This log is taken starting from the main function. We set a watchpoint to on dl_load_lock and dl_write_lock to monitor where locks and unlocks occur. This is a Fedora 38 machine with GNU ld 2.39 (according to ld --version command):
NOTE: There are a few places where the Glibc calls __rtld_lock_unlock_recursive but you don't see it in the call stack upon doing "up" (in the call stack) and "list" (show source code) because it was optimized out with a tail call. Unlocks are usually done at the end of a funciton so they may be optimized out like this. Glibc still runs __rtld_lock_unlock_recursive but it's jumped (jmp instruction) to instead of called (call instruction) thus improving performance.
I've confirmed the tail call by looking at the end of _dl_add_to_namespace_list where it jumps to ___rtld_mutex_unlock then lets that function return (ret instruction) instead of _dl_add_to_namespace_list returning itself:
=> 0x7ffff7fd556f <_dl_add_to_namespace_list+143>: add $0x8,%rsp
0x7ffff7fd5573 <_dl_add_to_namespace_list+147>: pop %rbx
0x7ffff7fd5574 <_dl_add_to_namespace_list+148>: pop %r12
0x7ffff7fd5576 <_dl_add_to_namespace_list+150>: pop %r13
0x7ffff7fd5578 <_dl_add_to_namespace_list+152>: pop %rbp
0x7ffff7fd5579 <_dl_add_to_namespace_list+153>:
jmp *0x274d1(%rip) # 0x7ffff7ffca50 <___rtld_mutex_unlock>
gdb ./main
Reading symbols from ./main...
(gdb) break main
Breakpoint 1 at 0x40112a: file main.c, line 4.
(gdb) run
Starting program: /home/user/QubesIncoming/lab-bin/load-library/main
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, main () at main.c:4
4 dlopen("lib1.so", RTLD_LAZY);
(gdb) list
1 #include <dlfcn.h>
2
3 int main() {
4 dlopen("lib1.so", RTLD_LAZY);
5 dlopen("lib2.so", RTLD_LAZY);
6 }
(gdb) set print pretty
(gdb) print _rtld_global
$1 = {
_dl_ns = {{
_ns_loaded = 0x7ffff7ffe2d0,
_ns_nloaded = 4,
_ns_main_searchlist = 0x7ffff7ffe5a8,
_ns_global_scope_alloc = 0,
_ns_global_scope_pending_adds = 0,
libc_map = 0x7ffff7fc2090,
_ns_unique_sym_table = {
lock = {
mutex = {
__data = {
__lock = 0,
__count = 0,
__owner = 0,
__nusers = 0,
__kind = 1,
__spins = 0,
__elision = 0,
__list = {
__prev = 0x0,
__next = 0x0
}
},
__size = '\000' <repeats 16 times>, "\001", '\000' <repeats 22 times>,
__align = 0
}
},
entries = 0x0,
size = 0,
n_elements = 0,
free = 0x0
},
_ns_debug = {
base = {
r_version = 0,
r_map = 0x0,
r_brk = 0,
r_state = RT_CONSISTENT,
r_ldbase = 0
},
r_next = 0x0
}
}, {
_ns_loaded = 0x0,
_ns_nloaded = 0,
_ns_main_searchlist = 0x0,
_ns_global_scope_alloc = 0,
_ns_global_scope_pending_adds = 0,
libc_map = 0x0,
_ns_unique_sym_table = {
lock = {
mutex = {
__data = {
__lock = 0,
__count = 0,
__owner = 0,
__nusers = 0,
__kind = 0,
__spins = 0,
__elision = 0,
__list = {
__prev = 0x0,
__next = 0x0
}
},
__size = '\000' <repeats 39 times>,
__align = 0
}
},
entries = 0x0,
size = 0,
n_elements = 0,
free = 0x0
},
_ns_debug = {
base = {
r_version = 0,
r_map = 0x0,
r_brk = 0,
r_state = RT_CONSISTENT,
r_ldbase = 0
},
r_next = 0x0
}
} <repeats 15 times>},
_dl_nns = 1,
_dl_load_lock = {
mutex = {
__data = {
__lock = 0,
__count = 0,
__owner = 0,
__nusers = 0,
__kind = 1,
__spins = 0,
__elision = 0,
__list = {
__prev = 0x0,
__next = 0x0
}
},
__size = '\000' <repeats 16 times>, "\001", '\000' <repeats 22 times>,
__align = 0
}
},
_dl_load_write_lock = {
mutex = {
__data = {
__lock = 0,
__count = 0,
__owner = 0,
__nusers = 0,
__kind = 1,
__spins = 0,
__elision = 0,
__list = {
__prev = 0x0,
__next = 0x0
}
},
__size = '\000' <repeats 16 times>, "\001", '\000' <repeats 22 times>,
__align = 0
}
},
_dl_load_tls_lock = {
mutex = {
__data = {
__lock = 0,
__count = 0,
__owner = 0,
__nusers = 0,
__kind = 1,
__spins = 0,
__elision = 0,
__list = {
__prev = 0x0,
__next = 0x0
}
},
__size = '\000' <repeats 16 times>, "\001", '\000' <repeats 22 times>,
__align = 0
}
},
_dl_load_adds = 4,
_dl_initfirst = 0x0,
_dl_profile_map = 0x0,
_dl_num_relocations = 93,
_dl_num_cache_relocations = 7,
_dl_all_dirs = 0x7ffff7fc2000,
_dl_rtld_map = {
l_addr = 140737353916416,
l_name = 0x400318 "/lib64/ld-linux-x86-64.so.2",
l_ld = 0x7ffff7ffce40,
l_next = 0x0,
l_prev = 0x7ffff7fc2090,
l_real = 0x7ffff7ffdab0 <_rtld_local+2736>,
l_ns = 0,
l_libname = 0x7ffff7ffe270 <_dl_rtld_libname>,
l_info = {0x0, 0x0, 0x0, 0x0, 0x7ffff7ffce50, 0x7ffff7ffce70, 0x7ffff7ffce80, 0x7ffff7ffceb0, 0x7ffff7ffcec0,
0x7ffff7ffced0, 0x7ffff7ffce90, 0x7ffff7ffcea0, 0x0, 0x0, 0x7ffff7ffce40, 0x0 <repeats 15 times>,
0x7ffff7ffcf00, 0x0, 0x0, 0x0, 0x0, 0x7ffff7ffcf40, 0x7ffff7ffcf30, 0x7ffff7ffcf50, 0x0, 0x0,
0x7ffff7ffcef0, 0x7ffff7ffcee0, 0x7ffff7ffcf10, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
0x7ffff7ffcf20, 0x0 <repeats 25 times>, 0x7ffff7ffce60},
l_phdr = 0x7ffff7fca040,
l_entry = 0,
l_phnum = 11,
l_ldnum = 0,
l_searchlist = {
r_list = 0x0,
r_nlist = 0
},
l_symbolic_searchlist = {
r_list = 0x0,
r_nlist = 0
},
l_loader = 0x0,
l_versions = 0x7ffff7fc2aa0,
l_nversions = 8,
l_nbuckets = 37,
l_gnu_bitmask_idxbits = 3,
l_gnu_shift = 8,
l_gnu_bitmask = 0x7ffff7fca458,
{
l_gnu_buckets = 0x7ffff7fca478,
l_chain = 0x7ffff7fca478
},
{
l_gnu_chain_zero = 0x7ffff7fca508,
l_buckets = 0x7ffff7fca508
},
l_direct_opencount = 0,
l_type = lt_library,
l_dt_relr_ref = 0,
l_relocated = 1,
l_init_called = 1,
l_global = 1,
l_reserved = 0,
l_main_map = 0,
l_visited = 1,
l_map_used = 1,
l_map_done = 0,
l_phdr_allocated = 0,
l_soname_added = 0,
l_faked = 0,
l_need_tls_init = 0,
l_auditing = 0,
l_audit_any_plt = 0,
l_removed = 0,
l_contiguous = 0,
l_free_initfini = 0,
l_ld_readonly = 0,
l_find_object_processed = 0,
l_nodelete_active = false,
l_nodelete_pending = false,
l_property = lc_property_unknown,
l_x86_feature_1_and = 0,
l_x86_isa_1_needed = 0,
l_1_needed = 0,
l_rpath_dirs = {
dirs = 0x0,
malloced = 0
},
l_reloc_result = 0x0,
l_versyms = 0x7ffff7fcac02,
l_origin = 0x0,
l_map_start = 140737353916416,
l_map_end = 140737354130120,
l_init_called_next = 0x0,
l_scope_mem = {0x0, 0x0, 0x0, 0x0},
l_scope_max = 0,
l_scope = 0x0,
l_local_scope = {0x0, 0x0},
l_file_id = {
dev = 0,
ino = 0
},
l_runpath_dirs = {
dirs = 0x0,
malloced = 0
},
l_initfini = 0x0,
l_reldeps = 0x0,
l_reldepsmax = 0,
l_used = 1,
l_feature_1 = 0,
l_flags_1 = 0,
l_flags = 0,
l_idx = 0,
l_mach = {
plt = 0,
gotplt = 0,
tlsdesc_table = 0x0
},
l_lookup_cache = {
sym = 0x7ffff7fca860,
type_class = 0,
value = 0x7ffff7ffdab0 <_rtld_local+2736>,
ret = 0x7ffff7fca860
},
l_tls_initimage = 0x0,
l_tls_initimage_size = 0,
l_tls_blocksize = 0,
l_tls_align = 0,
l_tls_firstbyte_offset = 0,
l_tls_offset = 0,
l_tls_modid = 0,
l_tls_dtor_count = 0,
l_relro_addr = 203040,
l_relro_size = 5856,
l_serial = 0
},
_dl_rtld_auditstate = {{
cookie = 0,
bindflags = 0
} <repeats 16 times>},
_dl_x86_feature_1 = 0,
_dl_x86_feature_control = {
ibt = cet_elf_property,
shstk = cet_elf_property
},
_dl_stack_flags = 6,
_dl_tls_dtv_gaps = false,
_dl_tls_max_dtv_idx = 1,
_dl_tls_dtv_slotinfo_list = 0x7ffff7fc2b60,
_dl_tls_static_nelem = 1,
_dl_tls_static_used = 136,
_dl_tls_static_optional = 512,
_dl_initial_dtv = 0x7ffff7dce0e0,
_dl_tls_generation = 1,
_dl_scope_free_list = 0x0,
_dl_stack_used = {
next = 0x7ffff7ffe0a0 <_rtld_local+4256>,
prev = 0x7ffff7ffe0a0 <_rtld_local+4256>
},
_dl_stack_user = {
next = 0x7ffff7dcda00,
prev = 0x7ffff7dcda00
},
_dl_stack_cache = {
next = 0x7ffff7ffe0c0 <_rtld_local+4288>,
prev = 0x7ffff7ffe0c0 <_rtld_local+4288>
},
_dl_stack_cache_actsize = 0,
_dl_in_flight_stack = 0,
_dl_stack_cache_lock = 0
}
(gdb) print &_rtld_global._dl_load_lock
$2 = (__rtld_lock_recursive_t *) 0x7ffff7ffda08 <_rtld_local+2568>
(gdb) print &_rtld_global._dl_load_write_lock
$3 = (__rtld_lock_recursive_t *) 0x7ffff7ffda30 <_rtld_local+2608>
(gdb) watch *0x7ffff7ffda08
Hardware watchpoint 2: *0x7ffff7ffda08
(gdb) watch *0x7ffff7ffda30
Hardware watchpoint 3: *0x7ffff7ffda30
(gdb) info watchpoints
Num Type Disp Enb Address What
2 hw watchpoint keep y *0x7ffff7ffda08
3 hw watchpoint keep y *0x7ffff7ffda30
(gdb) continue
Continuing.
Hardware watchpoint 2: *0x7ffff7ffda08
Old value = 0
New value = 1
___pthread_mutex_lock (mutex=<optimized out>) at pthread_mutex_lock.c:130
130 assert (mutex->__data.__owner == 0);
(gdb) backtrace
#0 ___pthread_mutex_lock (mutex=<optimized out>) at pthread_mutex_lock.c:130
#1 0x00007ffff7fd5edb in _dl_open (file=0x402010 "lib1.so", mode=-2147483647, caller_dlopen=0x40113e <main+24>,
nsid=-2, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128) at dl-open.c:830
#2 0x00007ffff7e58714 in dlopen_doit (a=a@entry=0x7fffffffdfa0) at dlopen.c:56
#3 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdee0,
operate=0x7ffff7e586b0 <dlopen_doit>, args=0x7fffffffdfa0) at dl-catch.c:237
#4 0x00007ffff7fcb679 in _dl_catch_error (objname=0x7fffffffdf48, errstring=0x7fffffffdf50,
mallocedp=0x7fffffffdf47, operate=<optimized out>, args=<optimized out>) at dl-catch.c:256
#5 0x00007ffff7e581f3 in _dlerror_run (operate=operate@entry=0x7ffff7e586b0 <dlopen_doit>,
args=args@entry=0x7fffffffdfa0) at dlerror.c:138
#6 0x00007ffff7e587cf in dlopen_implementation (dl_caller=<optimized out>, mode=<optimized out>,
file=<optimized out>) at dlopen.c:71
#7 ___dlopen (file=<optimized out>, mode=<optimized out>) at dlopen.c:81
#8 0x000000000040113e in main () at main.c:4
(gdb) up
#1 0x00007ffff7fd5edb in _dl_open (file=0x402010 "lib1.so", mode=-2147483647, caller_dlopen=0x40113e <main+24>,
nsid=-2, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128) at dl-open.c:830
830 __rtld_lock_lock_recursive (GL(dl_load_lock));
(gdb) list
825 if ((mode & RTLD_BINDING_MASK) == 0)
826 /* One of the flags must be set. */
827 _dl_signal_error (EINVAL, file, NULL, N_("invalid mode for dlopen()"));
828
829 /* Make sure we are alone. */
830 __rtld_lock_lock_recursive (GL(dl_load_lock));
831
832 if (__glibc_unlikely (nsid == LM_ID_NEWLM))
833 {
834 /* Find a new namespace. */
(gdb) continue
Continuing.
Hardware watchpoint 3: *0x7ffff7ffda30
Old value = 0
New value = 1
___pthread_mutex_lock (mutex=<optimized out>) at pthread_mutex_lock.c:130
130 assert (mutex->__data.__owner == 0);
(gdb) backtrace
#0 ___pthread_mutex_lock (mutex=<optimized out>) at pthread_mutex_lock.c:130
#1 0x00007ffff7fd5507 in _dl_add_to_namespace_list (new=0x4052e0, nsid=0) at dl-object.c:33
#2 0x00007ffff7fd1c76 in _dl_map_object_from_fd (name=name@entry=0x402010 "lib1.so", origname=origname@entry=0x0,
fd=-1, fbp=<optimized out>, realname=<optimized out>, loader=loader@entry=0x0, l_type=<optimized out>,
mode=<optimized out>, stack_endp=<optimized out>, nsid=<optimized out>) at dl-load.c:1494
#3 0x00007ffff7fd2839 in _dl_map_object (loader=<optimized out>, loader@entry=0x7ffff7ffe2d0,
name=name@entry=0x402010 "lib1.so", type=type@entry=2, trace_mode=trace_mode@entry=0,
mode=mode@entry=-1879048191, nsid=<optimized out>) at dl-load.c:2253
#4 0x00007ffff7fd63bc in dl_open_worker_begin (a=a@entry=0x7fffffffdcf0) at dl-open.c:534
#5 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdb40,
operate=operate@entry=0x7ffff7fd6310 <dl_open_worker_begin>, args=args@entry=0x7fffffffdcf0) at dl-catch.c:237
#6 0x00007ffff7fd5b70 in dl_open_worker (a=a@entry=0x7fffffffdcf0) at dl-open.c:782
#7 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdcd0,
operate=operate@entry=0x7ffff7fd5b30 <dl_open_worker>, args=args@entry=0x7fffffffdcf0) at dl-catch.c:237
#8 0x00007ffff7fd5f44 in _dl_open (file=0x402010 "lib1.so", mode=<optimized out>,
caller_dlopen=0x40113e <main+24>, nsid=<optimized out>, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128)
at dl-open.c:884
#9 0x00007ffff7e58714 in dlopen_doit (a=a@entry=0x7fffffffdfa0) at dlopen.c:56
#10 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdee0,
operate=0x7ffff7e586b0 <dlopen_doit>, args=0x7fffffffdfa0) at dl-catch.c:237
#11 0x00007ffff7fcb679 in _dl_catch_error (objname=0x7fffffffdf48, errstring=0x7fffffffdf50,
mallocedp=0x7fffffffdf47, operate=<optimized out>, args=<optimized out>) at dl-catch.c:256
#12 0x00007ffff7e581f3 in _dlerror_run (operate=operate@entry=0x7ffff7e586b0 <dlopen_doit>,
args=args@entry=0x7fffffffdfa0) at dlerror.c:138
#13 0x00007ffff7e587cf in dlopen_implementation (dl_caller=<optimized out>, mode=<optimized out>,
file=<optimized out>) at dlopen.c:71
#14 ___dlopen (file=<optimized out>, mode=<optimized out>) at dlopen.c:81
#15 0x000000000040113e in main () at main.c:4
(gdb) up
#1 0x00007ffff7fd5507 in _dl_add_to_namespace_list (new=0x4052e0, nsid=0) at dl-object.c:33
33 __rtld_lock_lock_recursive (GL(dl_load_write_lock));
(gdb) list
28 /* Add the new link_map NEW to the end of the namespace list. */
29 void
30 _dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
31 {
32 /* We modify the list of loaded objects. */
33 __rtld_lock_lock_recursive (GL(dl_load_write_lock));
34
35 if (GL(dl_ns)[nsid]._ns_loaded != NULL)
36 {
37 struct link_map *l = GL(dl_ns)[nsid]._ns_loaded;
(gdb) continue
Continuing.
Hardware watchpoint 3: *0x7ffff7ffda30
Old value = 1
New value = 0
__GI___pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:70
70 LIBC_PROBE (mutex_release, 1, mutex);
(gdb) backtrace
#0 __GI___pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:70
#1 0x00007ffff7fd1c76 in _dl_map_object_from_fd (name=name@entry=0x402010 "lib1.so", origname=origname@entry=0x0,
fd=-1, fbp=<optimized out>, realname=<optimized out>, loader=loader@entry=0x0, l_type=<optimized out>,
mode=<optimized out>, stack_endp=<optimized out>, nsid=<optimized out>) at dl-load.c:1494
#2 0x00007ffff7fd2839 in _dl_map_object (loader=<optimized out>, loader@entry=0x7ffff7ffe2d0,
name=name@entry=0x402010 "lib1.so", type=type@entry=2, trace_mode=trace_mode@entry=0,
mode=mode@entry=-1879048191, nsid=<optimized out>) at dl-load.c:2253
#3 0x00007ffff7fd63bc in dl_open_worker_begin (a=a@entry=0x7fffffffdcf0) at dl-open.c:534
#4 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdb40,
operate=operate@entry=0x7ffff7fd6310 <dl_open_worker_begin>, args=args@entry=0x7fffffffdcf0) at dl-catch.c:237
#5 0x00007ffff7fd5b70 in dl_open_worker (a=a@entry=0x7fffffffdcf0) at dl-open.c:782
#6 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdcd0,
operate=operate@entry=0x7ffff7fd5b30 <dl_open_worker>, args=args@entry=0x7fffffffdcf0) at dl-catch.c:237
#7 0x00007ffff7fd5f44 in _dl_open (file=0x402010 "lib1.so", mode=<optimized out>,
caller_dlopen=0x40113e <main+24>, nsid=<optimized out>, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128)
at dl-open.c:884
#8 0x00007ffff7e58714 in dlopen_doit (a=a@entry=0x7fffffffdfa0) at dlopen.c:56
#9 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdee0,
operate=0x7ffff7e586b0 <dlopen_doit>, args=0x7fffffffdfa0) at dl-catch.c:237
#10 0x00007ffff7fcb679 in _dl_catch_error (objname=0x7fffffffdf48, errstring=0x7fffffffdf50,
mallocedp=0x7fffffffdf47, operate=<optimized out>, args=<optimized out>) at dl-catch.c:256
#11 0x00007ffff7e581f3 in _dlerror_run (operate=operate@entry=0x7ffff7e586b0 <dlopen_doit>,
args=args@entry=0x7fffffffdfa0) at dlerror.c:138
#12 0x00007ffff7e587cf in dlopen_implementation (dl_caller=<optimized out>, mode=<optimized out>,
file=<optimized out>) at dlopen.c:71
#13 ___dlopen (file=<optimized out>, mode=<optimized out>) at dlopen.c:81
#14 0x000000000040113e in main () at main.c:4
(gdb) up
#1 0x00007ffff7fd1c76 in _dl_map_object_from_fd (name=name@entry=0x402010 "lib1.so", origname=origname@entry=0x0,
fd=-1, fbp=<optimized out>, realname=<optimized out>, loader=loader@entry=0x0, l_type=<optimized out>,
mode=<optimized out>, stack_endp=<optimized out>, nsid=<optimized out>) at dl-load.c:1494
1494 _dl_add_to_namespace_list (l, nsid);
(gdb) list
1489 #ifdef DL_AFTER_LOAD
1490 DL_AFTER_LOAD (l);
1491 #endif
1492
1493 /* Now that the object is fully initialized add it to the object list. */
1494 _dl_add_to_namespace_list (l, nsid);
1495
1496 /* Signal that we are going to add new objects. */
1497 if (r->r_state == RT_CONSISTENT)
1498 {
(gdb) continue
Continuing.
Library 1 loaded successfully!
Hardware watchpoint 2: *0x7ffff7ffda08
Old value = 1
New value = 0
__GI___pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:70
70 LIBC_PROBE (mutex_release, 1, mutex);
(gdb) backtrace
#0 __GI___pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:70
#1 0x00007ffff7fd5f91 in _dl_open (file=<optimized out>, mode=<optimized out>, caller_dlopen=0x40113e <main+24>,
nsid=<optimized out>, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128) at dl-open.c:933
#2 0x00007ffff7e58714 in dlopen_doit (a=a@entry=0x7fffffffdfa0) at dlopen.c:56
#3 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdee0,
operate=0x7ffff7e586b0 <dlopen_doit>, args=0x7fffffffdfa0) at dl-catch.c:237
#4 0x00007ffff7fcb679 in _dl_catch_error (objname=0x7fffffffdf48, errstring=0x7fffffffdf50,
mallocedp=0x7fffffffdf47, operate=<optimized out>, args=<optimized out>) at dl-catch.c:256
#5 0x00007ffff7e581f3 in _dlerror_run (operate=operate@entry=0x7ffff7e586b0 <dlopen_doit>,
args=args@entry=0x7fffffffdfa0) at dlerror.c:138
#6 0x00007ffff7e587cf in dlopen_implementation (dl_caller=<optimized out>, mode=<optimized out>,
file=<optimized out>) at dlopen.c:71
#7 ___dlopen (file=<optimized out>, mode=<optimized out>) at dlopen.c:81
#8 0x000000000040113e in main () at main.c:4
(gdb) up
#1 0x00007ffff7fd5f91 in _dl_open (file=<optimized out>, mode=<optimized out>, caller_dlopen=0x40113e <main+24>,
nsid=<optimized out>, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128) at dl-open.c:933
933 __rtld_lock_unlock_recursive (GL(dl_load_lock));
(gdb) list
928 }
929
930 assert (_dl_debug_update (args.nsid)->r_state == RT_CONSISTENT);
931
932 /* Release the lock. */
933 __rtld_lock_unlock_recursive (GL(dl_load_lock));
934
935 return args.map;
936 }
937
(gdb) continue
Continuing.
Hardware watchpoint 2: *0x7ffff7ffda08
Old value = 0
New value = 1
___pthread_mutex_lock (mutex=<optimized out>) at pthread_mutex_lock.c:130
130 assert (mutex->__data.__owner == 0);
(gdb) backtrace
#0 ___pthread_mutex_lock (mutex=<optimized out>) at pthread_mutex_lock.c:130
#1 0x00007ffff7fd5edb in _dl_open (file=0x402018 "lib2.so", mode=-2147483647, caller_dlopen=0x401152 <main+44>,
nsid=-2, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128) at dl-open.c:830
#2 0x00007ffff7e58714 in dlopen_doit (a=a@entry=0x7fffffffdfa0) at dlopen.c:56
#3 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdee0,
operate=0x7ffff7e586b0 <dlopen_doit>, args=0x7fffffffdfa0) at dl-catch.c:237
#4 0x00007ffff7fcb679 in _dl_catch_error (objname=0x7fffffffdf48, errstring=0x7fffffffdf50,
mallocedp=0x7fffffffdf47, operate=<optimized out>, args=<optimized out>) at dl-catch.c:256
#5 0x00007ffff7e581f3 in _dlerror_run (operate=operate@entry=0x7ffff7e586b0 <dlopen_doit>,
args=args@entry=0x7fffffffdfa0) at dlerror.c:138
#6 0x00007ffff7e587cf in dlopen_implementation (dl_caller=<optimized out>, mode=<optimized out>,
file=<optimized out>) at dlopen.c:71
#7 ___dlopen (file=<optimized out>, mode=<optimized out>) at dlopen.c:81
#8 0x0000000000401152 in main () at main.c:5
(gdb) up
#1 0x00007ffff7fd5edb in _dl_open (file=0x402018 "lib2.so", mode=-2147483647, caller_dlopen=0x401152 <main+44>,
nsid=-2, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128) at dl-open.c:830
830 __rtld_lock_lock_recursive (GL(dl_load_lock));
(gdb) list
825 if ((mode & RTLD_BINDING_MASK) == 0)
826 /* One of the flags must be set. */
827 _dl_signal_error (EINVAL, file, NULL, N_("invalid mode for dlopen()"));
828
829 /* Make sure we are alone. */
830 __rtld_lock_lock_recursive (GL(dl_load_lock));
831
832 if (__glibc_unlikely (nsid == LM_ID_NEWLM))
833 {
834 /* Find a new namespace. */
(gdb) continue
Continuing.
Hardware watchpoint 3: *0x7ffff7ffda30
Old value = 0
New value = 1
___pthread_mutex_lock (mutex=<optimized out>) at pthread_mutex_lock.c:130
130 assert (mutex->__data.__owner == 0);
(gdb) backtrace
#0 ___pthread_mutex_lock (mutex=<optimized out>) at pthread_mutex_lock.c:130
#1 0x00007ffff7fd5507 in _dl_add_to_namespace_list (new=0x406600, nsid=0) at dl-object.c:33
#2 0x00007ffff7fd1c76 in _dl_map_object_from_fd (name=name@entry=0x402018 "lib2.so", origname=origname@entry=0x0,
fd=-1, fbp=<optimized out>, realname=<optimized out>, loader=loader@entry=0x0, l_type=<optimized out>,
mode=<optimized out>, stack_endp=<optimized out>, nsid=<optimized out>) at dl-load.c:1494
#3 0x00007ffff7fd2839 in _dl_map_object (loader=<optimized out>, loader@entry=0x7ffff7ffe2d0,
name=name@entry=0x402018 "lib2.so", type=type@entry=2, trace_mode=trace_mode@entry=0,
mode=mode@entry=-1879048191, nsid=<optimized out>) at dl-load.c:2253
#4 0x00007ffff7fd63bc in dl_open_worker_begin (a=a@entry=0x7fffffffdcf0) at dl-open.c:534
#5 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdb40,
operate=operate@entry=0x7ffff7fd6310 <dl_open_worker_begin>, args=args@entry=0x7fffffffdcf0) at dl-catch.c:237
#6 0x00007ffff7fd5b70 in dl_open_worker (a=a@entry=0x7fffffffdcf0) at dl-open.c:782
#7 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdcd0,
operate=operate@entry=0x7ffff7fd5b30 <dl_open_worker>, args=args@entry=0x7fffffffdcf0) at dl-catch.c:237
#8 0x00007ffff7fd5f44 in _dl_open (file=0x402018 "lib2.so", mode=<optimized out>,
caller_dlopen=0x401152 <main+44>, nsid=<optimized out>, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128)
at dl-open.c:884
#9 0x00007ffff7e58714 in dlopen_doit (a=a@entry=0x7fffffffdfa0) at dlopen.c:56
#10 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdee0,
operate=0x7ffff7e586b0 <dlopen_doit>, args=0x7fffffffdfa0) at dl-catch.c:237
#11 0x00007ffff7fcb679 in _dl_catch_error (objname=0x7fffffffdf48, errstring=0x7fffffffdf50,
mallocedp=0x7fffffffdf47, operate=<optimized out>, args=<optimized out>) at dl-catch.c:256
#12 0x00007ffff7e581f3 in _dlerror_run (operate=operate@entry=0x7ffff7e586b0 <dlopen_doit>,
args=args@entry=0x7fffffffdfa0) at dlerror.c:138
#13 0x00007ffff7e587cf in dlopen_implementation (dl_caller=<optimized out>, mode=<optimized out>,
file=<optimized out>) at dlopen.c:71
#14 ___dlopen (file=<optimized out>, mode=<optimized out>) at dlopen.c:81
#15 0x0000000000401152 in main () at main.c:5
(gdb) up
#1 0x00007ffff7fd5507 in _dl_add_to_namespace_list (new=0x406600, nsid=0) at dl-object.c:33
33 __rtld_lock_lock_recursive (GL(dl_load_write_lock));
(gdb) list
28 /* Add the new link_map NEW to the end of the namespace list. */
29 void
30 _dl_add_to_namespace_list (struct link_map *new, Lmid_t nsid)
31 {
32 /* We modify the list of loaded objects. */
33 __rtld_lock_lock_recursive (GL(dl_load_write_lock));
34
35 if (GL(dl_ns)[nsid]._ns_loaded != NULL)
36 {
37 struct link_map *l = GL(dl_ns)[nsid]._ns_loaded;
(gdb) continue
Continuing.
Hardware watchpoint 3: *0x7ffff7ffda30
Old value = 1
New value = 0
__GI___pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:70
70 LIBC_PROBE (mutex_release, 1, mutex);
(gdb) backtrace
#0 __GI___pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:70
#1 0x00007ffff7fd1c76 in _dl_map_object_from_fd (name=name@entry=0x402018 "lib2.so", origname=origname@entry=0x0,
fd=-1, fbp=<optimized out>, realname=<optimized out>, loader=loader@entry=0x0, l_type=<optimized out>,
mode=<optimized out>, stack_endp=<optimized out>, nsid=<optimized out>) at dl-load.c:1494
#2 0x00007ffff7fd2839 in _dl_map_object (loader=<optimized out>, loader@entry=0x7ffff7ffe2d0,
name=name@entry=0x402018 "lib2.so", type=type@entry=2, trace_mode=trace_mode@entry=0,
mode=mode@entry=-1879048191, nsid=<optimized out>) at dl-load.c:2253
#3 0x00007ffff7fd63bc in dl_open_worker_begin (a=a@entry=0x7fffffffdcf0) at dl-open.c:534
#4 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdb40,
operate=operate@entry=0x7ffff7fd6310 <dl_open_worker_begin>, args=args@entry=0x7fffffffdcf0) at dl-catch.c:237
#5 0x00007ffff7fd5b70 in dl_open_worker (a=a@entry=0x7fffffffdcf0) at dl-open.c:782
#6 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdcd0,
operate=operate@entry=0x7ffff7fd5b30 <dl_open_worker>, args=args@entry=0x7fffffffdcf0) at dl-catch.c:237
#7 0x00007ffff7fd5f44 in _dl_open (file=0x402018 "lib2.so", mode=<optimized out>,
caller_dlopen=0x401152 <main+44>, nsid=<optimized out>, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128)
at dl-open.c:884
#8 0x00007ffff7e58714 in dlopen_doit (a=a@entry=0x7fffffffdfa0) at dlopen.c:56
#9 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdee0,
operate=0x7ffff7e586b0 <dlopen_doit>, args=0x7fffffffdfa0) at dl-catch.c:237
#10 0x00007ffff7fcb679 in _dl_catch_error (objname=0x7fffffffdf48, errstring=0x7fffffffdf50,
mallocedp=0x7fffffffdf47, operate=<optimized out>, args=<optimized out>) at dl-catch.c:256
#11 0x00007ffff7e581f3 in _dlerror_run (operate=operate@entry=0x7ffff7e586b0 <dlopen_doit>,
args=args@entry=0x7fffffffdfa0) at dlerror.c:138
#12 0x00007ffff7e587cf in dlopen_implementation (dl_caller=<optimized out>, mode=<optimized out>,
file=<optimized out>) at dlopen.c:71
#13 ___dlopen (file=<optimized out>, mode=<optimized out>) at dlopen.c:81
#14 0x0000000000401152 in main () at main.c:5
(gdb) up
#1 0x00007ffff7fd1c76 in _dl_map_object_from_fd (name=name@entry=0x402018 "lib2.so", origname=origname@entry=0x0,
fd=-1, fbp=<optimized out>, realname=<optimized out>, loader=loader@entry=0x0, l_type=<optimized out>,
mode=<optimized out>, stack_endp=<optimized out>, nsid=<optimized out>) at dl-load.c:1494
1494 _dl_add_to_namespace_list (l, nsid);
(gdb) list
1489 #ifdef DL_AFTER_LOAD
1490 DL_AFTER_LOAD (l);
1491 #endif
1492
1493 /* Now that the object is fully initialized add it to the object list. */
1494 _dl_add_to_namespace_list (l, nsid);
1495
1496 /* Signal that we are going to add new objects. */
1497 if (r->r_state == RT_CONSISTENT)
1498 {
(gdb) continue
Continuing.
Library 2 loaded successfully!
Hardware watchpoint 2: *0x7ffff7ffda08
Old value = 1
New value = 0
__GI___pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:70
70 LIBC_PROBE (mutex_release, 1, mutex);
(gdb) backtrace
#0 __GI___pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:70
#1 0x00007ffff7fd5f91 in _dl_open (file=<optimized out>, mode=<optimized out>, caller_dlopen=0x401152 <main+44>,
nsid=<optimized out>, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128) at dl-open.c:933
#2 0x00007ffff7e58714 in dlopen_doit (a=a@entry=0x7fffffffdfa0) at dlopen.c:56
#3 0x00007ffff7fcb523 in __GI__dl_catch_exception (exception=exception@entry=0x7fffffffdee0,
operate=0x7ffff7e586b0 <dlopen_doit>, args=0x7fffffffdfa0) at dl-catch.c:237
#4 0x00007ffff7fcb679 in _dl_catch_error (objname=0x7fffffffdf48, errstring=0x7fffffffdf50,
mallocedp=0x7fffffffdf47, operate=<optimized out>, args=<optimized out>) at dl-catch.c:256
#5 0x00007ffff7e581f3 in _dlerror_run (operate=operate@entry=0x7ffff7e586b0 <dlopen_doit>,
args=args@entry=0x7fffffffdfa0) at dlerror.c:138
#6 0x00007ffff7e587cf in dlopen_implementation (dl_caller=<optimized out>, mode=<optimized out>,
file=<optimized out>) at dlopen.c:71
#7 ___dlopen (file=<optimized out>, mode=<optimized out>) at dlopen.c:81
#8 0x0000000000401152 in main () at main.c:5
(gdb) up
#1 0x00007ffff7fd5f91 in _dl_open (file=<optimized out>, mode=<optimized out>, caller_dlopen=0x401152 <main+44>,
nsid=<optimized out>, argc=1, argv=0x7fffffffe118, env=0x7fffffffe128) at dl-open.c:933
933 __rtld_lock_unlock_recursive (GL(dl_load_lock));
(gdb) list
928 }
929
930 assert (_dl_debug_update (args.nsid)->r_state == RT_CONSISTENT);
931
932 /* Release the lock. */
933 __rtld_lock_unlock_recursive (GL(dl_load_lock));
934
935 return args.map;
936 }
937
(gdb) continue
Continuing.
Hardware watchpoint 2: *0x7ffff7ffda08
Old value = 0
New value = 1
___pthread_mutex_lock (mutex=<optimized out>) at pthread_mutex_lock.c:130
130 assert (mutex->__data.__owner == 0);
(gdb) backtrace
#0 ___pthread_mutex_lock (mutex=<optimized out>) at pthread_mutex_lock.c:130
#1 0x00007ffff7fced65 in _dl_fini () at dl-fini.c:34
#2 0x00007ffff7e101e6 in __run_exit_handlers (status=0, listp=<optimized out>,
run_list_atexit=run_list_atexit@entry=true, run_dtors=run_dtors@entry=true) at exit.c:111
#3 0x00007ffff7e1032e in __GI_exit (status=<optimized out>) at exit.c:141
#4 0x00007ffff7df7b91 in __libc_start_call_main (main=main@entry=0x401126 <main>, argc=argc@entry=1,
argv=argv@entry=0x7fffffffe118) at ../sysdeps/nptl/libc_start_call_main.h:74
#5 0x00007ffff7df7c4b in __libc_start_main_impl (main=0x401126 <main>, argc=1, argv=0x7fffffffe118,
init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffe108)
at ../csu/libc-start.c:360
#6 0x0000000000401065 in _start ()
(gdb) up
#1 0x00007ffff7fced65 in _dl_fini () at dl-fini.c:34
34 __rtld_lock_lock_recursive (GL(dl_load_lock));
(gdb) list
29 on new (relocation) dependencies. None of the objects are
30 unmapped, so applications can deal with this if their DSOs remain
31 in a consistent state after destructors have run. */
32
33 /* Protect against concurrent loads and unloads. */
34 __rtld_lock_lock_recursive (GL(dl_load_lock));
35
36 /* Ignore objects which are opened during shutdown. */
37 struct link_map *local_init_called_list = _dl_init_called_list;
38
(gdb) continue
Continuing.
Hardware watchpoint 2: *0x7ffff7ffda08
Old value = 1
New value = 0
__GI___pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:70
70 LIBC_PROBE (mutex_release, 1, mutex);
(gdb) backtrace
#0 __GI___pthread_mutex_unlock_usercnt (mutex=<optimized out>, decr=<optimized out>) at pthread_mutex_unlock.c:70
#1 0x00007ffff7fced9b in _dl_fini () at dl-fini.c:47
#2 0x00007ffff7e101e6 in __run_exit_handlers (status=0, listp=<optimized out>,
run_list_atexit=run_list_atexit@entry=true, run_dtors=run_dtors@entry=true) at exit.c:111
#3 0x00007ffff7e1032e in __GI_exit (status=<optimized out>) at exit.c:141
#4 0x00007ffff7df7b91 in __libc_start_call_main (main=main@entry=0x401126 <main>, argc=argc@entry=1,
argv=argv@entry=0x7fffffffe118) at ../sysdeps/nptl/libc_start_call_main.h:74
#5 0x00007ffff7df7c4b in __libc_start_main_impl (main=0x401126 <main>, argc=1, argv=0x7fffffffe118,
init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffffffe108)
at ../csu/libc-start.c:360
#6 0x0000000000401065 in _start ()
(gdb) up
#1 0x00007ffff7fced9b in _dl_fini () at dl-fini.c:47
47 __rtld_lock_unlock_recursive (GL(dl_load_lock));
(gdb) list
42 are not dlclose()ed from underneath us. */
43 ++l->l_direct_opencount;
44
45 /* After this point, everything linked from local_init_called_list
46 cannot be unloaded because of the reference counter update. */
47 __rtld_lock_unlock_recursive (GL(dl_load_lock));
48
49 /* Perform two passes: One for non-audit modules, one for audit
50 modules. This way, audit modules receive unload notifications
51 for non-audit objects, and the destructors for audit modules
(gdb) continue
Continuing.
[Inferior 1 (process 20248) exited normally]
(gdb) exit