Changeset e39d7b8 in mainline for kernel/generic/src/mm/as.c

Timestamp:

2019-06-17T15:12:44Z (6 years ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Children:

64b7854

Parents:

ef705e14

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2019-06-16 17:59:34)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2019-06-17 15:12:44)

Message:

Change type of uspace pointers in kernel from pointer type to numeric type

From kernel's perspective, userspace addresses are not valid pointers,
and can only be used in calls to copy_to/from_uspace().
Therefore, we change the type of those arguments and variables to
uspace_addr_t which is an alias for sysarg_t.

This allows the compiler to catch accidental direct accesses to
userspace addresses.

Additionally, to avoid losing the type information in code,
a macro uspace_ptr(type) is used that translates to uspace_addr_t.
I makes no functional difference, but allows keeping the type information
in code in case we implement some sort of static checking for it in the future.

File:

• kernel/generic/src/mm/as.c (modified) (4 diffs)

kernel/generic/src/mm/as.c

@@ -2092 +2092 @@
 
 sysarg_t sys_as_area_create(uintptr_t base, size_t size, unsigned int flags,
-    uintptr_t bound, as_area_pager_info_t *pager_info)
+    uintptr_t bound, uspace_ptr(as_area_pager_info_t) pager_info)
 {
         uintptr_t virt = base;
@@ -2098 +2098 @@
         mem_backend_data_t backend_data;
 
-        if (pager_info == AS_AREA_UNPAGED)
+        if (!pager_info)
                 backend = &anon_backend;
         else {
@@ -2125 +2125 @@
 }
 
-sys_errno_t sys_as_area_get_info(uintptr_t address, as_area_info_t *dest)
+sys_errno_t sys_as_area_get_info(uintptr_t address, uspace_ptr(as_area_info_t) dest)
 {
         as_area_t *area;
@@ -2136 +2136 @@
         }
 
-        dest->start_addr = area->base;
-        dest->size = P2SZ(area->pages);
-        dest->flags = area->flags;
+        as_area_info_t info = {
+                .start_addr = area->base,
+                .size = P2SZ(area->pages),
+                .flags = area->flags,
+        };
 
         mutex_unlock(&area->lock);
         mutex_unlock(&AS->lock);
+
+        copy_to_uspace(dest, &info, sizeof(info));
         return EOK;
 }