llext: fix flag evaluation for section grouping

When deciding which sections to group together, only the low 3
section attribute bits are relevant, ignore the rest.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

include/zephyr/llext/elf.h

@@ -212,6 +212,8 @@ struct elf64_shdr {
 #define SHF_ALLOC 0x2           /**< Section is present in memory */
 #define SHF_EXECINSTR 0x4       /**< Section contains executable instructions */
 
+#define SHF_BASIC_TYPE_MASK	(SHF_WRITE | SHF_ALLOC | SHF_EXECINSTR)
+
 /**
  * @brief Symbol table entry(32-bit)
  */

subsys/llext/llext_load.c

@@ -253,8 +253,10 @@ static int llext_map_sections(struct llext_loader *ldr, struct llext *ext)
 			memcpy(region, shdr, sizeof(*region));
 		} else {
 			/* Make sure this section is compatible with the region */
-			if (shdr->sh_flags != region->sh_flags) {
-				LOG_ERR("Unsupported section flags for %s (region %d)",
+			if ((shdr->sh_flags & SHF_BASIC_TYPE_MASK) !=
+			    (region->sh_flags & SHF_BASIC_TYPE_MASK)) {
+				LOG_ERR("Unsupported section flags %#x / %#x for %s (region %d)",
+					(uint32_t)shdr->sh_flags, (uint32_t)region->sh_flags,
 					name, mem_idx);
 				return -ENOEXEC;
 			}