Commit 2ae416b142 ("mm: new mm hook framework") introduced an empty
header file (mm-arch-hooks.h) for every architecture, even those which
doesn't need to define mm hooks.
As suggested by Geert Uytterhoeven, this could be cleaned through the use
of a generic header file included via each per architecture
asm/include/Kbuild file.
The PowerPC architecture is not impacted here since this architecture has
to defined the arch_remap MM hook.
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=0BDx
-----END PGP SIGNATURE-----
Merge tag 'module_init-device_initcall-v4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
Pull module_init replacement part one from Paul Gortmaker:
"Replace module_init with equivalent device_initcall in non modules.
This series of commits converts non-modular code that is using the
module_init() call to hook itself into the system to instead use
device_initcall().
The conversion is a runtime no-op, since module_init actually becomes
__initcall in the non-modular case, and that in turn gets mapped onto
device_initcall. A couple files show a larger negative diffstat,
representing ones that had a module_exit function that we remove here
vs previously relying on the linker to dispose of it.
We make this conversion now, so that we can relocate module_init from
init.h into module.h in the future.
The files changed here are just limited to those that would otherwise
have to add module.h to obviously non-modular code, in order to avoid
a compile fail, as testing has shown"
* tag 'module_init-device_initcall-v4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
MIPS: don't use module_init in non-modular cobalt/mtd.c file
drivers/leds: don't use module_init in non-modular leds-cobalt-raq.c
cris: don't use module_init for non-modular core eeprom.c code
tty/metag_da: Avoid module_init/module_exit in non-modular code
drivers/clk: don't use module_init in clk-nomadik.c which is non-modular
xtensa: don't use module_init for non-modular core network.c code
sh: don't use module_init in non-modular psw.c code
mn10300: don't use module_init in non-modular flash.c code
parisc64: don't use module_init for non-modular core perf code
parisc: don't use module_init for non-modular core pdc_cons code
cris: don't use module_init for non-modular core intmem.c code
ia64: don't use module_init in non-modular sim/simscsi.c code
ia64: don't use module_init for non-modular core kernel/mca.c code
arm: don't use module_init in non-modular mach-vexpress/spc.c code
powerpc: don't use module_init in non-modular 83xx suspend code
powerpc: use device_initcall for registering rtc devices
x86: don't use module_init in non-modular devicetree.c code
x86: don't use module_init in non-modular intel_mid_vrtc.c
Pull asm/scatterlist.h removal from Jens Axboe:
"We don't have any specific arch scatterlist anymore, since parisc
finally switched over. Kill the include"
* 'for-4.2/sg' of git://git.kernel.dk/linux-block:
remove scatterlist.h generation from arch Kbuild files
remove <asm/scatterlist.h>
CRIU is recreating the process memory layout by remapping the checkpointee
memory area on top of the current process (criu). This includes remapping
the vDSO to the place it has at checkpoint time.
However some architectures like powerpc are keeping a reference to the
vDSO base address to build the signal return stack frame by calling the
vDSO sigreturn service. So once the vDSO has been moved, this reference
is no more valid and the signal frame built later are not usable.
This patch serie is introducing a new mm hook framework, and a new
arch_remap hook which is called when mremap is done and the mm lock still
hold. The next patch is adding the vDSO remap and unmap tracking to the
powerpc architecture.
This patch (of 3):
This patch introduces a new set of header file to manage mm hooks:
- per architecture empty header file (arch/x/include/asm/mm-arch-hooks.h)
- a generic header (include/linux/mm-arch-hooks.h)
The architecture which need to overwrite a hook as to redefine it in its
header file, while architecture which doesn't need have nothing to do.
The default hooks are defined in the generic header and are used in the
case the architecture is not defining it.
In a next step, mm hooks defined in include/asm-generic/mm_hooks.h should
be moved here.
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The eeprom.c code is compiled based on the Kconfig setting
ETRAX_I2C_EEPROM, which is bool. So the code is either built in
or absent. It will never be modular, so using module_init as an
alias for __initcall is rather misleading.
Fix this up now, so that we can relocate module_init from
init.h into module.h in the future. If we don't do this, we'd
have to add module.h to obviously non-modular code, and that
would be a worse thing.
Direct use of __initcall is discouraged, vs prioritized ones.
Use of device_initcall is consistent with what __initcall
maps onto, and hence does not change the init order, making the
impact of this change zero. Should someone with real hardware
for boot testing want to change it later to arch_initcall or
something different, they can do that at a later date.
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: linux-cris-kernel@axis.com
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The intmem.c code is always built in. It will never be modular,
so using module_init as an alias for __initcall is rather
misleading.
Fix this up now, so that we can relocate module_init from
init.h into module.h in the future. If we don't do this, we'd
have to add module.h to obviously non-modular code, and that
would be a worse thing.
Direct use of __initcall is discouraged, vs prioritized ones.
Use of device_initcall is consistent with what __initcall
maps onto, and hence does not change the init order, making the
impact of this change zero. Should someone with real hardware
for boot testing want to change it later to arch_initcall or
something different, they can do that at a later date.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: linux-cris-kernel@axis.com
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Introduce faulthandler_disabled() and use it to check for irq context and
disabled pagefaults (via pagefault_disable()) in the pagefault handlers.
Please note that we keep the in_atomic() checks in place - to detect
whether in irq context (in which case preemption is always properly
disabled).
In contrast, preempt_disable() should never be used to disable pagefaults.
With !CONFIG_PREEMPT_COUNT, preempt_disable() doesn't modify the preempt
counter, and therefore the result of in_atomic() differs.
We validate that condition by using might_fault() checks when calling
might_sleep().
Therefore, add a comment to faulthandler_disabled(), describing why this
is needed.
faulthandler_disabled() and pagefault_disable() are defined in
linux/uaccess.h, so let's properly add that include to all relevant files.
This patch is based on a patch from Thomas Gleixner.
Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Link: http://lkml.kernel.org/r/1431359540-32227-7-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We don't have any arch specific scatterlist now that parisc switched over
to the generic one.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
iEYEABECAAYFAlU70nMACgkQ31LbvUHyf1cYgwCfSmPhyLFmr0pGM/BxsVY7K1v6
PaEAn2+7xfZV38E6hwrGMrT42ZvKyL6r
=LHQU
-----END PGP SIGNATURE-----
Merge tag 'cris-for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris
Pull arch/cris updates from Jesper Nilsson:
"Some much needed love for the CRIS-port.
There's a bunch of changes this time, giving the CRISv32 port a bit of
modern makeover with device-tree, irq domain and gpiolib support, and
more switchover to generic frameworks.
Some small fixes and removal of the theoretical SMP support brings up
the rear"
* tag 'cris-for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris:
cris: fix integer overflow in ELF_ET_DYN_BASE
CRISv32: use GENERIC_SCHED_CLOCK
CRISv32: use MMIO clocksource
CRISv32: use generic clockevents
CRIS: use generic headers via Kbuild
CRIS: use generic cmpxchg.h
CRIS: use generic atomic.h
CRIS: use generic atomic bitops
CRISv10: remove redundant macros from system.h
CRIS: remove SMP code
CRISv32: don't enable irqs in INIT_THREAD
CRISv32: handle multiple signals
CRISv32: prevent bogus restarts on sigreturn
CRISv32: don't attempt syscall restart on irq exit
Add binding documentation for CRIS
CRIS: add Axis 88 board device tree
CRISv32: add device tree support
CRISv32: add irq domains support
CRIS: enable GPIOLIB
Merge second patchbomb from Andrew Morton:
- the rest of MM
- various misc bits
- add ability to run /sbin/reboot at reboot time
- printk/vsprintf changes
- fiddle with seq_printf() return value
* akpm: (114 commits)
parisc: remove use of seq_printf return value
lru_cache: remove use of seq_printf return value
tracing: remove use of seq_printf return value
cgroup: remove use of seq_printf return value
proc: remove use of seq_printf return value
s390: remove use of seq_printf return value
cris fasttimer: remove use of seq_printf return value
cris: remove use of seq_printf return value
openrisc: remove use of seq_printf return value
ARM: plat-pxa: remove use of seq_printf return value
nios2: cpuinfo: remove use of seq_printf return value
microblaze: mb: remove use of seq_printf return value
ipc: remove use of seq_printf return value
rtc: remove use of seq_printf return value
power: wakeup: remove use of seq_printf return value
x86: mtrr: if: remove use of seq_printf return value
linux/bitmap.h: improve BITMAP_{LAST,FIRST}_WORD_MASK
MAINTAINERS: CREDITS: remove Stefano Brivio from B43
.mailmap: add Ricardo Ribalda
CREDITS: add Ricardo Ribalda Delgado
...
The seq_printf return value, because it's frequently misused,
will eventually be converted to void.
See: commit 1f33c41c03 ("seq_file: Rename seq_overflow() to
seq_has_overflowed() and make public")
Miscellanea:
o Coalesce formats, realign arguments
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The seq_printf return value, because it's frequently misused,
will eventually be converted to void.
See: commit 1f33c41c03 ("seq_file: Rename seq_overflow() to
seq_has_overflowed() and make public")
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Almost all arches define ELF_ET_DYN_BASE as 2/3 of TASK_SIZE.
Though it seems that some architectures do this in a wrong way.
The problem is that 2*TASK_SIZE may overflow 32-bits so
the real ELF_ET_DYN_BASE becomes wrong.
Fix this overflow by dividing TASK_SIZE prior to multiplying:
(TASK_SIZE / 3 * 2)
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
Provide a fast sched clock using the free-running timer and the generic
sched_clock infrastructure.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
Use a generic MMIO clocksource and get rid of some lines of code.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
Implement a oneshot-capable clockevents device so we get support for
things like hrtimers and NOHZ.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
Delete headers which do nothing but include the asm-generic versions and
use Kbuild magic instead.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
The generic atomic bitops are the same as the CRIS-specific ones.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
All of these are either unused or already provided by other headers, so
they can be removed.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
The CRIS SMP code cannot be built since there is no (and appears to
never have been) a CONFIG_SMP Kconfig option in arch/cris/. Remove it.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
INIT_THREAD enables interrupts in the thread_struct's saved flags. This
means that interrupts get enabled in the middle of context_switch()
while switching to new tasks that get forked off the init task during
boot. Don't do this.
Fixes the following splat on boot with spinlock debugging on:
BUG: spinlock cpu recursion on CPU#0, swapper/2
lock: runqueues+0x0/0x47c, .magic: dead4ead, .owner: swapper/0,
.owner_cpu: 0
CPU: 0 PID: 2 Comm: swapper Not tainted 3.19.0-08796-ga747b55 #285
Call Trace:
[<c0032b80>] spin_bug+0x2a/0x36
[<c0032c98>] do_raw_spin_lock+0xa2/0x126
[<c01964b0>] _raw_spin_lock+0x20/0x2a
[<c00286c8>] scheduler_tick+0x22/0x76
[<c003db2c>] update_process_times+0x5e/0x72
[<c0007a94>] timer_interrupt+0x4e/0x6a
[<c00378d6>] handle_irq_event_percpu+0x54/0xf2
[<c00379c4>] handle_irq_event+0x50/0x74
[<c003988e>] handle_simple_irq+0x6c/0xbe
[<c0037270>] generic_handle_irq+0x2a/0x36
[<c0004c40>] do_IRQ+0x38/0x84
[<c000662e>] crisv32_do_IRQ+0x54/0x60
[<c0006204>] IRQ0x4b_interrupt+0x34/0x3c
[<c0192baa>] __schedule+0x24a/0x532
[<c00056b4>] ret_from_kernel_thread+0x0/0x14
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
Al Viro noted that CRIS fails to handle multiple signals.
This fixes the problem for CRISv32 by making it use a C work_pending
handling loop similar to the ARM implementation in 0a267fa6a1
("ARM: 7472/1: pull all work_pending logics into C function").
This also happens to fixes the warnings which currently trigger on
CRISv32 due to do_signal() being called with interrupts disabled.
Test case (should die of the SIGSEGV which gets raised when setting up
the stack for SIGALRM, but instead reaches and executes the _exit(1)):
#include <unistd.h>
#include <signal.h>
#include <sys/time.h>
#include <err.h>
static void handler(int sig) { }
int main(int argc, char *argv[])
{
int ret;
struct itimerval t1 = { .it_value = {1} };
stack_t ss = {
.ss_sp = NULL,
.ss_size = SIGSTKSZ,
};
struct sigaction action = {
.sa_handler = handler,
.sa_flags = SA_ONSTACK,
};
ret = sigaltstack(&ss, NULL);
if (ret < 0)
err(1, "sigaltstack");
sigaction(SIGALRM, &action, NULL);
setitimer(ITIMER_REAL, &t1, NULL);
pause();
_exit(1);
return 0;
}
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Link: http://lkml.kernel.org/r/20121208074429.GC4939@ZenIV.linux.org.uk
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
Al Viro noted that CRIS is vulnerable to bogus restarts on sigreturn.
The fixes CRISv32 by using regs->exs as an additional indicator to
whether we should attempt to restart the syscall or not. EXS is only
used in the sigtrap handling, and in that path we already have r9 (the
other indicator, which indicates if we're in a syscall or not) cleared.
Test case, a port of Al's ARM version from 653d48b221 ("arm: fix
really nasty sigreturn bug"):
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <sys/time.h>
#include <errno.h>
void f(int n)
{
register int r10 asm ("r10") = n;
__asm__ __volatile__(
"ba 1f \n"
"nop \n"
"break 8 \n"
"1: ba . \n"
"nop \n"
:
: "r" (r10)
: "memory");
}
void handler1(int sig) { }
void handler2(int sig) { raise(1); }
void handler3(int sig) { exit(0); }
int main(int argc, char *argv[])
{
struct sigaction s = {.sa_handler = handler2};
struct itimerval t1 = { .it_value = {1} };
struct itimerval t2 = { .it_value = {2} };
signal(1, handler1);
sigemptyset(&s.sa_mask);
sigaddset(&s.sa_mask, 1);
sigaction(SIGALRM, &s, NULL);
signal(SIGVTALRM, handler3);
setitimer(ITIMER_REAL, &t1, NULL);
setitimer(ITIMER_VIRTUAL, &t2, NULL);
f(-513); /* -ERESTARTNOINTR */
return 0;
}
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Link: http://lkml.kernel.org/r/20121208074429.GC4939@ZenIV.linux.org.uk
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
r9 is used to determine whether syscall restarting must be performed or
not. Unfortunately, r9 is never set to zero in the non-syscall path,
and r9 is on top of that a callee-saved register which can be set to
non-zero by the C functions that are called during IRQ handling.
This means that if r10 (used for the syscall return value) is one of the
-ERESTART* values when a hardware interrupt occurs which leads to a
signal being delivered to the process, the kernel will "restart" a
syscall which never occurred. This will lead to the PC being moved back
by 2 on return to user space.
Fix the problem by setting r9 to zero in the interrupt path.
Test case (should loop forever but ends up executing the break 8 trap
instruction):
#include <signal.h>
#include <stdlib.h>
#include <sys/time.h>
void f(int n)
{
register int r9 asm ("r9") = 1;
register int r10 asm ("r10") = n;
__asm__ __volatile__(
"ba 1f \n"
"nop \n"
"break 8 \n"
"1: ba . \n"
"nop \n"
:
: "r" (r9), "r" (r10)
: "memory");
}
void handler1(int sig) { }
int main(int argc, char *argv[])
{
struct itimerval t1 = { .it_value = {1} };
signal(SIGALRM, handler1);
setitimer(ITIMER_REAL, &t1, NULL);
f(-513); /* -ERESTARTNOINTR */
return 0;
}
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
Add a minimal device tree for the ETRAX FS SoC and the Axis 88 developer
board.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
Add support for booting CRISv32 with a built-in device tree.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Add support for IRQ domains to the CRISv32 interrupt controller.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Enable GPIOLIB on CRIS so that we can use the generic GPIO APIs.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
While working on arch/cris/include/asm/uaccess.h, I noticed
that some macros within this header are made harder to read because they
violate a coding style rule: space is missing after comma.
Fix it up.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
virtio wants to read bitwise types from userspace using get_user. At the
moment this triggers sparse errors, since the value is passed through an
integer.
Fix that up using __force.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
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>
LKP has triggered a compiler warning after my recent patch "mm: account
pmd page tables to the process":
mm/mmap.c: In function 'exit_mmap':
>> mm/mmap.c:2857:2: warning: right shift count >= width of type [enabled by default]
The code:
> 2857 WARN_ON(mm_nr_pmds(mm) >
2858 round_up(FIRST_USER_ADDRESS, PUD_SIZE) >> PUD_SHIFT);
In this, on tile, we have FIRST_USER_ADDRESS defined as 0. round_up() has
the same type -- int. PUD_SHIFT.
I think the best way to fix it is to define FIRST_USER_ADDRESS as unsigned
long. On every arch for consistency.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.
That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works. However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.
In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV. And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.
However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d45 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space. And user space really
expected SIGSEGV, not SIGBUS.
To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it. They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.
This is the mindless minimal patch to do this. A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.
Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.
Reported-and-tested-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The time Kconfig expects that NR_CPUS is defined.
This patch removes this config warning:
"kernel/time/Kconfig:163:warning: range is invalid"
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Avoids the warning about:
warning: 'bite_in_progress' defined but not used [-Wunused-variable]
Variable is only used if the Kconfig CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
is set.
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Move declaration of waitqueue to beginning of block,
avoids warning about mixing declarations and code.
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Allows that symbol to be used in modules, and fixes
the following on allmodconfig:
ERROR: "csum_partial_copy_nocheck" [net/ipv6/ipv6.ko] undefined!
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Pull vfs fixes from Al Viro:
"A couple of fixes - deadlock in CIFS and build breakage in cris serial
driver (resurfaced f_dentry in there)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
VFS: Convert file->f_dentry->d_inode to file_inode()
fix deadlock in cifs_ioctl_clone()
Convert file->f_dentry->d_inode to file_inode() so as to get layered
filesystems right.
Found with: git grep '[.>]f_dentry'
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Nothing needs the module pointer any more, and the next patch will
call it from RCU, where the module itself might no longer exist.
Removing the arg is the safest approach.
This just codifies the use of the module_alloc/module_free pattern
which ftrace and bpf use.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: x86@kernel.org
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: linux-cris-kernel@axis.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: nios2-dev@lists.rocketboards.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Cc: netdev@vger.kernel.org
Laurent Dufour