEH
 G8VoasWKWYpYnlcOJb+XgkA3QTe6mOPgAPzNsbYr0Ep7hMFw66mOQgKbgi6k4Qts
 HHimG9pnBYpPlBUfvNh+6K4dHAm0C2IyoZyMhKWsyFH6hkhS8TVM8j0gPR8rTTmk
 0a9/e2vxcFnfBe3UAJaqzWRVFsBkOHrTNpG1hvID3Oq8IeywSBXw2VMSR93+mwaB
 sa/GCZKlqHGpOfmtILlhiXQX0E/tTHmcrI2VqyCpX0J2CW+MiGvkcGOwKHOJciSA
 Cj9D68y837QU/DCpMQ6ec/5wqWqZKz8yQb8kxb6vJcL19JcVKdAiPzbuOI49C3Ux
 YxDWoUutzDfVoUD5RhcJ
 =cP1w
 -----END PGP SIGNATURE-----

Merge tag 'restart-handler-for-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull restart handler infrastructure from Guenter Roeck:
 "This series was supposed to be pulled through various trees using it,
  and I did not plan to send a separate pull request.  As it turns out,
  the pinctrl tree did not merge with it, is now upstream, and uses it,
  meaning there are now build failures.

  Please pull this series directly to fix those build failures"

* tag 'restart-handler-for-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  arm/arm64: unexport restart handlers
  watchdog: sunxi: register restart handler with kernel restart handler
  watchdog: alim7101: register restart handler with kernel restart handler
  watchdog: moxart: register restart handler with kernel restart handler
  arm: support restart through restart handler call chain
  arm64: support restart through restart handler call chain
  power/restart: call machine_restart instead of arm_pm_restart
  kernel: add support for kernel restart handler call chain
2014-10-10 16:38:02 -04:00
Russell King
d5d1689224 Merge branches 'fiq' (early part), 'fixes', 'l2c' (early part) and 'misc' into for-next 2014-10-02 21:47:02 +01:00
Nathan Lynch
389522b0c0 ARM: 8155/1: place sigpage at a random offset above stack
The sigpage is currently placed alongside shared libraries etc in the
address space.  Similar to what x86_64 does for its VDSO, place the
sigpage at a randomized offset above the stack so that learning the
base address of the sigpage doesn't help expose where shared libraries
are loaded in the address space (and vice versa).

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-09-26 14:40:01 +01:00
Nathan Lynch
02e0409a65 ARM: 8154/1: use _install_special_mapping for sigpage
_install_special_mapping allows the VMA to be identifed in
/proc/pid/maps without the use of arch_vma_name, providing a
slight net reduction in object size:

  text    data     bss     dec     hex filename
  2996      96     144    3236     ca4 arch/arm/kernel/process.o (before)
  2956     104     144    3204     c84 arch/arm/kernel/process.o (after)

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-09-26 14:39:59 +01:00
Guenter Roeck
6cd6d94d96 arm/arm64: unexport restart handlers
Implementing a restart handler in a module don't make sense as there would
be no guarantee that the module is loaded when a restart is needed.
Unexport arm_pm_restart to ensure that no one gets the idea to do it
anyway.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonas Jensen <jonas.jensen@gmail.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2014-09-26 00:00:48 -07:00
Guenter Roeck
1a9607a3be arm: support restart through restart handler call chain
The kernel core now supports a restart handler call chain for system
restart functions.

With this change, the arm_pm_restart callback is now optional, so drop its
initialization and check if it is set before calling it.  Only call the
kernel restart handler if arm_pm_restart is not set.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonas Jensen <jonas.jensen@gmail.com>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2014-09-26 00:00:22 -07:00
Russell King
7f038073c0 ARM: remove extraneous newline in show_regs()
Remove an unnecessary newline in show_regs().

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-09-18 00:35:41 +01:00
Nathan Lynch
fbfb872f5f ARM: 8148/1: flush TLS and thumbee register state during exec
The TPIDRURO and TPIDRURW registers need to be flushed during exec;
otherwise TLS information is potentially leaked.  TPIDRURO in
particular needs careful treatment.  Since flush_thread basically
needs the same code used to set the TLS in arm_syscall, pull that into
a common set_tls helper in tls.h and use it in both places.

Similarly, TEEHBR needs to be cleared during exec as well.  Clearing
its save slot in thread_info isn't right as there is no guarantee
that a thread switch will occur before the new program runs.  Just
setting the register directly is sufficient.

Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-09-16 16:09:32 +01:00
Linus Torvalds
ede1d63fcc Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull second set of ARM changes from Russell King:
 "This is the remainder of the ARM changes for this merge window.
  Included in this request are:

   - fixes for kprobes for big-endian support
   - fix tracing in soft_restart
   - avoid phys address overflow in kdump code
   - fix reporting of read-only pmd bits in kernel page table dump
   - remove unnecessary (and possibly buggy) call to outer_flush_all()
   - fix a three sparse warnings (missing header file for function
     prototypes)
   - fix pj4 crashing single zImage (thanks to arm-soc merging changes
     which enables this with knowledge that the corresponding fix had
     not even been submitted for my tree before the merge window opened)
   - vfp macro cleanups
   - dump register state on undefined instruction userspace faults when
     debugging"

* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  Dump the registers on undefined instruction userspace faults
  ARM: 8018/1: Add {inc,dec}_preempt_count asm macros
  ARM: 8017/1: Move asm macro get_thread_info to asm/assembler.h
  ARM: 8016/1: Check cpu id in pj4_cp0_init.
  ARM: 8015/1: Add cpu_is_pj4 to distinguish PJ4 because it has some differences with V7
  ARM: add missing system_misc.h include to process.c
  ARM: 8009/1: dcscb.c: remove call to outer_flush_all()
  ARM: 8014/1: mm: fix reporting of read-only PMD bits
  ARM: 8012/1: kdump: Avoid overflow when converting pfn to physaddr
  ARM: 8010/1: avoid tracers in soft_restart
  ARM: kprobes-test: Workaround GAS .align bug
  ARM: kprobes-test: use <asm/opcodes.h> for Thumb instruction building
  ARM: kprobes-test: use <asm/opcodes.h> for ARM instruction building
  ARM: kprobes-test: use <asm/opcodes.h> for instruction accesses
  ARM: probes: fix instruction fetch order with <asm/opcodes.h>
2014-04-11 11:56:40 -07:00
Russell King
53f1d9afb4 Merge branches 'fixes' and 'misc' into for-next 2014-04-11 14:50:05 +01:00
Russell King
779dd9590b ARM: add missing system_misc.h include to process.c
arm_pm_restart(), arm_pm_idle() and soft_restart() are all declared in
system_misc.h, but this file is not included in process.c.  Add this
missing include.  Found via sparse:

arch/arm/kernel/process.c:98:6: warning: symbol 'soft_restart' was not declared. Should it be static?
arch/arm/kernel/process.c:127:6: warning: symbol 'arm_pm_restart' was not declared. Should it be static?
arch/arm/kernel/process.c:134:6: warning: symbol 'arm_pm_idle' was not declared. Should it be static?

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-04-08 15:29:37 +01:00
Sebastian Capella
c7d442f46c ARM: 8010/1: avoid tracers in soft_restart
Use of tracers in local_irq_disable is causes abort loops when called
with irqs disabled using a temporary stack.  Replace local_irq_disable
with raw_local_irq_disable instead to avoid tracers.

Signed-off-by: Sebastian Capella <sebastian.capella@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2014-04-07 12:10:00 +01:00
Linus Torvalds
2d1eb87ae1 Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM changes from Russell King:

 - Perf updates from Will Deacon:
   - Support for Qualcomm Krait processors (run perf on your phone!)
   - Support for Cortex-A12 (run perf stat on your FPGA!)
   - Support for perf_sample_event_took, allowing us to automatically decrease
     the sample rate if we can't handle the PMU interrupts quickly enough
     (run perf record on your FPGA!).

 - Basic uprobes support from David Long:
     This patch series adds basic uprobes support to ARM. It is based on
     patches developed earlier by Rabin Vincent. That approach of adding
     hooks into the kprobes instruction parsing code was not well received.
     This approach separates the ARM instruction parsing code in kprobes out
     into a separate set of functions which can be used by both kprobes and
     uprobes. Both kprobes and uprobes then provide their own semantic action
     tables to process the results of the parsing.

 - ARMv7M (microcontroller) updates from Uwe Kleine-König

 - OMAP DMA updates (recently added Vinod's Ack even though they've been
   sitting in linux-next for a few months) to reduce the reliance of
   omap-dma on the code in arch/arm.

 - SA11x0 changes from Dmitry Eremin-Solenikov and Alexander Shiyan

 - Support for Cortex-A12 CPU

 - Align support for ARMv6 with ARMv7 so they can cooperate better in a
   single zImage.

 - Addition of first AT_HWCAP2 feature bits for ARMv8 crypto support.

 - Removal of IRQ_DISABLED from various ARM files

 - Improved efficiency of virt_to_page() for single zImage

 - Patch from Ulf Hansson to permit runtime PM callbacks to be available for
   AMBA devices for suspend/resume as well.

 - Finally kill asm/system.h on ARM.

* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (89 commits)
  dmaengine: omap-dma: more consolidation of CCR register setup
  dmaengine: omap-dma: move IRQ handling to omap-dma
  dmaengine: omap-dma: move register read/writes into omap-dma.c
  ARM: omap: dma: get rid of 'p' allocation and clean up
  ARM: omap: move dma channel allocation into plat-omap code
  ARM: omap: dma: get rid of errata global
  ARM: omap: clean up DMA register accesses
  ARM: omap: remove almost-const variables
  ARM: omap: remove references to disable_irq_lch
  dmaengine: omap-dma: cleanup errata 3.3 handling
  dmaengine: omap-dma: provide register read/write functions
  dmaengine: omap-dma: use cached CCR value when enabling DMA
  dmaengine: omap-dma: move barrier to omap_dma_start_desc()
  dmaengine: omap-dma: move clnk_ctrl setting to preparation functions
  dmaengine: omap-dma: improve efficiency loading C.SA/C.EI/C.FI registers
  dmaengine: omap-dma: consolidate clearing channel status register
  dmaengine: omap-dma: move CCR buffering disable errata out of the fast path
  dmaengine: omap-dma: provide register definitions
  dmaengine: omap-dma: consolidate setup of CCR
  dmaengine: omap-dma: consolidate setup of CSDP
  ...
2014-04-05 13:20:43 -07:00
Nicolas Pitre
ad68cc7a77 sched/idle, ARM: Remove redundant cpuidle_idle_call()
The core idle loop now takes care of it.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-sh@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linaro-kernel@lists.linaro.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-y2nbw5j3ma5siy5584919z5i@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-11 09:58:22 +01:00
Uwe Kleine-König
e2e55fde3f ARM: show_regs: on v7-M there are no FIQs, different processor modes, ...
no indication about irqs in PSR and only a single ISA. So skip the whole
decoding and just print the xPSR on v7-M.

Also mark two static variables as __maybe_unused to prevent the compiler
from emitting:

	arch/arm/kernel/process.c:51:20: warning: 'processor_modes' defined but not used [-Wunused-variable]
	arch/arm/kernel/process.c:58:20: warning: 'isa_modes' defined but not used [-Wunused-variable]

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2014-02-03 17:30:21 +01:00
Konstantin Khlebnikov
1b15ec7a74 ARM: 7912/1: check stack pointer in get_wchan
get_wchan() is lockless. Task may wakeup at any time and change its own stack,
thus each next stack frame may be overwritten and filled with random stuff.

/proc/$pid/stack interface had been disabled for non-current tasks, see [1]
But 'wchan' still allows to trigger stack frame unwinding on volatile stack.

This patch fixes oops in unwind_frame() by adding stack pointer validation on
each step (as x86 code do), unwind_frame() already checks frame pointer.

Also I've found another report of this oops on stackoverflow (irony).

Link: http://www.spinics.net/lists/arm-kernel/msg110589.html [1]
Link: http://stackoverflow.com/questions/18479894/unwind-frame-cause-a-kernel-paging-error

Cc: <stable@vger.kernel.org>
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-12-09 23:24:31 +00:00
Russell King
2a2822475d Merge branch 'security-fixes' into fixes 2013-08-13 20:23:28 +01:00
Russell King
1d0bbf4289 ARM: Fix the world famous typo with is_gate_vma()
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-07 14:00:10 +01:00
Russell King
e35ac62d22 Merge branch 'security-fixes' into fixes 2013-08-03 10:49:38 +01:00
Russell King
e0d407564b ARM: fix a cockup in 48be69a02 (ARM: move signal handlers into a vdso-like page)
Unfortunately, I never committed the fix to a nasty oops which can
occur as a result of that commit:

------------[ cut here ]------------
kernel BUG at /home/olof/work/batch/include/linux/mm.h:414!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 490 Comm: killall5 Not tainted 3.11.0-rc3-00288-gabe0308 #53
task: e90acac0 ti: e9be8000 task.ti: e9be8000
PC is at special_mapping_fault+0xa4/0xc4
LR is at __do_fault+0x68/0x48c

This doesn't show up unless you do quite a bit of testing; a simple
boot test does not do this, so all my nightly tests were passing fine.

The reason for this is that install_special_mapping() expects the
page array to stick around, and as this was only inserting one page
which was stored on the kernel stack, that's why this was blowing up.

Reported-by: Olof Johansson <olof@lixom.net>
Tested-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-03 10:30:05 +01:00
Russell King
24195cad3e Merge branch 'security-fixes' into fixes 2013-08-01 20:51:13 +01:00
Stephen Boyd
44424c3404 ARM: 7803/1: Fix deadlock scenario with smp_send_stop()
If one process calls sys_reboot and that process then stops other
CPUs while those CPUs are within a spin_lock() region we can
potentially encounter a deadlock scenario like below.

CPU 0                   CPU 1
-----                   -----
                        spin_lock(my_lock)
smp_send_stop()
 <send IPI>             handle_IPI()
                         disable_preemption/irqs
                          while(1);
 <PREEMPT>
spin_lock(my_lock) <--- Waits forever

We shouldn't attempt to run any other tasks after we send a stop
IPI to a CPU so disable preemption so that this task runs to
completion. We use local_irq_disable() here for cross-arch
consistency with x86.

Reported-by: Sundarajan Srinivasan <sundaraj@codeaurora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-01 14:41:39 +01:00
Russell King
a5463cd343 ARM: make vectors page inaccessible from userspace
If kuser helpers are not provided by the kernel, disable user access to
the vectors page.  With the kuser helpers gone, there is no reason for
this page to be visible to userspace.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-01 14:31:58 +01:00
Russell King
48be69a026 ARM: move signal handlers into a vdso-like page
Move the signal handlers into a VDSO page rather than keeping them in
the vectors page.  This allows us to place them randomly within this
page, and also map the page at a random location within userspace
further protecting these code fragments from ROP attacks.  The new
VDSO page is also poisoned in the same way as the vector page.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-08-01 14:31:56 +01:00
Robin Holt
1b3a5d02ee reboot: move arch/x86 reboot= handling to generic kernel
Merge together the unicore32, arm, and x86 reboot= command line
parameter handling.

Signed-off-by: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:29 -07:00
Robin Holt
7b6d864b48 reboot: arm: change reboot_mode to use enum reboot_mode
Preparing to move the parsing of reboot= to generic kernel code forces
the change in reboot_mode handling to use the enum.

[akpm@linux-foundation.org: fix arch/arm/mach-socfpga/socfpga.c]
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:29 -07:00
Robin Holt
16d6d5b00e reboot: arm: prepare reboot_mode for moving to generic kernel code
Prepare for the moving the parsing of reboot= to the generic kernel code
by making reboot_mode into a more generic form.

Signed-off-by: Robin Holt <holt@sgi.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Russ Anderson <rja@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:29 -07:00
Russell King
cbd379b100 Merge branches 'fixes', 'mcpm', 'misc' and 'mmci' into for-next 2013-06-29 11:43:28 +01:00
André Hentschel
a4780adeef ARM: 7735/2: Preserve the user r/w register TPIDRURW on context switch and fork
Since commit 6a1c53124a the user writeable TLS register was zeroed to
prevent it from being used as a covert channel between two tasks.

There are more and more applications coming to Windows RT,
Wine could support them, but mostly they expect to have
the thread environment block (TEB) in TPIDRURW.

This patch preserves that register per thread instead of clearing it.
Unlike the TPIDRURO, which is already switched, the TPIDRURW
can be updated from userspace so needs careful treatment in the case that we
modify TPIDRURW and call fork(). To avoid this we must always read
TPIDRURW in copy_thread.

Signed-off-by: André Hentschel <nerv@dawncrow.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-06-24 15:21:59 +01:00
Stephen Warren
19ab428f4b ARM: 7759/1: decouple CPU offlining from reboot/shutdown
Add comments to machine_shutdown()/halt()/power_off()/restart() that
describe their purpose and/or requirements re: CPUs being active/not.

In machine_shutdown(), replace the call to smp_send_stop() with a call to
disable_nonboot_cpus(). This completely disables all but one CPU, thus
satisfying the requirement that only a single CPU be active for kexec.
Adjust Kconfig dependencies for this change.

In machine_halt()/power_off()/restart(), call smp_send_stop() directly,
rather than via machine_shutdown(); these functions don't need to
completely de-activate all CPUs using hotplug, but rather just quiesce
them.

Remove smp_kill_cpus(), and its call from smp_send_stop().
smp_kill_cpus() was indirectly calling smp_ops.cpu_kill() without calling
smp_ops.cpu_die() on the target CPUs first. At least some implementations
of smp_ops had issues with this; it caused cpu_kill() to hang on Tegra,
for example. Since smp_send_stop() is only used for shutdown, halt, and
power-off, there is no need to attempt any kind of CPU hotplug here.

Adjust Kconfig to reflect that machine_shutdown() (and hence kexec)
relies upon disable_nonboot_cpus(). However, this alone doesn't guarantee
that hotplug will work, or even that hotplug is implemented for a
particular piece of HW that a multi-platform zImage runs on. Hence, add
error-checking to machine_kexec() to determine whether it did work.

Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by:  Zhangfei Gao <zhangfei.gao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2013-06-17 21:35:25 +01:00