Commit 3a647607 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

objtool: Rework the elf_rebuild_reloc_section() logic 



Instead of manually calling elf_rebuild_reloc_section() on sections
we've called elf_add_reloc() on, have elf_write() DTRT.

This makes it easier to add random relocations in places without
carefully tracking when we're done and need to flush what section.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarMiroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/20210326151259.754213408@infradead.org
parent a958c4fe

tools/objtool/check.c

+0 −6
Original line number Diff line number Diff line
@@ -542,9 +542,6 @@ static int create_static_call_sections(struct objtool_file *file) 
		idx++;

	}



	if (elf_rebuild_reloc_section(file->elf, reloc_sec))

		return -1;



	return 0;

}
@@ -614,9 +611,6 @@ static int create_mcount_loc_sections(struct objtool_file *file) 
		idx++;

	}



	if (elf_rebuild_reloc_section(file->elf, reloc_sec))

		return -1;



	return 0;

}

tools/objtool/elf.c

+14 −6
Original line number Diff line number Diff line
@@ -479,6 +479,8 @@ void elf_add_reloc(struct elf *elf, struct reloc *reloc) 


	list_add_tail(&reloc->list, &sec->reloc_list);

	elf_hash_add(elf->reloc_hash, &reloc->hash, reloc_hash(reloc));



	sec->changed = true;

}



static int read_rel_reloc(struct section *sec, int i, struct reloc *reloc, unsigned int *symndx)
@@ -558,7 +560,9 @@ static int read_relocs(struct elf *elf) 
				return -1;

			}



			elf_add_reloc(elf, reloc);

			list_add_tail(&reloc->list, &sec->reloc_list);

			elf_hash_add(elf->reloc_hash, &reloc->hash, reloc_hash(reloc));



			nr_reloc++;

		}

		max_reloc = max(max_reloc, nr_reloc);
@@ -873,14 +877,11 @@ static int elf_rebuild_rela_reloc_section(struct section *sec, int nr) 
	return 0;

}



int elf_rebuild_reloc_section(struct elf *elf, struct section *sec)

static int elf_rebuild_reloc_section(struct elf *elf, struct section *sec)

{

	struct reloc *reloc;

	int nr;



	sec->changed = true;

	elf->changed = true;



	nr = 0;

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

		nr++;
@@ -944,9 +945,15 @@ int elf_write(struct elf *elf) 
	struct section *sec;

	Elf_Scn *s;



	/* Update section headers for changed sections: */

	/* Update changed relocation sections and section headers: */

	list_for_each_entry(sec, &elf->sections, list) {

		if (sec->changed) {

			if (sec->base &&

			    elf_rebuild_reloc_section(elf, sec)) {

				WARN("elf_rebuild_reloc_section");

				return -1;

			}



			s = elf_getscn(elf->elf, sec->idx);

			if (!s) {

				WARN_ELF("elf_getscn");
@@ -958,6 +965,7 @@ int elf_write(struct elf *elf) 
			}



			sec->changed = false;

			elf->changed = true;

		}

	}

tools/objtool/include/objtool/elf.h

+0 −1
Original line number Diff line number Diff line
@@ -142,7 +142,6 @@ struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *se 
struct symbol *find_func_containing(struct section *sec, unsigned long offset);

void insn_to_reloc_sym_addend(struct section *sec, unsigned long offset,

			      struct reloc *reloc);

int elf_rebuild_reloc_section(struct elf *elf, struct section *sec);



#define for_each_sec(file, sec)						\

	list_for_each_entry(sec, &file->elf->sections, list)

tools/objtool/orc_gen.c

+0 −3
Original line number Diff line number Diff line
@@ -254,8 +254,5 @@ int orc_create(struct objtool_file *file) 
			return -1;

	}



	if (elf_rebuild_reloc_section(file->elf, ip_rsec))

		return -1;



	return 0;

}