Currently parisc has the whole kernel marked as RWX, meaning any
kernel page at all is eligible to be executed.  This can cause a
theoretical problem on systems with combined I/D TLB because the act
of referencing a page causes a TLB insertion with an executable bit.
This TLB entry may be used by the CPU as the basis for speculating the
page into the I-Cache.  If this speculated page is subsequently used
for a user process, there is the possibility we will get a stale
I-cache line picked up as the binary executes.

As a point of good practise, only mark actual kernel text pages as
executable.  The same has to be done for init_text pages, but they're
converted to data pages (and the I-Cache flushed) when the init memory
is released.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

Bang in our own start_parisc call, which initializes the PDC
width, and turns on the FPU.

Previously, if CONFIG_PRINTK_TIME was on, we'd attempt to use
the FPU before we had enabled it, resulting in a difficult
to diagnose panic.

This patch causes init_per_cpu to redundantly set these for
cpu0, but this is harmless.

And explicitly list it in vmlinux.lds...

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

This reverts commit bd3bb8c15b9a80dbddfb7905b237a4a11a4725b4.

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

This trivial patch fixes the following section warnings on PARISC:
> WARNING: vmlinux.o (.text.1): unexpected section name.
>The (.[number]+) following section name are ld generated and not expected.
> Did you forget to use "ax"/"aw" in a .S file?
> Note that for example <linux/init.h> contains
> section definitions for use in .S files.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

- move boot_args[] into the init section
- move $global$ into the read_mostly section
- fix the following two section mismatches:
WARNING: vmlinux.o(.text+0x9c): Section mismatch: reference to .init.text:start_kernel (between '$pgt_fill_loop' and '$is_pa20')
WARNING: vmlinux.o(.text+0xa0): Section mismatch: reference to .init.text:start_kernel (between '$pgt_fill_loop' and '$is_pa20')

Signed-off-by: Helge Deller <deller@gmx.de>
SIgned-off-by: Kyle McMartin <kyle@mcmartin.ca>

It's been unfinished and broken long enough, and I have some ideas on how
to do it more cleanly.

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

Sam's previous patch missed a few uses of ASM_PAGE_SIZE.

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>