70f1913824
[ Upstream commit 32d85999680601d01b2a36713c9ffd7397c8688b ]
Dan reports that smatch complains about a potential uninitialized
variable being used in the compat alignment fixup code.
The logic is not wrong per se, but we do end up using an uninitialized
variable if reading the instruction that triggered the alignment fault
from user space faults, even if the fault ensures that the uninitialized
value doesn't propagate any further.
Given that we just give up and return 1 if any fault occurs when reading
the instruction, let's get rid of the 'success handling' pattern that
captures the fault in a variable and aborts later, and instead, just
return 1 immediately if any of the get_user() calls result in an
exception.
Fixes: 3fc24ef32d3b ("arm64: compat: Implement misalignment fixups for multiword loads")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/202304021214.gekJ8yRc-lkp@intel.com/
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20230404103625.2386382-1-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.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.
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.