From: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
To: Ashish Sadanandan <ashish.sadanandan@gmail.com>
Cc: dev@dpdk.org, john.levon@nutanix.com, stable@dpdk.org
Subject: Re: [PATCH v2 1/1] eal/linux: reject --huge-dir not parent of mountpt
Date: Wed, 4 Jan 2023 14:24:56 +0300 [thread overview]
Message-ID: <20230104142456.320fc95a@sovereign> (raw)
In-Reply-To: <20230104000030.187857-1-ashish.sadanandan@gmail.com>
2023-01-03 17:00 (UTC-0700), Ashish Sadanandan:
> The code added for allowing --huge-dir to specify hugetlbfs
> sub-directories has a bug where it incorrectly matches mounts that
> contain a prefix of the specified --huge-dir.
>
> Consider --huge-dir=/dev/hugepages1G is passed to rte_eal_init. Given
> the following hugetlbfs mounts
>
> $ mount | grep hugetlbfs
> hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M)
> hugetlbfs on /dev/hugepages1G type hugetlbfs (rw,relatime,pagesize=1024M)
> hugetlbfs on /mnt/huge type hugetlbfs (rw,relatime,pagesize=2M)
>
> get_hugepage_dir is first called with hugepage_sz=2097152. While
> iterating over all mount points, /dev/hugepages is incorrectly
> determined to be a match because it's a prefix of --huge-dir. The caller
> then obtains an exclusive lock on --huge-dir.
>
> In the next call to get_hugepage_dir, hugepage_sz=1073741824. This call
> correctly determines /dev/hugepages1G is a match. The caller again
> attempts to obtain an exclusive lock on --huge-dir and deadlocks because
> it's already holding a lock.
>
> This has been corrected by ensuring any matched mount point is either an
> exact match or a parent path of --huge-dir.
>
> Fixes: 24d5a1ce6b85 ("eal/linux: allow hugetlbfs sub-directories")
> Cc: john.levon@nutanix.com
> Cc: stable@dpdk.org
> Signed-off-by: Ashish Sadanandan <ashish.sadanandan@gmail.com>
Acked-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> ---
> lib/eal/linux/eal_hugepage_info.c | 15 +++++++++++++--
> 1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/lib/eal/linux/eal_hugepage_info.c b/lib/eal/linux/eal_hugepage_info.c
> index a1b6cb31ff..180abd930c 100644
> --- a/lib/eal/linux/eal_hugepage_info.c
> +++ b/lib/eal/linux/eal_hugepage_info.c
> @@ -265,12 +265,23 @@ get_hugepage_dir(uint64_t hugepage_sz, char *hugedir, int len)
> break;
> }
>
> + size_t mountpt_len = strlen(splitstr[MOUNTPT]);
> + size_t hugepage_dir_len = strlen(internal_conf->hugepage_dir);
The second one can be done before the loop.
Please declare all variables at the beginning of the block per code style.
> +
> /*
> * Ignore any mount that doesn't contain the --huge-dir
> * directory.
> */
> if (strncmp(internal_conf->hugepage_dir, splitstr[MOUNTPT],
> - strlen(splitstr[MOUNTPT])) != 0) {
> + mountpt_len) != 0) {
> + continue;
> + }
> + /*
> + * Ignore any mount where hugepage_dir is not a parent path of
> + * the mount
> + */
> + else if(hugepage_dir_len > mountpt_len &&
> + internal_conf->hugepage_dir[mountpt_len] != '/') {
Nit: maybe a single comment for both conditions would be more clear:
/*
* Ignore any mount that is not --huge-dir or its subdirectory.
*/
> continue;
> }
>
> @@ -278,7 +289,7 @@ get_hugepage_dir(uint64_t hugepage_sz, char *hugedir, int len)
> * We found a match, but only prefer it if it's a longer match
> * (so /mnt/1 is preferred over /mnt for matching /mnt/1/2)).
> */
> - if (strlen(splitstr[MOUNTPT]) > strlen(found))
> + if (mountpt_len > strlen(found))
> strlcpy(found, splitstr[MOUNTPT], len);
> } /* end while fgets */
next prev parent reply other threads:[~2023-01-04 11:25 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-03 18:57 [PATCH 1/1] eal/linux: reject mountpt shorter than --huge-dir Ashish Sadanandan
2023-01-03 23:53 ` Ashish Sadanandan
2023-01-04 0:00 ` [PATCH v2 1/1] eal/linux: reject --huge-dir not parent of mountpt Ashish Sadanandan
2023-01-04 11:24 ` Dmitry Kozlyuk [this message]
2023-01-04 18:17 ` Ashish Sadanandan
2023-01-04 16:22 ` John Levon
2023-01-04 18:17 ` Ashish Sadanandan
2023-01-04 18:17 ` [PATCH v3 " Ashish Sadanandan
2023-01-09 1:52 ` [PATCH v4 1/1] eal/linux: reject mountpt not parent of --huge-dir Ashish Sadanandan
2023-01-11 12:11 ` John Levon
2023-01-16 18:25 ` Ashish Sadanandan
2023-02-10 11:04 ` David Marchand
2023-02-10 11:01 ` David Marchand
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=20230104142456.320fc95a@sovereign \
--to=dmitry.kozliuk@gmail.com \
--cc=ashish.sadanandan@gmail.com \
--cc=dev@dpdk.org \
--cc=john.levon@nutanix.com \
--cc=stable@dpdk.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).