@@ -5,6 +5,7 @@
* User space memory access functions
*/
#include <linux/compiler.h>
+#include <linux/instrumented.h>
#include <linux/kasan-checks.h>
#include <linux/string.h>
#include <asm/asm.h>
@@ -103,6 +104,7 @@ extern int __get_user_bad(void);
: "=a" (__ret_gu), "=r" (__val_gu), \
ASM_CALL_CONSTRAINT \
: "0" (ptr), "i" (sizeof(*(ptr)))); \
+ instrument_get_user(__val_gu); \
(x) = (__force __typeof__(*(ptr))) __val_gu; \
__builtin_expect(__ret_gu, 0); \
})
@@ -192,9 +194,11 @@ extern void __put_user_nocheck_8(void);
int __ret_pu; \
void __user *__ptr_pu; \
register __typeof__(*(ptr)) __val_pu asm("%"_ASM_AX); \
- __chk_user_ptr(ptr); \
- __ptr_pu = (ptr); \
- __val_pu = (x); \
+ __typeof__(*(ptr)) __x = (x); /* eval x once */ \
+ __typeof__(ptr) __ptr = (ptr); /* eval ptr once */ \
+ __chk_user_ptr(__ptr); \
+ __ptr_pu = __ptr; \
+ __val_pu = __x; \
asm volatile("call __" #fn "_%P[size]" \
: "=c" (__ret_pu), \
ASM_CALL_CONSTRAINT \
@@ -202,6 +206,7 @@ extern void __put_user_nocheck_8(void);
"r" (__val_pu), \
[size] "i" (sizeof(*(ptr))) \
:"ebx"); \
+ instrument_put_user(__x, __ptr, sizeof(*(ptr))); \
__builtin_expect(__ret_pu, 0); \
})
@@ -248,23 +253,25 @@ extern void __put_user_nocheck_8(void);
#define __put_user_size(x, ptr, size, label) \
do { \
+ __typeof__(*(ptr)) __x = (x); /* eval x once */ \
__chk_user_ptr(ptr); \
switch (size) { \
case 1: \
- __put_user_goto(x, ptr, "b", "iq", label); \
+ __put_user_goto(__x, ptr, "b", "iq", label); \
break; \
case 2: \
- __put_user_goto(x, ptr, "w", "ir", label); \
+ __put_user_goto(__x, ptr, "w", "ir", label); \
break; \
case 4: \
- __put_user_goto(x, ptr, "l", "ir", label); \
+ __put_user_goto(__x, ptr, "l", "ir", label); \
break; \
case 8: \
- __put_user_goto_u64(x, ptr, label); \
+ __put_user_goto_u64(__x, ptr, label); \
break; \
default: \
__put_user_bad(); \
} \
+ instrument_put_user(__x, ptr, size); \
} while (0)
#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
@@ -305,6 +312,7 @@ do { \
default: \
(x) = __get_user_bad(); \
} \
+ instrument_get_user(x); \
} while (0)
#define __get_user_asm(x, addr, itype, ltype, label) \
@@ -153,4 +153,32 @@ instrument_copy_from_user_after(const void *to, const void __user *from,
{
}
+/**
+ * instrument_get_user() - add instrumentation to get_user()-like macros
+ *
+ * get_user() and friends are fragile, so it may depend on the implementation
+ * whether the instrumentation happens before or after the data is copied from
+ * the userspace.
+ *
+ * @to destination variable, may not be address-taken
+ */
+#define instrument_get_user(to) \
+({ \
+})
+
+/**
+ * instrument_put_user() - add instrumentation to put_user()-like macros
+ *
+ * put_user() and friends are fragile, so it may depend on the implementation
+ * whether the instrumentation happens before or after the data is copied from
+ * the userspace.
+ *
+ * @from source address
+ * @ptr userspace pointer to copy to
+ * @size number of bytes to copy
+ */
+#define instrument_put_user(from, ptr, size) \
+({ \
+})
+
#endif /* _LINUX_INSTRUMENTED_H */
Use hooks from instrumented.h to notify bug detection tools about usercopy events in variations of get_user() and put_user(). Signed-off-by: Alexander Potapenko <glider@google.com> --- v5: -- handle put_user(), make sure to not evaluate pointer/value twice v6: -- add missing empty definitions of instrument_get_user() and instrument_put_user() Link: https://linux-review.googlesource.com/id/Ia9f12bfe5832623250e20f1859fdf5cc485a2fce --- arch/x86/include/asm/uaccess.h | 22 +++++++++++++++------- include/linux/instrumented.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+), 7 deletions(-)