Commit Graph

132 Commits

Author SHA1 Message Date
David S. Miller 0ede1c4013 sparc64: Fix exception handling in UltraSPARC-III memcpy.
Mikael Pettersson reported that some test programs in the strace-4.18
testsuite cause an OOPS.

After some debugging it turns out that garbage values are returned
when an exception occurs, causing the fixup memset() to be run with
bogus arguments.

The problem is that two of the exception handler stubs write the
successfully copied length into the wrong register.

Fixes: ee841d0aff ("sparc64: Convert U3copy_{from,to}_user to accurate exception reporting.")
Reported-by: Mikael Pettersson <mikpelinux@gmail.com>
Tested-by: Mikael Pettersson <mikpelinux@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-04 09:47:52 -07:00
Linus Torvalds 3b06b1a744 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
Pull sparc fixes from David Miller:

 - Fix symbol version generation for assembler on sparc, from
   Nagarathnam Muthusamy.

 - Fix compound page handling in gup_huge_pmd(), from Nitin Gupta.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix gup_huge_pmd
  Adding the type of exported symbols
  sed regex in Makefile.build requires line break between exported symbols
  Adding asm-prototypes.h for genksyms to generate crc
2017-07-11 21:34:24 -07:00
Linus Torvalds 98ced886dd Kbuild thin archives updates for v4.13
Thin archives migration by Nicholas Piggin.
 
 THIN_ARCHIVES has been available for a while as an optional feature
 only for PowerPC architecture, but we do not need two different
 intermediate-artifact schemes.
 
 Using thin archives instead of conventional incremental linking has
 various advantages:
  - save disk space for builds
  - speed-up building a little
  - fix some link issues (for example, allyesconfig on ARM) due to
    more flexibility for the final linking
  - work better with dead code elimination we are planning
 
 As discussed before, this migration has been done unconditionally
 so that any problems caused by this will show up with "git bisect".
 
 With testing with 0-day and linux-next, some architectures actually
 showed up problems, but they were trivial and all fixed now.
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Merge tag 'kbuild-thinar-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild thin archives updates from Masahiro Yamada:
 "Thin archives migration by Nicholas Piggin.

  THIN_ARCHIVES has been available for a while as an optional feature
  only for PowerPC architecture, but we do not need two different
  intermediate-artifact schemes.

  Using thin archives instead of conventional incremental linking has
  various advantages:

   - save disk space for builds

   - speed-up building a little

   - fix some link issues (for example, allyesconfig on ARM) due to more
     flexibility for the final linking

   - work better with dead code elimination we are planning

  As discussed before, this migration has been done unconditionally so
  that any problems caused by this will show up with "git bisect".

  With testing with 0-day and linux-next, some architectures actually
  showed up problems, but they were trivial and all fixed now"

* tag 'kbuild-thinar-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  tile: remove unneeded extra-y in Makefile
  kbuild: thin archives make default for all archs
  x86/um: thin archives build fix
  tile: thin archives fix linking
  ia64: thin archives fix linking
  sh: thin archives fix linking
  kbuild: handle libs-y archives separately from built-in.o archives
  kbuild: thin archives use P option to ar
  kbuild: thin archives final link close --whole-archives option
  ia64: remove unneeded extra-y in Makefile.gate
  tile: fix dependency and .*.cmd inclusion for incremental build
  sparc64: Use indirect calls in hamming weight stubs
2017-07-07 15:11:12 -07:00
David S. Miller 9289ea7f95 sparc64: Use indirect calls in hamming weight stubs
Otherwise, depending upon link order, the branch relocation
limits could be exceeded.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-06-30 08:59:55 +09:00
Nagarathnam Muthusamy f5a651f1d5 Adding the type of exported symbols
Missing symbol type for few functions prevents genksyms from generating
symbol versions for those functions. This patch fixes them.

Signed-off-by: Nagarathnam Muthusamy <nagarathnam.muthusamy@oracle.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-19 11:13:06 -07:00
Nagarathnam Muthusamy d16c0649fe sed regex in Makefile.build requires line break between exported symbols
The following regex in Makefile.build matches only one ___EXPORT_SYMBOL per line.

sed
's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/'

ATOMIC_OPS macro in atomic_64.S expands multiple symbols in same line hence
version generation is done only for the last matched symbol. This patch adds
new line between the symbol expansions.

Signed-off-by: Nagarathnam Muthusamy <nagarathnam.muthusamy@oracle.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-19 11:13:05 -07:00
David S. Miller 1b4af13ff2 sparc64: Add __multi3 for gcc 7.x and later.
Reported-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-05 11:30:33 -07:00
Dave Aldridge 3c7f622120 sparc64: fix fault handling in NGbzero.S and GENbzero.S
When any of the functions contained in NGbzero.S and GENbzero.S
vector through *bzero_from_clear_user, we may end up taking a
fault when executing one of the store alternate address space
instructions. If this happens, the exception handler does not
restore the %asi register.

This commit fixes the issue by introducing a new exception
handler that ensures the %asi register is restored when
a fault is handled.

Orabug: 25577560

Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com>
Reviewed-by: Rob Gardner <rob.gardner@oracle.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-09 12:16:25 -07:00
Linus Torvalds 5db6db0d40 Merge branch 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull uaccess unification updates from Al Viro:
 "This is the uaccess unification pile. It's _not_ the end of uaccess
  work, but the next batch of that will go into the next cycle. This one
  mostly takes copy_from_user() and friends out of arch/* and gets the
  zero-padding behaviour in sync for all architectures.

  Dealing with the nocache/writethrough mess is for the next cycle;
  fortunately, that's x86-only. Same for cleanups in iov_iter.c (I am
  sold on access_ok() in there, BTW; just not in this pile), same for
  reducing __copy_... callsites, strn*... stuff, etc. - there will be a
  pile about as large as this one in the next merge window.

  This one sat in -next for weeks. -3KLoC"

* 'work.uaccess' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (96 commits)
  HAVE_ARCH_HARDENED_USERCOPY is unconditional now
  CONFIG_ARCH_HAS_RAW_COPY_USER is unconditional now
  m32r: switch to RAW_COPY_USER
  hexagon: switch to RAW_COPY_USER
  microblaze: switch to RAW_COPY_USER
  get rid of padding, switch to RAW_COPY_USER
  ia64: get rid of copy_in_user()
  ia64: sanitize __access_ok()
  ia64: get rid of 'segment' argument of __do_{get,put}_user()
  ia64: get rid of 'segment' argument of __{get,put}_user_check()
  ia64: add extable.h
  powerpc: get rid of zeroing, switch to RAW_COPY_USER
  esas2r: don't open-code memdup_user()
  alpha: fix stack smashing in old_adjtimex(2)
  don't open-code kernel_setsockopt()
  mips: switch to RAW_COPY_USER
  mips: get rid of tail-zeroing in primitives
  mips: make copy_from_user() zero tail explicitly
  mips: clean and reorder the forest of macros...
  mips: consolidate __invoke_... wrappers
  ...
2017-05-01 14:41:04 -07:00
Al Viro 31af2f36d5 sparc: switch to RAW_COPY_USER
... and drop zeroing in sparc32.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-04-02 12:53:15 -04:00
Babu Moger 0ae2d26ffe arch/sparc: Avoid DCTI Couples
Avoid un-intended DCTI Couples. Use of DCTI couples is deprecated.
Also address the "Programming Note" for optimal performance.

Here is the complete text from Oracle SPARC Architecture Specs.

6.3.4.7 DCTI Couples
"A delayed control transfer instruction (DCTI) in the delay slot of
another DCTI is referred to as a “DCTI couple”. The use of DCTI couples
is deprecated in the Oracle SPARC Architecture; no new software should
place a DCTI in the delay slot of another DCTI, because on future Oracle
SPARC Architecture implementations DCTI couples may execute either
slowly or differently than the programmer assumes it will.

SPARC V8 and SPARC V9 Compatibility Note
The SPARC V8 architecture left behavior undefined for a DCTI couple. The
SPARC V9 architecture defined behavior in that case, but as of
UltraSPARC Architecture 2005, use of DCTI couples was deprecated.
Software should not expect high performance from DCTI couples, and
performance of DCTI couples should be expected to decline further in
future processors.

Programming Note
As noted in TABLE 6-5 on page 115, an annulled branch-always
(branch-always with a = 1) instruction is not architecturally a DCTI.
However, since not all implementations make that distinction, for
optimal performance, a DCTI should not be placed in the instruction word
immediately following an annulled branch-always instruction (BA,A or
BPA,A)."

Signed-off-by: Babu Moger <babu.moger@oracle.com>
Reviewed-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-27 21:51:40 -07:00
David S. Miller 0fd0ff01d4 sparc64: Delete now unused user copy fixup functions.
Now that all of the user copy routines are converted to return
accurate residual lengths when an exception occurs, we no longer need
the broken fixup routines.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-24 21:26:04 -07:00
David S. Miller ee841d0aff sparc64: Convert U3copy_{from,to}_user to accurate exception reporting.
Report the exact number of bytes which have not been successfully
copied when an exception occurs, using the running remaining length.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-24 21:20:35 -07:00
David S. Miller e93704e446 sparc64: Convert NG2copy_{from,to}_user to accurate exception reporting.
Report the exact number of bytes which have not been successfully
copied when an exception occurs, using the running remaining length.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-24 20:46:44 -07:00
David S. Miller 7ae3aaf53f sparc64: Convert NGcopy_{from,to}_user to accurate exception reporting.
Report the exact number of bytes which have not been successfully
copied when an exception occurs, using the running remaining length.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-24 19:32:12 -07:00
David S. Miller 9570770480 sparc64: Convert NG4copy_{from,to}_user to accurate exception reporting.
Report the exact number of bytes which have not been successfully
copied when an exception occurs, using the running remaining length.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-24 18:58:05 -07:00
David S. Miller cb736fdbb2 sparc64: Convert U1copy_{from,to}_user to accurate exception reporting.
Report the exact number of bytes which have not been successfully
copied when an exception occurs, using the running remaining length.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-24 11:32:12 -07:00
David S. Miller d0796b555b sparc64: Convert GENcopy_{from,to}_user to accurate exception reporting.
Report the exact number of bytes which have not been successfully
copied when an exception occurs, using the running remaining length.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-24 11:31:58 -07:00
David S. Miller 0096ac9f47 sparc64: Convert copy_in_user to accurate exception reporting.
Report the exact number of bytes which have not been successfully
copied when an exception occurs, using the running remaining length.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-24 11:31:58 -07:00
David S. Miller 83a17d2661 sparc64: Prepare to move to more saner user copy exception handling.
The fixup helper function mechanism for handling user copy fault
handling is not %100 accurrate, and can never be made so.

We are going to transition the code to return the running return
return length, which is always kept track in one or more registers
of each of these routines.

In order to convert them one by one, we have to allow the existing
behavior to continue functioning.

Therefore make all the copy code that wants the fixup helper to be
used return negative one.

After all of the user copy routines have been converted, this logic
and the fixup helpers themselves can be removed completely.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-24 11:31:58 -07:00
Al Viro fb2e6fdbbd sparc32: debride memcpy.S a bit
unreachable code, unused macros...

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-08-07 23:55:49 -04:00
Al Viro 70a6fcf328 [sparc] unify 32bit and 64bit string.h
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-08-07 23:55:48 -04:00
Al Viro d3867f0483 sparc: move exports to definitions
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-08-07 23:55:43 -04:00
Peter Zijlstra 3a1adb23a5 locking/atomic, arch/sparc: 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>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: James Y Knight <jyknight@google.com>
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: sparclinux@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-16 10:48:30 +02:00
Rob Gardner a7c5724b5c sparc64: fix FP corruption in user copy functions
Short story: Exception handlers used by some copy_to_user() and
copy_from_user() functions do not diligently clean up floating point
register usage, and this can result in a user process seeing invalid
values in floating point registers. This sometimes makes the process
fail.

Long story: Several cpu-specific (NG4, NG2, U1, U3) memcpy functions
use floating point registers and VIS alignaddr/faligndata to
accelerate data copying when source and dest addresses don't align
well. Linux uses a lazy scheme for saving floating point registers; It
is not done upon entering the kernel since it's a very expensive
operation. Rather, it is done only when needed. If the kernel ends up
not using FP regs during the course of some trap or system call, then
it can return to user space without saving or restoring them.

The various memcpy functions begin their FP code with VISEntry (or a
variation thereof), which saves the FP regs. They conclude their FP
code with VISExit (or a variation) which essentially marks the FP regs
"clean", ie, they contain no unsaved values. fprs.FPRS_FEF is turned
off so that a lazy restore will be triggered when/if the user process
accesses floating point regs again.

The bug is that the user copy variants of memcpy, copy_from_user() and
copy_to_user(), employ an exception handling mechanism to detect faults
when accessing user space addresses, and when this handler is invoked,
an immediate return from the function is forced, and VISExit is not
executed, thus leaving the fprs register in an indeterminate state,
but often with fprs.FPRS_FEF set and one or more dirty bits. This
results in a return to user space with invalid values in the FP regs,
and since fprs.FPRS_FEF is on, no lazy restore occurs.

This bug affects copy_to_user() and copy_from_user() for NG4, NG2,
U3, and U1. All are fixed by using a new exception handler for those
loads and stores that are done during the time between VISEnter and
VISExit.

n.b. In NG4memcpy, the problematic code can be triggered by a copy
size greater than 128 bytes and an unaligned source address.  This bug
is known to be the cause of random user process memory corruptions
while perf is running with the callgraph option (ie, perf record -g).
This occurs because perf uses copy_from_user() to read user stacks,
and may fault when it follows a stack frame pointer off to an
invalid page. Validation checks on the stack address just obscure
the underlying problem.

Signed-off-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-24 12:13:18 -05:00
Linus Torvalds 2c302e7e41 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
Pull sparc updates from David Miller:
 "Just a couple of fixes/cleanups:

   - Correct NUMA latency calculations on sparc64, from Nitin Gupta.

   - ASI_ST_BLKINIT_MRU_S value was wrong, from Rob Gardner.

   - Fix non-faulting load handling of non-quad values, also from Rob
     Gardner.

   - Cleanup VISsave assembler, from Sam Ravnborg.

   - Fix iommu-common code so it doesn't emit rediculous warnings on
     some architectures, particularly ARM"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc64: Fix numa distance values
  sparc64: Don't restrict fp regs for no-fault loads
  iommu-common: Fix error code used in iommu_tbl_range_{alloc,free}().
  sparc64: use ENTRY/ENDPROC in VISsave
  sparc64: Fix incorrect ASI_ST_BLKINIT_MRU_S value
2015-11-05 16:34:48 -08:00
Linus Torvalds ca520cab25 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking and atomic updates from Ingo Molnar:
 "Main changes in this cycle are:

   - Extend atomic primitives with coherent logic op primitives
     (atomic_{or,and,xor}()) and deprecate the old partial APIs
     (atomic_{set,clear}_mask())

     The old ops were incoherent with incompatible signatures across
     architectures and with incomplete support.  Now every architecture
     supports the primitives consistently (by Peter Zijlstra)

   - Generic support for 'relaxed atomics':

       - _acquire/release/relaxed() flavours of xchg(), cmpxchg() and {add,sub}_return()
       - atomic_read_acquire()
       - atomic_set_release()

     This came out of porting qwrlock code to arm64 (by Will Deacon)

   - Clean up the fragile static_key APIs that were causing repeat bugs,
     by introducing a new one:

       DEFINE_STATIC_KEY_TRUE(name);
       DEFINE_STATIC_KEY_FALSE(name);

     which define a key of different types with an initial true/false
     value.

     Then allow:

       static_branch_likely()
       static_branch_unlikely()

     to take a key of either type and emit the right instruction for the
     case.  To be able to know the 'type' of the static key we encode it
     in the jump entry (by Peter Zijlstra)

   - Static key self-tests (by Jason Baron)

   - qrwlock optimizations (by Waiman Long)

   - small futex enhancements (by Davidlohr Bueso)

   - ... and misc other changes"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits)
  jump_label/x86: Work around asm build bug on older/backported GCCs
  locking, ARM, atomics: Define our SMP atomics in terms of _relaxed() operations
  locking, include/llist: Use linux/atomic.h instead of asm/cmpxchg.h
  locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics
  locking/qrwlock: Implement queue_write_unlock() using smp_store_release()
  locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition
  locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t'
  locking, asm-generic: Rework atomic-long.h to avoid bulk code duplication
  locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic operations
  locking, compiler.h: Cast away attributes in the WRITE_ONCE() magic
  locking/static_keys: Make verify_keys() static
  jump label, locking/static_keys: Update docs
  locking/static_keys: Provide a selftest
  jump_label: Provide a self-test
  s390/uaccess, locking/static_keys: employ static_branch_likely()
  x86, tsc, locking/static_keys: Employ static_branch_likely()
  locking/static_keys: Add selftest
  locking/static_keys: Add a new static_key interface
  locking/static_keys: Rework update logic
  locking/static_keys: Add static_key_{en,dis}able() helpers
  ...
2015-09-03 15:46:07 -07:00
Sam Ravnborg 73958c651f sparc64: use ENTRY/ENDPROC in VISsave
From 7d8a508d74e6cacf0f2438286a959c3195a35a37 Mon Sep 17 00:00:00 2001
From: Sam Ravnborg <sam@ravnborg.org>
Date: Fri, 7 Aug 2015 20:26:12 +0200
Subject: [PATCH] sparc64: use ENTRY/ENDPROC in VISsave

Commit 44922150d8
("sparc64: Fix userspace FPU register corruptions") left a
stale globl symbol which was not used.

Fix this and introduce use of ENTRY/ENDPROC

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-07 15:22:40 -07:00
David S. Miller 44922150d8 sparc64: Fix userspace FPU register corruptions.
If we have a series of events from userpsace, with %fprs=FPRS_FEF,
like follows:

ETRAP
	ETRAP
		VIS_ENTRY(fprs=0x4)
		VIS_EXIT
		RTRAP (kernel FPU restore with fpu_saved=0x4)
	RTRAP

We will not restore the user registers that were clobbered by the FPU
using kernel code in the inner-most trap.

Traps allocate FPU save slots in the thread struct, and FPU using
sequences save the "dirty" FPU registers only.

This works at the initial trap level because all of the registers
get recorded into the top-level FPU save area, and we'll return
to userspace with the FPU disabled so that any FPU use by the user
will take an FPU disabled trap wherein we'll load the registers
back up properly.

But this is not how trap returns from kernel to kernel operate.

The simplest fix for this bug is to always save all FPU register state
for anything other than the top-most FPU save area.

Getting rid of the optimized inner-slot FPU saving code ends up
making VISEntryHalf degenerate into plain VISEntry.

Longer term we need to do something smarter to reinstate the partial
save optimizations.  Perhaps the fundament error is having trap entry
and exit allocate FPU save slots and restore register state.  Instead,
the VISEntry et al. calls should be doing that work.

This bug is about two decades old.

Reported-by: James Y Knight <jyknight@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-06 19:13:25 -07:00
Peter Zijlstra 304a0d699a sparc: Provide atomic_{or,xor,and}
Implement atomic logic ops -- atomic_{or,xor,and}.

These will replace the atomic_{set,clear}_mask functions that are
available on some archs.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-27 14:06:23 +02:00
David S. Miller 2077cef4d5 sparc64: Fix several bugs in memmove().
Firstly, handle zero length calls properly.  Believe it or not there
are a few of these happening during early boot.

Next, we can't just drop to a memcpy() call in the forward copy case
where dst <= src.  The reason is that the cache initializing stores
used in the Niagara memcpy() implementations can end up clearing out
cache lines before we've sourced their original contents completely.

For example, considering NG4memcpy, the main unrolled loop begins like
this:

     load   src + 0x00
     load   src + 0x08
     load   src + 0x10
     load   src + 0x18
     load   src + 0x20
     store  dst + 0x00

Assume dst is 64 byte aligned and let's say that dst is src - 8 for
this memcpy() call.  That store at the end there is the one to the
first line in the cache line, thus clearing the whole line, which thus
clobbers "src + 0x28" before it even gets loaded.

To avoid this, just fall through to a simple copy only mildly
optimized for the case where src and dst are 8 byte aligned and the
length is a multiple of 8 as well.  We could get fancy and call
GENmemcpy() but this is good enough for how this thing is actually
used.

Reported-by: David Ahern <david.ahern@oracle.com>
Reported-by: Bob Picco <bpicco@meloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23 09:22:10 -07:00
Andreas Larsson 1a17fdc4f4 sparc32: Implement xchg and atomic_xchg using ATOMIC_HASH locks
Atomicity between xchg and cmpxchg cannot be guaranteed when xchg is
implemented with a swap and cmpxchg is implemented with locks.
Without this, e.g. mcs_spin_lock and mcs_spin_unlock are broken.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-07 12:51:44 -08:00
David S. Miller f4da3628dc sparc64: Fix FPU register corruption with AES crypto offload.
The AES loops in arch/sparc/crypto/aes_glue.c use a scheme where the
key material is preloaded into the FPU registers, and then we loop
over and over doing the crypt operation, reusing those pre-cooked key
registers.

There are intervening blkcipher*() calls between the crypt operation
calls.  And those might perform memcpy() and thus also try to use the
FPU.

The sparc64 kernel FPU usage mechanism is designed to allow such
recursive uses, but with a catch.

There has to be a trap between the two FPU using threads of control.

The mechanism works by, when the FPU is already in use by the kernel,
allocating a slot for FPU saving at trap time.  Then if, within the
trap handler, we try to use the FPU registers, the pre-trap FPU
register state is saved into the slot.  Then at trap return time we
notice this and restore the pre-trap FPU state.

Over the long term there are various more involved ways we can make
this work, but for a quick fix let's take advantage of the fact that
the situation where this happens is very limited.

All sparc64 chips that support the crypto instructiosn also are using
the Niagara4 memcpy routine, and that routine only uses the FPU for
large copies where we can't get the source aligned properly to a
multiple of 8 bytes.

We look to see if the FPU is already in use in this context, and if so
we use the non-large copy path which only uses integer registers.

Furthermore, we also limit this special logic to when we are doing
kernel copy, rather than a user copy.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-14 19:37:58 -07:00
Linus Torvalds dbb885fecc Merge branch 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull arch atomic cleanups from Ingo Molnar:
 "This is a series kept separate from the main locking tree, which
  cleans up and improves various details in the atomics type handling:

   - Remove the unused atomic_or_long() method

   - Consolidate and compress atomic ops implementations between
     architectures, to reduce linecount and to make it easier to add new
     ops.

   - Rewrite generic atomic support to only require cmpxchg() from an
     architecture - generate all other methods from that"

* 'locking-arch-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  locking,arch: Use ACCESS_ONCE() instead of cast to volatile in atomic_read()
  locking, mips: Fix atomics
  locking, sparc64: Fix atomics
  locking,arch: Rewrite generic atomic support
  locking,arch,xtensa: Fold atomic_ops
  locking,arch,sparc: Fold atomic_ops
  locking,arch,sh: Fold atomic_ops
  locking,arch,powerpc: Fold atomic_ops
  locking,arch,parisc: Fold atomic_ops
  locking,arch,mn10300: Fold atomic_ops
  locking,arch,mips: Fold atomic_ops
  locking,arch,metag: Fold atomic_ops
  locking,arch,m68k: Fold atomic_ops
  locking,arch,m32r: Fold atomic_ops
  locking,arch,ia64: Fold atomic_ops
  locking,arch,hexagon: Fold atomic_ops
  locking,arch,cris: Fold atomic_ops
  locking,arch,avr32: Fold atomic_ops
  locking,arch,arm64: Fold atomic_ops
  locking,arch,arm: Fold atomic_ops
  ...
2014-10-13 15:48:00 +02:00
Peter Zijlstra caa17d49f9 locking, sparc64: Fix atomics
The patch folding the atomic ops had a silly fail in the _return primitives.

Fixes: 4f3316c2b5 ("locking,arch,sparc: Fold atomic_ops")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20140902094016.GD31157@worktop.ger.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-09-10 11:45:04 +02:00
Andreas Larsson 74cad25c07 sparc: Let memset return the address argument
This makes memset follow the standard (instead of returning 0 on success). This
is needed when certain versions of gcc optimizes around memset calls and assume
that the address argument is preserved in %o0.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-09 16:38:10 -07:00
Peter Zijlstra 4f3316c2b5 locking,arch,sparc: Fold atomic_ops
Many of the atomic op implementations are the same except for one
instruction; fold the lot into a few CPP macros and reduce LoC.

This also prepares for easy addition of new ops.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Kirill Tkhai <tkhai@yandex.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20140508135852.825281379@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-14 12:48:13 +02:00
Linus Torvalds 049711bf3c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next
Pull sparc updates from David Miller:

 1) Add sparc RAM output to /proc/iomem, from Bob Picco.

 2) Allow seeks on /dev/mdesc, from Khalid Aziz.

 3) Cleanup sparc64 I/O accessors, from Sam Ravnborg.

 4) If update_mmu_cache{,_pmd}() is called with an not-valid mapping, do
    not insert it into the TLB miss hash tables otherwise we'll
    livelock.  Based upon work by Christopher Alexander Tobias Schulze.

 5) Fix BREAK detection in sunsab driver when no actual characters are
    pending, from Christopher Alexander Tobias Schulze.

 6) Because we have modules --> openfirmware --> vmalloc ordering of
    virtual memory, the lazy VMAP TLB flusher can cons up an invocation
    of flush_tlb_kernel_range() that covers the openfirmware address
    range.  Unfortunately this will flush out the firmware's locked TLB
    mapping which causes all kinds of trouble.  Just split up the flush
    request if this happens, but in the long term the lazy VMAP flusher
    should probably be made a little bit smarter.

    Based upon work by Christopher Alexander Tobias Schulze.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next:
  sparc64: Fix up merge thinko.
  sparc: Add "install" target
  arch/sparc/math-emu/math_32.c: drop stray break operator
  sparc64: ldc_connect() should not return EINVAL when handshake is in progress.
  sparc64: Guard against flushing openfirmware mappings.
  sunsab: Fix detection of BREAK on sunsab serial console
  bbc-i2c: Fix BBC I2C envctrl on SunBlade 2000
  sparc64: Do not insert non-valid PTEs into the TSB hash table.
  sparc64: avoid code duplication in io_64.h
  sparc64: reorder functions in io_64.h
  sparc64: drop unused SLOW_DOWN_IO definitions
  sparc64: remove macro indirection in io_64.h
  sparc64: update IO access functions in PeeCeeI
  sparcspkr: use sbus_*() primitives for IO
  sparc: Add support for seek and shorter read to /dev/mdesc
  sparc: use %s for unaligned panic
  drivers/sbus/char: Micro-optimization in display7seg.c
  display7seg: Introduce the use of the managed version of kzalloc
  sparc64 - add mem to iomem resource
2014-08-06 09:41:23 -07:00
Sam Ravnborg 6b8b5507ed sparc64: update IO access functions in PeeCeeI
The PeeCeeI.c code used in*() + out*() for IO access.
But these are in little endian and the native (big) endian
result was required which resulted in some bit-shifting.
Shift the code over to use the __raw_*() variants all over.

This simplifies the code as we can drop the calls
to le16_to_cpu() and le32_to_cpu().
And it should be a little faster too.

With this change we now uses the same type of IO access functions
in all of the file.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-21 21:43:18 -07:00
Steven Rostedt (Red Hat) 2563b9d965 sparc64,ftrace: Remove check of obsolete variable function_trace_stop
Nothing sets function_trace_stop to disable function tracing anymore.
Remove the check for it in the arch code.

Link: http://lkml.kernel.org/r/20140703.211820.1674895115102216877.davem@davemloft.net

Cc: David S. Miller <davem@davemloft.net>
OKed-to-go-through-tracing-tree-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-18 13:57:03 -04:00
Linus Torvalds c4222e4635 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next
Pull sparc fixes from David Miller:
 "Sparc sparse fixes from Sam Ravnborg"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next: (67 commits)
  sparc64: fix sparse warnings in int_64.c
  sparc64: fix sparse warning in ftrace.c
  sparc64: fix sparse warning in kprobes.c
  sparc64: fix sparse warning in kgdb_64.c
  sparc64: fix sparse warnings in compat_audit.c
  sparc64: fix sparse warnings in init_64.c
  sparc64: fix sparse warnings in aes_glue.c
  sparc: fix sparse warnings in smp_32.c + smp_64.c
  sparc64: fix sparse warnings in perf_event.c
  sparc64: fix sparse warnings in kprobes.c
  sparc64: fix sparse warning in tsb.c
  sparc64: clean up compat_sigset_t.seta handling
  sparc64: fix sparse "Should it be static?" warnings in signal32.c
  sparc64: fix sparse warnings in sys_sparc32.c
  sparc64: fix sparse warning in pci.c
  sparc64: fix sparse warnings in smp_64.c
  sparc64: fix sparse warning in prom_64.c
  sparc64: fix sparse warning in btext.c
  sparc64: fix sparse warnings in sys_sparc_64.c + unaligned_64.c
  sparc64: fix sparse warning in process_64.c
  ...

Conflicts:
	arch/sparc/include/asm/pgtable_64.h
2014-06-19 07:50:07 -10:00
David S. Miller 5aa4ecfd0d sparc64: Add membar to Niagara2 memcpy code.
This is the prevent previous stores from overlapping the block stores
done by the memcpy loop.

Based upon a glibc patch by Jose E. Marchesi

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-17 11:28:05 -07:00
Sam Ravnborg e1039fb426 sparc32: introduce asm-generic/io.h
Use asm-generic/io.h definitions where applicable.
The inxx() and outxx() methods whcih was duplicated in pcic.c +
leon_pci.c are replaced by a set of static inlins from asm-generic/io.h

iomap.c is replaced by the generic versions, but are still
present to support sparc64.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-02 01:30:21 -04:00
David S. Miller b2d4383480 sparc64: Make PAGE_OFFSET variable.
Choose PAGE_OFFSET dynamically based upon cpu type.

Original UltraSPARC-I (spitfire) chips only supported a 44-bit
virtual address space.

Newer chips (T4 and later) support 52-bit virtual addresses
and up to 47-bits of physical memory space.

Therefore we have to adjust PAGE_SIZE dynamically based upon
the capabilities of the chip.

Note that this change alone does not allow us to support > 43-bit
physical memory, to do that we need to re-arrange our page table
support.  The current encodings of the pmd_t and pgd_t pointers
restricts us to "32 + 11" == 43 bits.

This change can waste quite a bit of memory for the various tables.
In particular, a future change should work to size and allocate
kern_linear_bitmap[] and sparc64_valid_addr_bitmap[] dynamically.
This isn't easy as we really cannot take a TLB miss when accessing
kern_linear_bitmap[].  We'd have to lock it into the TLB or similar.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Bob Picco <bob.picco@oracle.com>
2013-11-12 15:22:34 -08:00
Kirill Tkhai 61d9b9355b sparc64: Remove RWSEM export leftovers
The functions

			__down_read
			__down_read_trylock
			__down_write
			__down_write_trylock
			__up_read
			__up_write
			__downgrade_write

are implemented inline, so remove corresponding EXPORT_SYMBOLs
(They lead to compile errors on RT kernel).

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-05 12:12:51 -07:00
Stephen Boyd 446f24d119 Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
The help text for this config is duplicated across the x86, parisc, and
s390 Kconfig.debug files.  Arnd Bergman noted that the help text was
slightly misleading and should be fixed to state that enabling this
option isn't a problem when using pre 4.4 gcc.

To simplify the rewording, consolidate the text into lib/Kconfig.debug
and modify it there to be more explicit about when you should say N to
this config.

Also, make the text a bit more generic by stating that this option
enables compile time checks so we can cover architectures which emit
warnings vs.  ones which emit errors.  The details of how an
architecture decided to implement the checks isn't as important as the
concept of compile time checking of copy_from_user() calls.

While we're doing this, remove all the copy_from_user_overflow() code
that's duplicated many times and place it into lib/ so that any
architecture supporting this option can get the function for free.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:09 -07:00
Akinobu Mita 54df2db36c sparc/srmmu: clear trailing edge of bitmap properly
srmmu_nocache_bitmap is cleared by bit_map_init().  But bit_map_init()
attempts to clear by memset(), so it can't clear the trailing edge of
bitmap properly on big-endian architecture if the number of bits is not
a multiple of BITS_PER_LONG.

Actually, the number of bits in srmmu_nocache_bitmap is not always
a multiple of BITS_PER_LONG.  It is calculated as below:

        bitmap_bits = srmmu_nocache_size >> SRMMU_NOCACHE_BITMAP_SHIFT;

srmmu_nocache_size is decided proportionally by the amount of system RAM
and it is rounded to a multiple of PAGE_SIZE.  SRMMU_NOCACHE_BITMAP_SHIFT
is defined as (PAGE_SHIFT - 4).  So it can only be said that bitmap_bits
is a multiple of 16.

This fixes the problem by using bitmap_clear() instead of memset()
in bit_map_init() and this also uses BITS_TO_LONGS() to calculate correct
size at bitmap allocation time.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-31 19:29:12 -04:00
David S. Miller 193d2aadc0 sparc: Support atomic64_dec_if_positive properly.
Sparc32 already supported it, as a consequence of using the
generic atomic64 implementation.  And the sparc64 implementation
is rather trivial.

This allows us to set ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE for all
of sparc, and avoid the annoying warning from lib/atomic64_test.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-09 19:37:59 -08:00
David S. Miller 9f825962ef sparc64: Niagara-4 bzero/memset, plus use MRU stores in page copy.
This adds optimized memset/bzero/page-clear routines for Niagara-4.

We basically can do what powerpc has been able to do for a decade (via
the "dcbz" instruction), which is use cache line clearing stores for
bzero and memsets with a 'c' argument of zero.

As long as we make the cache initializing store to each 32-byte
subblock of the L2 cache line, it works.

As with other Niagara-4 optimized routines, the key is to make sure to
avoid any usage of the %asi register, as reads and writes to it cost
at least 50 cycles.

For the user clear cases, we don't use these new routines, we use the
Niagara-1 variants instead.  Those have to use %asi in an unavoidable
way.

A Niagara-4 8K page clear costs just under 600 cycles.

Add definitions of the MRU variants of the cache initializing store
ASIs.  By default, cache initializing stores install the line as Least
Recently Used.  If we know we're going to use the data immediately
(which is true for page copies and clears) we can use the Most
Recently Used variant, to decrease the likelyhood of the lines being
evicted before they get used.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-05 13:45:26 -07:00
David S. Miller 954f9ac43b Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux
There's a Niagara 2 memcpy fix in this tree and I have
a Kconfig fix from Dave Jones which requires the sparc-next
changes which went upstream yesterday.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-02 23:02:10 -04:00