On Wed, Feb 16, 2022 at 2:13 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
+ * limit and catch all possible overflows.
+ * On architectures with separate user address space (m68k, s390, parisc,
+ * sparc64) or those without an MMU, this should always return true.
...
+static inline int __access_ok(const void __user *ptr, unsigned long size)
+{
+ unsigned long limit = user_addr_max();
+ unsigned long addr = (unsigned long)ptr;
+
+ if (IS_ENABLED(CONFIG_ALTERNATE_USER_ADDRESS_SPACE))
+ return true;
I noticed that I'm missing the check for !CONFIG_MMU here, despite
mentioning that in the comment above it. I've added it now.
Arnd
