Commit a1a664ec authored by Martin Schwidefsky's avatar Martin Schwidefsky Committed by Josh Poimboeuf
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objtool: Fix reloc generation on big endian cross-compiles 



Relocations generated in elf_rebuild_rel[a]_reloc_section() are broken
if objtool is built and run on a big endian system.

The following errors pop up during x86 cross-compilation:

  x86_64-9.1.0-ld: fs/efivarfs/inode.o: bad reloc symbol index (0x2000000 >= 0x22) for offset 0 in section `.orc_unwind_ip'
  x86_64-9.1.0-ld: final link failed: bad value

Convert those functions to use gelf_update_rel[a](), similar to what
elf_write_reloc() does.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Co-developed-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
parent 1d509f2a

tools/objtool/elf.c

+19 −15
Original line number Diff line number Diff line
@@ -855,25 +855,27 @@ static int elf_rebuild_rel_reloc_section(struct section *sec, int nr) 
{

	struct reloc *reloc;

	int idx = 0, size;

	GElf_Rel *relocs;

	void *buf;



	/* Allocate a buffer for relocations */

	size = nr * sizeof(*relocs);

	relocs = malloc(size);

	if (!relocs) {

	size = nr * sizeof(GElf_Rel);

	buf = malloc(size);

	if (!buf) {

		perror("malloc");

		return -1;

	}



	sec->data->d_buf = relocs;

	sec->data->d_buf = buf;

	sec->data->d_size = size;

	sec->data->d_type = ELF_T_REL;



	sec->sh.sh_size = size;



	idx = 0;

	list_for_each_entry(reloc, &sec->reloc_list, list) {

		relocs[idx].r_offset = reloc->offset;

		relocs[idx].r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);

		reloc->rel.r_offset = reloc->offset;

		reloc->rel.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);

		gelf_update_rel(sec->data, idx, &reloc->rel);

		idx++;

	}
@@ -884,26 +886,28 @@ static int elf_rebuild_rela_reloc_section(struct section *sec, int nr) 
{

	struct reloc *reloc;

	int idx = 0, size;

	GElf_Rela *relocs;

	void *buf;



	/* Allocate a buffer for relocations with addends */

	size = nr * sizeof(*relocs);

	relocs = malloc(size);

	if (!relocs) {

	size = nr * sizeof(GElf_Rela);

	buf = malloc(size);

	if (!buf) {

		perror("malloc");

		return -1;

	}



	sec->data->d_buf = relocs;

	sec->data->d_buf = buf;

	sec->data->d_size = size;

	sec->data->d_type = ELF_T_RELA;



	sec->sh.sh_size = size;



	idx = 0;

	list_for_each_entry(reloc, &sec->reloc_list, list) {

		relocs[idx].r_offset = reloc->offset;

		relocs[idx].r_addend = reloc->addend;

		relocs[idx].r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);

		reloc->rela.r_offset = reloc->offset;

		reloc->rela.r_addend = reloc->addend;

		reloc->rela.r_info = GELF_R_INFO(reloc->sym->idx, reloc->type);

		gelf_update_rela(sec->data, idx, &reloc->rela);

		idx++;

	}