<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/lib/ubsan.c, branch v4.9.7</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>UBSAN: fix typo in format string</title>
<updated>2016-08-02T21:31:41+00:00</updated>
<author>
<name>Nicolas Iooss</name>
<email>nicolas.iooss_linux@m4x.org</email>
</author>
<published>2016-08-02T21:03:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=901d805c33fc4c029fc6b2d94ee5fb7d30278045'/>
<id>901d805c33fc4c029fc6b2d94ee5fb7d30278045</id>
<content type='text'>
handle_object_size_mismatch() used %pk to format a kernel pointer with
pr_err().  This seemed to be a misspelling for %pK, but using this to
format a kernel pointer does not make much sence here.

Therefore use %p instead, like in handle_missaligned_access().

Link: http://lkml.kernel.org/r/20160730083010.11569-1-nicolas.iooss_linux@m4x.org
Signed-off-by: Nicolas Iooss &lt;nicolas.iooss_linux@m4x.org&gt;
Acked-by: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
handle_object_size_mismatch() used %pk to format a kernel pointer with
pr_err().  This seemed to be a misspelling for %pK, but using this to
format a kernel pointer does not make much sence here.

Therefore use %p instead, like in handle_missaligned_access().

Link: http://lkml.kernel.org/r/20160730083010.11569-1-nicolas.iooss_linux@m4x.org
Signed-off-by: Nicolas Iooss &lt;nicolas.iooss_linux@m4x.org&gt;
Acked-by: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>UBSAN: run-time undefined behavior sanity checker</title>
<updated>2016-01-21T01:09:18+00:00</updated>
<author>
<name>Andrey Ryabinin</name>
<email>aryabinin@virtuozzo.com</email>
</author>
<published>2016-01-20T23:00:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c6d308534aef6c99904bf5862066360ae067abc4'/>
<id>c6d308534aef6c99904bf5862066360ae067abc4</id>
<content type='text'>
UBSAN uses compile-time instrumentation to catch undefined behavior
(UB).  Compiler inserts code that perform certain kinds of checks before
operations that could cause UB.  If check fails (i.e.  UB detected)
__ubsan_handle_* function called to print error message.

So the most of the work is done by compiler.  This patch just implements
ubsan handlers printing errors.

GCC has this capability since 4.9.x [1] (see -fsanitize=undefined
option and its suboptions).
However GCC 5.x has more checkers implemented [2].
Article [3] has a bit more details about UBSAN in the GCC.

[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
[3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/

Issues which UBSAN has found thus far are:

Found bugs:

 * out-of-bounds access - 97840cb67ff5 ("netfilter: nfnetlink: fix
   insufficient validation in nfnetlink_bind")

undefined shifts:

 * d48458d4a768 ("jbd2: use a better hash function for the revoke
   table")

 * 10632008b9e1 ("clockevents: Prevent shift out of bounds")

 * 'x &lt;&lt; -1' shift in ext4 -
   http://lkml.kernel.org/r/&lt;5444EF21.8020501@samsung.com&gt;

 * undefined rol32(0) -
   http://lkml.kernel.org/r/&lt;1449198241-20654-1-git-send-email-sasha.levin@oracle.com&gt;

 * undefined dirty_ratelimit calculation -
   http://lkml.kernel.org/r/&lt;566594E2.3050306@odin.com&gt;

 * undefined roundown_pow_of_two(0) -
   http://lkml.kernel.org/r/&lt;1449156616-11474-1-git-send-email-sasha.levin@oracle.com&gt;

 * [WONTFIX] undefined shift in __bpf_prog_run -
   http://lkml.kernel.org/r/&lt;CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com&gt;

   WONTFIX here because it should be fixed in bpf program, not in kernel.

signed overflows:

 * 32a8df4e0b33f ("sched: Fix odd values in effective_load()
   calculations")

 * mul overflow in ntp -
   http://lkml.kernel.org/r/&lt;1449175608-1146-1-git-send-email-sasha.levin@oracle.com&gt;

 * incorrect conversion into rtc_time in rtc_time64_to_tm() -
   http://lkml.kernel.org/r/&lt;1449187944-11730-1-git-send-email-sasha.levin@oracle.com&gt;

 * unvalidated timespec in io_getevents() -
   http://lkml.kernel.org/r/&lt;CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com&gt;

 * [NOTABUG] signed overflow in ktime_add_safe() -
   http://lkml.kernel.org/r/&lt;CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com&gt;

[akpm@linux-foundation.org: fix unused local warning]
[akpm@linux-foundation.org: fix __int128 build woes]
Signed-off-by: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Sasha Levin &lt;sasha.levin@oracle.com&gt;
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Michal Marek &lt;mmarek@suse.cz&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Yury Gribov &lt;y.gribov@samsung.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Cc: Kostya Serebryany &lt;kcc@google.com&gt;
Cc: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
UBSAN uses compile-time instrumentation to catch undefined behavior
(UB).  Compiler inserts code that perform certain kinds of checks before
operations that could cause UB.  If check fails (i.e.  UB detected)
__ubsan_handle_* function called to print error message.

So the most of the work is done by compiler.  This patch just implements
ubsan handlers printing errors.

GCC has this capability since 4.9.x [1] (see -fsanitize=undefined
option and its suboptions).
However GCC 5.x has more checkers implemented [2].
Article [3] has a bit more details about UBSAN in the GCC.

[1] - https://gcc.gnu.org/onlinedocs/gcc-4.9.0/gcc/Debugging-Options.html
[2] - https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html
[3] - http://developerblog.redhat.com/2014/10/16/gcc-undefined-behavior-sanitizer-ubsan/

Issues which UBSAN has found thus far are:

Found bugs:

 * out-of-bounds access - 97840cb67ff5 ("netfilter: nfnetlink: fix
   insufficient validation in nfnetlink_bind")

undefined shifts:

 * d48458d4a768 ("jbd2: use a better hash function for the revoke
   table")

 * 10632008b9e1 ("clockevents: Prevent shift out of bounds")

 * 'x &lt;&lt; -1' shift in ext4 -
   http://lkml.kernel.org/r/&lt;5444EF21.8020501@samsung.com&gt;

 * undefined rol32(0) -
   http://lkml.kernel.org/r/&lt;1449198241-20654-1-git-send-email-sasha.levin@oracle.com&gt;

 * undefined dirty_ratelimit calculation -
   http://lkml.kernel.org/r/&lt;566594E2.3050306@odin.com&gt;

 * undefined roundown_pow_of_two(0) -
   http://lkml.kernel.org/r/&lt;1449156616-11474-1-git-send-email-sasha.levin@oracle.com&gt;

 * [WONTFIX] undefined shift in __bpf_prog_run -
   http://lkml.kernel.org/r/&lt;CACT4Y+ZxoR3UjLgcNdUm4fECLMx2VdtfrENMtRRCdgHB2n0bJA@mail.gmail.com&gt;

   WONTFIX here because it should be fixed in bpf program, not in kernel.

signed overflows:

 * 32a8df4e0b33f ("sched: Fix odd values in effective_load()
   calculations")

 * mul overflow in ntp -
   http://lkml.kernel.org/r/&lt;1449175608-1146-1-git-send-email-sasha.levin@oracle.com&gt;

 * incorrect conversion into rtc_time in rtc_time64_to_tm() -
   http://lkml.kernel.org/r/&lt;1449187944-11730-1-git-send-email-sasha.levin@oracle.com&gt;

 * unvalidated timespec in io_getevents() -
   http://lkml.kernel.org/r/&lt;CACT4Y+bBxVYLQ6LtOKrKtnLthqLHcw-BMp3aqP3mjdAvr9FULQ@mail.gmail.com&gt;

 * [NOTABUG] signed overflow in ktime_add_safe() -
   http://lkml.kernel.org/r/&lt;CACT4Y+aJ4muRnWxsUe1CMnA6P8nooO33kwG-c8YZg=0Xc8rJqw@mail.gmail.com&gt;

[akpm@linux-foundation.org: fix unused local warning]
[akpm@linux-foundation.org: fix __int128 build woes]
Signed-off-by: Andrey Ryabinin &lt;aryabinin@virtuozzo.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Sasha Levin &lt;sasha.levin@oracle.com&gt;
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Cc: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Cc: Jonathan Corbet &lt;corbet@lwn.net&gt;
Cc: Michal Marek &lt;mmarek@suse.cz&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Yury Gribov &lt;y.gribov@samsung.com&gt;
Cc: Dmitry Vyukov &lt;dvyukov@google.com&gt;
Cc: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Cc: Kostya Serebryany &lt;kcc@google.com&gt;
Cc: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
