Commit Graph

13 Commits

Author SHA1 Message Date
Linus Torvalds
d607526296 nios2 update for v5.1-rc1
nios2: Fix update_mmu_cache preload the TLB with the new PTE
 nios2: update_mmu_cache preload the TLB with the new PTE
 nios2: User address TLB flush break after finding the matching entry
 nios2: flush_tlb_all use TLBMISC way auto-increment feature
 nios2: improve readability of tlb functions
 nios2: flush_tlb_mm flush only the pid
 nios2: flush_tlb_pid can just restore TLBMISC once
 nios2: TLBMISC writes do not require PID bits to be set
 nios2: Use an invalid TLB entry address helper function
 nios2: pte_clear does not need to flush TLB
 nios2: flush_tlb_page use PID based flush
 nios2: update_mmu_cache clear the old entry from the TLB
 nios2: remove redundant 'default n' from Kconfig-s
 nios2: ksyms: Add missing symbol exports
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Merge tag 'nios2-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2

Pull nios2 updates from Ley Foon Tan:
 "Most of updates are MMU related"

* tag 'nios2-v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan/nios2:
  nios2: Fix update_mmu_cache preload the TLB with the new PTE
  nios2: update_mmu_cache preload the TLB with the new PTE
  nios2: User address TLB flush break after finding the matching entry
  nios2: flush_tlb_all use TLBMISC way auto-increment feature
  nios2: improve readability of tlb functions
  nios2: flush_tlb_mm flush only the pid
  nios2: flush_tlb_pid can just restore TLBMISC once
  nios2: TLBMISC writes do not require PID bits to be set
  nios2: Use an invalid TLB entry address helper function
  nios2: pte_clear does not need to flush TLB
  nios2: flush_tlb_page use PID based flush
  nios2: update_mmu_cache clear the old entry from the TLB
  nios2: remove redundant 'default n' from Kconfig-s
  nios2: ksyms: Add missing symbol exports
2019-03-10 10:13:37 -07:00
Sabyasachi Gupta
9587d19924 arch/nios2/mm/fault.c: remove duplicate include
Remove linux/ptrace.h which is included more than once

Link: http://lkml.kernel.org/r/5c45d345.1c69fb81.d90ed.8e05@mx.google.com
Signed-off-by: Sabyasachi Gupta <sabyasachi.linux@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-07 18:32:03 -08:00
Nicholas Piggin
195568a10a nios2: flush_tlb_page use PID based flush
flush_tlb_page is for flushing user pages, so it should not be using
flush_tlb_one (which flushes all pages).

This patch implements it with the flush_tlb_range, which is a user
flush that does the right thing.

flush_tlb_one is made static to mm/tlb.c because it's a bit confusing.
It is used in do_page_fault to flush the kernel non-linear mappings,
so that is replaced with flush_tlb_kernel_page. The end result is that
functionality is identical.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
2019-03-07 05:29:35 +08:00
Souptick Joarder
50a7ca3c6f mm: convert return type of handle_mm_fault() caller to vm_fault_t
Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-> commit 1c8f422059 ("mm: change return type to vm_fault_t")

In this patch all the caller of handle_mm_fault() are changed to return
vm_fault_t type.

Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: David S. Miller <davem@davemloft.net>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:28 -07:00
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
Paul Gortmaker
7e227e8818 nios2: migrate exception table users off module.h and onto extable.h
This file was only including module.h for exception table related
functions.  We've now separated that content out into its own file
"extable.h" so now move over to that and avoid all the extra header
content in module.h that we don't really need to compile this file.

Reported-by: kbuild test robot <lkp@intel.com>
Cc: Ley Foon Tan <lftan@altera.com>
Reviewed-by: Tobias Klauser <tklauser@distanz.ch>
Cc: nios2-dev@lists.rocketboards.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2017-01-26 10:58:14 -05:00
Kirill A. Shutemov
dcddffd41d mm: do not pass mm_struct into handle_mm_fault
We always have vma->vm_mm around.

Link: http://lkml.kernel.org/r/1466021202-61880-8-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 16:19:19 -07:00
David Hildenbrand
70ffdb9393 mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler
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>
2015-05-19 08:39:15 +02:00
Ley Foon Tan
6347e2a10f nios2: mm: do not invoke OOM killer on kernel fault OOM
Follow commit 871341023c.

Kernel faults are expected to handle OOM conditions gracefully (gup,
uaccess etc.), so they should never invoke the OOM killer.  Reserve
this for faults triggered in user context when it is the only option.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
2015-03-16 15:35:25 +08:00
Ley Foon Tan
96f3a5cc33 nios2: Port OOM changes to do_page_fault()
Commit d065bd810b ("mm: retry page fault when blocking on disk transfer") and
and commit 37b23e0525 ("x86,mm: make pagefault killable")

The above commits introduced changes into the nios2 pagefault handler
for making the page fault handler retryable as well as killable.

These changes reduce the mmap_sem hold time, which is crucial
during OOM killer invocation.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
2015-02-09 18:11:29 +08:00
Chung-Ling Tang
a3248d609b nios2: fix unhandled signals
Follow other architectures for user fault handling.

Signed-off-by: Chung-Ling Tang <cltang@codesourcery.com>
Acked-by: Ley Foon Tan <lftan@altera.com>
2015-02-09 09:47:05 +08:00
Linus Torvalds
33692f2759 vm: add VM_FAULT_SIGSEGV handling support
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>
2015-01-29 10:51:32 -08:00
Ley Foon Tan
862674d424 nios2: MMU Fault handling
This patch adds support for the handling of the MMU faults (exception
entry code introduced by a previous patch, kernel/entry.S).

Signed-off-by: Ley Foon Tan <lftan@altera.com>
2014-12-08 12:55:52 +08:00