Commit 214a8876 authored by Michael Davidson's avatar Michael Davidson Committed by H. Peter Anvin
Browse files

x86, relocs: Add manual debug mode 



Improve the debuggability of relocations output. When trying to compare
the output between different linkers, it's handy to be able to see the
section names in output.

Signed-off-by: default avatarMichael Davidson <md@google.com>
Link: http://lkml.kernel.org/r/20140121203223.GA12649@www.outflux.net


Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 6f34152f

arch/x86/tools/relocs.c

+29 −1
Original line number Diff line number Diff line
@@ -1015,6 +1015,29 @@ static void emit_relocs(int as_text, int use_real_mode) 
	}

}



/*

 * As an aid to debugging problems with different linkers

 * print summary information about the relocs.

 * Since different linkers tend to emit the sections in

 * different orders we use the section names in the output.

 */

static int do_reloc_info(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,

				const char *symname)

{

	printf("%s\t%s\t%s\t%s\n",

		sec_name(sec->shdr.sh_info),

		rel_type(ELF_R_TYPE(rel->r_info)),

		symname,

		sec_name(sym->st_shndx));

	return 0;

}



static void print_reloc_info(void)

{

	printf("reloc section\treloc type\tsymbol\tsymbol section\n");

	walk_relocs(do_reloc_info);

}



#if ELF_BITS == 64

# define process process_64

#else
@@ -1022,7 +1045,8 @@ static void emit_relocs(int as_text, int use_real_mode) 
#endif



void process(FILE *fp, int use_real_mode, int as_text,

	     int show_absolute_syms, int show_absolute_relocs)

	     int show_absolute_syms, int show_absolute_relocs,

	     int show_reloc_info)

{

	regex_init(use_real_mode);

	read_ehdr(fp);
@@ -1040,5 +1064,9 @@ void process(FILE *fp, int use_real_mode, int as_text, 
		print_absolute_relocs();

		return;

	}

	if (show_reloc_info) {

		print_reloc_info();

		return;

	}

	emit_relocs(as_text, use_real_mode);

}

arch/x86/tools/relocs.h

+4 −3
Original line number Diff line number Diff line
@@ -29,8 +29,9 @@ enum symtype { 
};



void process_32(FILE *fp, int use_real_mode, int as_text,

		int show_absolute_syms, int show_absolute_relocs);

		int show_absolute_syms, int show_absolute_relocs,

		int show_reloc_info);

void process_64(FILE *fp, int use_real_mode, int as_text,

		int show_absolute_syms, int show_absolute_relocs);



		int show_absolute_syms, int show_absolute_relocs,

		int show_reloc_info);

#endif /* RELOCS_H */

arch/x86/tools/relocs_common.c

+12 −4
Original line number Diff line number Diff line
@@ -11,12 +11,13 @@ void die(char *fmt, ...) 


static void usage(void)

{

	die("relocs [--abs-syms|--abs-relocs|--text|--realmode] vmlinux\n");

	die("relocs [--abs-syms|--abs-relocs|--reloc-info|--text|--realmode]" \

	    " vmlinux\n");

}



int main(int argc, char **argv)

{

	int show_absolute_syms, show_absolute_relocs;

	int show_absolute_syms, show_absolute_relocs, show_reloc_info;

	int as_text, use_real_mode;

	const char *fname;

	FILE *fp;
@@ -25,6 +26,7 @@ int main(int argc, char **argv) 


	show_absolute_syms = 0;

	show_absolute_relocs = 0;

	show_reloc_info = 0;

	as_text = 0;

	use_real_mode = 0;

	fname = NULL;
@@ -39,6 +41,10 @@ int main(int argc, char **argv) 
				show_absolute_relocs = 1;

				continue;

			}

			if (strcmp(arg, "--reloc-info") == 0) {

				show_reloc_info = 1;

				continue;

			}

			if (strcmp(arg, "--text") == 0) {

				as_text = 1;

				continue;
@@ -67,10 +73,12 @@ int main(int argc, char **argv) 
	rewind(fp);

	if (e_ident[EI_CLASS] == ELFCLASS64)

		process_64(fp, use_real_mode, as_text,

			   show_absolute_syms, show_absolute_relocs);

			   show_absolute_syms, show_absolute_relocs,

			   show_reloc_info);

	else

		process_32(fp, use_real_mode, as_text,

			   show_absolute_syms, show_absolute_relocs);

			   show_absolute_syms, show_absolute_relocs,

			   show_reloc_info);

	fclose(fp);

	return 0;

}