Messages in this thread | | | Date | Wed, 29 Feb 2012 10:52:10 +1100 | From | Stephen Rothwell <> | Subject | Re: [RFC][PATCH 5/6] x86, efi: Fix endian issues and unaligned accesses |
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Hi all,
On Tue, 28 Feb 2012 13:37:24 +0000 Matt Fleming <matt@console-pimps.org> wrote: > > From: Matt Fleming <matt.fleming@intel.com> > > We may need to convert the endianness of the data we read from/write > to 'buf', so let's use {get,put}_unaligned_le32() to do that. Failure > to do so can result in accessing invalid memory, leading to a > segfault. Stephen Rothwell noticed this bug while cross-building an > x86_64 allmodconfig kernel on PowerPC. > > We need to read from and write to 'buf' a byte at a time otherwise > it's possible we'll perform an unaligned access, which can lead to bus > errors when cross-building an x86 kernel on risc architectures. > > Cc: H. Peter Anvin <hpa@zytor.com> > Cc: Nick Bowler <nbowler@elliptictech.com> > Tested-by: Stephen Rothwell <sfr@canb.auug.org.au> > Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> > Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Just to be absolutely clear, I have not yet tested this version of the patch and also this fixes a problem with cross building Linus' tree (i.e. this is a regression with cross building introduced in v3.3-rc1).
-- Cheers, Stephen Rothwell sfr@canb.auug.org.au http://www.canb.auug.org.au/~sfr/ [unhandled content-type:application/pgp-signature] | |