[ Upstream commit e0d17c842c0f824fd4df9f4688709fc6907201e1 ]
As per the table 4.4 of version "20190608-Priv-MSU-Ratified" of the
RISC-V instruction set manual[0], the PTE permission bit combination of
"write+exec only" is reserved for future use. Hence, don't allow such
mapping request in mmap call.
An issue is been reported by David Abdurachmanov, that while running
stress-ng with "sysbadaddr" argument, RCU stalls are observed on RISC-V
specific kernel.
This issue arises when the stress-sysbadaddr request for pages with
"write+exec only" permission bits and then passes the address obtain
from this mmap call to various system call. For the riscv kernel, the
mmap call should fail for this particular combination of permission bits
since it's not valid.
[0]: http://dabbelt.com/~palmer/keep/riscv-isa-manual/riscv-privileged-20190608-1.pdf
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Reported-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
[Palmer: Refer to the latest ISA specification at the only link I could
find, and update the terminology.]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0502bee37cdef755d63eee60236562e5605e2480 ]
Drop static declaration to fix following build error if FRAME_POINTER disabled,
riscv64-linux-ld: arch/riscv/kernel/perf_callchain.o: in function `.L0':
perf_callchain.c:(.text+0x2b8): undefined reference to `walk_stackframe'
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3c1918c8f54166598195d938564072664a8275b1 ]
When building with the LLVM linker this error occurrs:
LD arch/riscv/kernel/vdso/vdso-syms.o
ld.lld: error: no input files
This happens because the lld treats -R as an alias to -rpath, as opposed
to ld where -R means --just-symbols.
Use the long option name for compatibility between the two.
Link: https://github.com/ClangBuiltLinux/linux/issues/805
Reported-by: Dmitry Golovin <dima@golovin.in>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Ilie Halip <ilie.halip@gmail.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Yash Shah