Commit 79a9ff02 authored by Luca Burelli's avatar Luca Burelli Committed by Benjamin Cabé
Browse files

llext: (cosmetic) cleaner region overlap checks 



Rewrite the overlap checks in llext_map_sections() to use a pair of
macros to calculate the top and bottom of a region. This makes the
code more readable and less error-prone.

No functional change is introduced in this commit apart from a log
message format change.

Signed-off-by: default avatarLuca Burelli <l.burelli@arduino.cc>
parent 8f9ab18c

subsys/llext/llext_load.c

+19 −16
Original line number Diff line number Diff line
@@ -209,6 +209,15 @@ static int llext_find_tables(struct llext_loader *ldr, struct llext *ext) 
	return 0;

}



/* First (bottom) and last (top) entries of a region, inclusive, for a specific field. */

#define REGION_BOT(reg, field) (size_t)(reg->field)

#define REGION_TOP(reg, field) (size_t)(reg->field + reg->sh_size - 1)



/* Check if two regions x and y have any overlap on a given field. Any shared value counts. */

#define REGIONS_OVERLAP_ON(x, y, f) \

	((REGION_BOT(x, f) <= REGION_BOT(y, f) && REGION_TOP(x, f) >= REGION_BOT(y, f)) || \

	 (REGION_BOT(y, f) <= REGION_BOT(x, f) && REGION_TOP(y, f) >= REGION_BOT(x, f)))



/*

 * Maps the ELF sections into regions according to their usage flags,

 * calculating ldr->sects and ldr->sect_map.
@@ -406,14 +415,11 @@ static int llext_map_sections(struct llext_loader *ldr, struct llext *ext, 
				/*

				 * Test regions that have VMA ranges for overlaps

				 */

				if ((x->sh_addr <= y->sh_addr &&

				     x->sh_addr + x->sh_size > y->sh_addr) ||

				    (y->sh_addr <= x->sh_addr &&

				     y->sh_addr + y->sh_size > x->sh_addr)) {

					LOG_ERR("Region %d VMA range (%#zx +%zd) "

						"overlaps with %d (%#zx +%zd)",

						i, (size_t)x->sh_addr, (size_t)x->sh_size,

						j, (size_t)y->sh_addr, (size_t)y->sh_size);

				if (REGIONS_OVERLAP_ON(x, y, sh_addr)) {

					LOG_ERR("Region %d VMA range (%#zx-%#zx) "

						"overlaps with %d (%#zx-%#zx)",

						i, REGION_BOT(x, sh_addr), REGION_TOP(x, sh_addr),

						j, REGION_BOT(y, sh_addr), REGION_TOP(y, sh_addr));

					return -ENOEXEC;

				}

			}
@@ -427,14 +433,11 @@ static int llext_map_sections(struct llext_loader *ldr, struct llext *ext, 
				continue;

			}



			if ((x->sh_offset <= y->sh_offset &&

			     x->sh_offset + x->sh_size > y->sh_offset) ||

			    (y->sh_offset <= x->sh_offset &&

			     y->sh_offset + y->sh_size > x->sh_offset)) {

				LOG_ERR("Region %d ELF file range (%#zx +%zd) "

					"overlaps with %d (%#zx +%zd)",

					i, (size_t)x->sh_offset, (size_t)x->sh_size,

					j, (size_t)y->sh_offset, (size_t)y->sh_size);

			if (REGIONS_OVERLAP_ON(x, y, sh_offset)) {

				LOG_ERR("Region %d ELF file range (%#zx-%#zx) "

					"overlaps with %d (%#zx-%#zx)",

					i, REGION_BOT(x, sh_offset), REGION_TOP(x, sh_offset),

					j, REGION_BOT(y, sh_offset), REGION_TOP(y, sh_offset));

				return -ENOEXEC;

			}

		}

CRA Git | Maintained and supported by SUSTech CRA and CCSE