From: Kees Cook <keescook@chromium.org>
To: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
"Steven Rostedt (VMware)" <rostedt@goodmis.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux Next Mailing List <linux-next@vger.kernel.org>
Subject: Re: linux-next: build failure after merge of the kspp tree
Date: Mon, 24 Jan 2022 23:44:05 -0800 [thread overview]
Message-ID: <202201242230.C54A6BCDFE@keescook> (raw)
In-Reply-To: <20220125145006.677e3709@canb.auug.org.au>
On Tue, Jan 25, 2022 at 02:50:06PM +1100, Stephen Rothwell wrote:
> Hi all,
>
> After merging the kspp tree, today's linux-next build (powerpc
> allmodconfig) failed like this:
>
> In file included from include/linux/string.h:253,
> from include/linux/bitmap.h:11,
> from include/linux/cpumask.h:12,
> from include/linux/mm_types_task.h:14,
> from include/linux/mm_types.h:5,
> from include/linux/buildid.h:5,
> from include/linux/module.h:14,
> from samples/trace_events/trace-events-sample.c:2:
> In function '__fortify_strcpy',
> inlined from 'perf_trace_foo_rel_loc' at samples/trace_events/./trace-events-sample.h:519:1:
> include/linux/fortify-string.h:47:33: error: '__builtin_strcpy' offset 12 is out of the bounds [0, 4] [-Werror=array-bounds]
-Warray-bounds thinks something is trying to get at offset 12 of an
object it thinks is only 4 bytes in size.
> 47 | #define __underlying_strcpy __builtin_strcpy
> | ^
> include/linux/fortify-string.h:445:24: note: in expansion of macro '__underlying_strcpy'
> 445 | return __underlying_strcpy(p, q);
> | ^~~~~~~~~~~~~~~~~~~
>
> Exposed by (probably) commit
>
> 602670289b69 ("fortify: Detect struct member overflows in memcpy() at compile-time")
>
> Introduced by commit
>
> b466b1332164 ("samples/trace_event: Add '__rel_loc' using sample event")
>
> I have reverted that latter commit for today.
Digging through the macros, I end up reconstructing this:
strcpy( (char *)((void *)(&__entry->__rel_loc_foo) +
sizeof(__entry->__rel_loc_foo) +
(__entry->__rel_loc_foo & 0xffff)),
foo ? (const char *)(foo) : "(null)");
I couldn't figure out how __entry is being allocated, but it seemed
maybe related to this note:
/*
* struct trace_event_data_offsets_<call> {
* u32 <item1>;
* u32 <item2>;
* [...]
* };
*
* The __dynamic_array() macro will create each u32 <item>, this is
* to keep the offset of each array from the beginning of the event.
* The size of an array is also encoded, in the higher 16 bits of
* <item>.
*/
So, I think -Warray-bounds is refusing to see the destination as
anything except a u32, but being accessed at 4 (sizeof(u32)) + 8
(address && 0xffff) (?)
But if this is true, I would imagine there would be plenty of other
warnings? I'm currently stumped.
Reading 55de2c0b5610 ("tracing: Add '__rel_loc' using trace event
macros") did not help me. ;)
-Kees
--
Kees Cook
next prev parent reply other threads:[~2022-01-25 9:09 UTC|newest]
Thread overview: 108+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-25 3:50 linux-next: build failure after merge of the kspp tree Stephen Rothwell
2022-01-25 7:44 ` Kees Cook [this message]
2022-01-25 13:27 ` Masami Hiramatsu
2022-01-25 14:01 ` Steven Rostedt
2022-01-25 17:53 ` Kees Cook
2022-01-25 14:31 ` Masami Hiramatsu
2022-01-25 15:49 ` Steven Rostedt
2022-01-25 17:54 ` Kees Cook
2022-01-25 18:41 ` Steven Rostedt
2022-01-25 20:57 ` Kees Cook
2022-01-25 21:23 ` Steven Rostedt
2022-01-25 21:28 ` Steven Rostedt
2022-01-25 22:07 ` Kees Cook
2022-01-25 22:21 ` Steven Rostedt
2022-01-26 0:35 ` Masami Hiramatsu
2022-01-26 1:16 ` Steven Rostedt
2022-01-26 3:18 ` Kees Cook
2022-01-26 3:26 ` Steven Rostedt
2022-01-26 19:41 ` Beau Belgrave
2022-01-26 21:00 ` Steven Rostedt
2022-01-26 3:52 ` Masami Hiramatsu
2022-01-26 4:06 ` Steven Rostedt
2022-01-26 3:17 ` Kees Cook
2022-01-25 22:01 ` Kees Cook
-- strict thread matches above, loose matches on Subject: below --
2024-03-05 3:50 Stephen Rothwell
2024-03-05 9:54 ` Kees Cook
2023-09-14 1:50 Stephen Rothwell
2023-09-14 3:07 ` Kees Cook
2023-01-05 2:25 Stephen Rothwell
2023-01-05 3:22 ` Kees Cook
2023-01-05 4:24 ` Stephen Rothwell
2022-12-01 3:07 Stephen Rothwell
2022-12-01 16:31 ` Kees Cook
2022-07-28 10:55 Stephen Rothwell
2022-07-28 15:12 ` Matthias Kaehlcke
2022-05-05 7:40 Stephen Rothwell
2022-05-07 17:18 ` Kees Cook
2022-03-16 7:32 Stephen Rothwell
2022-03-17 1:01 ` Linus Walleij
2022-03-17 8:24 ` Marc Zyngier
2022-03-09 10:10 Stephen Rothwell
2022-03-09 16:52 ` Kees Cook
2022-03-09 16:58 ` Hans de Goede
2022-03-09 17:18 ` Kees Cook
2022-02-28 22:27 Stephen Rothwell
2022-02-28 23:02 ` Kees Cook
2022-03-02 9:16 ` Stephen Rothwell
2022-03-03 7:29 ` Stephen Rothwell
2022-01-30 23:09 Stephen Rothwell
2022-01-31 4:04 ` Kees Cook
2022-01-31 4:59 ` Stephen Rothwell
2022-01-31 6:19 ` Kees Cook
2022-01-31 19:10 ` Saeed Mahameed
2022-01-31 21:06 ` Kees Cook
2022-01-30 22:34 Stephen Rothwell
2022-01-30 23:24 ` Herbert Xu
2022-01-31 0:15 ` Stephen Rothwell
2022-01-31 0:20 ` Herbert Xu
2022-01-31 0:41 ` Stephen Rothwell
2022-01-25 3:24 Stephen Rothwell
2022-01-25 3:43 ` Kees Cook
2022-02-08 4:42 ` Stephen Rothwell
2022-02-08 6:13 ` Kees Cook
2022-01-25 2:55 Stephen Rothwell
2022-01-25 3:02 ` Stephen Rothwell
2022-01-25 3:22 ` Kees Cook
2022-01-25 0:57 Stephen Rothwell
2022-01-25 3:35 ` Kees Cook
2022-01-25 14:07 ` David Sterba
2021-09-16 3:34 Stephen Rothwell
2021-09-16 6:00 ` Kees Cook
2021-08-26 7:52 Stephen Rothwell
2021-08-26 15:38 ` Kees Cook
2020-06-23 3:51 Stephen Rothwell
2020-06-23 3:56 ` David Miller
2020-06-21 13:48 Stephen Rothwell
2020-06-21 15:36 ` Kees Cook
2018-07-27 9:02 Stephen Rothwell
2018-07-27 9:06 ` Stephen Rothwell
2018-07-27 10:55 ` Stephen Rothwell
2018-07-27 12:55 ` Will Deacon
2018-07-27 13:01 ` Will Deacon
2018-07-27 13:27 ` Will Deacon
2018-07-27 16:00 ` Kees Cook
2018-07-30 7:33 ` Stephen Rothwell
2018-07-30 14:47 ` Laura Abbott
2018-07-30 16:37 ` Will Deacon
2018-07-31 10:09 ` Will Deacon
2018-07-31 11:27 ` Stephen Rothwell
2017-11-08 5:23 Stephen Rothwell
2017-11-08 23:43 ` Kees Cook
2017-11-09 0:18 ` Darrick J. Wong
2017-11-09 0:31 ` Kees Cook
2017-06-20 4:56 Stephen Rothwell
2017-06-20 5:39 ` Kees Cook
2017-06-20 5:42 ` John Johansen
2017-06-20 5:39 ` John Johansen
2017-06-26 18:19 ` Kees Cook
2017-06-27 3:33 ` James Morris
2017-06-27 22:16 ` Kees Cook
2017-06-28 5:48 ` James Morris
2017-06-16 1:30 Stephen Rothwell
2017-06-16 2:51 ` Daniel Micay
2017-06-16 2:52 ` Daniel Micay
2017-06-16 3:20 ` Kees Cook
2017-06-16 3:31 ` Stephen Rothwell
2017-06-19 0:23 ` Stephen Rothwell
2017-06-19 21:01 ` Kees Cook
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