From: Joel Stanley <joel@jms.id.au>
To: Jonathan Corbet <corbet@lwn.net>, "Tobin C . Harding" <me@tobin.cc>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] Documentation: Mention why %p prints ptrval
Date: Thu, 22 Mar 2018 15:53:36 +1030 [thread overview]
Message-ID: <20180322052336.1001-1-joel@jms.id.au> (raw)
When debugging recent kernels, people will see '(ptrval)' but there
isn't much information as to what that means. Briefly describe why it's
there.
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
Documentation/core-api/printk-formats.rst | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
index 934559b3c130..eb30efdd2e78 100644
--- a/Documentation/core-api/printk-formats.rst
+++ b/Documentation/core-api/printk-formats.rst
@@ -60,8 +60,8 @@ Plain Pointers
Pointers printed without a specifier extension (i.e unadorned %p) are
hashed to prevent leaking information about the kernel memory layout. This
has the added benefit of providing a unique identifier. On 64-bit machines
-the first 32 bits are zeroed. If you *really* want the address see %px
-below.
+the first 32 bits are zeroed. The kernel will print ``(ptrval)`` until it
+gathers enough entropy. If you *really* want the address see %px below.
Symbols/Function Pointers
-------------------------
--
2.15.1
next reply other threads:[~2018-03-22 5:23 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-22 5:23 Joel Stanley [this message]
2018-03-22 20:12 ` Tobin C . Harding
2018-03-23 18:42 ` Jonathan Corbet
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