Commit Graph

558 Commits

Author SHA1 Message Date
Helge Deller
e3d2adaaf9 parisc/mm: Ensure IRQs are off in switch_mm()
commit 649aa24254 upstream.

This is because of commit f98db6013c ("sched/core: Add switch_mm_irqs_off()
and use it in the scheduler") in which switch_mm_irqs_off() is called by the
scheduler, vs switch_mm() which is used by use_mm().

This patch lets the parisc code mirror the x86 and powerpc code, ie. it
disables interrupts in switch_mm(), and optimises the scheduler case by
defining switch_mm_irqs_off().

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21 07:42:20 +02:00
Thomas Bogendoerfer
8ed89cfc86 parisc: DMA API: return error instead of BUG_ON for dma ops on non dma devs
commit 33f9e02495 upstream.

Enabling parport pc driver on a B2600 (and probably other 64bit PARISC
systems) produced following BUG:

CPU: 0 PID: 1 Comm: swapper Not tainted 4.12.0-rc5-30198-g1132d5e #156
task: 000000009e050000 task.stack: 000000009e04c000

     YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001101111111100001111 Not tainted
r00-03  000000ff0806ff0f 000000009e04c990 0000000040871b78 000000009e04cac0
r04-07  0000000040c14de0 ffffffffffffffff 000000009e07f098 000000009d82d200
r08-11  000000009d82d210 0000000000000378 0000000000000000 0000000040c345e0
r12-15  0000000000000005 0000000040c345e0 0000000000000000 0000000040c9d5e0
r16-19  0000000040c345e0 00000000f00001c4 00000000f00001bc 0000000000000061
r20-23  000000009e04ce28 0000000000000010 0000000000000010 0000000040b89e40
r24-27  0000000000000003 0000000000ffffff 000000009d82d210 0000000040c14de0
r28-31  0000000000000000 000000009e04ca90 000000009e04cb40 0000000000000000
sr00-03  0000000000000000 0000000000000000 0000000000000000 0000000000000000
sr04-07  0000000000000000 0000000000000000 0000000000000000 0000000000000000

IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000404aece0 00000000404aece4
 IIR: 03ffe01f    ISR: 0000000010340000  IOR: 000001781304cac8
 CPU:        0   CR30: 000000009e04c000 CR31: 00000000e2976de2
 ORIG_R28: 0000000000000200
 IAOQ[0]: sba_dma_supported+0x80/0xd0
 IAOQ[1]: sba_dma_supported+0x84/0xd0
 RP(r2): parport_pc_probe_port+0x178/0x1200

Cause is a call to dma_coerce_mask_and_coherenet in parport_pc_probe_port,
which PARISC DMA API doesn't handle very nicely. This commit gives back
DMA_ERROR_CODE for DMA API calls, if device isn't capable of DMA
transaction.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21 07:42:20 +02:00
Helge Deller
a28acecbaf parisc: Fix get_user() for 64-bit value on 32-bit kernel
commit 3f795cef0e upstream.

This fixes a bug in which the upper 32-bits of a 64-bit value which is
read by get_user() was lost on a 32-bit kernel.
While touching this code, split out pre-loading of %sr2 space register
and clean up code indent.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-21 09:31:23 +02:00
Helge Deller
09b931fcb8 parisc: Clean up fixup routines for get_user()/put_user()
commit d19f5e41b3 upstream.

Al Viro noticed that userspace accesses via get_user()/put_user() can be
simplified a lot with regard to usage of the exception handling.

This patch implements a fixup routine for get_user() and put_user() in such
that the exception handler will automatically load -EFAULT into the register
%r8 (the error value) in case on a fault on userspace.  Additionally the fixup
routine will zero the target register on fault in case of a get_user() call.
The target register is extracted out of the faulting assembly instruction.

This patch brings a few benefits over the old implementation:
1. Exception handling gets much cleaner, easier and smaller in size.
2. Helper functions like fixup_get_user_skip_1 (all of fixup.S) can be dropped.
3. No need to hardcode %r9 as target register for get_user() any longer. This
   helps the compiler register allocator and thus creates less assembler
   statements.
4. No dependency on the exception_data contents any longer.
5. Nested faults will be handled cleanly.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 09:30:34 +02:00
John David Anglin
a690a42ae7 parisc: Optimize flush_kernel_vmap_range and invalidate_kernel_vmap_range
commit 316ec0624f upstream.

The previously submitted patch did not resolve the random segmentation
faults observed on the phantom buildd system.  There are still
unresolved problems with the Debian 4.8 and 4.9 kernels on C8000.

The attached patch removes the flush of the offset map pages and does a
whole data cache flush for large ranges.  No other arch flushes the
offset map in these routines as far as I can tell.

I have not observed any random segmentation faults on rp3440 in two
weeks of testing with 4.10.0 and 4.10.1.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-26 13:05:57 +02:00
Helge Deller
2b95f1210e parisc: Don't use BITS_PER_LONG in userspace-exported swab.h header
commit 2ad5d52d42 upstream.

In swab.h the "#if BITS_PER_LONG > 32" breaks compiling userspace programs if
BITS_PER_LONG is #defined by userspace with the sizeof() compiler builtin.

Solve this problem by using __BITS_PER_LONG instead.  Since we now
#include asm/bitsperlong.h avoid further potential userspace pollution
by moving the #define of SHIFT_PER_LONG to bitops.h which is not
exported to userspace.

This patch unbreaks compiling qemu on hppa/parisc.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-01 08:33:08 +01:00
John David Anglin
c78e710c1c parisc: Purge TLB before setting PTE
The attached change interchanges the order of purging the TLB and
setting the corresponding page table entry.  TLB purges are strongly
ordered.  It occurred to me one night that setting the PTE first might
have subtle ordering issues on SMP machines and cause random memory
corruption.

A TLB lock guards the insertion of user TLB entries.  So after the TLB
is purged, a new entry can't be inserted until the lock is released.
This ensures that the new PTE value is used when the lock is released.

Since making this change, no random segmentation faults have been
observed on the Debian hppa buildd servers.

Signed-off-by: John David Anglin  <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: Helge Deller <deller@gmx.de>
2016-12-07 08:56:40 +01:00
Helge Deller
18088db042 parisc: Ignore the pkey system calls for now
Signed-off-by: Helge Deller <deller@gmx.de>
2016-11-02 23:07:14 +01:00
Linus Torvalds
1573d2caf7 Merge branch 'parisc-4.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc fixes from Helge Deller:
 "Some final updates and fixes for this merge window for the parisc
  architecture. Changes include:

   - Fix boot problems with new memblock allocator on rp3410 machine

   - Increase initial kernel mapping size for 32- and 64-bit kernels,
     this allows to boot bigger kernels which have many modules built-in

   - Fix kernel layout regarding __gp and move exception table into RO
     section

   - Show trap names in crashes, use extable.h header instead of
     module.h"

* 'parisc-4.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Show trap name in kernel crash
  parisc: Zero-initialize newly alloced memblock
  parisc: Move exception table into read-only section
  parisc: Fix kernel memory layout regarding position of __gp
  parisc: Increase initial kernel mapping size
  parisc: Migrate exception table users off module.h and onto extable.h
2016-10-11 23:59:07 -07:00
Helge Deller
0a862485f4 parisc: Show trap name in kernel crash
Show the real trap name when the kernel crashes.

Signed-off-by: Helge Deller <deller@gmx.de>
2016-10-11 20:52:47 +02:00
Linus Torvalds
93c26d7dc0 Merge branch 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull protection keys syscall interface from Thomas Gleixner:
 "This is the final step of Protection Keys support which adds the
  syscalls so user space can actually allocate keys and protect memory
  areas with them. Details and usage examples can be found in the
  documentation.

  The mm side of this has been acked by Mel"

* 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/pkeys: Update documentation
  x86/mm/pkeys: Do not skip PKRU register if debug registers are not used
  x86/pkeys: Fix pkeys build breakage for some non-x86 arches
  x86/pkeys: Add self-tests
  x86/pkeys: Allow configuration of init_pkru
  x86/pkeys: Default to a restrictive init PKRU
  pkeys: Add details of system call use to Documentation/
  generic syscalls: Wire up memory protection keys syscalls
  x86: Wire up protection keys system calls
  x86/pkeys: Allocation/free syscalls
  x86/pkeys: Make mprotect_key() mask off additional vm_flags
  mm: Implement new pkey_mprotect() system call
  x86/pkeys: Add fault handling for PF_PK page fault bit
2016-10-10 11:01:51 -07:00
Helge Deller
65bf34f595 parisc: Increase initial kernel mapping size
Increase the initial kernel default page mapping size for 64-bit kernels to
64 MB and for 32-bit kernels to 32 MB.

Due to the additional support of ftrace, tracepoint and huge pages the kernel
size can exceed the sizes we used up to now.

Cc: stable@vger.kernel.org # 4.4+
Signed-off-by: Helge Deller <deller@gmx.de>
2016-10-09 09:57:54 +02:00
Helge Deller
690d097c00 parisc: Increase KERNEL_INITIAL_SIZE for 32-bit SMP kernels
Increase the initial kernel default page mapping size for SMP kernels to 32MB
and add a runtime check which panics early if the kernel is bigger than the
initial mapping size.

This fixes boot crashes of 32bit SMP kernels. Due to the introduction of huge
page support in kernel 4.4 and it's required initial kernel layout in memory, a
32bit SMP kernel usually got bigger (in layout, not size) than 16MB.

Cc: stable@vger.kernel.org #4.4+
Signed-off-by: Helge Deller <deller@gmx.de>
2016-10-07 18:23:43 +02:00
Helge Deller
9e91db6b4a parisc: Add hardened usercopy feature
Add hardened usercopy checks to parisc architecture and clean up
indenting.

Signed-off-by: Helge Deller <deller@gmx.de>
2016-10-06 22:10:19 +02:00
Helge Deller
f39cce654f parisc: Add cfi_startproc and cfi_endproc to assembly code
Add ENTRY_CFI() and ENDPROC_CFI() macros for dwarf debug info and
convert assembly users to new macros.

Signed-off-by: Helge Deller <deller@gmx.de>
2016-10-05 22:54:40 +02:00
Linus Torvalds
77e5bdf9f7 Merge branch 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull uaccess fixes from Al Viro:
 "Fixes for broken uaccess primitives - mostly lack of proper zeroing
  in copy_from_user()/get_user()/__get_user(), but for several
  architectures there's more (broken clear_user() on frv and
  strncpy_from_user() on hexagon)"

* 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
  avr32: fix copy_from_user()
  microblaze: fix __get_user()
  microblaze: fix copy_from_user()
  m32r: fix __get_user()
  blackfin: fix copy_from_user()
  sparc32: fix copy_from_user()
  sh: fix copy_from_user()
  sh64: failing __get_user() should zero
  score: fix copy_from_user() and friends
  score: fix __get_user/get_user
  s390: get_user() should zero on failure
  ppc32: fix copy_from_user()
  parisc: fix copy_from_user()
  openrisc: fix copy_from_user()
  nios2: fix __get_user()
  nios2: copy_from_user() should zero the tail of destination
  mn10300: copy_from_user() should zero on access_ok() failure...
  mn10300: failing __get_user() and get_user() should zero
  mips: copy_from_user() must zero the destination on access_ok() failure
  ARC: uaccess: get_user to zero out dest in cause of fault
  ...
2016-09-14 09:35:05 -07:00
Al Viro
aace880fee parisc: fix copy_from_user()
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-13 17:49:44 -04:00
Dave Hansen
e8c24d3a23 x86/pkeys: Allocation/free syscalls
This patch adds two new system calls:

	int pkey_alloc(unsigned long flags, unsigned long init_access_rights)
	int pkey_free(int pkey);

These implement an "allocator" for the protection keys
themselves, which can be thought of as analogous to the allocator
that the kernel has for file descriptors.  The kernel tracks
which numbers are in use, and only allows operations on keys that
are valid.  A key which was not obtained by pkey_alloc() may not,
for instance, be passed to pkey_mprotect().

These system calls are also very important given the kernel's use
of pkeys to implement execute-only support.  These help ensure
that userspace can never assume that it has control of a key
unless it first asks the kernel.  The kernel does not promise to
preserve PKRU (right register) contents except for allocated
pkeys.

The 'init_access_rights' argument to pkey_alloc() specifies the
rights that will be established for the returned pkey.  For
instance:

	pkey = pkey_alloc(flags, PKEY_DENY_WRITE);

will allocate 'pkey', but also sets the bits in PKRU[1] such that
writing to 'pkey' is already denied.

The kernel does not prevent pkey_free() from successfully freeing
in-use pkeys (those still assigned to a memory range by
pkey_mprotect()).  It would be expensive to implement the checks
for this, so we instead say, "Just don't do it" since sane
software will never do it anyway.

Any piece of userspace calling pkey_alloc() needs to be prepared
for it to fail.  Why?  pkey_alloc() returns the same error code
(ENOSPC) when there are no pkeys and when pkeys are unsupported.
They can be unsupported for a whole host of reasons, so apps must
be prepared for this.  Also, libraries or LD_PRELOADs might steal
keys before an application gets access to them.

This allocation mechanism could be implemented in userspace.
Even if we did it in userspace, we would still need additional
user/kernel interfaces to tell userspace which keys are being
used by the kernel internally (such as for execute-only
mappings).  Having the kernel provide this facility completely
removes the need for these additional interfaces, or having an
implementation of this in userspace at all.

Note that we have to make changes to all of the architectures
that do not use mman-common.h because we use the new
PKEY_DENY_ACCESS/WRITE macros in arch-independent code.

1. PKRU is the Protection Key Rights User register.  It is a
   usermode-accessible register that controls whether writes
   and/or access to each individual pkey is allowed or denied.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: arnd@arndb.de
Cc: linux-api@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: luto@kernel.org
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/20160729163015.444FE75F@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-09 13:02:27 +02:00
Josh Poimboeuf
0d025d271e mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
There are three usercopy warnings which are currently being silenced for
gcc 4.6 and newer:

1) "copy_from_user() buffer size is too small" compile warning/error

   This is a static warning which happens when object size and copy size
   are both const, and copy size > object size.  I didn't see any false
   positives for this one.  So the function warning attribute seems to
   be working fine here.

   Note this scenario is always a bug and so I think it should be
   changed to *always* be an error, regardless of
   CONFIG_DEBUG_STRICT_USER_COPY_CHECKS.

2) "copy_from_user() buffer size is not provably correct" compile warning

   This is another static warning which happens when I enable
   __compiletime_object_size() for new compilers (and
   CONFIG_DEBUG_STRICT_USER_COPY_CHECKS).  It happens when object size
   is const, but copy size is *not*.  In this case there's no way to
   compare the two at build time, so it gives the warning.  (Note the
   warning is a byproduct of the fact that gcc has no way of knowing
   whether the overflow function will be called, so the call isn't dead
   code and the warning attribute is activated.)

   So this warning seems to only indicate "this is an unusual pattern,
   maybe you should check it out" rather than "this is a bug".

   I get 102(!) of these warnings with allyesconfig and the
   __compiletime_object_size() gcc check removed.  I don't know if there
   are any real bugs hiding in there, but from looking at a small
   sample, I didn't see any.  According to Kees, it does sometimes find
   real bugs.  But the false positive rate seems high.

3) "Buffer overflow detected" runtime warning

   This is a runtime warning where object size is const, and copy size >
   object size.

All three warnings (both static and runtime) were completely disabled
for gcc 4.6 with the following commit:

  2fb0815c9e ("gcc4: disable __compiletime_object_size for GCC 4.6+")

That commit mistakenly assumed that the false positives were caused by a
gcc bug in __compiletime_object_size().  But in fact,
__compiletime_object_size() seems to be working fine.  The false
positives were instead triggered by #2 above.  (Though I don't have an
explanation for why the warnings supposedly only started showing up in
gcc 4.6.)

So remove warning #2 to get rid of all the false positives, and re-enable
warnings #1 and #3 by reverting the above commit.

Furthermore, since #1 is a real bug which is detected at compile time,
upgrade it to always be an error.

Having done all that, CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is no longer
needed.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-30 10:10:21 -07:00
Helge Deller
3eb53b20d7 parisc: Fix order of EREFUSED define in errno.h
When building gccgo in userspace, errno.h gets parsed and the go include file
sysinfo.go is generated.

Since EREFUSED is defined to the same value as ECONNREFUSED, and ECONNREFUSED
is defined later on in errno.h, this leads to go complaining that EREFUSED
isn't defined yet.

Fix this trivial problem by moving the define of EREFUSED down after
ECONNREFUSED in errno.h (and clean up the indenting while touching this line).

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
2016-08-20 13:33:53 +02:00
Linus Torvalds
6c84239d59 Merge tag 'rtc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC updates from Alexandre Belloni:
 "RTC for 4.8

  Cleanups:
   - huge cleanup of rtc-generic and char/genrtc this allowed to cleanup
     rtc-cmos, rtc-sh, rtc-m68k, rtc-powerpc and rtc-parisc
   - move mn10300 to rtc-cmos

  Subsystem:
   - fix wakealarms after hibernate
   - multiples fixes for rctest
   - simplify implementations of .read_alarm

  New drivers:
   - Maxim MAX6916

  Drivers:
   - ds1307: fix weekday
   - m41t80: add wakeup support
   - pcf85063: add support for PCF85063A variant
   - rv8803: extend i2c fix and other fixes
   - s35390a: fix alarm reading, this fixes instant reboot after
     shutdown for QNAP TS-41x
   - s3c: clock fixes"

* tag 'rtc-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (65 commits)
  rtc: rv8803: Clear V1F when setting the time
  rtc: rv8803: Stop the clock while setting the time
  rtc: rv8803: Always apply the I²C workaround
  rtc: rv8803: Fix read day of week
  rtc: rv8803: Remove the check for valid time
  rtc: rv8803: Kconfig: Indicate rx8900 support
  rtc: asm9260: remove .owner field for driver
  rtc: at91sam9: Fix missing spin_lock_init()
  rtc: m41t80: add suspend handlers for alarm IRQ
  rtc: m41t80: make it a real error message
  rtc: pcf85063: Add support for the PCF85063A device
  rtc: pcf85063: fix year range
  rtc: hym8563: in .read_alarm set .tm_sec to 0 to signal minute accuracy
  rtc: explicitly set tm_sec = 0 for drivers with minute accurancy
  rtc: s3c: Add s3c_rtc_{enable/disable}_clk in s3c_rtc_setfreq()
  rtc: s3c: Remove unnecessary call to disable already disabled clock
  rtc: abx80x: use devm_add_action_or_reset()
  rtc: m41t80: use devm_add_action_or_reset()
  rtc: fix a typo and reduce three empty lines to one
  rtc: s35390a: improve two comments in .set_alarm
  ...
2016-08-05 09:48:22 -04:00
Linus Torvalds
b067c9045a Merge branch 'parisc-4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc updates from Helge Deller:

 - added an optimized hash implementation for parisc (George Spelvin)

 - C99 style cleanups in iomap.c (Amitoj Kaur Chawla)

 - added breaks to switch statement in PDC function (noticed by Dan
   Carpenter)

* 'parisc-4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Change structure intialisation to C99 style in iomap.c
  parisc: Add break statements to pdc_pat_io_pci_cfg_read()
  parisc: Add <asm/hash.h>
2016-08-04 18:31:14 -04:00
George Spelvin
773e1c5fa4 parisc: Add <asm/hash.h>
PA-RISC is interesting; integer multiplies are implemented in the
FPU, so are painful in the kernel.  But it tries to be friendly to
shift-and-add sequences for constant multiplies.

__hash_32 is implemented using the same shift-and-add sequence as
Microblaze, just scheduled for the PA7100.  (It's 2-way superscalar
but in-order, like the Pentium.)

hash_64 was tricky, but a suggestion from Jason Thong allowed a
good solution by breaking up the multiplier.  After a lot of manual
optimization, I found a 19-instruction sequence for the multiply that
can be executed in 10 cycles using only 4 temporaries.

(The PA8xxx can issue 4 instructions per cycle, but 2 must be ALU ops
and 2 must be loads/stores.  And the final add can't be paired.)

An alternative considered, but ultimately not used, was Thomas Wang's
64-to-32-bit integer hash.  At 12 instructions, it's smaller, but they're
all sequentially dependent, so it has longer latency.

https://web.archive.org/web/2011/http://www.concentric.net/~Ttwang/tech/inthash.htm
http://burtleburtle.net/bob/hash/integer.html

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
2016-08-02 16:44:29 +02:00
Linus Torvalds
c86ad14d30 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
 "The locking tree was busier in this cycle than the usual pattern - a
  couple of major projects happened to coincide.

  The main changes are:

   - implement the atomic_fetch_{add,sub,and,or,xor}() API natively
     across all SMP architectures (Peter Zijlstra)

   - add atomic_fetch_{inc/dec}() as well, using the generic primitives
     (Davidlohr Bueso)

   - optimize various aspects of rwsems (Jason Low, Davidlohr Bueso,
     Waiman Long)

   - optimize smp_cond_load_acquire() on arm64 and implement LSE based
     atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
     on arm64 (Will Deacon)

   - introduce smp_acquire__after_ctrl_dep() and fix various barrier
     mis-uses and bugs (Peter Zijlstra)

   - after discovering ancient spin_unlock_wait() barrier bugs in its
     implementation and usage, strengthen its semantics and update/fix
     usage sites (Peter Zijlstra)

   - optimize mutex_trylock() fastpath (Peter Zijlstra)

   - ... misc fixes and cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits)
  locking/atomic: Introduce inc/dec variants for the atomic_fetch_$op() API
  locking/barriers, arch/arm64: Implement LDXR+WFE based smp_cond_load_acquire()
  locking/static_keys: Fix non static symbol Sparse warning
  locking/qspinlock: Use __this_cpu_dec() instead of full-blown this_cpu_dec()
  locking/atomic, arch/tile: Fix tilepro build
  locking/atomic, arch/m68k: Remove comment
  locking/atomic, arch/arc: Fix build
  locking/Documentation: Clarify limited control-dependency scope
  locking/atomic, arch/rwsem: Employ atomic_long_fetch_add()
  locking/atomic, arch/qrwlock: Employ atomic_fetch_add_acquire()
  locking/atomic, arch/mips: Convert to _relaxed atomics
  locking/atomic, arch/alpha: Convert to _relaxed atomics
  locking/atomic: Remove the deprecated atomic_{set,clear}_mask() functions
  locking/atomic: Remove linux/atomic.h:atomic_fetch_or()
  locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
  locking/atomic: Fix atomic64_relaxed() bits
  locking/atomic, arch/xtensa: Implement atomic_fetch_{add,sub,and,or,xor}()
  locking/atomic, arch/x86: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
  locking/atomic, arch/tile: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
  locking/atomic, arch/sparc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
  ...
2016-07-25 12:41:29 -07:00
Michal Hocko
aade311a50 parisc: get rid of superfluous __GFP_REPEAT
__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.

pmd_alloc_one allocate PMD_ORDER which is 1.  This means that this flag
has never been actually useful here because it has always been used only
for PAGE_ALLOC_COSTLY requests.

Link: http://lkml.kernel.org/r/1464599699-30131-10-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-24 17:23:52 -07:00
Michal Hocko
32d6bd9059 tree wide: get rid of __GFP_REPEAT for order-0 allocations part I
This is the third version of the patchset previously sent [1].  I have
basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get
rid of superfluous gfp flags" which went through dm tree.  I am sending
it now because it is tree wide and chances for conflicts are reduced
considerably when we want to target rc2.  I plan to send the next step
and rename the flag and move to a better semantic later during this
release cycle so we will have a new semantic ready for 4.8 merge window
hopefully.

Motivation:

While working on something unrelated I've checked the current usage of
__GFP_REPEAT in the tree.  It seems that a majority of the usage is and
always has been bogus because __GFP_REPEAT has always been about costly
high order allocations while we are using it for order-0 or very small
orders very often.  It seems that a big pile of them is just a
copy&paste when a code has been adopted from one arch to another.

I think it makes some sense to get rid of them because they are just
making the semantic more unclear.  Please note that GFP_REPEAT is
documented as

* __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt

* _might_ fail.  This depends upon the particular VM implementation.
  while !costly requests have basically nofail semantic.  So one could
  reasonably expect that order-0 request with __GFP_REPEAT will not loop
  for ever.  This is not implemented right now though.

I would like to move on with __GFP_REPEAT and define a better semantic
for it.

  $ git grep __GFP_REPEAT origin/master | wc -l
  111
  $ git grep __GFP_REPEAT | wc -l
  36

So we are down to the third after this patch series.  The remaining
places really seem to be relying on __GFP_REPEAT due to large allocation
requests.  This still needs some double checking which I will do later
after all the simple ones are sorted out.

I am touching a lot of arch specific code here and I hope I got it right
but as a matter of fact I even didn't compile test for some archs as I
do not have cross compiler for them.  Patches should be quite trivial to
review for stupid compile mistakes though.  The tricky parts are usually
hidden by macro definitions and thats where I would appreciate help from
arch maintainers.

[1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org

This patch (of 19):

__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.  Yet we
have the full kernel tree with its usage for apparently order-0
allocations.  This is really confusing because __GFP_REPEAT is
explicitly documented to allow allocation failures which is a weaker
semantic than the current order-0 has (basically nofail).

Let's simply drop __GFP_REPEAT from those places.  This would allow to
identify place which really need allocator to retry harder and formulate
a more specific semantic for what the flag is supposed to do actually.

Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andy Lutomirski <luto@kernel.org>
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> [for tile]
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: John Crispin <blogic@openwrt.org>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
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>
2016-06-24 17:23:52 -07:00
Peter Zijlstra
b53d6bedbe locking/atomic: Remove linux/atomic.h:atomic_fetch_or()
Since all architectures have this implemented now natively, remove this
dead code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-16 10:48:32 +02:00
Peter Zijlstra
e5857a6ed6 locking/atomic, arch/parisc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
Implement FETCH-OP atomic primitives, these are very similar to the
existing OP-RETURN primitives we already have, except they return the
value of the atomic variable _before_ modification.

This is especially useful for irreversible operations -- such as
bitops (because it becomes impossible to reconstruct the state prior
to modification).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-16 10:48:28 +02:00
Peter Zijlstra
726328d92a locking/spinlock, arch: Update and fix spin_unlock_wait() implementations
This patch updates/fixes all spin_unlock_wait() implementations.

The update is in semantics; where it previously was only a control
dependency, we now upgrade to a full load-acquire to match the
store-release from the spin_unlock() we waited on. This ensures that
when spin_unlock_wait() returns, we're guaranteed to observe the full
critical section we waited on.

This fixes a number of spin_unlock_wait() users that (not
unreasonably) rely on this.

I also fixed a number of ticket lock versions to only wait on the
current lock holder, instead of for a full unlock, as this is
sufficient.

Furthermore; again for ticket locks; I added an smp_rmb() in between
the initial ticket load and the spin loop testing the current value
because I could not convince myself the address dependency is
sufficient, esp. if the loads are of different sizes.

I'm more than happy to remove this smp_rmb() again if people are
certain the address dependency does indeed work as expected.

Note: PPC32 will be fixed independently

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: chris@zankel.net
Cc: cmetcalf@mellanox.com
Cc: davem@davemloft.net
Cc: dhowells@redhat.com
Cc: james.hogan@imgtec.com
Cc: jejb@parisc-linux.org
Cc: linux@armlinux.org.uk
Cc: mpe@ellerman.id.au
Cc: ralf@linux-mips.org
Cc: realmz6@gmail.com
Cc: rkuo@codeaurora.org
Cc: rth@twiddle.net
Cc: schwidefsky@de.ibm.com
Cc: tony.luck@intel.com
Cc: vgupta@synopsys.com
Cc: ysato@users.sourceforge.jp
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 11:55:15 +02:00
Helge Deller
58f1c654d1 parisc: Move die_if_kernel() prototype into traps.h header
Signed-off-by: Helge Deller <deller@gmx.de>
2016-06-05 08:49:01 +02:00
Arnd Bergmann
8bbe6b6f00 char/genrtc: remove parisc support
This architecture selects RTC_CLASS unconditionally, so the GEN_RTC
has not worked here for a long time.

Now we can remove both the asm/rtc.h header and the Kconfig dependency
for CONFIG_GEN_RTC.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-06-04 00:23:04 +02:00
Arnd Bergmann
f09c5142ee rtc: cmos: remove empty asm/mc146818rtc.h files
Nothing on these architectures ever includes the asm/mc146818rtc.h
file, the drivers that used to do this have been fixed long ago,
and the remaining users are all PC-specific.

This removes the files for good.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-06-04 00:19:04 +02:00
Helge Deller
784c2213e7 parisc: Whitespace cleanups in unistd.h
Clean up whitespaces and mark unused syscalls as such.

Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-25 15:40:49 +02:00
Andrea Gelmini
1a2a0f7817 parisc: Fix typos in eisa_eeprom.h
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-22 21:57:40 +02:00
Andrea Gelmini
d14b3dfc25 parisc: Fix typo in ldcw.h
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-22 21:56:37 +02:00
Andrea Gelmini
13ff6313f9 parisc: Fix typo in pdc.h
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-22 21:55:33 +02:00
John David Anglin
99aed91a8d parisc: Update futex.h to match generic implementation
The attached patch updates the parisc version of futex.h to match the
current generic implementation except for the spinlock code.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-22 21:48:54 +02:00
Helge Deller
54b6680090 parisc: Add native high-resolution sched_clock() implementation
Add a native implementation for the sched_clock() function which utilizes the
processor-internal cycle counter (Control Register 16) as high-resolution time
source.

With this patch we now get much more fine-grained resolutions in various
in-kernel time measurements (e.g. when viewing the function tracing logs), and
probably a more accurate scheduling on SMP systems.

There are a few specific implementation details in this patch:

1. On a 32bit kernel we emulate the higher 32bits of the required 64-bit
resolution of sched_clock() by increasing a per-cpu counter at every
wrap-around of the 32bit cycle counter.

2. In a SMP system, the cycle counters of the various CPUs are not syncronized
(similiar to the TSC in a x86_64 system). To cope with this we define
HAVE_UNSTABLE_SCHED_CLOCK and let the upper layers do the adjustment work.

3. Since we need HAVE_UNSTABLE_SCHED_CLOCK, we need to provide a cmpxchg64()
function even on a 32-bit kernel.

4. A 64-bit SMP kernel which is started on a UP system will mark the
sched_clock() implementation as "stable", which means that we don't expect any
jumps in the returned counter. This is true because we then run only on one
CPU.

Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-22 21:39:25 +02:00
Helge Deller
64e2a42bca parisc: Add ARCH_TRACEHOOK and regset support
By adding TRACEHOOK support we now get a clean user interface to access
registers via PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS and
PTRACE_SETFPREGS.

The user-visible regset struct user_regs_struct and user_fp_struct are
modelled similiar to x86 and can be accessed via PTRACE_GETREGSET.

Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-22 21:39:13 +02:00
Helge Deller
d2ad824f4b parisc: Add 64bit get_user() and put_user() for 32bit kernel
Allow accessing 64-bit values in userspace from a 32-bit kernel.
The access is not atomic.

Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-22 21:39:04 +02:00
Helge Deller
06bff6b9d7 parisc: Simplify and speed up get_user() and put_user()
This patch simplifies the code for get_user() and put_user() a lot.

Instead of accessing kernel memory (%sr0) and userspace memory (%sr3)
hard-coded in the assembler instruction, we now preload %sr2 with either
%sr0 (for accessing KERNEL_DS) or with sr3 (to access USER_DS) and
use %sr2 in the load directly.

The generated code avoids a branch and speeds up execution by generating
less assembler instructions.

Signed-off-by: Helge Deller <deller@gmx.de>
Tested-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
2016-05-22 21:38:56 +02:00
Helge Deller
fc79168a7c parisc: Add syscall tracepoint support
This patch adds support for the TIF_SYSCALL_TRACEPOINT on the parisc
architecture. Basically, it calls the appropriate tracepoints on syscall
entry and exit.

Signed-off-by: Helge Deller <deller@gmx.de>
2016-05-22 21:38:47 +02:00
Linus Torvalds
60ea7bb007 Merge branch 'parisc-4.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc ftrace fixes from Helge Deller:
 "This is (most likely) the last pull request for v4.6 for the parisc
  architecture.

  It fixes the FTRACE feature for parisc, which is horribly broken since
   quite some time and doesn't even compile.  This patch just fixes the
  bare minimum (it actually removes more lines than it adds), so that
  the function tracer works again on 32- and 64bit kernels.

  I've queued up additional patches on top of this patch which e.g. add
  the syscall tracer, but those have to wait for the merge window for
  v4.7."

* 'parisc-4.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix ftrace function tracer
2016-04-15 14:51:45 -07:00
Helge Deller
366dd4ea9d parisc: Fix ftrace function tracer
Fix the FTRACE function tracer for 32- and 64-bit kernel.
The former code was horribly broken.

Reimplement most coding in assembly and utilize optimizations, e.g. put
mcount() and ftrace_stub() into one L1 cacheline.

Signed-off-by: Helge Deller <deller@gmx.de>
2016-04-14 17:47:19 +02:00
Helge Deller
cb910c1714 parisc: Update comment regarding relative extable support
Update the comment to reflect the changes of commit 0de7985 (parisc: Use
generic extable search and sort routines).

Signed-off-by: Helge Deller <deller@gmx.de>
2016-04-08 22:14:26 +02:00
Helge Deller
2ef4dfd9d9 parisc: Unbreak handling exceptions from kernel modules
Handling exceptions from modules never worked on parisc.
It was just masked by the fact that exceptions from modules
don't happen during normal use.

When a module triggers an exception in get_user() we need to load the
main kernel dp value before accessing the exception_data structure, and
afterwards restore the original dp value of the module on exit.

Noticed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
2016-04-08 22:14:14 +02:00
Linus Torvalds
c05c2ec96b Merge branch 'parisc-4.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull parisc fixes from Helge Deller:
 "Fix seccomp filter support and SIGSYS signals on compat kernel.

  Both patches are tagged for v4.5 stable kernel"

* 'parisc-4.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Fix and enable seccomp filter support
  parisc: Fix SIGSYS signals in compat case
2016-03-31 07:55:14 -05:00
Helge Deller
910cd32e55 parisc: Fix and enable seccomp filter support
The seccomp filter support requires careful handling of task registers.  This
includes reloading of the return value (%r28) and proper syscall exit if
secure_computing() returned -1.

Additionally we need to sign-extend the syscall number from signed 32bit to
signed 64bit in do_syscall_trace_enter() since the ptrace interface only allows
storing 32bit values in compat mode.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v4.5
2016-03-31 12:28:38 +02:00
Helge Deller
4f4acc9472 parisc: Fix SIGSYS signals in compat case
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v4.5
2016-03-31 12:28:37 +02:00
Helge Deller
119a0a3c13 parisc: Wire up preadv2 and pwritev2 syscalls
Signed-off-by: Helge Deller <deller@gmx.de>
2016-03-23 16:22:42 +01:00