Commit f404a58d authored by Aaron Plattner's avatar Aaron Plattner Committed by Josh Poimboeuf
Browse files

objtool: Remove max symbol name length limitation 



If one of the symbols processed by read_symbols() happens to have a
.cold variant with a name longer than objtool's MAX_NAME_LEN limit, the
build fails.

Avoid this problem by just using strndup() to copy the parent function's
name, rather than strncpy()ing it onto the stack.

Signed-off-by: default avatarAaron Plattner <aplattner@nvidia.com>
Link: https://lore.kernel.org/r/41e94cfea1d9131b758dd637fecdeacd459d4584.1696355111.git.aplattner@nvidia.com


Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
parent e959c279

tools/objtool/elf.c

+6 −8
Original line number Diff line number Diff line
@@ -22,8 +22,6 @@ 
#include <objtool/elf.h>

#include <objtool/warn.h>



#define MAX_NAME_LEN 128



static inline u32 str_hash(const char *str)

{

	return jhash(str, strlen(str), 0);
@@ -515,7 +513,7 @@ static int read_symbols(struct elf *elf) 
	/* Create parent/child links for any cold subfunctions */

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

		sec_for_each_sym(sec, sym) {

			char pname[MAX_NAME_LEN + 1];

			char *pname;

			size_t pnamelen;

			if (sym->type != STT_FUNC)

				continue;
@@ -531,15 +529,15 @@ static int read_symbols(struct elf *elf) 
				continue;



			pnamelen = coldstr - sym->name;

			if (pnamelen > MAX_NAME_LEN) {

				WARN("%s(): parent function name exceeds maximum length of %d characters",

				     sym->name, MAX_NAME_LEN);

			pname = strndup(sym->name, pnamelen);

			if (!pname) {

				WARN("%s(): failed to allocate memory",

				     sym->name);

				return -1;

			}



			strncpy(pname, sym->name, pnamelen);

			pname[pnamelen] = '\0';

			pfunc = find_symbol_by_name(elf, pname);

			free(pname);



			if (!pfunc) {

				WARN("%s(): can't find parent function",