From: Florian Weimer <fweimer@redhat.com>
To: libc-alpha@sourceware.org
Subject: [PATCH v3 28/32] elf: Add fast path to dlopen for fully-opened maps
Date: Thu, 07 Dec 2023 11:32:44 +0100 [thread overview]
Message-ID: <a4400193c257759deb92bf9bf431b1fd71e6707f.1701944612.git.fweimer@redhat.com> (raw)
In-Reply-To: <cover.1701944612.git.fweimer@redhat.com>
---
elf/dl-open.c | 36 +++++++++++++++++++++++++++++++-----
1 file changed, 31 insertions(+), 5 deletions(-)
diff --git a/elf/dl-open.c b/elf/dl-open.c
index 52e44804cf..a8c9945f2b 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -533,6 +533,23 @@ call_dl_init (void *closure)
_dl_init (args->new, args->argc, args->argv, args->env);
}
+/* Return true if the object does not need any processing beyond the
+ l_direct_opencount update. Needs to be kept in sync with the logic
+ in dl_o-en_worker_begin after the l->l_searchlist.r_list != NULL check.
+ MODE is the dlopen mode argument. */
+static bool
+is_already_fully_open (struct link_map_private *map, int mode)
+{
+ return (map != NULL /* An existing map was found. */
+ /* dlopen completed initialization of this map. Maps with
+ l_type == lt_library start out as partially initialized. */
+ && map->l_searchlist.r_list != NULL
+ /* The object is already in the global scope if requested. */
+ && (!(mode & RTLD_GLOBAL) || map->l_global)
+ /* The object is already NODELETE if requested. */
+ && (!(mode & RTLD_NODELETE) || map->l_rw->l_nodelete_active));
+}
+
static void
dl_open_worker_begin (void *a)
{
@@ -559,9 +576,10 @@ dl_open_worker_begin (void *a)
_dl_debug_initialize (0, args->nsid);
/* Load the named object. */
- struct link_map_private *new;
- args->map = new = _dl_map_object (args->caller_map, file, lt_loaded, 0,
- mode | __RTLD_CALLMAP, args->nsid);
+ struct link_map_private *new = args->map;
+ if (new == NULL)
+ args->map = new = _dl_map_new_object (args->caller_map, file, lt_loaded, 0,
+ mode | __RTLD_CALLMAP, args->nsid);
/* If the pointer returned is NULL this means the RTLD_NOLOAD flag is
set and the object is not already loaded. */
@@ -578,7 +596,7 @@ dl_open_worker_begin (void *a)
/* This object is directly loaded. */
++new->l_rw->l_direct_opencount;
- /* It was already open. */
+ /* It was already open. See is_already_fully_open above. */
if (__glibc_unlikely (new->l_searchlist.r_list != NULL))
{
/* Let the user know about the opencount. */
@@ -881,7 +899,6 @@ no more namespaces available for dlmopen()"));
struct dl_open_args args;
args.file = file;
args.mode = mode;
- args.map = NULL;
args.nsid = nsid;
/* args.libc_already_loaded is always assigned by dl_open_worker
(before any explicit/non-local returns). */
@@ -906,6 +923,15 @@ no more namespaces available for dlmopen()"));
else
args.caller_map = NULL;
+ args.map = _dl_lookup_map (args.nsid, file);
+ if (is_already_fully_open (args.map, mode))
+ {
+ /* We can use the fast path. */
+ ++args.map->l_rw->l_direct_opencount;
+ __rtld_lock_unlock_recursive (GL(dl_load_lock));
+ return args.map;
+ }
+
struct dl_exception exception;
int errcode = _dl_catch_exception (&exception, dl_open_worker, &args);
--
2.43.0
next prev parent reply other threads:[~2023-12-07 10:34 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-07 10:30 [PATCH v3 00/32] RELRO linkmaps Florian Weimer
2023-12-07 10:30 ` [PATCH v3 01/32] support: Add <support/memprobe.h> for protection flags probing Florian Weimer
2024-02-22 22:39 ` Joseph Myers
2023-12-07 10:30 ` [PATCH v3 02/32] misc: Enable internal use of memory protection keys Florian Weimer
2024-02-22 1:06 ` Joseph Myers
2023-12-07 10:31 ` [PATCH v3 03/32] elf: Remove _dl_sysdep_open_object hook function Florian Weimer
2024-01-31 13:10 ` Joseph Myers
2024-03-11 17:19 ` Florian Weimer
2024-03-11 17:33 ` Joseph Myers
2024-03-11 17:46 ` Florian Weimer
2024-03-11 18:02 ` Joseph Myers
2024-03-11 18:16 ` Florian Weimer
2023-12-07 10:31 ` [PATCH v3 04/32] elf: Eliminate second loop in find_version in dl-version.c Florian Weimer
2024-02-19 22:17 ` Joseph Myers
2023-12-07 10:31 ` [PATCH v3 05/32] elf: In rtld_setup_main_map, assume ld.so has a DYNAMIC segment Florian Weimer
2024-02-19 22:18 ` Joseph Myers
2023-12-07 10:31 ` [PATCH v3 06/32] elf: Remove version assert in check_match in elf/dl-lookup.c Florian Weimer
2024-03-04 23:22 ` Joseph Myers
2023-12-07 10:31 ` [PATCH v3 07/32] elf: Disambiguate some failures in _dl_load_cache_lookup Florian Weimer
2024-02-19 23:07 ` Joseph Myers
2023-12-07 10:31 ` [PATCH v3 08/32] elf: Eliminate alloca in open_verify Florian Weimer
2024-02-19 23:26 ` Joseph Myers
2023-12-07 10:31 ` [PATCH v3 09/32] Do not export <alloc_buffer.h> functions from libc Florian Weimer
2024-02-21 17:13 ` Joseph Myers
2023-12-07 10:31 ` [PATCH v3 10/32] elf: Make <alloc_buffer.h> usable in ld.so Florian Weimer
2024-02-21 17:19 ` Joseph Myers
2023-12-07 10:31 ` [PATCH v3 11/32] elf: Merge the three implementations of _dl_dst_substitute Florian Weimer
2024-02-28 17:52 ` Joseph Myers
2023-12-07 10:31 ` [PATCH v3 12/32] elf: Move __rtld_malloc_init_stubs call into _dl_start_final Florian Weimer
2024-02-22 22:30 ` Joseph Myers
2024-02-22 23:06 ` Andreas Schwab
2023-12-07 10:31 ` [PATCH v3 13/32] elf: Merge __dl_libc_freemem into __rtld_libc_freeres Florian Weimer
2024-02-22 23:23 ` Joseph Myers
2023-12-07 10:31 ` [PATCH v3 14/32] elf: Use struct link_map_private for the internal link map Florian Weimer
2024-02-22 23:36 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 15/32] elf: Remove run-time-writable fields from struct link_map_private Florian Weimer
2024-02-23 0:09 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 16/32] elf: Move l_tls_offset into read-write part of link map Florian Weimer
2024-02-26 21:57 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 17/32] elf: Allocate auditor state after read-write " Florian Weimer
2024-02-26 22:01 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 18/32] elf: Move link map fields used by dependency sorting to writable part Florian Weimer
2024-02-27 17:51 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 19/32] elf: Split _dl_lookup_map, _dl_map_new_object from _dl_map_object Florian Weimer
2024-02-27 17:56 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 20/32] elf: Add l_soname accessor function for DT_SONAME values Florian Weimer
2024-02-27 22:14 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 21/32] elf: _dl_rtld_map should not exist in static builds Florian Weimer
2024-02-28 12:38 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 22/32] elf: Introduce GLPM accessor for the protected memory area Florian Weimer
2024-02-28 12:44 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 23/32] elf: Bootstrap allocation for future protected memory allocator Florian Weimer
2024-02-28 15:04 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 24/32] elf: Implement a basic " Florian Weimer
2024-02-28 18:46 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 25/32] elf: Move most of the _dl_find_object data to the protected heap Florian Weimer
2024-02-28 19:06 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 26/32] elf: Switch to a region-based protected memory allocator Florian Weimer
2024-03-05 23:36 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 27/32] elf: Determine the caller link map in _dl_open Florian Weimer
2024-02-28 19:23 ` Joseph Myers
2023-12-07 10:32 ` Florian Weimer [this message]
2024-02-28 19:26 ` [PATCH v3 28/32] elf: Add fast path to dlopen for fully-opened maps Joseph Myers
2023-12-07 10:32 ` [PATCH v3 29/32] elf: Use _dl_find_object instead of _dl_find_dso_for_object in dlopen Florian Weimer
2024-02-28 19:27 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 30/32] elf: Put critical _dl_find_object pointers into protected memory area Florian Weimer
2024-03-04 21:39 ` Joseph Myers
2023-12-07 10:32 ` [PATCH v3 31/32] elf: Add hash tables to speed up DT_NEEDED, dlopen lookups Florian Weimer
2024-03-06 0:04 ` Joseph Myers
2023-12-07 10:33 ` [PATCH v3 32/32] elf: Use memory protection keys for the protected memory allocator Florian Weimer
2024-03-06 0:11 ` Joseph Myers
2023-12-07 10:53 ` [PATCH v3 00/32] RELRO linkmaps Andreas Schwab
2023-12-07 10:56 ` Florian Weimer
2023-12-07 11:34 ` Andreas Schwab
2024-03-01 14:45 ` Adhemerval Zanella Netto
2024-03-11 17:24 ` Florian Weimer
2024-03-12 12:51 ` Adhemerval Zanella Netto
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