linux-stable.git/arch/xtensa, branch v3.14.78 Linux kernel stable tree xtensa: clear all DBREAKC registers on start 2016-04-12T16:12:46+00:00 Max Filippov jcmvbkbc@gmail.com 2016-03-03T15:34:29+00:00 380787a73fb5fc0b3d1733e6811fcb2cf7e96834 commit 7de7ac785ae18a2cdc78d7560f48e3213d9ea0ab upstream. There are XCHAL_NUM_DBREAK registers, clear them all. This also fixes cryptic assembler error message with binutils 2.25 when XCHAL_NUM_DBREAK is 0: as: out of memory allocating 18446744073709551575 bytes after a total of 495616 bytes Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 7de7ac785ae18a2cdc78d7560f48e3213d9ea0ab upstream.

There are XCHAL_NUM_DBREAK registers, clear them all.
This also fixes cryptic assembler error message with binutils 2.25 when
XCHAL_NUM_DBREAK is 0:

  as: out of memory allocating 18446744073709551575 bytes after a total
  of 495616 bytes

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xtensa: ISS: don't hang if stdin EOF is reached 2016-04-12T16:12:46+00:00 Max Filippov jcmvbkbc@gmail.com 2016-02-08T22:02:38+00:00 14e50d8e66e5f067de6f15fc911839001089812d commit 362014c8d9d51d504c167c44ac280169457732be upstream. Simulator stdin may be connected to a file, when its end is reached kernel hangs in infinite loop inside rs_poll, because simc_poll always signals that descriptor 0 is readable and simc_read always returns 0. Check simc_read return value and exit loop if it's not positive. Also don't rewind polling timer if it's zero. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 362014c8d9d51d504c167c44ac280169457732be upstream.

Simulator stdin may be connected to a file, when its end is reached
kernel hangs in infinite loop inside rs_poll, because simc_poll always
signals that descriptor 0 is readable and simc_read always returns 0.
Check simc_read return value and exit loop if it's not positive. Also
don't rewind polling timer if it's zero.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xtensa: fix kernel register spilling 2015-09-21T17:02:19+00:00 Max Filippov jcmvbkbc@gmail.com 2015-07-16T07:41:02+00:00 aa997211a028c9f80b2db1e9d6a81da8408c674e commit 77d6273e79e3a86552fcf10cdd31a69b46ed2ce6 upstream. call12 can't be safely used as the first call in the inline function, because the compiler does not extend the stack frame of the bounding function accordingly, which may result in corruption of local variables. If a call needs to be done, do call8 first followed by call12. For pure assembly code in _switch_to increase stack frame size of the bounding function. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 77d6273e79e3a86552fcf10cdd31a69b46ed2ce6 upstream.

call12 can't be safely used as the first call in the inline function,
because the compiler does not extend the stack frame of the bounding
function accordingly, which may result in corruption of local variables.

If a call needs to be done, do call8 first followed by call12.

For pure assembly code in _switch_to increase stack frame size of the
bounding function.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xtensa: fix threadptr reload on return to userspace 2015-09-21T17:02:19+00:00 Max Filippov jcmvbkbc@gmail.com 2015-07-04T12:27:39+00:00 5f77cd85b800c08c7c344ca6526a43872afc13b8 commit 4229fb12a03e5da5882b420b0aa4a02e77447b86 upstream. Userspace return code may skip restoring THREADPTR register if there are no registers that need to be zeroed. This leads to spurious failures in libc NPTL tests. Always restore THREADPTR on return to userspace. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4229fb12a03e5da5882b420b0aa4a02e77447b86 upstream.

Userspace return code may skip restoring THREADPTR register if there are
no registers that need to be zeroed. This leads to spurious failures in
libc NPTL tests.

Always restore THREADPTR on return to userspace.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xtensa: ISS: fix locking in TAP network adapter 2015-05-06T19:59:18+00:00 Max Filippov jcmvbkbc@gmail.com 2015-04-03T06:56:21+00:00 4d3c833b8ce626a03ef482610decdc09f996b656 commit 24e94454c8cb6a13634f5a2f5a01da53a546a58d upstream. - don't lock lp->lock in the iss_net_timer for the call of iss_net_poll, it will lock it itself; - invert order of lp->lock and opened_lock acquisition in the iss_net_open to make it consistent with iss_net_poll; - replace spin_lock with spin_lock_bh when acquiring locks used in iss_net_timer from non-atomic context; - replace spin_lock_irqsave with spin_lock_bh in the iss_net_start_xmit as the driver doesn't use lp->lock in the hard IRQ context; - replace __SPIN_LOCK_UNLOCKED(lp.lock) with spin_lock_init, otherwise lockdep is unhappy about using non-static key. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 24e94454c8cb6a13634f5a2f5a01da53a546a58d upstream.

- don't lock lp->lock in the iss_net_timer for the call of iss_net_poll,
  it will lock it itself;
- invert order of lp->lock and opened_lock acquisition in the
  iss_net_open to make it consistent with iss_net_poll;
- replace spin_lock with spin_lock_bh when acquiring locks used in
  iss_net_timer from non-atomic context;
- replace spin_lock_irqsave with spin_lock_bh in the iss_net_start_xmit
  as the driver doesn't use lp->lock in the hard IRQ context;
- replace __SPIN_LOCK_UNLOCKED(lp.lock) with spin_lock_init, otherwise
  lockdep is unhappy about using non-static key.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xtensa: provide __NR_sync_file_range2 instead of __NR_sync_file_range 2015-05-06T19:59:18+00:00 Max Filippov jcmvbkbc@gmail.com 2015-02-27T08:02:38+00:00 21cabb66dd97558f02c2cc20de1efbfb6921f19b commit 01e84c70fe40c8111f960987bcf7f931842e6d07 upstream. xtensa actually uses sync_file_range2 implementation, so it should define __NR_sync_file_range2 as other architectures that use that function. That fixes userspace interface (that apparently never worked) and avoids special-casing xtensa in libc implementations. See the thread ending at http://lists.busybox.net/pipermail/uclibc/2015-February/048833.html for more details. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 01e84c70fe40c8111f960987bcf7f931842e6d07 upstream.

xtensa actually uses sync_file_range2 implementation, so it should
define __NR_sync_file_range2 as other architectures that use that
function. That fixes userspace interface (that apparently never worked)
and avoids special-casing xtensa in libc implementations.
See the thread ending at
http://lists.busybox.net/pipermail/uclibc/2015-February/048833.html
for more details.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xtensa: xtfpga: fix hardware lockup caused by LCD driver 2015-05-06T19:59:18+00:00 Max Filippov jcmvbkbc@gmail.com 2015-02-27T03:28:00+00:00 e089e567352dd6083806332687c4a9c95f7fbb36 commit 4949009eb8d40a441dcddcd96e101e77d31cf1b2 upstream. LCD driver is always built for the XTFPGA platform, but its base address is not configurable, and is wrong for ML605/KC705. Its initialization locks up KC705 board hardware. Make the whole driver optional, and its base address and bus width configurable. Implement 4-bit bus access method. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4949009eb8d40a441dcddcd96e101e77d31cf1b2 upstream.

LCD driver is always built for the XTFPGA platform, but its base address
is not configurable, and is wrong for ML605/KC705. Its initialization
locks up KC705 board hardware.

Make the whole driver optional, and its base address and bus width
configurable. Implement 4-bit bus access method.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vm: add VM_FAULT_SIGSEGV handling support 2015-04-29T08:31:55+00:00 Linus Torvalds torvalds@linux-foundation.org 2015-01-29T18:51:32+00:00 1c2af9193ede7cd223d65c53e72113a24e64ae75 commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream. The core VM already knows about VM_FAULT_SIGBUS, but cannot return a "you should SIGSEGV" error, because the SIGSEGV case was generally handled by the caller - usually the architecture fault handler. That results in lots of duplication - all the architecture fault handlers end up doing very similar "look up vma, check permissions, do retries etc" - but it generally works. However, there are cases where the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV. In particular, when accessing the stack guard page, libsigsegv expects a SIGSEGV. And it usually got one, because the stack growth is handled by that duplicated architecture fault handler. However, when the generic VM layer started propagating the error return from the stack expansion in commit fee7e49d4514 ("mm: propagate error from stack expansion even for guard page"), that now exposed the existing VM_FAULT_SIGBUS result to user space. And user space really expected SIGSEGV, not SIGBUS. To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those duplicate architecture fault handlers about it. They all already have the code to handle SIGSEGV, so it's about just tying that new return value to the existing code, but it's all a bit annoying. This is the mindless minimal patch to do this. A more extensive patch would be to try to gather up the mostly shared fault handling logic into one generic helper routine, and long-term we really should do that cleanup. Just from this patch, you can generally see that most architectures just copied (directly or indirectly) the old x86 way of doing things, but in the meantime that original x86 model has been improved to hold the VM semaphore for shorter times etc and to handle VM_FAULT_RETRY and other "newer" things, so it would be a good idea to bring all those improvements to the generic case and teach other architectures about them too. Reported-and-tested-by: Takashi Iwai <tiwai@suse.de> Tested-by: Jan Engelhardt <jengelh@inai.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots" Cc: linux-arch@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [shengyong: Backport to 3.14 - adjust context - ignore modification for arch nios2, because 3.14 does not support it - add SIGSEGV handling to powerpc/cell spu_fault.c, because 3.14 does not separate it to copro_fault.c - add SIGSEGV handling to mm/memory.c, because 3.14 does not separate it to gup.c ] Signed-off-by: Sheng Yong <shengyong1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[shengyong: Backport to 3.14
 - adjust context
 - ignore modification for arch nios2, because 3.14 does not support it
 - add SIGSEGV handling to powerpc/cell spu_fault.c, because 3.14 does not
   separate it to copro_fault.c
 - add SIGSEGV handling to mm/memory.c, because 3.14 does not separate it
   to gup.c
]
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xtensa: re-wire umount syscall to sys_oldumount 2014-11-21T17:23:01+00:00 Max Filippov jcmvbkbc@gmail.com 2014-10-06T17:01:17+00:00 b120357fe04dd1783773d5a502d05612bb6eb5a1 commit 2651cc6974d47fc43bef1cd8cd26966e4f5ba306 upstream. Userspace actually passes single parameter (path name) to the umount syscall, so new umount just fails. Fix it by requesting old umount syscall implementation and re-wiring umount to it. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2651cc6974d47fc43bef1cd8cd26966e4f5ba306 upstream.

Userspace actually passes single parameter (path name) to the umount
syscall, so new umount just fails. Fix it by requesting old umount
syscall implementation and re-wiring umount to it.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xtensa: fix a6 and a7 handling in fast_syscall_xtensa 2014-10-05T21:52:13+00:00 Max Filippov jcmvbkbc@gmail.com 2014-07-31T18:40:57+00:00 a98cf00477ea274737dc330d23221db6c14484e6 commit d1b6ba82a50cecf94be540a3a153aa89d97511a0 upstream. Remove restoring a6 on some return paths and instead modify and restore it in a single place, using symbolic name. Correctly restore a7 from PT_AREG7 in case of illegal a6 value. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d1b6ba82a50cecf94be540a3a153aa89d97511a0 upstream.

Remove restoring a6 on some return paths and instead modify and restore
it in a single place, using symbolic name.
Correctly restore a7 from PT_AREG7 in case of illegal a6 value.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>