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commit86be36f650upstream. Yauheni Kaliuta pointed out that PTR_TO_STACK store/load verifier test was failing on powerpc64 BE, and rightfully indicated that the PPC_LD() macro is not masking away the last two bits of the offset per the ISA, resulting in the generation of 'lwa' instruction instead of the intended 'ld' instruction. Segher also pointed out that we can't simply mask away the last two bits as that will result in loading/storing from/to a memory location that was not intended. This patch addresses this by using ldx/stdx if the offset is not word-aligned. We load the offset into a temporary register (TMP_REG_2) and use that as the index register in a subsequent ldx/stdx. We fix PPC_LD() macro to mask off the last two bits, but enhance PPC_BPF_LL() and PPC_BPF_STL() to factor in the offset value and generate the proper instruction sequence. We also convert all existing users of PPC_LD() and PPC_STD() to use these macros. All existing uses of these macros have been audited to ensure that TMP_REG_2 can be clobbered. Fixes:156d0e290e("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Cc: stable@vger.kernel.org # v4.9+ Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.