linux-kernel - [RFC][PATCH v5 50/51] objtool: mcount: Remove useless lookup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 18 Jun 2020 13:38:36 -0700
From:   Matt Helsley <mhelsley@...are.com>
To:     <linux-kernel@...r.kernel.org>
CC:     Josh Poimboeuf <jpoimboe@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Steven Rostedt <rostedt@...dmis.org>,
        Julien Thierry <jthierry@...hat.com>,
        Kamalesh Babulal <kamalesh@...ux.vnet.ibm.com>,
        Matt Helsley <mhelsley@...are.com>
Subject: [RFC][PATCH v5 50/51] objtool: mcount: Remove useless lookup

Since the relocation section's sh_info points back to the text
section it applies to and we already have that we can just pass
it in and greatly simplify find_section_sym_index().

Signed-off-by: Matt Helsley <mhelsley@...are.com>
---
 tools/objtool/mcount.c | 39 +++++++++++++++------------------------
 1 file changed, 15 insertions(+), 24 deletions(-)

diff --git a/tools/objtool/mcount.c b/tools/objtool/mcount.c
index 084bbc02de0c..a74625aed09b 100644
--- a/tools/objtool/mcount.c
+++ b/tools/objtool/mcount.c
@@ -198,35 +198,27 @@ static const unsigned int missing_sym = (unsigned int)-1;
  *    Num:    Value  Size Type    Bind   Vis      Ndx Name
  *      2: 00000000     0 SECTION LOCAL  DEFAULT    1
  */
-static int find_section_sym_index(unsigned const txtndx,
-				char const *const txtname,
-				unsigned long *const recvalp,
-				unsigned int *sym_index)
+static int find_section_sym_index(const struct section * const txts,
+				  unsigned long *const recvalp,
+				  unsigned int *sym_index)
 {
 	struct symbol *sym;
-	struct section *txts = find_section_by_index(lf, txtndx);
-
-	if (!txts) {
-		fprintf(stderr, "Cannot find section %u: %s.\n",
-			txtndx, txtname);
-		return missing_sym;
-	}
 
 	list_for_each_entry(sym, &txts->symbol_list, list) {
 		/* avoid symbols with weak binding */
-		if ((sym->bind == STB_LOCAL) || (sym->bind == STB_GLOBAL)) {
-			/* function symbols on ARM have quirks, avoid them */
-			if (lf->ehdr.e_machine == EM_ARM
-			    && sym->type == STT_FUNC)
-				continue;
-
-			*recvalp = sym->sym.st_value;
-			*sym_index = sym->idx;
-			return 0;
-		}
+		if ((sym->bind != STB_LOCAL) && (sym->bind != STB_GLOBAL))
+			continue;
+
+		/* function symbols on ARM have quirks, avoid them */
+		if (lf->ehdr.e_machine == EM_ARM && sym->type == STT_FUNC)
+			continue;
+
+		*recvalp = sym->sym.st_value;
+		*sym_index = sym->idx;
+		return 0;
 	}
 	fprintf(stderr, "Cannot find symbol for section %u: %s.\n",
-		txtndx, txtname);
+		txts->idx, txts->name);
 	return missing_sym;
 }
 
@@ -414,8 +406,7 @@ static int do_mcount(unsigned const reltype)
 			unsigned long recval = 0;
 			unsigned int recsym;
 
-			if (find_section_sym_index(sec->sh.sh_info,
-						txts->name, &recval, &recsym))
+			if (find_section_sym_index(txts, &recval, &recsym))
 				goto out;
 
 			sift_rel_mcount(&r_offset, sec, mrels, mlocs,
-- 
2.20.1