Yash Shah db9138d06e RISC-V: Don't allow write+exec only page mapping request in mmap ... [ 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>		2020-06-30 23:17:15 -04:00
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configs
include	riscv/atomic: Fix sign extension for RV64I	2020-06-30 23:17:14 -04:00
kernel	RISC-V: Don't allow write+exec only page mapping request in mmap	2020-06-30 23:17:15 -04:00
lib	riscv: Fix udelay in RV32.	2019-07-14 08:11:09 +02:00
mm	RISC-V: Avoid corrupting the upper 32-bit of phys_addr_t in ioremap	2019-12-01 09:16:53 +01:00
Kconfig
Kconfig.debug
Makefile