From: Uladzislau Rezki <urezki@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
Hillf Danton <hdanton@sina.com>, Michal Hocko <mhocko@suse.com>,
Matthew Wilcox <willy@infradead.org>,
Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH 1/1] mm/vmalloc.c: Add an error message if two areas overlap
Date: Fri, 10 Jul 2020 21:44:03 +0200 [thread overview]
Message-ID: <20200710194403.GA19388@pc636> (raw)
In-Reply-To: <20200710194042.2510-1-urezki@gmail.com>
> Before triggering a BUG() it would be useful to understand
> how two areas overlap between each other. Print information
> about start/end addresses of both VAs and their addresses.
>
> For example if both are identical it could mean double free.
>
> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
> ---
> mm/vmalloc.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 5a2b55c8dd9a..1679b01febcd 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -549,8 +549,13 @@ find_va_links(struct vmap_area *va,
> else if (va->va_end > tmp_va->va_start &&
> va->va_start >= tmp_va->va_end)
> link = &(*link)->rb_right;
> - else
> + else {
> + pr_err("Overlaps: 0x%px(0x%lx-0x%lx), 0x%px(0x%lx-0x%lx)\n",
> + va, va->va_start, va->va_end, tmp_va,
> + tmp_va->va_start, tmp_va->va_end);
> +
> BUG();
> + }
> } while (*link);
>
> *parent = &tmp_va->rb_node;
> @@ -1993,6 +1998,9 @@ static void vmap_init_free_space(void)
> insert_vmap_area_augment(free, NULL,
> &free_vmap_area_root,
> &free_vmap_area_list);
> + insert_vmap_area_augment(free, NULL,
> + &free_vmap_area_root,
> + &free_vmap_area_list);
> }
> }
> }
>
Please ignore this patch, i will upload v2.
Sorry for inconvenience.
--
Vlad Rezki
next prev parent reply other threads:[~2020-07-10 19:44 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-10 19:40 [PATCH 1/1] mm/vmalloc.c: Add an error message if two areas overlap Uladzislau Rezki (Sony)
2020-07-10 19:44 ` Uladzislau Rezki [this message]
2020-07-10 19:44 ` Matthew Wilcox
2020-07-10 19:45 ` Uladzislau Rezki
2020-07-10 20:00 ` Uladzislau Rezki
2020-07-10 20:01 ` Matthew Wilcox
2020-07-10 20:04 ` Uladzislau Rezki
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