[PATCH] riscv: vdso: Prevent the compiler from inserting calls to memset()

[Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>]

The compiler is smart enough to insert a call to memset() in
riscv_vdso_get_cpus(), which generates a dynamic relocation.

So prevent this by using -fno-builtin option.

Fixes: e2c0cdfba7f6 ("RISC-V: User-facing API")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
Reviewed-by: Guo Ren <guoren@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20241016083625.136311-2-alexghiti@xxxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
---
 arch/riscv/kernel/vdso/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index 960feb1526caa..3f1c4b2d0b064 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -18,6 +18,7 @@ obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
 
 ccflags-y := -fno-stack-protector
 ccflags-y += -DDISABLE_BRANCH_PROFILING
+ccflags-y += -fno-builtin
 
 ifneq ($(c-gettimeofday-y),)
   CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
-- 
2.43.0