ab4458bc32
[ Upstream commit 994af1825a2aa286f4903ff64a1c7378b52defe6 ] On riscv32, it is possible for the last page in virtual address space (0xfffff000) to be allocated. This page overlaps with PTR_ERR, so that shouldn't happen. There is already some code to ensure memblock won't allocate the last page. However, buddy allocator is left unchecked. Fix this by reserving physical memory that would be mapped at virtual addresses greater than 0xfffff000. Reported-by: Björn Töpel <bjorn@kernel.org> Closes: https://lore.kernel.org/linux-riscv/878r1ibpdn.fsf@all.your.base.are.belong.to.us Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code") Signed-off-by: Nam Cao <namcao@linutronix.de> Cc: <stable@vger.kernel.org> Tested-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Link: https://lore.kernel.org/r/20240425115201.3044202-1-namcao@linutronix.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.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.