From: Michael Schmitz <schmitzmic@gmail.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Andreas Schwab <schwab@linux-m68k.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Greg Ungerer <gerg@linux-m68k.org>,
linux-m68k@lists.linux-m68k.org,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: RFC: remove set_fs for m68k
Date: Thu, 12 Aug 2021 15:37:59 +1200 [thread overview]
Message-ID: <96e587de-9600-16aa-d1fb-686ab1f3ed06@gmail.com> (raw)
In-Reply-To: <20210811091259.GA15014@lst.de>
Hi Christoph,
I run my tests on a 030, so that patch is unlikely to have any effect
there. I'll give it a spin though (once my current tests with restoring
USER_DATA everywhere but logging if get_fc() reads something else) are
done.
I wonder whether copy_thread() ought to set SUPER_DATA when creating
kernel threads though (see the comment there). With init_thread starting
out with USER_DATA now, we'd have to explicitly set SUPER_DATA instead
of just copying the current value there...
Leaves flush_icache_range() and flush_tlb_page() to worry about.
Cheers,
Michael
Am 11.08.2021 um 21:12 schrieb Christoph Hellwig:
> Hi Michael,
>
> from looking at your patches I suspect the 040 traps might be able
> to be called witha different fc. Can you check if the below patch,
> which is a cut down version of your changes makes all the issues
> go away?
>
> diff --git a/arch/m68k/include/asm/processor.h b/arch/m68k/include/asm/processor.h
> index debb4537eab5..a554e529fd26 100644
> --- a/arch/m68k/include/asm/processor.h
> +++ b/arch/m68k/include/asm/processor.h
> @@ -94,6 +94,13 @@ static inline void set_fc(unsigned long val)
> "movec %0,%/dfc\n\t"
> : /* no outputs */ : "r" (val) : "memory");
> }
> +static inline unsigned long get_fc(void)
> +{
> + unsigned long val;
> + __asm__ ("movec %/dfc,%0":"=r" (val):);
> + WARN_ON_ONCE(val != USER_DATA);
> + return val;
> +}
> #else
> static inline void set_fc(unsigned long val)
> {
> diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c
> index c5e0a4f93bd5..1b073299fa55 100644
> --- a/arch/m68k/kernel/traps.c
> +++ b/arch/m68k/kernel/traps.c
> @@ -181,6 +181,7 @@ static inline void access_error060 (struct frame *fp)
> static inline unsigned long probe040(int iswrite, unsigned long addr, int wbs)
> {
> unsigned long mmusr;
> + unsigned long old_fc = get_fc();
>
> set_fc(wbs);
>
> @@ -191,7 +192,7 @@ static inline unsigned long probe040(int iswrite, unsigned long addr, int wbs)
>
> asm volatile (".chip 68040; movec %%mmusr,%0; .chip 68k" : "=r" (mmusr));
>
> - set_fc(USER_DATA);
> + set_fc(old_fc);
>
> return mmusr;
> }
> @@ -200,6 +201,7 @@ static inline int do_040writeback1(unsigned short wbs, unsigned long wba,
> unsigned long wbd)
> {
> int res = 0;
> + unsigned long old_fc = get_fc();
>
> set_fc(wbs);
>
> @@ -215,7 +217,7 @@ static inline int do_040writeback1(unsigned short wbs, unsigned long wba,
> break;
> }
>
> - set_fc(USER_DATA);
> + set_fc(old_fc);
>
> pr_debug("do_040writeback1, res=%d\n", res);
>
>
next prev parent reply other threads:[~2021-08-12 3:38 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-09 7:01 RFC: remove set_fs for m68k Christoph Hellwig
2021-07-09 7:01 ` [PATCH 1/7] m68k: document that access_ok is broken for !CONFIG_CPU_HAS_ADDRESS_SPACES Christoph Hellwig
2021-07-09 7:01 ` [PATCH 2/7] m68k: use BUILD_BUG for passing invalid sizes to get_user/put_user Christoph Hellwig
2021-07-09 7:01 ` [PATCH 3/7] m68k: remove the inline copy_{from,to}_user variants Christoph Hellwig
2021-07-09 7:01 ` [PATCH 4/7] m68k: remove the err argument to the get_user/put_user assembly helpers Christoph Hellwig
2021-07-09 7:01 ` [PATCH 5/7] m68k: factor the 8-byte lowlevel {get,put}_user code into helpers Christoph Hellwig
2021-07-09 7:01 ` [PATCH 6/7] m68k: provide __{get,put}_kernel_nofault Christoph Hellwig
2021-07-09 7:01 ` [PATCH 7/7] m68k: remove set_fs() Christoph Hellwig
2021-07-11 7:20 ` RFC: remove set_fs for m68k Michael Schmitz
2021-07-12 9:50 ` Christoph Hellwig
2021-07-12 10:20 ` Andreas Schwab
2021-07-12 19:12 ` Michael Schmitz
2021-07-13 5:41 ` Christoph Hellwig
2021-07-13 8:16 ` Michael Schmitz
2021-07-13 8:54 ` Christoph Hellwig
2021-07-14 19:26 ` Michael Schmitz
2021-07-14 20:03 ` Andreas Schwab
2021-07-15 5:44 ` Michael Schmitz
2021-07-16 2:03 ` Michael Schmitz
2021-07-17 5:41 ` Michael Schmitz
2021-07-18 1:14 ` Michael Schmitz
2021-07-21 17:05 ` Christoph Hellwig
2021-07-21 19:20 ` Michael Schmitz
2021-07-23 4:00 ` Michael Schmitz
2021-07-23 5:11 ` Christoph Hellwig
2021-07-25 7:36 ` Michael Schmitz
2021-07-31 19:31 ` Michael Schmitz
2021-08-06 3:10 ` Michael Schmitz
2021-08-11 9:12 ` Christoph Hellwig
2021-08-12 3:37 ` Michael Schmitz [this message]
2021-08-15 7:42 ` Christoph Hellwig
2021-08-15 19:17 ` Michael Schmitz
2021-08-16 6:58 ` Christoph Hellwig
[not found] ` <23f745f2-9086-81fb-3d9e-40ea08a1923@linux-m68k.org>
[not found] ` <20210816075155.GA29187@lst.de>
[not found] ` <d407a2a1-738b-5cd5-c2ed-b7250c5da8ec@gmail.com>
[not found] ` <83571ae-10ae-2919-cde-b6b4a5769c9@linux-m68k.org>
[not found] ` <dc594142-e459-533e-cac2-c7a213cec464@gmail.com>
[not found] ` <f4ab2dcb-6761-c60b-54ce-35d0d017d371@gmail.com>
[not found] ` <d772d22e-a945-3e35-80a2-f4783893bea@linux-m68k.org>
[not found] ` <b2c55280-657b-51c2-065c-3fc93db050b9@gmail.com>
[not found] ` <d7b8f7eb-fc18-c8d-fe3e-dcdf19d3f4b@linux-m68k.org>
[not found] ` <755e55ba-4ce2-b4e4-a628-5abc183a557a@linux-m68k.org>
[not found] ` <b52a10fe-3e4b-5740-d3f8-52bce3bc988@linux-m68k.org>
[not found] ` <31f27da7-be60-8eb-9834-748b653c2246@linux-m68k.org>
2021-09-07 3:28 ` Mainline kernel crashes, was " Finn Thain
2021-09-07 5:53 ` Michael Schmitz
2021-09-07 23:50 ` Finn Thain
2021-09-08 8:54 ` Michael Schmitz
2021-09-09 9:40 ` Finn Thain
2021-09-09 23:29 ` Michael Schmitz
2021-09-09 22:51 ` Finn Thain
2021-09-10 0:03 ` Michael Schmitz
2021-09-12 0:51 ` Finn Thain
2021-09-12 3:55 ` Brad Boyer
2021-09-13 1:27 ` Finn Thain
2021-09-13 3:26 ` Michael Schmitz
2021-09-13 5:22 ` Finn Thain
2021-09-13 7:20 ` Michael Schmitz
2021-09-14 3:13 ` Michael Schmitz
2021-09-15 1:38 ` Finn Thain
2021-09-15 8:37 ` Michael Schmitz
2021-09-16 9:04 ` Finn Thain
2021-09-16 22:28 ` Michael Schmitz
2021-09-21 21:14 ` Michael Schcmitz
2021-08-22 19:33 ` Michael Schmitz
2021-08-23 4:04 ` Michael Schmitz
2021-08-23 17:59 ` Linus Torvalds
2021-08-23 21:31 ` Michael Schmitz
2021-08-23 21:49 ` Linus Torvalds
2021-08-24 8:08 ` Andreas Schwab
2021-08-24 8:44 ` Michael Schmitz
2021-08-24 8:59 ` Andreas Schwab
2021-08-25 7:51 ` Michael Schmitz
2021-08-25 8:44 ` Andreas Schwab
2021-08-25 22:59 ` Michael Schmitz
2021-08-25 23:30 ` Brad Boyer
2021-08-26 7:46 ` Michael Schmitz
2021-08-26 7:45 ` Andreas Schwab
2021-09-14 2:43 ` Michael Schmitz
2021-09-14 15:54 ` Linus Torvalds
2021-09-14 16:28 ` Al Viro
2021-09-14 16:38 ` Linus Torvalds
2021-09-15 1:06 ` Al Viro
2021-07-12 19:04 ` Michael Schmitz
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