svn commit: r357450 - head/contrib/elftoolchain/addr2line
Mark Johnston
markj at FreeBSD.org
Mon Feb 3 16:41:40 UTC 2020
Author: markj
Date: Mon Feb 3 16:41:40 2020
New Revision: 357450
URL: https://svnweb.freebsd.org/changeset/base/357450
Log:
addr2line: Cache CU DIEs upon a successful address lookup.
Previously, addr2line would sequentially search all CUs for each input
address. For some uses, notably syzkaller's code coverage map generator,
this was extremely slow. Add a CU cache into which entries are added
following a successful lookup, and search the cache before falling back
to a scan. When translating a large number of addresses this yields
slightly better performance than GNU addr2line.
Garbage-collect an unused hash table which appears to have been intended
for the same purpose. A hash table doesn't seem particularly suitable
since each CU spans a range of addresses.
Submitted by: Tiger Gao <tig at freebsdfoundation.org>
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D23418
Modified:
head/contrib/elftoolchain/addr2line/addr2line.c
Modified: head/contrib/elftoolchain/addr2line/addr2line.c
==============================================================================
--- head/contrib/elftoolchain/addr2line/addr2line.c Mon Feb 3 15:22:46 2020 (r357449)
+++ head/contrib/elftoolchain/addr2line/addr2line.c Mon Feb 3 16:41:40 2020 (r357450)
@@ -25,6 +25,7 @@
*/
#include <sys/param.h>
+#include <sys/tree.h>
#include <capsicum_helpers.h>
#include <dwarf.h>
@@ -39,7 +40,6 @@
#include <stdlib.h>
#include <string.h>
-#include "uthash.h"
#include "_elftc.h"
ELFTC_VCSID("$Id: addr2line.c 3499 2016-11-25 16:06:29Z emaste $");
@@ -57,13 +57,14 @@ struct Func {
};
struct CU {
+ RB_ENTRY(CU) entry;
Dwarf_Off off;
Dwarf_Unsigned lopc;
Dwarf_Unsigned hipc;
char **srcfiles;
Dwarf_Signed nsrcfiles;
STAILQ_HEAD(, Func) funclist;
- UT_hash_handle hh;
+ Dwarf_Die die;
};
static struct option longopts[] = {
@@ -80,11 +81,23 @@ static struct option longopts[] = {
{"version", no_argument, NULL, 'V'},
{NULL, 0, NULL, 0}
};
+
static int demangle, func, base, inlines, print_addr, pretty_print;
static char unknown[] = { '?', '?', '\0' };
static Dwarf_Addr section_base;
-static struct CU *culist;
+/* Need a new curlopc that stores last lopc value. */
+static Dwarf_Unsigned curlopc = ~0ULL;
+static RB_HEAD(cutree, CU) head = RB_INITIALIZER(&head);
+static int
+lopccmp(struct CU *e1, struct CU *e2)
+{
+ return (e1->lopc < e2->lopc ? -1 : e1->lopc > e2->lopc);
+}
+
+RB_PROTOTYPE(cutree, CU, entry, lopccmp);
+RB_GENERATE(cutree, CU, entry, lopccmp)
+
#define USAGE_MESSAGE "\
Usage: %s [options] hexaddress...\n\
Map program addresses to source file names and line numbers.\n\n\
@@ -378,6 +391,26 @@ print_inlines(struct CU *cu, struct Func *f, Dwarf_Uns
f->call_line);
}
+static struct CU *
+culookup(Dwarf_Unsigned addr)
+{
+ struct CU find, *res;
+
+ find.lopc = addr;
+ res = RB_NFIND(cutree, &head, &find);
+ if (res != NULL) {
+ if (res->lopc != addr)
+ res = RB_PREV(cutree, &head, res);
+ if (res != NULL && addr >= res->lopc && addr < res->hipc)
+ return (res);
+ } else {
+ res = RB_MAX(cutree, &head);
+ if (res != NULL && addr >= res->lopc && addr < res->hipc)
+ return (res);
+ }
+ return (NULL);
+}
+
static void
translate(Dwarf_Debug dbg, Elf *e, const char* addrstr)
{
@@ -400,11 +433,30 @@ translate(Dwarf_Debug dbg, Elf *e, const char* addrstr
addr += section_base;
lineno = 0;
file = unknown;
- cu = NULL;
die = NULL;
+ ret = DW_DLV_OK;
- while ((ret = dwarf_next_cu_header(dbg, NULL, NULL, NULL, NULL, NULL,
- &de)) == DW_DLV_OK) {
+ cu = culookup(addr);
+ if (cu != NULL) {
+ die = cu->die;
+ goto status_ok;
+ }
+
+ while (true) {
+ /*
+ * We resume the CU scan from the last place we found a match.
+ * Because when we have 2 sequential addresses, and the second
+ * one is of the next CU, it is faster to just go to the next CU
+ * instead of starting from the beginning.
+ */
+ ret = dwarf_next_cu_header(dbg, NULL, NULL, NULL, NULL, NULL,
+ &de);
+ if (ret == DW_DLV_NO_ENTRY) {
+ if (curlopc == ~0ULL)
+ goto out;
+ ret = dwarf_next_cu_header(dbg, NULL, NULL, NULL, NULL,
+ NULL, &de);
+ }
die = NULL;
while (dwarf_siblingof(dbg, die, &ret_die, &de) == DW_DLV_OK) {
if (die != NULL)
@@ -420,12 +472,15 @@ translate(Dwarf_Debug dbg, Elf *e, const char* addrstr
if (tag == DW_TAG_compile_unit)
break;
}
+
if (ret_die == NULL) {
warnx("could not find DW_TAG_compile_unit die");
goto next_cu;
}
if (dwarf_attrval_unsigned(die, DW_AT_low_pc, &lopc, &de) ==
DW_DLV_OK) {
+ if (lopc == curlopc)
+ goto out;
if (dwarf_attrval_unsigned(die, DW_AT_high_pc, &hipc,
&de) == DW_DLV_OK) {
/*
@@ -440,31 +495,27 @@ translate(Dwarf_Debug dbg, Elf *e, const char* addrstr
hipc = ~0ULL;
}
- /*
- * Record the CU in the hash table for faster lookup
- * later.
- */
if (dwarf_dieoffset(die, &off, &de) != DW_DLV_OK) {
warnx("dwarf_dieoffset failed: %s",
dwarf_errmsg(de));
goto out;
}
- HASH_FIND(hh, culist, &off, sizeof(off), cu);
- if (cu == NULL) {
+
+ if (addr >= lopc && addr < hipc) {
if ((cu = calloc(1, sizeof(*cu))) == NULL)
err(EXIT_FAILURE, "calloc");
cu->off = off;
cu->lopc = lopc;
cu->hipc = hipc;
+ cu->die = die;
STAILQ_INIT(&cu->funclist);
- HASH_ADD(hh, culist, off, sizeof(off), cu);
- }
+ RB_INSERT(cutree, &head, cu);
- if (addr >= lopc && addr < hipc)
+ curlopc = lopc;
break;
+ }
}
-
- next_cu:
+next_cu:
if (die != NULL) {
dwarf_dealloc(dbg, die, DW_DLA_DIE);
die = NULL;
@@ -474,6 +525,7 @@ translate(Dwarf_Debug dbg, Elf *e, const char* addrstr
if (ret != DW_DLV_OK || die == NULL)
goto out;
+status_ok:
switch (dwarf_srclines(die, &lbuf, &lcount, &de)) {
case DW_DLV_OK:
break;
@@ -572,21 +624,6 @@ out:
cu->srcfiles != NULL && f != NULL && f->inlined_caller != NULL)
print_inlines(cu, f->inlined_caller, f->call_file,
f->call_line);
-
- if (die != NULL)
- dwarf_dealloc(dbg, die, DW_DLA_DIE);
-
- /*
- * Reset internal CU pointer, so we will start from the first CU
- * next round.
- */
- while (ret != DW_DLV_NO_ENTRY) {
- if (ret == DW_DLV_ERROR)
- errx(EXIT_FAILURE, "dwarf_next_cu_header: %s",
- dwarf_errmsg(de));
- ret = dwarf_next_cu_header(dbg, NULL, NULL, NULL, NULL, NULL,
- &de);
- }
}
static void
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