linux-toradex.git/arch/alpha/include/asm, branch v4.4.136

locking/xchg/alpha: Fix xchg() and cmpxchg() memory ordering bugs

2018-05-30T05:49:01+00:00

[ Upstream commit 472e8c55cf6622d1c112dc2bc777f68bbd4189db ]

Successful RMW operations are supposed to be fully ordered, but
Alpha's xchg() and cmpxchg() do not meet this requirement.

Will Deacon noticed the bug:

  > So MP using xchg:
  >
  > WRITE_ONCE(x, 1)
  > xchg(y, 1)
  >
  > smp_load_acquire(y) == 1
  > READ_ONCE(x) == 0
  >
  > would be allowed.

... which thus violates the above requirement.

Fix it by adding a leading smp_mb() to the xchg() and cmpxchg() implementations.

Reported-by: Will Deacon 
Signed-off-by: Andrea Parri 
Acked-by: Paul E. McKenney 
Cc: Alan Stern 
Cc: Andrew Morton 
Cc: Ivan Kokshaysky 
Cc: Linus Torvalds 
Cc: Matt Turner 
Cc: Peter Zijlstra 
Cc: Richard Henderson 
Cc: Thomas Gleixner 
Cc: linux-alpha@vger.kernel.org
Link: http://lkml.kernel.org/r/1519291488-5752-1-git-send-email-parri.andrea@gmail.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

locking/xchg/alpha: Add unconditional memory barrier to cmpxchg()

2018-05-30T05:48:59+00:00

[ Upstream commit cb13b424e986aed68d74cbaec3449ea23c50e167 ]

Continuing along with the fight against smp_read_barrier_depends() [1]
(or rather, against its improper use), add an unconditional barrier to
cmpxchg.  This guarantees that dependency ordering is preserved when a
dependency is headed by an unsuccessful cmpxchg.  As it turns out, the
change could enable further simplification of LKMM as proposed in [2].

[1] https://marc.info/?l=linux-kernel&m=150884953419377&w=2
    https://marc.info/?l=linux-kernel&m=150884946319353&w=2
    https://marc.info/?l=linux-kernel&m=151215810824468&w=2
    https://marc.info/?l=linux-kernel&m=151215816324484&w=2

[2] https://marc.info/?l=linux-kernel&m=151881978314872&w=2

Signed-off-by: Andrea Parri 
Acked-by: Peter Zijlstra 
Acked-by: Paul E. McKenney 
Cc: Alan Stern 
Cc: Ivan Kokshaysky 
Cc: Linus Torvalds 
Cc: Matt Turner 
Cc: Richard Henderson 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: linux-alpha@vger.kernel.org
Link: http://lkml.kernel.org/r/1519152356-4804-1-git-send-email-parri.andrea@gmail.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

futex: Remove duplicated code and fix undefined behaviour

2018-05-26T06:48:50+00:00

commit 30d6e0a4190d37740e9447e4e4815f06992dd8c3 upstream.

There is code duplicated over all architecture's headers for
futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr,
and comparison of the result.

Remove this duplication and leave up to the arches only the needed
assembly which is now in arch_futex_atomic_op_inuser.

This effectively distributes the Will Deacon's arm64 fix for undefined
behaviour reported by UBSAN to all architectures. The fix was done in
commit 5f16a046f8e1 (arm64: futex: Fix undefined behaviour with
FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump.

And as suggested by Thomas, check for negative oparg too, because it was
also reported to cause undefined behaviour report.

Note that s390 removed access_ok check in d12a29703 ("s390/uaccess:
remove pointless access_ok() checks") as access_ok there returns true.
We introduce it back to the helper for the sake of simplicity (it gets
optimized away anyway).

Signed-off-by: Jiri Slaby 
Signed-off-by: Thomas Gleixner 
Acked-by: Russell King 
Acked-by: Michael Ellerman  (powerpc)
Acked-by: Heiko Carstens  [s390]
Acked-by: Chris Metcalf  [for tile]
Reviewed-by: Darren Hart (VMware) 
Reviewed-by: Will Deacon  [core/arm64]
Cc: linux-mips@linux-mips.org
Cc: Rich Felker 
Cc: linux-ia64@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: peterz@infradead.org
Cc: Benjamin Herrenschmidt 
Cc: Max Filippov 
Cc: Paul Mackerras 
Cc: sparclinux@vger.kernel.org
Cc: Jonas Bonn 
Cc: linux-s390@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: Yoshinori Sato 
Cc: linux-hexagon@vger.kernel.org
Cc: Helge Deller 
Cc: "James E.J. Bottomley" 
Cc: Catalin Marinas 
Cc: Matt Turner 
Cc: linux-snps-arc@lists.infradead.org
Cc: Fenghua Yu 
Cc: Arnd Bergmann 
Cc: linux-xtensa@linux-xtensa.org
Cc: Stefan Kristiansson 
Cc: openrisc@lists.librecores.org
Cc: Ivan Kokshaysky 
Cc: Stafford Horne 
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Henderson 
Cc: Chris Zankel 
Cc: Michal Simek 
Cc: Tony Luck 
Cc: linux-parisc@vger.kernel.org
Cc: Vineet Gupta 
Cc: Ralf Baechle 
Cc: Richard Kuo 
Cc: linux-alpha@vger.kernel.org
Cc: Martin Schwidefsky 
Cc: linuxppc-dev@lists.ozlabs.org
Cc: "David S. Miller" 
Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

alpha: fix build failures

2017-12-25T13:22:16+00:00

commit 8ee912dab95f1483156b6e994004bfcc3158d798 upstream.

The build of alpha allmodconfig is giving error:

  arch/alpha/include/asm/mmu_context.h: In function 'ev5_switch_mm':
  arch/alpha/include/asm/mmu_context.h:160:2: error:
	implicit declaration of function 'task_thread_info';
	did you mean 'init_thread_info'? [-Werror=implicit-function-declaration]

The file 'mmu_context.h' needed an extra header file.

Link: http://lkml.kernel.org/r/1505668810-7497-1-git-send-email-sudipm.mukherjee@gmail.com
Signed-off-by: Sudip Mukherjee 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Cc: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

alpha: uapi: Add support for __SANE_USERSPACE_TYPES__

2017-09-07T06:34:09+00:00

commit cec80d82142ab25c71eee24b529cfeaf17c43062 upstream.

This fixes compiler errors in perf such as:

tests/attr.c: In function 'store_event':
tests/attr.c:66:27: error: format '%llu' expects argument of type 'long long unsigned int', but argument 6 has type '__u64 {aka long unsigned int}' [-Werror=format=]
  snprintf(path, PATH_MAX, "%s/event-%d-%llu-%d", dir,
                           ^

Signed-off-by: Ben Hutchings 
Tested-by: Michael Cree 
Signed-off-by: Matt Turner 
Signed-off-by: Greg Kroah-Hartman

alpha: fix copy_from_user()

2016-09-24T08:07:45+00:00

commit 2561d309dfd1555e781484af757ed0115035ddb3 upstream.

it should clear the destination even when access_ok() fails.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'v4.3-rc6' into locking/core, to pick up fixes before applying new changes

2015-10-20T08:16:46+00:00

Signed-off-by: Ingo Molnar

word-at-a-time.h: support zero_bytemask() on alpha and tile

2015-10-06T18:53:16+00:00

Both alpha and tile needed implementations of zero_bytemask.

The alpha version is untested.

Signed-off-by: Chris Metcalf

atomic, arch: Audit atomic_{read,set}()

2015-09-23T07:54:28+00:00

This patch makes sure that atomic_{read,set}() are at least
{READ,WRITE}_ONCE().

We already had the 'requirement' that atomic_read() should use
ACCESS_ONCE(), and most archs had this, but a few were lacking.
All are now converted to use READ_ONCE().

And, by a symmetry and general paranoia argument, upgrade atomic_set()
to use WRITE_ONCE().

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Andrew Morton 
Cc: Dmitry Vyukov 
Cc: Linus Torvalds 
Cc: Paul E. McKenney 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: james.hogan@imgtec.com
Cc: linux-kernel@vger.kernel.org
Cc: oleg@redhat.com
Cc: will.deacon@arm.com
Signed-off-by: Ingo Molnar

alpha: io: define ioremap_uc

2015-09-18T04:16:07+00:00

ioremap_uc was not defined and as a result while building with
allmodconfig were getting build error of: implicit declaration of
function 'ioremap_uc'.

Signed-off-by: Sudip Mukherjee 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds