Merge tag 'riscv-for-linus-5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Palmer Dabbelt:

 - a workaround for a compiler surprise related to the "r" inline
   assembly that allows LLVM to boot.

 - a fix to avoid WX-only mappings, which the ISA does not allow. While
   this probably manifests in many ways, the bug was found in stress-ng.

 - a missing lock in set_direct_map_*(), which due to a recent lockdep
   change started asserting.

* tag 'riscv-for-linus-5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  RISC-V: Acquire mmap lock before invoking walk_page_range
  RISC-V: Don't allow write+exec only page mapping request in mmap
  riscv/atomic: Fix sign extension for RV64I

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
index f3619f59d85c..12f8a7fce78b 100644
--- a/arch/riscv/kernel/sys_riscv.c
+++ b/arch/riscv/kernel/sys_riscv.c
@@ -8,6 +8,7 @@
 #include <linux/syscalls.h>
 #include <asm/unistd.h>
 #include <asm/cacheflush.h>
+#include <asm-generic/mman-common.h>
 
 static long riscv_sys_mmap(unsigned long addr, unsigned long len,
 			   unsigned long prot, unsigned long flags,
@@ -16,6 +17,11 @@ static long riscv_sys_mmap(unsigned long addr, unsigned long len,
 {
 	if (unlikely(offset & (~PAGE_MASK >> page_shift_offset)))
 		return -EINVAL;
+
+	if ((prot & PROT_WRITE) && (prot & PROT_EXEC))
+		if (unlikely(!(prot & PROT_READ)))
+			return -EINVAL;
+
 	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
 			       offset >> (PAGE_SHIFT - page_shift_offset));
 }