Karol Herbst
eb41efa138
[ Upstream commit fe9748b7b4 ]
Fixes failure to compile with recent envyas as a result of the 'movw'
alias being removed for v5.
A bit of history:
v3 only has a 16-bit sign-extended immediate mov op. In order to set
the high bits, there's a separate 'sethi' op. envyas validates that
the value passed to mov(imm) is between -0x8000 and 0x7fff. In order
to simplify macros that load both the low and high word, a 'movw'
alias was added which takes an unsigned 16-bit immediate. However the
actual hardware op still sign extends.
v5 has a full 32-bit immediate mov op. The v3 16-bit immediate mov op
is gone (loads 0 into the dst reg). However due to a bug in envyas,
the movw alias still existed, and selected the no-longer-present v3
16-bit immediate mov op. As a result usage of movw on v5 is the same
as mov with a 0x0 argument.
The proper fix throughout is to only ever use the 'movw' alias in
combination with 'sethi'. Anything else should get the sign-extended
validation to ensure that the intended value ends up in the
destination register.
Changes in fuc3 binaries is the result of a different encoding being
selected for a mov with an 8-bit value.
v2: added commit message written by Ilia, thanks for that!
v3: messed up rebasing, now it should apply
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. 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.