Re: [Qemu-devel] [PATCH] m25p80: fix test on blk_pread() return value

["Cédric Le Goater" <clg@kaod.org>]

On 06/13/2016 06:47 PM, Eric Blake wrote:
> On 06/13/2016 10:25 AM, Cédric Le Goater wrote:
> 
>>
>> It seems that commit 243e6f69c129 ("m25p80: Switch to byte-based block access") 
>> is bringing another issue :
>>
>> qemu-system-arm: /home/legoater/work/qemu/qemu-ast2400-mainline.git/block/io.c:1252: bdrv_aligned_pwritev: Assertion `!qiov || bytes == qiov->size' failed.
>> Aborted (core dumped)
> 
> Can you provide a more complete stack dump, 

yes, see below. 

> and/or a recipe on how to repeat the assertion?

That's more difficult right now. The patchset I am working on is not 
mainline. It adds the SPI controller to the ast2400 soc and it uses 
m25p80 flash modules with -mtdblock. 

I am trying to rebase on qemu's head to send it and I am hitting this 
issue. So I need to find a simpler way to reproduce, with code only in
mainline of course.

Until then, here is a gdb backtrace. Sorry about that.

Thanks,

C.

$ gdb /home/legoater/work/qemu/qemu-ast2400-mainline.git/install/bin/qemu-system-arm  core GNU gdb (Debian 7.7.1+dfsg-5) 7.7.1
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and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
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Reading symbols from /home/legoater/work/qemu/qemu-ast2400-mainline.git/install/bin/qemu-system-arm...done.
[New LWP 662]
[New LWP 1120]
[New LWP 674]
[New LWP 663]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Core was generated by `/home/legoater/work/qemu/qemu-ast2400-mainline.git/install/bin/qemu-system-arm'.
Program terminated with signal SIGABRT, Aborted.
#0  0x00007fa818e98067 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
56	../nptl/sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0  0x00007fa818e98067 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
#1  0x00007fa818e99448 in __GI_abort () at abort.c:89
#2  0x00007fa818e91266 in __assert_fail_base (fmt=0x7fa818fca238 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", 
    assertion=assertion@entry=0x7fa81c7bffc4 "!qiov || bytes == qiov->size", 
    file=file@entry=0x7fa81c7bfaa0 "/home/legoater/work/qemu/qemu-ast2400-mainline.git/block/io.c", 
    line=line@entry=1243, 
    function=function@entry=0x7fa81c7c0170 <__PRETTY_FUNCTION__.34512> "bdrv_aligned_pwritev") at assert.c:92
#3  0x00007fa818e91312 in __GI___assert_fail (
    assertion=assertion@entry=0x7fa81c7bffc4 "!qiov || bytes == qiov->size", 
    file=file@entry=0x7fa81c7bfaa0 "/home/legoater/work/qemu/qemu-ast2400-mainline.git/block/io.c", 
    line=line@entry=1243, 
    function=function@entry=0x7fa81c7c0170 <__PRETTY_FUNCTION__.34512> "bdrv_aligned_pwritev") at assert.c:101
#4  0x00007fa81c6694ac in bdrv_aligned_pwritev (bs=0x7fa81d4dd050, req=<optimized out>, offset=30878208, 
    bytes=512, qiov=0x7fa7f47fee60, flags=0)
    at /home/legoater/work/qemu/qemu-ast2400-mainline.git/block/io.c:1243
#5  0x00007fa81c669ecb in bdrv_co_pwritev (bs=0x7fa81d4dd050, offset=8, bytes=512, qiov=0x7fa80d5191c0, 
    flags=(BDRV_REQ_COPY_ON_READ | BDRV_REQ_ZERO_WRITE | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_SERIALISING | BDRV_REQ_FUA | unknown: 4278124256), flags@entry=(unknown: 0))
    at /home/legoater/work/qemu/qemu-ast2400-mainline.git/block/io.c:1492
#6  0x00007fa81c65e367 in blk_co_pwritev (blk=0x7fa81d4c5b60, offset=30878208, bytes=256, qiov=0x7fa80d5191c0, 
    flags=(unknown: 0)) at /home/legoater/work/qemu/qemu-ast2400-mainline.git/block/block-backend.c:788
#7  0x00007fa81c65e49b in blk_aio_write_entry (opaque=0x7fa7e849aca0)
    at /home/legoater/work/qemu/qemu-ast2400-mainline.git/block/block-backend.c:977
#8  0x00007fa81c6c823a in coroutine_trampoline (i0=<optimized out>, i1=<optimized out>)
    at /home/legoater/work/qemu/qemu-ast2400-mainline.git/util/coroutine-ucontext.c:78
#9  0x00007fa818ea8f00 in ?? () from /lib/x86_64-linux-gnu/libc.so.6
#10 0x00007fa80d5189d0 in ?? ()
#11 0x0000000000000000 in ?? ()
(gdb) up 4
#4  0x00007fa81c6694ac in bdrv_aligned_pwritev (bs=0x7fa81d4dd050, req=<optimized out>, offset=30878208, 
    bytes=512, qiov=0x7fa7f47fee60, flags=0)
    at /home/legoater/work/qemu/qemu-ast2400-mainline.git/block/io.c:1243
1243	    assert(!qiov || bytes == qiov->size);
(gdb) p *qiov 
$1 = {iov = 0x7fa81da671d0, niov = 1, nalloc = 1, size = 256}