linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Niels Dossche <dossche.niels@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Mina Almasry <almasrymina@google.com>,
	Niels Dossche <dossche.niels@gmail.com>
Subject: [PATCH 1/2] mm: mremap: fix sign for EFAULT error return value
Date: Thu, 28 Apr 2022 00:44:38 +0200	[thread overview]
Message-ID: <20220427224439.23828-2-dossche.niels@gmail.com> (raw)
In-Reply-To: <20220427224439.23828-1-dossche.niels@gmail.com>

The mremap syscall is supposed to return a pointer to the new virtual
memory area on success, and a negative value of the error code in case
of failure. Currently, EFAULT is returned when the VMA is not found,
instead of -EFAULT. The users of this syscall will therefore believe
the syscall succeeded in case the VMA didn't exist, as it returns a
pointer to address 0xe (0xe being the value of EFAULT).
Fix the sign of the error value.

Fixes: 550a7d60bd5e ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Niels Dossche <dossche.niels@gmail.com>
---
 mm/mremap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/mremap.c b/mm/mremap.c
index 303d3290b938..0b93fac76851 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -947,7 +947,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 		return -EINTR;
 	vma = vma_lookup(mm, addr);
 	if (!vma) {
-		ret = EFAULT;
+		ret = -EFAULT;
 		goto out;
 	}
 
-- 
2.35.2



  reply	other threads:[~2022-04-27 22:46 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-27 22:44 [PATCH 0/2] mm: mremap: fix sign for EFAULT error return value Niels Dossche
2022-04-27 22:44 ` Niels Dossche [this message]
2022-04-27 22:44 ` [PATCH 2/2] selftest/vm: test that mremap fails on non-existent vma Niels Dossche

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=20220427224439.23828-2-dossche.niels@gmail.com \
    --to=dossche.niels@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=almasrymina@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    /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 NNTP newsgroup(s).