linux.git/arch/alpha/lib, branch v6.6.131

alpha: replace #include with #include

2023-08-22T09:12:46+00:00

Commit ddb5cdbafaaa ("kbuild: generate KSYMTAB entries by modpost")
deprecated , which is now a wrapper of .

Replace #include  with #include .

After all the  lines are converted,  and
 will be removed.

Signed-off-by: Masahiro Yamada

alpha: fix lazy-FPU mis(merged/applied/whatnot)

2023-03-07T01:13:49+00:00

Looks like a braino that used to be fixed in e.g. #next.alpha
had gotten into alpha.git cherry-picked version of that patch.

Sure, alpha has no preempt, but preempt_enable() in place of
preempt_disable() is actively confusing the readers...

Other than that, the cherry-picked variant matches what I have.

Signed-off-by: Al Viro

alpha: lazy FPU switching

2023-02-25T04:14:22+00:00

	On each context switch we save the FPU registers on stack
of old process and restore FPU registers from the stack of new one.
That allows us to avoid doing that each time we enter/leave the
kernel mode; however, that can get suboptimal in some cases.

	For one thing, we don't need to bother saving anything
for kernel threads.  For another, if between entering and leaving
the kernel a thread gives CPU up more than once, it will do
useless work, saving the same values every time, only to discard
the saved copy as soon as it returns from switch_to().

	Alternative solution:

* move the array we save into from switch_stack to thread_info
* have a (thread-synchronous) flag set when we save them
* have another flag set when they should be restored on return to userland.
* do *NOT* save/restore them in do_switch_stack()/undo_switch_stack().
* restore on the exit to user mode if the restore flag had
been set.  Clear both flags.
* on context switch, entry to fork/clone/vfork, before entry into do_signal()
and on entry into straced syscall save the registers and set the 'saved' flag
unless it had been already set.
* on context switch set the 'restore' flag as well.
* have copy_thread() set both flags for child, so the registers would be
restored once the child returns to userland.
* use the saved data in setup_sigcontext(); have restore_sigcontext() set both flags
and copy from sigframe to save area.
* teach ptrace to look for FPU registers in thread_info instead of
switch_stack.
* teach isolated accesses to FPU registers (rdfpcr, wrfpcr, etc.)
to check the 'saved' flag (under preempt_disable()) and work with the save area
if it's been set; if 'saved' flag is found upon write access, set 'restore' flag
as well.

Signed-off-by: Al Viro 
Signed-off-by: Matt Turner

alpha: Implement "current_stack_pointer"

2023-02-14T17:36:22+00:00

To follow the existing per-arch conventions replace open-coded use
of asm "$30" as "current_stack_pointer". This will let it be used in
non-arch places (like HARDENED_USERCOPY).

Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: Geert Uytterhoeven 
Cc: Andrew Morton 
Cc: Mike Rapoport 
Cc: Mark Rutland 
Cc: "Peter Zijlstra (Intel)" 
Cc: Kefeng Wang 
Cc: "Alexander A. Klimov" 
Cc: linux-alpha@vger.kernel.org
Signed-off-by: Kees Cook 
Signed-off-by: Matt Turner

net: unexport csum_and_copy_{from,to}_user

2022-04-29T21:37:59+00:00

csum_and_copy_from_user and csum_and_copy_to_user are exported by a few
architectures, but not actually used in modular code.  Drop the exports.

Link: https://lkml.kernel.org/r/20220421070440.1282704-1-hch@lst.de
Signed-off-by: Christoph Hellwig 
Acked-by: Jakub Kicinski 
Acked-by: Geert Uytterhoeven 
Acked-by: Arnd Bergmann 
Acked-by: Michael Ellerman  (powerpc)
Cc: David Miller 
Signed-off-by: Andrew Morton

alpha: move __udiv_qrnnd library function to arch/alpha/lib/

2021-09-18T21:45:48+00:00

We already had the implementation for __udiv_qrnnd (unsigned divide for
multi-precision arithmetic) as part of the alpha math emulation code.

But you can disable the math emulation code - even if you shouldn't -
and then the MPI code that actually wants this functionality (and is
needed by various crypto functions) will fail to build.

So move the extended-precision divide code to be a regular library
function, just like all the regular division code is.  That way ie is
available regardless of math-emulation.

Signed-off-by: Linus Torvalds

alpha: csum_partial_copy.c: add function prototypes from

2021-05-07T02:24:11+00:00

Fix "no previous prototype" W=1 warnings from the kernel test robot:

  arch/alpha/lib/csum_partial_copy.c:349:1: error: no previous prototype for 'csum_and_copy_from_user' [-Werror=missing-prototypes]
  349 | csum_and_copy_from_user(const void __user *src, void *dst, int len)
      | ^~~~~~~~~~~~~~~~~~~~~~~
  arch/alpha/lib/csum_partial_copy.c:358:1: error: no previous prototype for 'csum_partial_copy_nocheck' [-Werror=missing-prototypes]
  358 | csum_partial_copy_nocheck(const void *src, void *dst, int len)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~

Link: https://lkml.kernel.org/r/20210425235749.19113-1-rdunlap@infradead.org
Fixes: 808b49da54e6 ("alpha: turn csum_partial_copy_from_user() into csum_and_copy_from_user()")
Signed-off-by: Randy Dunlap 
Reported-by: kernel test robot 
Cc: Al Viro 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

alpha: propagate the calling convention changes down to csum_partial_copy.c helpers

2020-08-20T19:45:16+00:00

get rid of set_fs() in csum_partial_copy_nocheck(), while we are at it -
just take the part of csum_and_copy_from_user() sans the access_ok() check
into a helper function and have csum_partial_copy_nocheck() call that.

Signed-off-by: Al Viro

saner calling conventions for csum_and_copy_..._user()

2020-08-20T19:45:15+00:00

All callers of these primitives will
	* discard anything we might've copied in case of error
	* ignore the csum value in case of error
	* always pass 0xffffffff as the initial sum, so the
resulting csum value (in case of success, that is) will never be 0.

That suggest the following calling conventions:
	* don't pass err_ptr - just return 0 on error.
	* don't bother with zeroing destination, etc. in case of error
	* don't pass the initial sum - just use 0xffffffff.

This commit does the minimal conversion in the instances of csum_and_copy_...();
the changes of actual asm code behind them are done later in the series.
Note that this asm code is often shared with csum_partial_copy_nocheck();
the difference is that csum_partial_copy_nocheck() passes 0 for initial
sum while csum_and_copy_..._user() pass 0xffffffff.  Fortunately, we are
free to pass 0xffffffff in all cases and subsequent patches will use that
freedom without any special comments.

A part that could be split off: parisc and uml/i386 claimed to have
csum_and_copy_to_user() instances of their own, but those were identical
to the generic one, so we simply drop them.  Not sure if it's worth
a separate commit...

Signed-off-by: Al Viro

csum_partial_copy_nocheck(): drop the last argument

2020-08-20T19:45:14+00:00

It's always 0.  Note that we theoretically could use ~0U as well -
result will be the same modulo 0xffff, _if_ the damn thing did the
right thing for any value of initial sum; later we'll make use of
that when convenient.

However, unlike csum_and_copy_..._user(), there are instances that
did not work for arbitrary initial sums; c6x is one such.

Signed-off-by: Al Viro