[PATCH] riscv: Disable KSAN_SANITIZE for vDSO

[Tobias Klauser]

Dmitry Vyukov reports:
> I've localized one issue with riscv/KASAN:
> KASAN breaks VDSO and that's I think the root cause of weird faults I
> saw earlier. The following patch fixes it.
> Could somebody please upstream this fix? I don't know how to add/run
> tests for this.

Verified the fix on a kernel with KASAN enabled using vDSO selftests.

Link: https://lore.kernel.org/lkml/CACT4Y+ZNJBnkKHXUf=tm_yuowvZvHwN=0rmJ=7J+xFd+9r_6pQ@mail.gmail.com/
Cc: Dmitry Vyukov <dvyukov at google.com>
Tested-by: Tobias Klauser <tklauser at distanz.ch>
Signed-off-by: Tobias Klauser <tklauser at distanz.ch>
---
 arch/riscv/kernel/vdso/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index 0cfd6da784f8..71a315e73cbe 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -32,9 +32,10 @@ CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
 # Disable -pg to prevent insert call site
 CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
 
-# Disable gcov profiling for VDSO code
+# Disable profiling and instrumentation for VDSO code
 GCOV_PROFILE := n
 KCOV_INSTRUMENT := n
+KASAN_SANITIZE := n
 
 # Force dependency
 $(obj)/vdso.o: $(obj)/vdso.so
-- 
2.30.0