From: Steven Rostedt <rostedt@goodmis.org>
To: "Tobin C. Harding" <me@tobin.cc>
Cc: "Theodore Ts'o" <tytso@mit.edu>,
Linus Torvalds <torvalds@linux-foundation.org>,
Randy Dunlap <rdunlap@infradead.org>,
Kees Cook <keescook@chromium.org>,
Anna-Maria Gleixner <anna-maria@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Arnd Bergmann <arnd@arndb.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 3/4] vsprintf: Use hw RNG for ptr_key
Date: Tue, 12 Jun 2018 14:44:58 -0400 [thread overview]
Message-ID: <20180612144458.31930370@vmware.local.home> (raw)
In-Reply-To: <1528763954-27731-4-git-send-email-me@tobin.cc>
On Tue, 12 Jun 2018 10:39:13 +1000
"Tobin C. Harding" <me@tobin.cc> wrote:
> Currently we must wait for enough entropy to become available before
> hashed pointers can be printed. We can remove this wait by using the
> hw RNG if available.
>
> Use hw RNG to get keying material.
>
> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
-- Steve
> Suggested-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Tobin C. Harding <me@tobin.cc>
> ---
> lib/vsprintf.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index a48aaa79d352..c445f9f28760 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -1675,8 +1675,16 @@ static struct random_ready_callback random_ready = {
>
> static int __init initialize_ptr_random(void)
> {
> - int ret = add_random_ready_callback(&random_ready);
> + int key_size = sizeof(ptr_key);
> + int ret;
> +
> + /* Use hw RNG if available */
> + if (get_random_bytes_arch(&ptr_key, key_size) == key_size) {
> + static_branch_disable(¬_filled_random_ptr_key);
> + return 0;
> + }
>
> + ret = add_random_ready_callback(&random_ready);
> if (!ret) {
> return 0;
> } else if (ret == -EALREADY) {
next prev parent reply other threads:[~2018-06-12 18:45 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-12 0:39 [PATCH v7 0/4] enable early printing of hashed pointers Tobin C. Harding
2018-06-12 0:39 ` [PATCH v7 1/4] random: Fix whitespace pre random-bytes work Tobin C. Harding
2018-06-12 0:39 ` [PATCH v7 2/4] random: Return nbytes filled from hw RNG Tobin C. Harding
2018-06-12 8:39 ` Andy Shevchenko
2018-06-12 18:28 ` Steven Rostedt
2018-06-12 21:42 ` Tobin C. Harding
2018-06-12 0:39 ` [PATCH v7 3/4] vsprintf: Use hw RNG for ptr_key Tobin C. Harding
2018-06-12 18:44 ` Steven Rostedt [this message]
2018-06-12 21:41 ` Tobin C. Harding
2018-06-12 0:39 ` [PATCH v7 4/4] vsprintf: Add command line option debug_boot_weak_hash Tobin C. Harding
2018-06-13 18:46 ` Steven Rostedt
2018-06-13 19:01 ` Steven Rostedt
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