On Fri, Feb 18, 2022 at 10:00 AM Geert Uytterhoeven
<geert@xxxxxxxxxxxxxx> wrote:
/* We let the MMU do all checking */
-static inline int access_ok(const void __user *addr,
+static inline int access_ok(const void __user *ptr,
unsigned long size)
{
+ unsigned long limit = TASK_SIZE;
+ unsigned long addr = (unsigned long)ptr;
+
/*
* XXX: for !CONFIG_CPU_HAS_ADDRESS_SPACES this really needs to check
* for TASK_SIZE!
+ * Removing this helper is probably sufficient.
*/
Shouldn't the above comment block be removed completely,
as this is now implemented below?
Yes, obviously. Fixed now.
- return 1;
+ if (IS_ENABLED(CONFIG_CPU_HAS_ADDRESS_SPACES))
+ return 1;
I just noticed this should have the same change that I made for the
generic version, changed it now to
+ if (IS_ENABLED(CONFIG_CPU_HAS_ADDRESS_SPACES) ||
+ !IS_ENABLED(CONFIG_MMU))
This is gone again after the cleanup patch, when the generic version
is used instead.
+ return (size <= limit) && (addr <= (limit - size));
}
Any pesky compilers that warn (or worse with -Werror) about
"condition always true" for TASK_SIZE = 0xFFFFFFFFUL?
No, using a local variable avoids this warning.
Arnd
