On Mon, 22 Mar 2021 at 18:14, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > From: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> > > [ Upstream commit bd67b711bfaa02cf19e88aa2d9edae5c1c1d2739 ] > > BMIPS is one of the few platforms that do change the exception base. > After commit 2dcb39645441 ("memblock: do not start bottom-up allocations > with kernel_end") we started seeing BMIPS boards fail to boot with the > built-in FDT being corrupted. > > Before the cited commit, early allocations would be in the [kernel_end, > RAM_END] range, but after commit they would be within [RAM_START + > PAGE_SIZE, RAM_END]. > > The custom exception base handler that is installed by > bmips_ebase_setup() done for BMIPS5000 CPUs ends-up trampling on the > memory region allocated by unflatten_and_copy_device_tree() thus > corrupting the FDT used by the kernel. > > To fix this, we need to perform an early reservation of the custom > exception space. Additional we reserve the first 4k (1k for R3k) for > either normal exception vector space (legacy CPUs) or special vectors > like cache exceptions. > > Huge thanks to Serge for analysing and proposing a solution to this > issue. > > Fixes: 2dcb39645441 ("memblock: do not start bottom-up allocations with kernel_end") > Reported-by: Kamal Dasu <kdasu.kdev@xxxxxxxxx> > Debugged-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> > Acked-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> > Tested-by: Florian Fainelli <f.fainelli@xxxxxxxxx> > Reviewed-by: Serge Semin <fancer.lancer@xxxxxxxxx> > Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- > arch/mips/include/asm/traps.h | 3 +++ > arch/mips/kernel/cpu-probe.c | 6 ++++++ > arch/mips/kernel/cpu-r3k-probe.c | 3 +++ > arch/mips/kernel/traps.c | 10 +++++----- mipc tinyconfig and allnoconfig builds failed on stable-rc 5.10 branch make --silent --keep-going --jobs=8 O=/home/tuxbuild/.cache/tuxmake/builds/1/tmp ARCH=mips CROSS_COMPILE=mips-linux-gnu- 'CC=sccache mips-linux-gnu-gcc' 'HOSTCC=sccache gcc' WARNING: modpost: vmlinux.o(.text+0x6a88): Section mismatch in reference from the function reserve_exception_space() to the function .meminit.text:memblock_reserve() The function reserve_exception_space() references the function __meminit memblock_reserve(). This is often because reserve_exception_space lacks a __meminit annotation or the annotation of memblock_reserve is wrong. FATAL: modpost: Section mismatches detected. Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them. make[2]: *** [/builds/linux/scripts/Makefile.modpost:59: vmlinux.symvers] Error 1 Here is the list of build failed, - gcc-8-allnoconfig - gcc-8-tinyconfig - gcc-9-allnoconfig - gcc-9-tinyconfig - gcc-10-allnoconfig - gcc-10-tinyconfig - clang-10-tinyconfig - clang-10-allnoconfig - clang-11-allnoconfig - clang-11-tinyconfig - clang-12-tinyconfig - clang-12-allnoconfig Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> link: https://gitlab.com/Linaro/lkft/mirrors/stable/linux-stable-rc/-/jobs/1117167411#L142 steps to reproduce: --------------------------- # TuxMake is a command line tool and Python library that provides # portable and repeatable Linux kernel builds across a variety of # architectures, toolchains, kernel configurations, and make targets. # # TuxMake supports the concept of runtimes. # See https://docs.tuxmake.org/runtimes/, for that to work it requires # that you install podman or docker on your system. # # To install tuxmake on your system globally: # sudo pip3 install -U tuxmake # # See https://docs.tuxmake.org/ for complete documentation. tuxmake --runtime podman --target-arch mips --toolchain gcc-10 --kconfig tinyconfig -- Linaro LKFT https://lkft.linaro.org