feat: update ELF parser

- added more header validity checks
- create section name retrieval

1 files changed, 29 insertions, 0 deletions

diff --git a/kernel/elf.c b/kernel/elf.c
index f1ceb2d..69c4128 100644
--- a/kernel/elf.c
+++ b/kernel/elf.c
@@ -8,5 +8,34 @@ int elf_chk_header(struct elf_header *header) {
         return -1;
     }
 
+    if (header->e_ident[EI_CLASS] != ELFHOSTCLASS) {
+        return -1;
+    }
+
+    if (header->e_ident[EI_DATA] != ELFHOSTDATA) {
+        return -1;
+    }
+
+    if (header->e_ident[EI_VERSION] != EV_CURRENT) {
+        return -1;
+    }
+
     return 0;
 }
+
+struct elf_section_header *elf_get_section(struct elf_header *hdr, void *data, uint32_t index) {
+    uint8_t *base = (uint8_t *)data;
+
+    if (index >= hdr->e_shnum) {
+        return 0;
+    }
+
+    return (struct elf_section_header *)(base
+        + hdr->e_shoff
+        + index * hdr->e_shentsize);
+}
+
+char *elf_get_section_name(struct elf_header *hdr, struct elf_section_header *section, void *data) {
+    struct elf_section_header *shstrtab = elf_get_section(hdr, data, hdr->e_shstrndx);
+    return (char *)((uintptr_t)section->sh_name + (uintptr_t)shstrtab->sh_offset + (uintptr_t)data);
+}