Hi Fengguang,
This is about 'Kernel Address sanitizer (KASan)'.
not only cxd2841 affected but some others:
drivers/media/tuners/r820t.c:1333:1: warning: the frame size of 2904
bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:1858:1: warning: the frame size
of 3008 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:2141:1: warning: the frame size
of 2104 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:2513:1: warning: the frame size
of 2304 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:4565:1: warning: the frame size
of 2096 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:1956:1: warning: the frame size
of 3264 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:1599:1: warning: the frame size
of 5296 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:1211:1: warning: the frame size
of 2080 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:4250:1: warning: the frame size
of 4840 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:4759:1: warning: the frame size
of 2056 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:1168:1: warning: the frame size
of 2080 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:2073:1: warning: the frame size
of 2552 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:3095:1: warning: the frame size
of 5864 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv090x.c:3436:1: warning: the frame size
of 6816 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/stv0367.c:3147:1: warning: the frame size
of 4144 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/cxd2841er.c:2404:1: warning: the frame
size of 2984 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/cxd2841er.c:2282:1: warning: the frame
size of 4336 bytes is larger than 2048 bytes [-Wframe-larger-than=]
drivers/media/dvb-frontends/si2165.c:683:1: warning: the frame size of
2064 bytes is larger than 2048 bytes [-Wframe-larger-than=]
cause of this 'Kernel Address sanitizer (KASan)' is enabled in your
config. With gcc-4.9 kasan was disabled in compile time because of:
"scripts/Makefile.kasan:23: CONFIG_KASAN: compiler does not support
all options. Trying minimal configuration"
but with gcc-5 it's enabled.
and
objdump -d drivers/media/dvb-frontends/cxd2841er.o
shows that KASan adds some instructions to 'cxd2841er_sleep_tc' which
writes necessary data to -fasan-shadow-offset=0xdffffc0000000000:
1476: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
...
14d3: c7 00 f1 f1 f1 f1 movl $0xf1f1f1f1,(%rax)
14d9: c7 40 04 01 f4 f4 f4 movl $0xf4f4f401,0x4(%rax)
14e0: c7 40 08 f2 f2 f2 f2 movl $0xf2f2f2f2,0x8(%rax)
14e7: c7 40 0c 01 f4 f4 f4 movl $0xf4f4f401,0xc(%rax)
...
and function will grow and we get '-Wframe-larger-than=2048' warnings.
So, this warning looks normal (until they less than 8K I think) for
configurations with KASan enabled.
I can suggest:
* ignore this warning if KASan enabled
* Increase -Wframe-larger-than=2048 to -Wframe-larger-than=8192 if
KASan enabled ( CONFIG_FRAME_WARN=8192 in kernel .config)
2015-09-25 12:46 GMT+03:00 Fengguang Wu <fengguang.wu@xxxxxxxxx>:
> Hi Abylay,
>
> This warning can be reproduced with gcc-5.2:
>
> =============== commit a6dc60ff1 ===============
> /home/wfg/linux
> HEAD is now at a6dc60ff... [media] cxd2841er: Sony CXD2841ER DVB-S/S2/T/T2/C demodulator driver
> /home/wfg/linux/obj-compiletest
>
> make ARCH=x86_64 drivers/media/dvb-frontends/cxd2841er.o
>
> grep -a -F drivers/media/dvb-frontends/cxd2841er.c /tmp/build-err-a6dc60ff1209df29ee4668024e93d31f31421932-wfg --color
> ../drivers/media/dvb-frontends/cxd2841er.c: In function 'cxd2841er_sleep_tc':
> ../drivers/media/dvb-frontends/cxd2841er.c:2393:1: warning: the frame size of 2992 bytes is larger than 2048 bytes [-Wframe-larger-than=]
> }
> ^
> ../drivers/media/dvb-frontends/cxd2841er.c: In function 'cxd2841er_set_frontend_tc':
> ../drivers/media/dvb-frontends/cxd2841er.c:2274:1: warning: the frame size of 4336 bytes is larger than 2048 bytes [-Wframe-larger-than=]
> }
> ^
>
> =============== PREV commit e025273b86fb4a6440192b809e05332777c3faa5 ===============
> /home/wfg/linux
> Previous HEAD position was a6dc60ff... [media] cxd2841er: Sony CXD2841ER DVB-S/S2/T/T2/C demodulator driver
> HEAD is now at e025273... [media] lnbh25: LNBH25 SEC controller driver
> /home/wfg/linux/obj-compiletest
>
> make ARCH=x86_64 drivers/media/dvb-frontends/cxd2841er.o
>
> !!! BUILD ERROR !!!
> grep -a -F drivers/media/dvb-frontends/cxd2841er.c /tmp/build-err-e025273b86fb4a6440192b809e05332777c3faa5-wfg --color
>
> =============== linus/master linus/master ===============
> /home/wfg/linux
> Previous HEAD position was e025273... [media] lnbh25: LNBH25 SEC controller driver
> HEAD is now at 8e64a73... Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
> /home/wfg/linux/obj-compiletest
>
> make ARCH=x86_64 drivers/media/dvb-frontends/cxd2841er.o
>
> grep -a -F drivers/media/dvb-frontends/cxd2841er.c /tmp/build-err-8e64a7331702b7888ccf84b2b9ff46ab8e167c7f-wfg --color
> ../drivers/media/dvb-frontends/cxd2841er.c: In function 'cxd2841er_sleep_tc':
> ../drivers/media/dvb-frontends/cxd2841er.c:2401:1: warning: the frame size of 2984 bytes is larger than 2048 bytes [-Wframe-larger-than=]
> }
> ^
> ../drivers/media/dvb-frontends/cxd2841er.c: In function 'cxd2841er_set_frontend_tc':
> ../drivers/media/dvb-frontends/cxd2841er.c:2282:1: warning: the frame size of 4336 bytes is larger than 2048 bytes [-Wframe-larger-than=]
> }
> ^
>
> Thanks,
> Fengguang
>
> On Fri, Sep 25, 2015 at 12:21:57PM +0300, Abylay Ospan wrote:
>> Hello,
>>
>> I cannot reproduce this warning. I'm compiling with your config and
>> following commands:
>>
>> git checkout a6dc60ff1209df29ee4668024e93d31f31421932
>> make ARCH=x86_64
>>
>> my gcc version is 4.9.2 (Ubuntu 4.9.2-10ubuntu13)
>>
>> warning doesn't appear even if I set:
>> CONFIG_FRAME_WARN=128
>>
>> Please point me if problem still exist.
>>
>> thanks !
>>
>>
>>
>> 2015-09-17 9:05 GMT+03:00 kbuild test robot <fengguang.wu@xxxxxxxxx>:
>> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
>> > head: 72714841b705a5b9bccf37ee85a62352bee3a3ef
>> > commit: a6dc60ff1209df29ee4668024e93d31f31421932 [media] cxd2841er: Sony CXD2841ER DVB-S/S2/T/T2/C demodulator driver
>> > date: 5 weeks ago
>> > config: x86_64-randconfig-b0-09171322 (attached as .config)
>> > reproduce:
>> > git checkout a6dc60ff1209df29ee4668024e93d31f31421932
>> > # save the attached .config to linux build tree
>> > make ARCH=x86_64
>> >
>> > All warnings (new ones prefixed by >>):
>> >
>> > drivers/media/dvb-frontends/cxd2841er.c: In function 'cxd2841er_sleep_tc':
>> >>> drivers/media/dvb-frontends/cxd2841er.c:2393:1: warning: the frame size of 2992 bytes is larger than 2048 bytes [-Wframe-larger-than=]
>> > }
>> > ^
>> > drivers/media/dvb-frontends/cxd2841er.c: In function 'cxd2841er_set_frontend_tc':
>> > drivers/media/dvb-frontends/cxd2841er.c:2274:1: warning: the frame size of 4336 bytes is larger than 2048 bytes [-Wframe-larger-than=]
>> > }
>> > ^
>> >
>> > vim +2393 drivers/media/dvb-frontends/cxd2841er.c
>> >
>> > 2377 case SYS_DVBC_ANNEX_A:
>> > 2378 cxd2841er_active_c_to_sleep_tc(priv);
>> > 2379 break;
>> > 2380 default:
>> > 2381 dev_warn(&priv->i2c->dev,
>> > 2382 "%s(): unknown delivery system %d\n",
>> > 2383 __func__, priv->system);
>> > 2384 }
>> > 2385 }
>> > 2386 if (priv->state != STATE_SLEEP_TC) {
>> > 2387 dev_err(&priv->i2c->dev, "%s(): invalid state %d\n",
>> > 2388 __func__, priv->state);
>> > 2389 return -EINVAL;
>> > 2390 }
>> > 2391 cxd2841er_sleep_tc_to_shutdown(priv);
>> > 2392 return 0;
>> >> 2393 }
>> > 2394
>> > 2395 static int cxd2841er_send_burst(struct dvb_frontend *fe,
>> > 2396 enum fe_sec_mini_cmd burst)
>> > 2397 {
>> > 2398 u8 data;
>> > 2399 struct cxd2841er_priv *priv = fe->demodulator_priv;
>> > 2400
>> > 2401 dev_dbg(&priv->i2c->dev, "%s(): burst mode %s\n", __func__,
>> >
>> > ---
>> > 0-DAY kernel test infrastructure Open Source Technology Center
>> > https://lists.01.org/pipermail/kbuild-all Intel Corporation
>>
>>
>>
>> --
>> Abylay Ospan,
>> NetUP Inc.
>> http://www.netup.tv
>> _______________________________________________
>> kbuild-all mailing list
>> kbuild-all@xxxxxxxxxxxx
>> https://lists.01.org/mailman/listinfo/kbuild-all
--
Abylay Ospan,
NetUP Inc.
http://www.netup.tv
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
