diff options
Diffstat (limited to 'src/lib/rmodule.c')
| -rw-r--r-- | src/lib/rmodule.c | 38 |
1 files changed, 20 insertions, 18 deletions
diff --git a/src/lib/rmodule.c b/src/lib/rmodule.c index 4276ed33e8..b56ec322be 100644 --- a/src/lib/rmodule.c +++ b/src/lib/rmodule.c @@ -16,6 +16,7 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ +#include <assert.h> #include <stdint.h> #include <stdlib.h> #include <string.h> @@ -254,16 +255,22 @@ int rmodule_load(void *base, struct rmodule *module) return 0; } -void *rmodule_find_region_below(void *addr, size_t rmodule_size, - void **program_start, void **rmodule_start) +int rmodule_calc_region(unsigned int region_alignment, size_t rmodule_size, + size_t *region_size, int *load_offset) { - unsigned long ceiling; - unsigned long program_base; - unsigned long placement_loc; - unsigned long program_begin; + /* region_alignment must be a power of 2. */ + if (region_alignment & (region_alignment - 1)) + BUG(); - ceiling = (unsigned long)addr; - /* Place the rmodule just under the ceiling. The rmodule files + if (region_alignment < 4096) + region_alignment = 4096; + + /* Sanity check rmodule_header size. The code below assumes it is less + * than the minimum alignment required. */ + if (region_alignment < sizeof(struct rmodule_header)) + BUG(); + + /* Place the rmodule according to alignment. The rmodule files * themselves are packed as a header and a payload, however the rmodule * itself is linked along with the header. The header starts at address * 0. Immediately following the header in the file is the program, @@ -273,13 +280,13 @@ void *rmodule_find_region_below(void *addr, size_t rmodule_size, * to place the rmodule so that the program falls on the aligned * address with the header just before it. Therefore, we need at least * a page to account for the size of the header. */ - program_base = ALIGN((ceiling - (rmodule_size + 4096)), 4096); + *region_size = ALIGN(rmodule_size + region_alignment, 4096); /* The program starts immediately after the header. However, * it needs to be aligned to a 4KiB boundary. Therefore, adjust the * program location so that the program lands on a page boundary. The * layout looks like the following: * - * +--------------------------------+ ceiling + * +--------------------------------+ region_alignment + region_size * | >= 0 bytes from alignment | * +--------------------------------+ program end (4KiB aligned) * | program size | @@ -287,14 +294,9 @@ void *rmodule_find_region_below(void *addr, size_t rmodule_size, * | sizeof(struct rmodule_header) | * +--------------------------------+ rmodule header start * | >= 0 bytes from alignment | - * +--------------------------------+ program_base (4KiB aligned) + * +--------------------------------+ region_alignment */ - placement_loc = ALIGN(program_base + sizeof(struct rmodule_header), - 4096) - sizeof(struct rmodule_header); - program_begin = placement_loc + sizeof(struct rmodule_header); - - *program_start = (void *)program_begin; - *rmodule_start = (void *)placement_loc; + *load_offset = region_alignment; - return (void *)program_base; + return region_alignment - sizeof(struct rmodule_header); } |