linux-kernel - [PATCH 0/3] add support for never printing hashed addresses

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Date:   Tue, 9 Feb 2021 23:05:26 -0600
From:   Timur Tabi <ttabi@...dia.com>
To:     Petr Mladek <pmladek@...e.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Matthew Wilcox <willy@...radead.org>,
        <akpm@...ux-foundation.org>,
        "Linus Torvalds" <torvalds@...ux-foundation.org>,
        <roman.fietze@...na.com>, "Kees Cook" <keescook@...omium.org>,
        John Ogness <john.ogness@...utronix.de>,
        <akinobu.mita@...il.com>, <glider@...gle.com>,
        Andrey Konovalov <andreyknvl@...gle.com>,
        Marco Elver <elver@...gle.com>,
        Rasmus Villemoes <linux@...musvillemoes.dk>,
        Pavel Machek <pavel@....cz>, <linux-kernel@...r.kernel.org>,
        <linux-mm@...ck.org>
Subject: [PATCH 0/3] add support for never printing hashed addresses

[The list of email addresses on CC: is getting quite lengthy,
so I hope I've included everyone.]

Although hashing addresses printed via printk does make the
kernel more secure, it interferes with debugging, especially
with some functions like print_hex_dump() which always uses
hashed addresses.

To avoid having to choose between %p and %px, it's easier to
add a kernel command line that treats all %p as %px.  This
encourages developers to use %p more without making debugging
more difficult.

Patches #1 and #2 upgrade the kselftest framework so that
it can report on tests that were skipped outright.  This
is needed for the test_printf module which will now skip
%p hashing tests if hashing is disabled.

Patch #2 upgrades the printf library to check the command
line.  It also updates test_printf().

Timur Tabi (3):
  lib/test_printf: use KSTM_MODULE_GLOBALS macro
  kselftest: add support for skipped tests
  [v2] lib/vsprintf: make-printk-non-secret printks all addresses as
    unhashed

 .../admin-guide/kernel-parameters.txt         | 15 +++++++
 lib/test_printf.c                             | 12 +++++-
 lib/vsprintf.c                                | 40 ++++++++++++++++++-
 tools/testing/selftests/kselftest_module.h    | 18 ++++++---
 4 files changed, 75 insertions(+), 10 deletions(-)

-- 
2.25.1