[PATCH v2 0/6] crash: Bundle of fixes for Xen
anderson at redhat.com
Tue Aug 14 10:04:00 EDT 2012
----- Original Message -----
> On Mon, Aug 13, 2012 at 03:16:53PM -0400, Dave Anderson wrote:
> > OK good. It tests OK on a few older pvops kernels that I have on
> > hand.
> > The only thing I've changed is to handle compiler warnings in x86_64.c and
> > x86.c by initializing p2m_top to NULL in x86_64_pvops_xendump_p2m_l3_create()
> > and x86_pvops_xendump_p2m_l3_create(). I also used GETBUF() in those two
> > functions to avoid having to add the malloc-failure line.
> No problem. However, I am a bit surprised that you have seen some warnings.
> I have not seen any. Did you compiled crash with extra options or something
> like that? Or maybe there is a diffrence in our compilers (mine is gcc version
> 4.1.2 20061115 (prerelease) (Debian 4.1.1-21) - quite ancient).
Extra options (also with gcc 4.1.2) -- try building with "make warn". It adds:
WARNING_OPTIONS=-Wall -O2 -Wstrict-prototypes -Wmissing-prototypes -fstack-protector
or "make Warn", which adds -Werror to the above.
In those two functions there are "goto err" statements prior to allocating
p2m_top, and so the free(p2m_top) could receive a random stack value. Of
course even if it did get by the free() call in that highly unlikely case,
the crash session is just about to fatally shut itself down.
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