From: Jarkko Sakkinen <jarkko@kernel.org>
To: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Dinh Nguyen <dinguyen@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
linux-sgx@vger.kernel.org, amd-gfx@lists.freedesktop.org,
linux-mm@kvack.org
Subject: Re: [PATCH 2/5] x86/sgx: use VM_ACCESS_FLAGS
Date: Sun, 23 Oct 2022 23:09:24 +0300 [thread overview]
Message-ID: <Y1WfdDBzOUumhJ65@kernel.org> (raw)
In-Reply-To: <Y1WfD1x+XDi3xvpL@kernel.org>
On Sun, Oct 23, 2022 at 11:07:47PM +0300, Jarkko Sakkinen wrote:
> On Wed, Oct 19, 2022 at 11:49:42AM +0800, Kefeng Wang wrote:
> > Simplify VM_READ|VM_WRITE|VM_EXEC with VM_ACCESS_FLAGS.
> >
> > Cc: Jarkko Sakkinen <jarkko@kernel.org>
> > Cc: Dave Hansen <dave.hansen@linux.intel.com>
> > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> > ---
> > arch/x86/kernel/cpu/sgx/encl.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/x86/kernel/cpu/sgx/encl.c b/arch/x86/kernel/cpu/sgx/encl.c
> > index 1ec20807de1e..6225c525372d 100644
> > --- a/arch/x86/kernel/cpu/sgx/encl.c
> > +++ b/arch/x86/kernel/cpu/sgx/encl.c
> > @@ -268,7 +268,7 @@ static struct sgx_encl_page *sgx_encl_load_page_in_vma(struct sgx_encl *encl,
> > unsigned long addr,
> > unsigned long vm_flags)
> > {
> > - unsigned long vm_prot_bits = vm_flags & (VM_READ | VM_WRITE | VM_EXEC);
> > + unsigned long vm_prot_bits = vm_flags & VM_ACCESS_FLAGS;
> > struct sgx_encl_page *entry;
> >
> > entry = xa_load(&encl->page_array, PFN_DOWN(addr));
> > @@ -502,7 +502,7 @@ static void sgx_vma_open(struct vm_area_struct *vma)
> > int sgx_encl_may_map(struct sgx_encl *encl, unsigned long start,
> > unsigned long end, unsigned long vm_flags)
> > {
> > - unsigned long vm_prot_bits = vm_flags & (VM_READ | VM_WRITE | VM_EXEC);
> > + unsigned long vm_prot_bits = vm_flags & VM_ACCESS_FLAGS;
> > struct sgx_encl_page *page;
> > unsigned long count = 0;
> > int ret = 0;
> > --
> > 2.35.3
> >
>
> Why?
Only benefit I see is a downside: you have xref VM_ACCESS_FLAGS, which
is counter-productive. Zero gain.
BR, Jarkko
next prev parent reply other threads:[~2022-10-23 20:09 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-19 3:49 [PATCH 0/5] mm: cleanup with VM_ACCESS_FLAGS Kefeng Wang
2022-10-19 3:49 ` [PATCH 1/5] nios2: remove unused INIT_MMAP Kefeng Wang
2022-10-19 3:49 ` [PATCH 2/5] x86/sgx: use VM_ACCESS_FLAGS Kefeng Wang
2022-10-23 20:07 ` Jarkko Sakkinen
2022-10-23 20:09 ` Jarkko Sakkinen [this message]
2022-10-19 3:49 ` [PATCH 3/5] mm: mprotect: " Kefeng Wang
2022-10-19 3:49 ` [PATCH 4/5] mm: debug_vm_pgtable: " Kefeng Wang
2022-10-19 3:49 ` [PATCH 5/5] amdgpu: " Kefeng Wang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Y1WfdDBzOUumhJ65@kernel.org \
--to=jarkko@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=amd-gfx@lists.freedesktop.org \
--cc=dave.hansen@linux.intel.com \
--cc=dinguyen@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-sgx@vger.kernel.org \
--cc=wangkefeng.wang@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).