Some fixes, nothing too exciting this time as well...
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=8o17
-----END PGP SIGNATURE-----
Merge tag 'arc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC updates from Vineet Gupta:
"Some fixes, nothing too exciting this time as well..."
* tag 'arc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE
ARC: Fix earlycon build breakage
ARC: Dynamically determine BASE_BAUD from DeviceTree
arc: Remove unused prepare_to_copy()
ARC: use ACCESS_ONCE in cmpxchg loop
ARC: add some more comments to ret_from_fork
ARC: fix /proc/cpuinfo for offline cpus
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>
Commit ffb7fcd66f ("ARC: Dynamically determine BASE_BAUD from DeviceTree")
breaks arc:defconfig build:
drivers/built-in.o: In function `of_setup_earlycon':
(.init.text+0xb3e): undefined reference to `arc_early_base_baud'
drivers/built-in.o: In function `setup_earlycon':
(.init.text+0xcd0): undefined reference to `arc_early_base_baud'
make: *** [vmlinux] Error 1
BASE_BAUD is only required for earlycon, which should depend on
CONFIG_SERIAL_EARLYCON.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
8250 earlycon is broken on multi-platform ARC because the UART clk
value (BASE_BAUD) is fixed at build time.
Instead, determine the appropriate UART clk at runtime; parse the
devicetree early for platforms requiring alternate UART clk values
(currently only the TB10X platform).
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Rob Herring <robh@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
function, where an architecture can override it by providing a strong
version.
Some header file declarations included the "weak" attribute. That's
error-prone because it causes every implementation to be weak, with no
strong version at all, and the linker chooses one based on link order.
What we want is the "weak" attribute only on the *definition* of the
default implementation. These changes remove "weak" from the declarations,
leaving it on the default definitions.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=P4fi
-----END PGP SIGNATURE-----
Merge tag 'remove-weak-declarations' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull weak function declaration removal from Bjorn Helgaas:
"The "weak" attribute is commonly used for the default version of a
function, where an architecture can override it by providing a strong
version.
Some header file declarations included the "weak" attribute. That's
error-prone because it causes every implementation to be weak, with no
strong version at all, and the linker chooses one based on link order.
What we want is the "weak" attribute only on the *definition* of the
default implementation. These changes remove "weak" from the
declarations, leaving it on the default definitions"
* tag 'remove-weak-declarations' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
uprobes: Remove "weak" from function declarations
memory-hotplug: Remove "weak" from memory_block_size_bytes() declaration
kgdb: Remove "weak" from kgdb_arch_pc() declaration
ARC: kgdb: generic kgdb_arch_pc() suffices
vmcore: Remove "weak" from function declarations
clocksource: Remove "weak" from clocksource_default_clock() declaration
x86, intel-mid: Remove "weak" from function declarations
audit: Remove "weak" from audit_classify_compat_syscall() declaration
The ARC version of kgdb_arch_pc() is identical to the generic version in
kernel/debug/debug_core.c. Drop the ARC version so we use the generic one.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
* No active users of this flag anymore
* flag itself was no longer usable with new simualtor which acts just like
hardware, not providing the special chip-id = 0xffff which good old
ISS used to do.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
All the platforms do the same thing in init_machine callback so move it
out of callback into caller of callback
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
In light of recent SNAFU with SMP build, allow simple platform to build
as SMP but run UP.
* Remove the dependence on simulation SMP extension to enable quick
build/test iterations of SMP kernel.
* In absence of platform SMP registration, prevent the NULL smp feature
name from borkign the system
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Pull arch signal handling cleanup from Richard Weinberger:
"This patch series moves all remaining archs to the get_signal(),
signal_setup_done() and sigsp() functions.
Currently these archs use open coded variants of the said functions.
Further, unused parameters get removed from get_signal_to_deliver(),
tracehook_signal_handler() and signal_delivered().
At the end of the day we save around 500 lines of code."
* 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (43 commits)
powerpc: Use sigsp()
openrisc: Use sigsp()
mn10300: Use sigsp()
mips: Use sigsp()
microblaze: Use sigsp()
metag: Use sigsp()
m68k: Use sigsp()
m32r: Use sigsp()
hexagon: Use sigsp()
frv: Use sigsp()
cris: Use sigsp()
c6x: Use sigsp()
blackfin: Use sigsp()
avr32: Use sigsp()
arm64: Use sigsp()
arc: Use sigsp()
sas_ss_flags: Remove nested ternary if
Rip out get_signal_to_deliver()
Clean up signal_delivered()
tracehook_signal_handler: Remove sig, info, ka and regs
...
Mostly cleanup/refactoring in core intc, cache flush, IPI send...
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.14 (GNU/Linux)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=Mx5r
-----END PGP SIGNATURE-----
Merge tag 'arc-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC changes from Vineet Gupta:
"Mostly cleanup/refactoring in core intc, cache flush, IPI send..."
* tag 'arc-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
mm, arc: remove obsolete pagefault oom killer comment
ARC: help gcc elide icache helper for !SMP
ARC: move common ops for line/full cache into helpers
ARC: cache boot reporting updates
ARC: [intc] mask/unmask can be hidden again
ARC: [plat-arcfpga] No need for init_irq hack
ARC: [intc] don't mask all IRQ by default
ARC: prune extra header includes from smp.c
ARC: update some comments
ARC: [SMP] unify cpu private IRQ requests (TIMER/IPI)
Use the more generic functions get_signal() signal_setup_done()
for signal delivery.
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJT1VYNAAoJEHm+PkMAQRiGQJwIAKSYp1Uqz5O/e5r0V1TlZKT4
1B4Njopl57PwSrJQWcGEuH2yHyM896vfPO4L6BJIOfyWzh8kwpQqclDt6uhXoF/v
OsO1zb/7/j+n/pDZsePqP9AyIgErsHEBgUbhecDqzjN++ITPcZjQ6TIMPglZaumN
jFAdAZuAaEwqAk8jqN2wlm689Fh9MuUEarHXbXLCqu5RgLrWhFGhp/cTWY62aqnZ
XfEeQ9KtpRZmlR/IYjerbb1eRH7ZdJsZ88WngLX9dj/JdNxHWBkWQBXGAusXk5Fk
y6LsIV3TjyBdrRKJ1Ifyg/2EIXHNBs8HxTFGXpjtp2HPuMLDxZOWOWikb9URtNg=
=Fjf4
-----END PGP SIGNATURE-----
Merge tag 'v3.16-rc7' into perf/core, to merge in the latest fixes before applying new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Hardware keeps them enabled on reset, and Linux needs to keep status quo.
Any spurious interrupts will be reported/blocked by genirq.
This helps remove a SMP IRQ quirk (next commit), where a peripheral IRQ
is hard wired to core0, and request_irq()->unmask() happens on core1,
keeping the IRQ masked on core0, needing an explicit unmask.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The current cpu-private IRQ registration is ugly as it requires need to
expose arch_unmask_irq() outside of intc code.
So switch to percpu IRQ APIs:
-request_percpu_irq [boot core]
-enable_percpu_irq [all cores]
Encapsulated in helper arc_request_percpu_irq()
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Handle it just like timer. Current request_percpu_irq() would fail on
non-boot cpus and thus IRQ will remian unmasked on those cpus.
[vgupta: fix changelong]
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This patch adds implementation of GET_THREAD_AREA ptrace request type. This
is required by GDB to debug NPTL applications.
Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Transition to using the new generic PERF_PMU_CAP_NO_INTERRUPT method for
failing a sampling event when no PMU interrupt is available.
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rob Herring <robh+dt@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1406150159280.16738@vincent-weaver-1.umelst.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Moving cache disabling to early boot
* ARC UART enabled only if earlyprintk setup in cmdline
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.14 (GNU/Linux)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=neQc
-----END PGP SIGNATURE-----
Merge tag 'arc-v3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC updates from Vineet Gupta:
"Nothing too exciting here, just minor fixes/cleanup. Only noteworthy
ones are:
- Moving cache disabling to early boot
- ARC UART enabled only if earlyprintk setup in cmdline"
* tag 'arc-v3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: Disable caches in early boot if so configured
ARC: [arcfpga] Early ARC UART to be only activated by cmdline
ARC: [arcfpga] Get rid of legacy BVCI latency unit support
ARC: remove duplicate header exports
ARC: arc_local_timer_setup() need not pass own cpu id
ARC: Fixed spelling errors within comments
ARC: make start_thread() out-of-line
ARC: fix mmuv2 warning
ARC: [SMP] ISS SMP extension bitrot
Performing vma lookups without taking the mm->mmap_sem is asking for
trouble. While doing the search, the vma in question can be modified or
even removed before returning to the caller. Take the lock (shared) in
order to avoid races while iterating through the vmacache and/or rbtree.
[akpm@linux-foundation.org: CSE current->active_mm, per Vineet]
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There was a very small race window where resume to kernel mode from a
Exception Path (or pure kernel mode which is true for most of ARC
exceptions anyways), was not disabling interrupts in restore_regs,
clobbering the exception regs
Anton found the culprit call flow (after many sleepless nights)
| 1. we got a Trap from user land
| 2. started to service it.
| 3. While doing some stuff on user-land memory (I think it is padzero()),
| we got a DataTlbMiss
| 4. On return from it we are taking "resume_kernel_mode" path
| 5. NEED_RESHED is not set, so we go to "return from exception" path in
| restore regs.
| 6. there seems to be IRQ happening
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: <stable@vger.kernel.org> #3.10, 3.12, 3.13, 3.14
Cc: Anton Kolesov <Anton.Kolesov@synopsys.com>
Cc: Francois Bedard <Francois.Bedard@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make of_get_flat_dt_prop arguments compatible with libfdt fdt_getprop
call in preparation to convert FDT code to use libfdt. Make the return
value const and the property length ptr type an int.
Signed-off-by: Rob Herring <robh@kernel.org>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Tested-by: Grant Likely <grant.likely@linaro.org>
Tested-by: Stephen Chivers <schivers@csc.com>
With commit 9df62f0544 "arch: use ASM_NL instead of ';'" the generic
macros can handle the arch specific newline quirk. Hence we can get rid
of ARC asm macros and use the "C" style macros.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* Moved cmdline copy from asm to "C" - allows for more robust checking
of pointer validity etc.
* Remove the Kconfig option to do so, base it on a runtime value passed
by u-boot
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* Don't send an IPI if receiver already has a pending IPI.
Atomically piggyback the new msg with pending msg.
* IPI receiver looping on xchg() not required
References: https://lkml.org/lkml/2013/11/25/232
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>