Imagelibrary/rtems
1
0
Fork 1
mirror of https://gitlab.rtems.org/rtems/rtos/rtems.git synced 2025-12-25 05:47:12 +00:00
Code Issues Packages Projects Releases Wiki Activity

aarch64/mmu: Prevent block descriptors at level -1

Browse Source 
In the original implementation, level -1 was unused and all levels could
have block-like descriptors (level 2 block descriptors are called page
descriptors). When support for level -1 page tables was added the
constraint on level -1 block descriptors was not honored. This prevents
block descriptors from being mapped at level -1 since the hardware will
not map them properly.
This commit is contained in:
Kinsey Moore
2022-11-16 09:22:34 -06:00
committed by Chris Johns
parent 3f644aa874
commit a9861ceea0
1 changed files with 17 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
bsps/aarch64/include/bsp/aarch64-mmu.h
View File

@@ -243,26 +243,29 @@ BSP_START_TEXT_SECTION static inline rtems_status_code aarch64_mmu_map_block(
/* check for perfect block match */
if ( block_bottom == addr ) {
if ( size >= chunk_size ) {
/* when page_flag is set the last level must be a page descriptor */
if ( page_flag || ( page_table[index] & MMU_DESC_TYPE_TABLE ) != MMU_DESC_TYPE_TABLE ) {
/* level -1 can't contain block descriptors, fall through to subtable */
if ( level != -1 ) {
/* when page_flag is set the last level must be a page descriptor */
if ( page_flag || ( page_table[index] & MMU_DESC_TYPE_TABLE ) != MMU_DESC_TYPE_TABLE ) {
/* no sub-table, apply block properties */
page_table[index] = addr | flags | page_flag;
size -= chunk_size;
addr += chunk_size;
continue;
}
}
} else {
/* block starts on a boundary, but is short */
chunk_size = size;
/* it isn't possible to go beyond page table level 2 */
if ( page_flag ) {
/* no sub-table, apply block properties */
page_table[index] = addr | flags | page_flag;
size -= chunk_size;
addr += chunk_size;
continue;
}
} else {
/* block starts on a boundary, but is short */
chunk_size = size;
/* it isn't possible to go beyond page table level 2 */
if ( page_flag ) {
/* no sub-table, apply block properties */
page_table[index] = addr | flags | page_flag;
size -= chunk_size;
addr += chunk_size;
continue;
}
}
} else {
uintptr_t block_top = RTEMS_ALIGN_UP( addr, granularity );