linux-kernel - Re: [PATCH v1] kernel/trace:check the val against the available mem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180330174209.4cb77003@gandalf.local.home>
Date:   Fri, 30 Mar 2018 17:42:09 -0400
From:   Steven Rostedt <rostedt@...dmis.org>
To:     Matthew Wilcox <willy@...radead.org>
Cc:     Zhaoyang Huang <huangzhaoyang@...il.com>,
        Ingo Molnar <mingo@...nel.org>, linux-kernel@...r.kernel.org,
        kernel-patch-test@...ts.linaro.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        Joel Fernandes <joelaf@...gle.com>,
        Michal Hocko <mhocko@...e.com>, linux-mm@...ck.org,
        Vlastimil Babka <vbabka@...e.cz>,
        Michal Hocko <mhocko@...nel.org>
Subject: Re: [PATCH v1] kernel/trace:check the val against the available mem

On Fri, 30 Mar 2018 17:30:31 -0400
Steven Rostedt <rostedt@...dmis.org> wrote:

> I'll take a look at si_mem_available() that Joel suggested and see if
> we can make that work.

Wow, this appears to work great! Joel and Zhaoyang, can you test this?

-- Steve

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index a2fd3893cc02..32a803626ee2 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1164,6 +1164,11 @@ static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu)
 	struct buffer_page *bpage, *tmp;
 	long i;
 
+	/* Check if the available memory is there first */
+	i = si_mem_available();
+	if (i < nr_pages)
+		return -ENOMEM;
+
 	for (i = 0; i < nr_pages; i++) {
 		struct page *page;
 		/*