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References: <20230403111020.3136-1-kirill.shutemov@linux.intel.com> <20230403111020.3136-2-kirill.shutemov@linux.intel.com>
In-Reply-To: <20230403111020.3136-2-kirill.shutemov@linux.intel.com>
From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Mon, 3 Apr 2023 15:55:43 +0200
Message-ID: <CACT4Y+b=+DOuL2tR_q2F608xXms-MwWLBsz_+PtVojvQj98rcA@mail.gmail.com>
Subject: Re: [PATCH 1/2] x86/mm/iommu/sva: Fix error code for LAM enabling
 failure due to SVA
To:     "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc:     Dave Hansen <dave.hansen@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, x86@kernel.org,
        Kostya Serebryany <kcc@google.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        Andrey Konovalov <andreyknvl@gmail.com>,
        Alexander Potapenko <glider@google.com>,
        Taras Madan <tarasmadan@google.com>,
        "H . J . Lu" <hjl.tools@gmail.com>,
        Andi Kleen <ak@linux.intel.com>,
        Rick Edgecombe <rick.p.edgecombe@intel.com>,
        Bharata B Rao <bharata@amd.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>,
        Ashok Raj <ashok.raj@intel.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
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On Mon, 3 Apr 2023 at 13:10, Kirill A. Shutemov
<kirill.shutemov@linux.intel.com> wrote:
>
> Normally, LAM and SVA are mutually exclusive. LAM enabling will fail if
> SVA is already in use.
>
> Correct error code for the failure. EINTR is nonsensical there.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Fixes: 23e5d9ec2bab ("x86/mm/iommu/sva: Make LAM and SVA mutually exclusive")
> Reported-by: Dmitry Vyukov <dvyukov@google.com>

Reviewed-by: Dmitry Vyukov <dvyukov@google.com>

> ---
>  arch/x86/kernel/process_64.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
> index 74c7e84a94d8..c7dfd727c9ec 100644
> --- a/arch/x86/kernel/process_64.c
> +++ b/arch/x86/kernel/process_64.c
> @@ -760,7 +760,7 @@ static int prctl_enable_tagged_addr(struct mm_struct *mm, unsigned long nr_bits)
>
>         if (mm_valid_pasid(mm) &&
>             !test_bit(MM_CONTEXT_FORCE_TAGGED_SVA, &mm->context.flags))
> -               return -EINTR;
> +               return -EINVAL;
>
>         if (mmap_write_lock_killable(mm))
>                 return -EINTR;
> --
> 2.39.2
>