Re: [GIT PULL] Please pull powerpc/linux.git powerpc-5.9-1 tag

[Michael Ellerman <mpe@ellerman.id.au>]

Linus Torvalds <torvalds@linux-foundation.org> writes:
> On Fri, Aug 7, 2020 at 6:14 AM Michael Ellerman <mpe@ellerman.id.au> wrote:
>>
>> Just one minor conflict, in a comment in drivers/misc/ocxl/config.c.
>
> Well, this morning I merged the ptrace ->regset_get() updates from Al,
> and that brought in a different conflict.

Ah fooey.

> I _think_ I resolved it correctly, but while the new model is fairly
> readable, the old one sure wasn't, and who knows how messed up my
> attempt to sort it out was. I don't know the pkey details on powerpc..

The old API was horrible, nice to see it gone.

> So I'd appreciate it if both Al and Aneesh Kumar would check that what
> I did to pkey_get() in arch/powerpc/kernel/ptrace/ptrace-view.c makes
> sense and works..

It looks right to me, except it doesn't build due to ret now being unused:

  /linux/arch/powerpc/kernel/ptrace/ptrace-view.c: In function ‘pkey_get’:
  /linux/arch/powerpc/kernel/ptrace/ptrace-view.c:473:6: error: unused variable ‘ret’ [-Werror=unused-variable]
    473 |  int ret;


Patch below, do you mind taking it directly?

With that fixed our pkey selftests pass and show the expected values in
those regs.

> Side note - it might have been cleaner to just make it do
>
>         membuf_store(&to, target->thread.amr);
>         membuf_store(&to, target->thread.iamr);
>         return membuf_store(&to, default_uamor);
>
> instead of doing that membuf_write() for the first two ones and then
> the membuf_store() for the uamor field, but I did what I did to keep
> the logic as close to what it used to be as possible.

Yep fair enough.

> If I messed up, I apologize.
>
> And if you agree that making it three membuf_store() instead of that
> odd "depend on the exact order of the thread struct and pick two
> consecutive values", I'll leave that to you as a separate cleanup.

Will do.

cheers


From a280ae69f248a0f87b36170a94c5665ef5353f51 Mon Sep 17 00:00:00 2001
From: Michael Ellerman <mpe@ellerman.id.au>
Date: Sat, 8 Aug 2020 09:12:03 +1000
Subject: [PATCH] powerpc/ptrace: Fix build error in pkey_get()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The merge resolution in commit 25d8d4eecace left ret no longer used,
leading to:

  /linux/arch/powerpc/kernel/ptrace/ptrace-view.c: In function ‘pkey_get’:
  /linux/arch/powerpc/kernel/ptrace/ptrace-view.c:473:6: error: unused variable ‘ret’
    473 |  int ret;

Fix it by removing ret.

Fixes: 25d8d4eecace ("Merge tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/kernel/ptrace/ptrace-view.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/powerpc/kernel/ptrace/ptrace-view.c b/arch/powerpc/kernel/ptrace/ptrace-view.c
index 19823a250aa0..7e6478e7ed07 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-view.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-view.c
@@ -470,8 +470,6 @@ static int pkey_active(struct task_struct *target, const struct user_regset *reg
 static int pkey_get(struct task_struct *target, const struct user_regset *regset,
 		    struct membuf to)
 {
-	int ret;
-
 	BUILD_BUG_ON(TSO(amr) + sizeof(unsigned long) != TSO(iamr));
 
 	if (!arch_pkeys_enabled())
-- 
2.25.1