# tls.exp -- Expect script to test thread-local storage # Copyright (C) 1992-2023 Free Software Foundation, Inc. # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program. If not, see . */ load_lib gdb-python.exp standard_testfile tls.c tls2.c if {[istarget "*-*-linux"]} { set target_cflags "-D_MIT_POSIX_THREADS" } else { set target_cflags "" } if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile} ${srcdir}/${subdir}/${srcfile2}" "${binfile}" executable [list c++ debug]] != "" } { return -1 } ### Compute the value of the a_thread_local variable. proc compute_expected_value {value} { set expected_value 0 set i 0 while { $i <= $value} { incr expected_value $i incr i } return $expected_value } ### Get the value of the variable 'me' for the current thread. proc get_me_variable {tnum} { global expect_out global gdb_prompt global decimal set value_of_me -1 send_gdb "print me\n" gdb_expect { -re ".*= ($decimal).*\r\n$gdb_prompt $" { set value_of_me $expect_out(1,string) pass "$tnum thread print me" } -re "$gdb_prompt $" { fail "$tnum thread print me" } timeout { fail "$tnum thread print me (timeout)" } } return ${value_of_me} } ### Check the values of the thread local variables in the thread. ### Also check that info address print the right things. proc check_thread_local {number} { set me_variable [get_me_variable $number] set expected_value [compute_expected_value ${me_variable}] gdb_test "p a_thread_local" \ "= $expected_value" \ "${number} thread local storage" if {[allow_python_tests]} { gdb_test_no_output \ "python sym = gdb.lookup_symbol('a_thread_local')\[0\]" \ "${number} look up a_thread_local symbol" # We intentionally do not pass a frame to "value" here. If a # TLS variable requires a frame, this will fail. However, if # it does not require a frame, then it will succeed. gdb_test "python print(sym.value())" "$expected_value" \ "${number} get symbol value without frame" } gdb_test "p K::another_thread_local" \ "= $me_variable" \ "${number} another thread local storage" gdb_test "info address a_thread_local" \ ".*a_thread_local.*a thread-local variable at offset.*" \ "${number} info address a_thread_local" gdb_test "info address K::another_thread_local" \ ".*another_thread_local.*a thread-local variable at offset.*" \ "${number} info address another_thread_local" } ### Select a particular thread. proc select_thread {thread} { global gdb_prompt send_gdb "thread $thread\n" gdb_expect { -re "\\\[Switching to thread .*\\\].*\r\n$gdb_prompt $" { pass "selected thread: $thread" } -re "$gdb_prompt $" { fail "selected thread: $thread" } timeout { fail "selected thread: $thread (timeout)" } } } ### Do a backtrace for the current thread, and check that the 'spin' routine ### is in it. This means we have one of the threads we created, rather ### than the main thread. Record the thread in the spin_threads ### array. Also remember the level of the 'spin' routine in the backtrace, for ### later use. proc check_thread_stack {number spin_threads spin_threads_level} { global gdb_prompt global expect_out global decimal global hex upvar $spin_threads tarr upvar $spin_threads_level tarrl with_test_prefix "thread stack" { select_thread $number } send_gdb "where\n" gdb_expect { -re ".*(\[0-9\]+)\[ \t\]+$hex in spin \\(vp=(0x\[0-9a-f\]+).*\r\n$gdb_prompt $" { if {[info exists tarr($number)]} { fail "backtrace of thread number $number in spin" } else { pass "backtrace of thread number $number in spin" set level $expect_out(1,string) set tarrl($number) $level set tarr($number) 1 } } -re ".*$gdb_prompt $" { set tarr($number) 0 set tarrl($number) 0 pass "backtrace of thread number $number not relevant" } timeout { fail "backtrace of thread number $number (timeout)" } } } clean_restart ${binfile} gdb_test_multiple "print a_thread_local" "" { -re -wrap "Cannot find thread-local variables on this target" { kfail "gdb/25807" $gdb_test_name } -re -wrap "Cannot read .a_thread_local. without registers" { pass $gdb_test_name } } if {![runto_main]} { return 0 } # Set a breakpoint at the "spin" routine to # test the thread local's value. # gdb_test "b [gdb_get_line_number "here we know tls value"]" \ ".*Breakpoint 2.*tls.*" "set breakpoint at all threads" # Set a bp at a point where we know all threads are alive. # gdb_test "b [gdb_get_line_number "still alive"]" \ ".*Breakpoint 3.*tls.*" "set breakpoint at synch point" # Set a bp at the end to see if all threads are finished. # gdb_test "b [gdb_get_line_number "before exit"]" \ ".*Breakpoint 4.*tls.*" "set breakpoint at exit" send_gdb "continue\n" gdb_expect { -re ".* received signal SIGSEGV.*a_thread_local = 0;.*$gdb_prompt $" { # This is the first symptom if the gcc and binutils versions # in use support TLS, but the system glibc does not. unsupported "continue to first thread: system does not support TLS" return -1 } -re ".*$inferior_exited_re normally.*$gdb_prompt $" { fail "continue to first thread: program runaway" } -re ".*Pass 0 done.*Pass 1 done.*$gdb_prompt $" { fail "continue to first thread: program runaway 2" } -re ".*Breakpoint 2.*tls value.*$gdb_prompt $" { pass "continue to first thread: get to thread" } -re ".*$gdb_prompt $" { fail "continue to first thread: no progress?" } timeout { fail "continue to first thread (timeout)" } } gdb_test "info thread" ".*Thread.*spin.*" \ "at least one th in spin while stopped at first th" check_thread_local "first" gdb_test "continue" ".*Breakpoint 2.*tls value.*" "continue to second thread" gdb_test "info thread" "Thread.*spin.*" \ "at least one th in spin while stopped at second th" check_thread_local "second" gdb_test "continue" ".*Breakpoint 2.*tls value.*" "continue to third thread" gdb_test "info thread" ".*Thread.*spin.*" \ "at least one th in spin while stopped at third th" check_thread_local "third" gdb_test "continue" ".*Breakpoint 3.*still alive.*" "continue to synch point" set no_of_threads 0 send_gdb "info thread\n" gdb_expect { -re "^info thread\[ \t\r\n\]+ *Id .*Frame\[ \t\r\n\]+.*(\[0-9\]+) *Thread\[^\r\n\]+\r\n$gdb_prompt $" { set no_of_threads $expect_out(1,string) pass "get number of threads" } -re "$gdb_prompt $" { fail "get number of threads" } timeout { fail "get number of threads (timeout)" } } array set spin_threads {} unset spin_threads array set spin_threads_level {} unset spin_threads_level # For each thread check its backtrace to see if it is stopped at the # spin routine. for {set i 1} {$i <= $no_of_threads} {incr i} { check_thread_stack $i spin_threads spin_threads_level } ### Loop through the threads and check the values of the tls variables. ### keep track of how many threads we find in the spin routine. set thrs_in_spin 0 foreach i [array names spin_threads] { if {$spin_threads($i) == 1} { incr thrs_in_spin with_test_prefix "spin_threads" { select_thread $i } set level $spin_threads_level($i) # We expect to be in sem_wait, but if the thread has not yet # been scheduled, we might be in sem_post still. We could be at # any intermediate point in spin, too, but that is much less # likely. gdb_test "up $level" ".*spin.*sem_(wait|post).*" "thread $i up" check_thread_local $i } } if {$thrs_in_spin == 0} { fail "no thread backtrace reported spin (vsyscall kernel problem?)" } gdb_test "continue" ".*Breakpoint 4.*before exit.*" "threads exited" send_gdb "info thread\n" gdb_expect { -re ".* 1 *Thread.*2 *Thread.*$gdb_prompt $" { fail "too many threads left at end" } -re ".*\\\* 1 *Thread.*main.*$gdb_prompt $" { pass "expect only base thread at end" } -re ".*No stack.*$gdb_prompt $" { fail "runaway at end" } -re ".*$gdb_prompt $" { fail "mess at end" } timeout { fail "at end (timeout)" } } # Start over and do some "info address" stuff # runto spin gdb_test "info address a_global" \ ".*a_global.*static storage at address.*" gdb_test "info address me" ".*me.*is a (complex DWARF expression:|variable).*" # Test LOC_UNRESOLVED references resolving for `extern' TLS variables. gdb_test "p a_thread_local" " = \[0-9\]+" # Here it could crash with: Cannot access memory at address 0x0 gdb_test "p file2_thread_local" " = \[0-9\]+" # Depending on the current lookup scope we get LOC_UNRESOLVED or LOC_COMPUTED # both printing: # Symbol "file2_thread_local" is a thread-local variable at offset 8 in the thread-local storage for `.../gdb.threads/tls'. gdb_test "info address file2_thread_local" "Symbol \"file2_thread_local\" is a thread-local variable.*" # Here it could also crash with: Cannot access memory at address 0x0 gdb_test "p a_thread_local" " = \[0-9\]+" "p a_thread_local second time" gdb_test "info address a_thread_local" "Symbol \"a_thread_local\" is a thread-local variable.*" # Done! # gdb_exit