public inbox for linux-arm-kernel@lists.infradead.org 
 help / color / mirror / Atom feed
From: jreiser@bitwagon•com (John Reiser)
To: linux-arm-kernel@lists•infradead.org
Subject: ARM cacheflush syscall with range that spans multiple vma
Date: Sun, 09 Jun 2013 17:05:24 -0700	[thread overview]
Message-ID: <51B51844.9050108@bitwagon.com> (raw)

Why does the ARM cacheflush syscall stop after the lowest vma
which intersects the user-requested range?  The range could
span more than one vma having contiguous addresses, such as
two files MAP_SHARED into adjacent pages; or even a region
that contains holes (pages not present.)

The code path in arch/arm/kernel/traps.c is:

arm_syscall():
        case NR(cacheflush):
                return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);

do_cache_op() contains no loop for more than one vma:
        vma = find_vma(mm, start);

-- 

             reply	other threads:[~2013-06-10  0:05 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-10  0:05 John Reiser [this message]
2013-06-10  8:59 ` ARM cacheflush syscall with range that spans multiple vma Russell King - ARM Linux
2013-06-10  9:09   ` Will Deacon
2013-06-10 20:16     ` John Reiser
2013-06-10 23:42       ` Russell King - ARM Linux
2013-06-11 10:11   ` Will Deacon

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=51B51844.9050108@bitwagon.com \
    --to=jreiser@bitwagon$(echo .)com \
    --cc=linux-arm-kernel@lists$(echo .)infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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