Re: raspberry pi panic 7.0_BETA after install fs resize

[mlelstv%serpens.de@localhost (Michael van Elst)]

petri.laakso%asd.fi@localhost (Petri Laakso) writes:


>On Fri, 31 Oct 2014, Maxime Villard wrote:
>> That's KMEM_SIZE. Great.
>> It means that it caught a memory corruption somewhere.
>> That being said, I don't think I can help without a trace...

>Here's backtrace and steps how I ended up with panic. This was in
>single user mode after fresh 7.0_BETA install (sources from last night)

>http://www.asd.fi/~petri/tmp/rpi_bt.jpg

>Petri

malloc considered useful:

allocation in ffs_mountfs:
        bsize = fs->fs_cssize;
        if (fs->fs_contigsumsize > 0)
                bsize += fs->fs_ncg * sizeof(int32_t);
        bsize += fs->fs_ncg * sizeof(*fs->fs_contigdirs);
        allocsbsize = bsize;
        space = kmem_alloc((u_long)allocsbsize, KM_SLEEP);
        fs->fs_csp = space;

deallocation in ffs_unmount:
        bsize = fs->fs_cssize;
        if (fs->fs_contigsumsize > 0)
                bsize += fs->fs_ncg * sizeof(int32_t);
        bsize += fs->fs_ncg * sizeof(*fs->fs_contigdirs);
        kmem_free(fs->fs_csp, bsize);

 
allocsbsize only exists to handle some error paths, but since
it is not stored globally, the value is recalculated, assuming
that the underlying values do not change.

Apparently that's not true after the resize of the filesystem.
The other question is, does anyone use the fs->fs_csp buffer
and assumes it is calculated for the updated values before it
is freed?