elf: add 64 bits elf loading support

This patch add elf64 loading support to the elf loader. Since
elf32 and elf64 uses completely different types, to avoid copying all
the code and simply replace elf32 with elf64, use a macro which will
return the appropriate field for each type of header. This macro
generates getter for elf structures according to the class of the loaded
elf.
All direct elf struct dereference are then replaced by call to generated
functions. This allows to keep a common loader code even if types are
different.

Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Clement Leger <cleger@kalray.eu>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 28 insertions, 1 deletions

diff --git a/include/elf.h b/include/elf.h
index 92c8d9c127..633f4992dd 100644
--- a/include/elf.h
+++ b/include/elf.h
@@ -400,11 +400,38 @@ static inline void arch_write_notes(struct file *file) { }
 
 struct elf_image {
 	struct list_head list;
-	unsigned long entry;
+	u8 class;
+	u64 entry;
 	void *buf;
 };
 
 struct elf_image *elf_load_image(void *buf);
 void elf_release_image(struct elf_image *elf);
 
+#define ELF_GET_FIELD(__s, __field, __type) \
+static inline __type elf_##__s##_##__field(struct elf_image *elf, void *arg) { \
+	if (elf->class == ELFCLASS32) \
+		return (__type) ((struct elf32_##__s *) arg)->__field; \
+	else \
+		return (__type) ((struct elf64_##__s *) arg)->__field; \
+}
+
+ELF_GET_FIELD(hdr, e_entry, u64)
+ELF_GET_FIELD(hdr, e_phnum, u16)
+ELF_GET_FIELD(hdr, e_phoff, u64)
+ELF_GET_FIELD(hdr, e_type, u16)
+ELF_GET_FIELD(phdr, p_paddr, u64)
+ELF_GET_FIELD(phdr, p_filesz, u64)
+ELF_GET_FIELD(phdr, p_memsz, u64)
+ELF_GET_FIELD(phdr, p_type, u32)
+ELF_GET_FIELD(phdr, p_offset, u64)
+
+static inline unsigned long elf_size_of_phdr(struct elf_image *elf)
+{
+	if (elf->class == ELFCLASS32)
+		return sizeof(Elf32_Phdr);
+	else
+		return sizeof(Elf64_Phdr);
+}
+
 #endif /* _LINUX_ELF_H */