The __copy_user function can corrupt the stack in the case of a
non-trivial length of data, and either of the first two move instructions
cause an exception. This is because the fixup for these two instructions
is mapped to the no_pop case, but these instructions execute after the
stack is pushed.
This change creates an explicit NO_POP exception mapping macro, and uses
it for the two instructions executed in the trivial case where no stack
pushes occur.
More information at ST Linux bugzilla:
https://bugzilla.stlinux.com/show_bug.cgi?id=4824
Signed-off-by: Dylan Reid <dylan_reid@bose.com>
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Presently these are restricted to SH-3 and SH-4, so we reorder the
ifdefs a bit to let other parts use these also.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Now that copy_to_user_page()/copy_from_user_page() are wired up, we
can drop the old __copy_xxx() implementations. Now that the page
colouring scheme has changed via kmap_coherent(), we can avoid the
flush in these specific helpers.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
movca.l is restricted to SH-4 and up only, though compilers that
are unable to support ISA tuning (especially older versions of
binutils) will happily compile in the bogus opcode on older parts.
Conditionalize it to fix SH-3 regressions noted by Kristoffer.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This implements a fast-path for small (less than 12 bytes) copies,
with the existing path treated as the slow-path and left as the default
behaviour for all other copy sizes.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
SH-3 comes up with the PAGE_SIZE on a misaligned boundary:
arch/sh/mm/copy_page.S: Assembler messages:
arch/sh/mm/copy_page.S:132: Warning: misaligned data
fix it up with explicit alignment.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
There were a number of places that made evil PAGE_SIZE == 4k
assumptions that ended up breaking when trying to play with
8k and 64k page sizes, this fixes those up.
The most significant change is the way we load THREAD_SIZE,
previously this was done via:
mov #(THREAD_SIZE >> 8), reg
shll8 reg
to avoid a memory access and allow the immediate load. With
a 64k PAGE_SIZE, we're out of range for the immediate load
size without resorting to special instructions available in
later ISAs (movi20s and so on). The "workaround" for this is
to bump up the shift to 10 and insert a shll2, which gives a
bit more flexibility while still being much cheaper than a
memory access.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Stuart MENEFY