diff options
Diffstat (limited to 'cpukit/posix/src/munmap.c')
| -rw-r--r-- | cpukit/posix/src/munmap.c | 43 |
1 files changed, 31 insertions, 12 deletions
diff --git a/cpukit/posix/src/munmap.c b/cpukit/posix/src/munmap.c index d3687dfef4..323a24e6f4 100644 --- a/cpukit/posix/src/munmap.c +++ b/cpukit/posix/src/munmap.c @@ -1,5 +1,6 @@ /* * Copyright (c) 2012 Chris Johns (chrisj@rtems.org) + * Copyright (c) 2017 Gedare Bloom (gedare@rtems.org) * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at @@ -16,13 +17,21 @@ #include <sys/mman.h> #include <rtems/posix/mmanimpl.h> +#include <rtems/posix/shmimpl.h> -int munmap( - void *addr, size_t len -) +static void shm_munmap( rtems_libio_t *iop ) { - mmap_mapping* mapping; - rtems_chain_node* node; + POSIX_Shm_Control *shm = iop_to_shm( iop ); + + /* decrement mmap's shm reference_count and maybe delete the object */ + POSIX_Shm_Attempt_delete(shm); +} + +int munmap(void *addr, size_t len) +{ + mmap_mapping *mapping; + rtems_chain_node *node; + uint32_t refcnt; /* * Clear errno. @@ -45,19 +54,29 @@ int munmap( node = rtems_chain_first (&mmap_mappings); while ( !rtems_chain_is_tail( &mmap_mappings, node )) { - /* - * If the map is fixed see if this address is already mapped. At this - * point in time if there is an overlap in the mappings we return an - * error. - */ mapping = (mmap_mapping*) node; if ( ( addr >= mapping->addr ) && ( addr < ( mapping->addr + mapping->len )) ) { rtems_chain_extract( node ); + /* FIXME: generally need a way to clean-up the backing object, but + * currently it only matters for MAP_SHARED shm objects. */ + if ( mapping->is_shared_shm == true ) { + shm_munmap(mapping->iop); + } + refcnt = rtems_libio_decrement_mapping_refcnt(mapping->iop); + if ( refcnt == 0 ) { + rtems_libio_check_deferred_free(mapping->iop); + } + /* only free the mapping address for non-fixed mapping */ if (( mapping->flags & MAP_FIXED ) != MAP_FIXED ) { - free( mapping->addr ); - free( mapping ); + /* only free the mapping address for non-shared mapping, because we + * re-use the mapping address across all of the shared mappings, and + * it is memory managed independently... */ + if (( mapping->flags & MAP_SHARED ) != MAP_SHARED ) { + free( mapping->addr ); + } } + free( mapping ); break; } node = rtems_chain_next( node ); |