all architectures converted
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

[kudos to Piotr Sroka for spotting a braino in the previous variant]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Merced is fucked, so what else is new?
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

it hadn't been biarch for years
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

turn into static inline, kill the 'segment' argument.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

it's only evaluated if the first argument is not 0, and in those
cases it's always equal to get_fs()
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

always equal to get_fs()
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

for one thing, the last argument is always __access_mask and had been such
since 2.4.0-test3pre8; for another, it can bloody well be a static inline -
-O2 or -Os, __builtin_constant_p() propagates through static inline calls.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Switch to using raw user copy instead of providing metag specific
[__]copy_{to,from}_user[_inatomic](). This simplifies the metag
uaccess.h and allows us to take advantage of extra checking in the
generic versions.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-metag@vger.kernel.org
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The rapf copy loops in the Meta usercopy code is missing some extable
entries for HTP cores with unaligned access checking enabled, where
faults occur on the instruction immediately after the faulting access.

Add the fixup labels and extable entries for these cases so that corner
case user copy failures don't cause kernel crashes.

Fixes: 373cd784 ("metag: Memory handling")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
Cc: stable@vger.kernel.org

The fixup code to rewind the source pointer in
__asm_copy_from_user_{32,64}bit_rapf_loop() always rewound the source by
a single unit (4 or 8 bytes), however this is insufficient if the fault
didn't occur on the first load in the loop, as the source pointer will
have been incremented but nothing will have been stored until all 4
register [pairs] are loaded.

Read the LSM_STEP field of TXSTATUS (which is already loaded into a
register), a bit like the copy_to_user versions, to determine how many
iterations of MGET[DL] have taken place, all of which need rewinding.

Fixes: 373cd784 ("metag: Memory handling")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
Cc: stable@vger.kernel.org

The fixup code for the copy_to_user rapf loops reads TXStatus.LSM_STEP
to decide how far to rewind the source pointer. There is a special case
for the last execution of an MGETL/MGETD, since it leaves LSM_STEP=0
even though the number of MGETLs/MGETDs attempted was 4. This uses ADDZ
which is conditional upon the Z condition flag, but the AND instruction
which masked the TXStatus.LSM_STEP field didn't set the condition flags
based on the result.

Fix that now by using ANDS which does set the flags, and also marking
the condition codes as clobbered by the inline assembly.

Fixes: 373cd784 ("metag: Memory handling")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
Cc: stable@vger.kernel.org

Currently we try to zero the destination for a failed read from userland
in fixup code in the usercopy.c macros. The rest of the destination
buffer is then zeroed from __copy_user_zeroing(), which is used for both
copy_from_user() and __copy_from_user().

Unfortunately we fail to zero in the fixup code as D1Ar1 is set to 0
before the fixup code entry labels, and __copy_from_user() shouldn't even
be zeroing the rest of the buffer.

Move the zeroing out into copy_from_user() and rename
__copy_user_zeroing() to raw_copy_from_user() since it no longer does
any zeroing. This also conveniently matches the name needed for
RAW_COPY_USER support in a later patch.

Fixes: 373cd784 ("metag: Memory handling")
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
Cc: stable@vger.kernel.org

When copying to userland on Meta, if any faults are encountered
immediately abort the copy instead of continuing on and repeatedly
faulting, and worse potentially copying further bytes successfully to
subsequent valid pages.

Fixes: 373cd784 ("metag: Memory handling")
Reported-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
Cc: stable@vger.kernel.org

Fix the error checking of the alignment adjustment code in
raw_copy_from_user(), which mistakenly considers it safe to skip the
error check when aligning the source buffer on a 2 or 4 byte boundary.

If the destination buffer was unaligned it may have started to copy
using byte or word accesses, which could well be at the start of a new
(valid) source page. This would result in it appearing to have copied 1
or 2 bytes at the end of the first (invalid) page rather than none at
all.

Fixes: 373cd784 ("metag: Memory handling")
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
Cc: stable@vger.kernel.org

Metag's lib/usercopy.c has a bunch of copy_from_user macros for larger
copies between 5 and 16 bytes which are completely unused. Before fixing
zeroing lets drop these macros so there is less to fix.
Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-metag@vger.kernel.org
Cc: stable@vger.kernel.org

'from' is the input buffer, it should be prefetched with prefetch, not
prefetchw.
Tested-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and drop zeroing in sparc32.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and remove dead declarations, while we are at it
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

[folded a fix from Martin]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and switch to generic out of line version in lib/usercopy.c
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit 73580dac ("parisc: Fix system shutdown halt") introduced an endless
loop for systems which don't provide a software power off function.  But the
soft lockup detector will detect this and report stalled CPUs after some time.
Avoid those unwanted warnings by disabling the soft lockup detector.

Fixes: 73580dac ("parisc: Fix system shutdown halt")
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.9+

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: NAl Viro <viro@ZenIV.linux.org.uk>
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: NHelge Deller <deller@gmx.de>

pa_memcpy() is the major memcpy implementation in the parisc kernel which is
used to do any kind of userspace/kernel memory copies.

Al Viro noticed various bugs in the implementation of pa_mempcy(), most notably
that in case of faults it may report back to have copied more bytes than it
actually did.

Fixing those bugs is quite hard in the C-implementation, because the compiler
is messing around with the registers and we are not guaranteed that specific
variables are always in the same processor registers. This makes proper fault
handling complicated.

This patch implements pa_memcpy() in assembler. That way we have correct fault
handling and adding a 64-bit copy routine was quite easy.

Runtime tested with 32- and 64bit kernels.
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Signed-off-by: NHelge Deller <deller@gmx.de>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... especially since copy_in_user() doesn't
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>