linux-stable.git/arch, branch v3.10.97

parisc: Fix __ARCH_SI_PREAMBLE_SIZE

2016-02-19T22:22:38+00:00

commit e60fc5aa608eb38b47ba4ee058f306f739eb70a0 upstream.

On a 64bit kernel build the compiler aligns the _sifields union in the
struct siginfo_t on a 64bit address. The __ARCH_SI_PREAMBLE_SIZE define
compensates for this alignment and thus fixes the wait testcase of the
strace package.

The symptoms of a wrong __ARCH_SI_PREAMBLE_SIZE value is that
_sigchld.si_stime variable is missed to be copied and thus after a
copy_siginfo() will have uninitialized values.

Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

parisc: Fix syscall restarts

2016-02-19T22:22:38+00:00

commit 71a71fb5374a23be36a91981b5614590b9e722c3 upstream.

On parisc syscalls which are interrupted by signals sometimes failed to
restart and instead returned -ENOSYS which in the worst case lead to
userspace crashes.
A similiar problem existed on MIPS and was fixed by commit e967ef02
("MIPS: Fix restart of indirect syscalls").

On parisc the current syscall restart code assumes that all syscall
callers load the syscall number in the delay slot of the ble
instruction. That's how it is e.g. done in the unistd.h header file:
	ble 0x100(%sr2, %r0)
	ldi #syscall_nr, %r20
Because of that assumption the current code never restored %r20 before
returning to userspace.

This assumption is at least not true for code which uses the glibc
syscall() function, which instead uses this syntax:
	ble 0x100(%sr2, %r0)
	copy regX, %r20
where regX depend on how the compiler optimizes the code and register
usage.

This patch fixes this problem by adding code to analyze how the syscall
number is loaded in the delay branch and - if needed - copy the syscall
number to regX prior returning to userspace for the syscall restart.

Signed-off-by: Helge Deller 
Cc: Mathieu Desnoyers 
Signed-off-by: Greg Kroah-Hartman

parisc: Drop unused MADV_xxxK_PAGES flags from asm/mman.h

2016-02-19T22:22:38+00:00

commit dcbf0d299c00ed4f82ea8d6e359ad88a5182f9b8 upstream.

Drop the MADV_xxK_PAGES flags, which were never used and were from a proposed
API which was never integrated into the generic Linux kernel code.

Signed-off-by: Helge Deller 
Signed-off-by: Greg Kroah-Hartman

sh64: fix __NR_fgetxattr

2016-02-19T22:22:38+00:00

commit 2d33fa1059da4c8e816627a688d950b613ec0474 upstream.

According to arch/sh/kernel/syscalls_64.S and common sense, __NR_fgetxattr
has to be defined to 259, but it doesn't.  Instead, it's defined to 269,
which is of course used by another syscall, __NR_sched_setaffinity in this
case.

This bug was found by strace test suite.

Signed-off-by: Dmitry V. Levin 
Acked-by: Geert Uytterhoeven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mn10300: Select CONFIG_HAVE_UID16 to fix build failure

2016-01-29T05:49:37+00:00

commit c86576ea114a9a881cf7328dc7181052070ca311 upstream.

mn10300 builds fail with

fs/stat.c: In function 'cp_old_stat':
fs/stat.c:163:2: error: 'old_uid_t' undeclared

ipc/util.c: In function 'ipc64_perm_to_ipc_perm':
ipc/util.c:540:2: error: 'old_uid_t' undeclared

Select CONFIG_HAVE_UID16 and remove local definition of CONFIG_UID16
to fix the problem.

Fixes: fbc416ff8618 ("arm64: fix building without CONFIG_UID16")
Cc: Arnd Bergmann 
Acked-by: Arnd Bergmann 
Acked-by: Acked-by: David Howells 
Signed-off-by: Guenter Roeck 
Signed-off-by: Greg Kroah-Hartman

openrisc: fix CONFIG_UID16 setting

2016-01-29T05:49:36+00:00

commit 04ea1e91f85615318ea91ce8ab50cb6a01ee4005 upstream.

openrisc-allnoconfig:

  kernel/uid16.c: In function 'SYSC_setgroups16':
  kernel/uid16.c:184:2: error: implicit declaration of function 'groups_alloc'
  kernel/uid16.c:184:13: warning: assignment makes pointer from integer without a cast

openrisc shouldn't be setting CONFIG_UID16 when CONFIG_MULTIUSER=n.

Fixes: 2813893f8b197a1 ("kernel: conditionally support non-root users, groups and capabilities")
Reported-by: Fengguang Wu 
Cc: Iulia Manda 
Cc: Josh Triplett 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

arm64: mm: ensure that the zero page is visible to the page table walker

2016-01-29T05:49:36+00:00

commit 32d6397805d00573ce1fa55f408ce2bca15b0ad3 upstream.

In paging_init, we allocate the zero page, memset it to zero and then
point TTBR0 to it in order to avoid speculative fetches through the
identity mapping.

In order to guarantee that the freshly zeroed page is indeed visible to
the page table walker, we need to execute a dsb instruction prior to
writing the TTBR.

Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

arm64: Clear out any singlestep state on a ptrace detach operation

2016-01-29T05:49:36+00:00

commit 5db4fd8c52810bd9740c1240ebf89223b171aa70 upstream.

Make sure to clear out any ptrace singlestep state when a ptrace(2)
PTRACE_DETACH call is made on arm64 systems.

Otherwise, the previously ptraced task will die off with a SIGTRAP
signal if the debugger just previously singlestepped the ptraced task.

Signed-off-by: John Blackwood 
[will: added comment to justify why this is in the arch code]
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

powerpc: Make {cmp}xchg* and their atomic_ versions fully ordered

2016-01-29T05:49:35+00:00

commit 81d7a3294de7e9828310bbf986a67246b13fa01e upstream.

According to memory-barriers.txt, xchg*, cmpxchg* and their atomic_
versions all need to be fully ordered, however they are now just
RELEASE+ACQUIRE, which are not fully ordered.

So also replace PPC_RELEASE_BARRIER and PPC_ACQUIRE_BARRIER with
PPC_ATOMIC_ENTRY_BARRIER and PPC_ATOMIC_EXIT_BARRIER in
__{cmp,}xchg_{u32,u64} respectively to guarantee fully ordered semantics
of atomic{,64}_{cmp,}xchg() and {cmp,}xchg(), as a complement of commit
b97021f85517 ("powerpc: Fix atomic_xxx_return barrier semantics")

This patch depends on patch "powerpc: Make value-returning atomics fully
ordered" for PPC_ATOMIC_ENTRY_BARRIER definition.

Signed-off-by: Boqun Feng 
Reviewed-by: Paul E. McKenney 
Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc: Make value-returning atomics fully ordered

2016-01-29T05:49:35+00:00

commit 49e9cf3f0c04bf76ffa59242254110309554861d upstream.

According to memory-barriers.txt:

> Any atomic operation that modifies some state in memory and returns
> information about the state (old or new) implies an SMP-conditional
> general memory barrier (smp_mb()) on each side of the actual
> operation ...

Which mean these operations should be fully ordered. However on PPC,
PPC_ATOMIC_ENTRY_BARRIER is the barrier before the actual operation,
which is currently "lwsync" if SMP=y. The leading "lwsync" can not
guarantee fully ordered atomics, according to Paul Mckenney:

https://lkml.org/lkml/2015/10/14/970

To fix this, we define PPC_ATOMIC_ENTRY_BARRIER as "sync" to guarantee
the fully-ordered semantics.

This also makes futex atomics fully ordered, which can avoid possible
memory ordering problems if userspace code relies on futex system call
for fully ordered semantics.

Fixes: b97021f85517 ("powerpc: Fix atomic_xxx_return barrier semantics")
Signed-off-by: Boqun Feng 
Reviewed-by: Paul E. McKenney 
Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman