riscv: Fix spurious errors from __get/put_kernel_nofault

commit d080a08b06b6266cc3e0e86c5acfd80db937cb6b upstream.

These macros did not initialize __kr_err, so they could fail even if
the access did not fault.

Cc: stable@vger.kernel.org
Fixes: d464118cdc41 ("riscv: implement __get_kernel_nofault and __put_user_nofault")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240312022030.320789-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
index ec0cab9fbddd0da98cb415af2732a4ede083886b..72ec1d9bd3f312ec05c6dc5f2342f06e24c58468 100644 (file)
--- a/arch/riscv/include/asm/uaccess.h
+++ b/arch/riscv/include/asm/uaccess.h
@@ -319,7 +319,7 @@ unsigned long __must_check clear_user(void __user *to, unsigned long n)
 
 #define __get_kernel_nofault(dst, src, type, err_label)                        \
 do {                                                                   \
-       long __kr_err;                                                  \
+       long __kr_err = 0;                                              \
                                                                        \
        __get_user_nocheck(*((type *)(dst)), (type *)(src), __kr_err);  \
        if (unlikely(__kr_err))                                         \
@@ -328,7 +328,7 @@ do {                                                                        \
 
 #define __put_kernel_nofault(dst, src, type, err_label)                        \
 do {                                                                   \
-       long __kr_err;                                                  \
+       long __kr_err = 0;                                              \
                                                                        \
        __put_user_nocheck(*((type *)(src)), (type *)(dst), __kr_err);  \
        if (unlikely(__kr_err))                                         \