From: Kees Cook <keescook@chromium.org>
To: kernel-hardening@lists.openwall.com
Cc: Emese Revfy <re.emese@gmail.com>
Subject: [kernel-hardening] [PATCH] latent_entropy: provide userspace visibility
Date: Sat, 18 Jun 2016 11:03:20 -0700 [thread overview]
Message-ID: <20160618180320.GA862@www.outflux.net> (raw)
This is just a toy to look at the latent_entropy value as it changes
from userspace. Not intended for actual use...
Signed-off-by: Kees Cook <keescook@chromium.org>
---
kernel/ksysfs.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 152da4a48867..64aed735098a 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -180,6 +180,15 @@ static ssize_t rcu_normal_store(struct kobject *kobj,
KERNEL_ATTR_RW(rcu_normal);
#endif /* #ifndef CONFIG_TINY_RCU */
+#ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
+static ssize_t latent_entropy_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sprintf(buf, "0x%08llx\n", latent_entropy);
+}
+KERNEL_ATTR_RO(latent_entropy);
+#endif
+
/*
* Make /sys/kernel/notes give the raw contents of our kernel .notes section.
*/
@@ -225,6 +234,9 @@ static struct attribute * kernel_attrs[] = {
&rcu_expedited_attr.attr,
&rcu_normal_attr.attr,
#endif
+#ifdef CONFIG_GCC_PLUGIN_LATENT_ENTROPY
+ &latent_entropy_attr.attr,
+#endif
NULL
};
--
2.7.4
--
Kees Cook
Chrome OS & Brillo Security
reply other threads:[~2016-06-18 18:03 UTC|newest]
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