From: Mark Wielaard <mark@klomp.org>
To: elfutils-devel@sourceware.org
Cc: hsm2@rice.edu, Mark Wielaard <mark@klomp.org>
Subject: [PATCH 13/16] libdw: Make libdw_findcu thread-safe
Date: Tue, 10 Oct 2023 15:42:57 +0200 [thread overview]
Message-ID: <20231010134300.53830-13-mark@klomp.org> (raw)
In-Reply-To: <20231010134300.53830-1-mark@klomp.org>
From: Heather McIntyre <hsm2@rice.edu>
* libdw/libdw_findcu.c (findcu_cb): Use eu_tsearch.
(__libdw_findcu): Use eu_tfind and next_tucu_offset_lock.
(__libdw_findcu_addr): Use eu_tfind.
(__libdw_find_split_dbg_addr): Likewise.
Signed-off-by: Heather S. McIntyre <hsm2@rice.edu>
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
libdw/libdw_findcu.c | 54 ++++++++++++++++++++++++++++----------------
1 file changed, 35 insertions(+), 19 deletions(-)
diff --git a/libdw/libdw_findcu.c b/libdw/libdw_findcu.c
index ed744231..e546fb0f 100644
--- a/libdw/libdw_findcu.c
+++ b/libdw/libdw_findcu.c
@@ -32,9 +32,13 @@
#endif
#include <assert.h>
-#include <search.h>
+#include <eu-search.h>
#include "libdwP.h"
+/* __libdw_findcu modifies "&dbg->next_tu_offset : &dbg->next_cu_offset".
+ May read or write, so mutual exclusion is enforced to prevent a race. */
+rwlock_define(static, next_tucu_offset_lock);
+
static int
findcu_cb (const void *arg1, const void *arg2)
{
@@ -213,7 +217,7 @@ __libdw_intern_next_unit (Dwarf *dbg, bool debug_types)
Dwarf_Sig8_Hash_insert (&dbg->sig8_hash, unit_id8, newp);
/* Add the new entry to the search tree. */
- if (tsearch (newp, tree, findcu_cb) == NULL)
+ if (eu_tsearch (newp, tree, findcu_cb) == NULL)
{
/* Something went wrong. Undo the operation. */
*offsetp = oldoff;
@@ -234,28 +238,40 @@ __libdw_findcu (Dwarf *dbg, Dwarf_Off start, bool v4_debug_types)
/* Maybe we already know that CU. */
struct Dwarf_CU fake = { .start = start, .end = 0 };
- struct Dwarf_CU **found = tfind (&fake, tree, findcu_cb);
+ struct Dwarf_CU **found = eu_tfind (&fake, tree, findcu_cb);
+ struct Dwarf_CU *result = NULL;
+
if (found != NULL)
return *found;
- if (start < *next_offset)
- {
- __libdw_seterrno (DWARF_E_INVALID_DWARF);
- return NULL;
- }
+ rwlock_wrlock(next_tucu_offset_lock);
- /* No. Then read more CUs. */
- while (1)
+ if (start < *next_offset)
+ __libdw_seterrno (DWARF_E_INVALID_DWARF);
+ else
{
- struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg, v4_debug_types);
- if (newp == NULL)
- return NULL;
+ /* No. Then read more CUs. */
+ while (1)
+ {
+ struct Dwarf_CU *newp = __libdw_intern_next_unit (dbg,
+ v4_debug_types);
+ if (newp == NULL)
+ {
+ result = NULL;
+ break;
+ }
- /* Is this the one we are looking for? */
- if (start < *next_offset || start == newp->start)
- return newp;
+ /* Is this the one we are looking for? */
+ if (start < *next_offset || start == newp->start)
+ {
+ result = newp;
+ break;
+ }
+ }
}
- /* NOTREACHED */
+
+ rwlock_unlock(next_tucu_offset_lock);
+ return result;
}
struct Dwarf_CU *
@@ -283,7 +299,7 @@ __libdw_findcu_addr (Dwarf *dbg, void *addr)
return NULL;
struct Dwarf_CU fake = { .start = start, .end = 0 };
- struct Dwarf_CU **found = tfind (&fake, tree, findcu_cb);
+ struct Dwarf_CU **found = eu_tfind (&fake, tree, findcu_cb);
if (found != NULL)
return *found;
@@ -298,7 +314,7 @@ __libdw_find_split_dbg_addr (Dwarf *dbg, void *addr)
/* XXX Assumes split DWARF only has CUs in main IDX_debug_info. */
Elf_Data fake_data = { .d_buf = addr, .d_size = 0 };
Dwarf fake = { .sectiondata[IDX_debug_info] = &fake_data };
- Dwarf **found = tfind (&fake, &dbg->split_tree, __libdw_finddbg_cb);
+ Dwarf **found = eu_tfind (&fake, &dbg->split_tree, __libdw_finddbg_cb);
if (found != NULL)
return *found;
--
2.41.0
next prev parent reply other threads:[~2023-10-10 13:43 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-08 17:07 [PATCH] Fix thread-safety for elfutils Heather McIntyre
2023-08-21 22:08 ` John Mellor-Crummey
2023-08-25 14:10 ` Mark Wielaard
2023-10-10 13:40 ` Mark Wielaard
2023-10-10 13:42 ` [PATCH 01/16] lib: Add new once_define and once macros to eu-config.h Mark Wielaard
2023-10-10 13:42 ` [PATCH 02/16] libelf: Make elf_version thread-safe Mark Wielaard
2023-10-10 14:00 ` Mark Wielaard
2023-10-17 19:05 ` Heather McIntyre
2023-10-19 21:00 ` Mark Wielaard
2023-10-10 13:42 ` [PATCH 03/16] libelf: Fix deadlock in __libelf_readall Mark Wielaard
2023-10-10 15:06 ` Mark Wielaard
2023-10-17 19:11 ` Heather McIntyre
2023-11-09 13:26 ` Mark Wielaard
2023-10-10 13:42 ` [PATCH 04/16] libelf: Fix deadlock in elf_cntl Mark Wielaard
2023-10-10 15:23 ` Mark Wielaard
2023-10-17 19:14 ` Heather McIntyre
2023-10-10 13:42 ` [PATCH 05/16] libelf: Fix elf_end deadlock Mark Wielaard
2023-10-10 15:28 ` Mark Wielaard
2023-10-10 13:42 ` [PATCH 06/16] libelf: Make elf32_getchdr and elf64_getchdr thread-safe Mark Wielaard
2023-10-10 16:28 ` Mark Wielaard
2023-10-10 13:42 ` [PATCH 07/16] lib: Add eu_tsearch and eu_tfind Mark Wielaard
2023-10-10 16:51 ` Mark Wielaard
2023-10-17 20:52 ` Heather McIntyre
2023-10-10 13:42 ` [PATCH 08/16] libcpu: Change calls for tsearch/tfind to eu_tsearch/eu_tfind Mark Wielaard
2023-10-10 21:10 ` Mark Wielaard
2023-10-10 13:42 ` [PATCH 09/16] src: Use eu-search in nm and findtextrel Mark Wielaard
2023-10-10 21:25 ` Mark Wielaard
2023-10-17 19:20 ` Heather McIntyre
2023-10-10 13:42 ` [PATCH 10/16] libdw: make dwarf_getalt thread-safe Mark Wielaard
2023-10-10 22:02 ` Mark Wielaard
2023-10-17 19:25 ` Heather McIntyre
2023-10-10 13:42 ` [PATCH 11/16] libdw: Add locking around __libdw_dieabbrev for dwarf_hasattr Mark Wielaard
2023-10-11 15:10 ` Mark Wielaard
2023-10-17 19:57 ` Heather McIntyre
2023-10-19 22:06 ` Mark Wielaard
2023-10-10 13:42 ` [PATCH 12/16] libdw: Make libdw_find_split_unit thread-safe Mark Wielaard
2023-10-11 17:17 ` Mark Wielaard
2023-10-17 20:01 ` Heather McIntyre
2023-10-10 13:42 ` Mark Wielaard [this message]
2023-10-12 22:02 ` [PATCH 13/16] libdw: Make libdw_findcu thread-safe Mark Wielaard
2023-10-17 20:10 ` Heather McIntyre
2023-10-10 13:42 ` [PATCH 14/16] libdw,libdwfl: Use eu-search for thread-safety Mark Wielaard
2023-10-12 22:05 ` Mark Wielaard
2023-10-10 13:42 ` [PATCH 15/16] tests: Add eu-search tests Mark Wielaard
2023-10-13 14:38 ` Mark Wielaard
2023-10-10 13:43 ` [PATCH 16/16] configure: No longer mark --enable-thread-safety as EXPERIMENTAL Mark Wielaard
2023-10-12 22:09 ` Mark Wielaard
2023-10-10 13:54 ` [PATCH 01/16] lib: Add new once_define and once macros to eu-config.h Mark Wielaard
2023-10-14 15:39 ` [PATCH] Fix thread-safety for elfutils Mark Wielaard
2023-10-14 18:29 ` Heather McIntyre
2023-10-17 15:04 ` Mark Wielaard
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231010134300.53830-13-mark@klomp.org \
--to=mark@klomp.org \
--cc=elfutils-devel@sourceware.org \
--cc=hsm2@rice.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).