Linux callas 3.8.0-19-generic #30-Ubuntu SMP Wed May 1 16:35:23 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

valgrind -v --tool=drd --read-var-info=yes ./a.out 
==10376== drd, a thread error detector
==10376== Copyright (C) 2006-2012, and GNU GPL'd, by Bart Van Assche.
==10376== Using Valgrind-3.9.0.SVN and LibVEX; rerun with -h for copyright info
==10376== Command: ./a.out
==10376== 
--10376-- Valgrind options:
--10376--    -v
--10376--    --tool=drd
--10376--    --read-var-info=yes
--10376-- Contents of /proc/version:
--10376--   Linux version 3.8.0-19-generic (buildd@allspice) (gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1) ) #30-Ubuntu SMP Wed May 1 16:35:23 UTC 2013
--10376-- Arch and hwcaps: AMD64, amd64-cx16-rdtscp-sse3-avx
--10376-- Page sizes: currently 4096, max supported 4096
--10376-- Valgrind library directory: /tmp/lib/valgrind
--10376-- Reading syms from /tmp/a.out
--10376-- Reading syms from /lib/x86_64-linux-gnu/ld-2.17.so
--10376--   Considering /lib/x86_64-linux-gnu/ld-2.17.so ..
--10376--   .. CRC mismatch (computed 0e805c9a wanted d5b108bd)
--10376--   Considering /usr/lib/debug/lib/x86_64-linux-gnu/ld-2.17.so ..
--10376--   .. CRC is valid
--10376-- warning: addVar: unknown size (loadcmds)
--10376-- warning: addVar: unknown size (loadcmds)
--10376-- warning: addVar: unknown size (loadcmds)
--10376-- warning: addVar: unknown size (loadcmds)
--10376-- warning: addVar: unknown size (loadcmds)
--10376-- warning: addVar: unknown size (loadcmds)
--10376-- warning: addVar: unknown size (loadcmds)
--10376-- warning: addVar: unknown size (loadcmds)
--10376-- warning: addVar: unknown size (loadcmds)
--10376-- Reading syms from /tmp/lib/valgrind/drd-amd64-linux
--10376--    object doesn't have a dynamic symbol table
--10376-- warning: addVar: unknown size (ips)
--10376-- Scheduler: using generic scheduler lock implementation.
--10376-- Reading suppressions file: /tmp/lib/valgrind/default.supp
==10376== embedded gdbserver: reading from /tmp/vgdb-pipe-from-vgdb-to-10376-by-kristian-on-???
==10376== embedded gdbserver: writing to   /tmp/vgdb-pipe-to-vgdb-from-10376-by-kristian-on-???
==10376== embedded gdbserver: shared mem   /tmp/vgdb-pipe-shared-mem-vgdb-10376-by-kristian-on-???
==10376== 
==10376== TO CONTROL THIS PROCESS USING vgdb (which you probably
==10376== don't want to do, unless you know exactly what you're doing,
==10376== or are doing some strange experiment):
==10376==   /tmp/lib/valgrind/../../bin/vgdb --pid=10376 ...command...
==10376== 
==10376== TO DEBUG THIS PROCESS USING GDB: start GDB like this
==10376==   /path/to/gdb ./a.out
==10376== and then give GDB the following command
==10376==   target remote | /tmp/lib/valgrind/../../bin/vgdb --pid=10376
==10376== --pid is optional if only one valgrind process is running
==10376== 
--10376-- Reading syms from /tmp/lib/valgrind/vgpreload_core-amd64-linux.so
--10376-- Reading syms from /tmp/lib/valgrind/vgpreload_drd-amd64-linux.so
--10376-- REDIR: 0x4018f40 (strlen) redirected to 0x4c3c2c0 (strlen)
--10376-- Reading syms from /lib/x86_64-linux-gnu/libpthread-2.17.so
--10376--   Considering /lib/x86_64-linux-gnu/libpthread-2.17.so ..
--10376--   .. CRC mismatch (computed da6bb310 wanted d2233b1f)
--10376--   Considering /usr/lib/debug/lib/x86_64-linux-gnu/libpthread-2.17.so ..
--10376--   .. CRC is valid
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e49240 (pthread_create@@GLIB) W-> (0000.0) 0x04c2f080 pthread_create@*
--10376--     new: 0x04e49240 (pthread_create@@GLIB) W-> (0000.0) 0x04c2ed90 pthread_create
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4c9e0 (pthread_cond_init@@G) W-> (0000.0) 0x04c32cf0 pthread_cond_init@*
--10376--     new: 0x04e4c9e0 (pthread_cond_init@@G) W-> (0000.0) 0x04c32b70 pthread_cond_init
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4ca60 (pthread_cond_destroy) W-> (0000.0) 0x04c33170 pthread_cond_destroy@*
--10376--     new: 0x04e4ca60 (pthread_cond_destroy) W-> (0000.0) 0x04c32ff0 pthread_cond_destroy
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4cbe0 (pthread_cond_wait@@G) W-> (0000.0) 0x04c33600 pthread_cond_wait@*
--10376--     new: 0x04e4cbe0 (pthread_cond_wait@@G) W-> (0000.0) 0x04c33470 pthread_cond_wait
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4cf20 (pthread_cond_timedwa) W-> (0000.0) 0x04c33ac0 pthread_cond_timedwait@*
--10376--     new: 0x04e4cf20 (pthread_cond_timedwa) W-> (0000.0) 0x04c33920 pthread_cond_timedwait
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4d4a0 (pthread_cond_signal@) W-> (0000.0) 0x04c33f80 pthread_cond_signal@*
--10376--     new: 0x04e4d4a0 (pthread_cond_signal@) W-> (0000.0) 0x04c33e00 pthread_cond_signal
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4d580 (pthread_cond_broadca) W-> (0000.0) 0x04c34400 pthread_cond_broadcast@*
--10376--     new: 0x04e4d580 (pthread_cond_broadca) W-> (0000.0) 0x04c34280 pthread_cond_broadcast
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4d6c0 (pthread_cond_init@GL) W-> (0000.0) 0x04c32cf0 pthread_cond_init@*
--10376--     new: 0x04e4d6c0 (pthread_cond_init@GL) W-> (0000.0) 0x04c32b70 pthread_cond_init
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4d6f0 (pthread_cond_destroy) W-> (0000.0) 0x04c33170 pthread_cond_destroy@*
--10376--     new: 0x04e4d6f0 (pthread_cond_destroy) W-> (0000.0) 0x04c32ff0 pthread_cond_destroy
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4d710 (pthread_cond_wait@GL) W-> (0000.0) 0x04c33600 pthread_cond_wait@*
--10376--     new: 0x04e4d710 (pthread_cond_wait@GL) W-> (0000.0) 0x04c33470 pthread_cond_wait
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4d7a0 (pthread_cond_timedwa) W-> (0000.0) 0x04c33ac0 pthread_cond_timedwait@*
--10376--     new: 0x04e4d7a0 (pthread_cond_timedwa) W-> (0000.0) 0x04c33920 pthread_cond_timedwait
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4d850 (pthread_cond_signal@) W-> (0000.0) 0x04c33f80 pthread_cond_signal@*
--10376--     new: 0x04e4d850 (pthread_cond_signal@) W-> (0000.0) 0x04c33e00 pthread_cond_signal
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4d8d0 (pthread_cond_broadca) W-> (0000.0) 0x04c34400 pthread_cond_broadcast@*
--10376--     new: 0x04e4d8d0 (pthread_cond_broadca) W-> (0000.0) 0x04c34280 pthread_cond_broadcast
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4da30 (pthread_spin_init   ) W-> (0000.0) 0x04c34700 pthread_spin_init
--10376--     new: 0x04e4da30 (pthread_spin_init   ) W-> (0000.0) 0x04c35930 pthread_spin_unlock
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4da30 (pthread_spin_init   ) W-> (0000.0) 0x04c34700 pthread_spin_init
--10376--     new: 0x04e4da30 (pthread_spin_init   ) W-> (0000.0) 0x04c35930 pthread_spin_unlock
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4e530 (sem_init@@GLIBC_2.2.) W-> (0000.0) 0x04c36d20 sem_init@*
--10376--     new: 0x04e4e530 (sem_init@@GLIBC_2.2.) W-> (0000.0) 0x04c36b90 sem_init
==10376== WARNING: new redirection conflicts with existing -- ignoring it
--10376--     old: 0x04e4e560 (sem_destroy@@GLIBC_2) W-> (0000.0) 0x04c371c0 sem_destroy@*
--10376--     new: 0x04e4e560 (sem_destroy@@GLIBC_2) W-> (0000.0) 0x04c37040 sem_destroy
--10376-- Reading syms from /lib/x86_64-linux-gnu/libc-2.17.so
--10376--   Considering /lib/x86_64-linux-gnu/libc-2.17.so ..
--10376--   .. CRC mismatch (computed 7a0d6b10 wanted 5a2fe04b)
--10376--   Considering /usr/lib/debug/lib/x86_64-linux-gnu/libc-2.17.so ..
--10376--   .. CRC is valid
--10376-- REDIR: 0x50e7d20 (strnlen) redirected to 0x4a2570e (_vgnU_ifunc_wrapper)
--10376-- REDIR: 0x4e49240 (pthread_create@@GLIBC_2.2.5) redirected to 0x4c2f080 (pthread_create@*)
--10376-- REDIR: 0x4e4ae40 (pthread_mutex_init) redirected to 0x4c30ec0 (pthread_mutex_init)
--10376-- REDIR: 0x50e2010 (calloc) redirected to 0x4c2ca0d (calloc)
--10376-- REDIR: 0x4e4af90 (pthread_mutex_lock) redirected to 0x4c31880 (pthread_mutex_lock)
--10376-- REDIR: 0x4e4c100 (pthread_mutex_unlock) redirected to 0x4c326c0 (pthread_mutex_unlock)
--10376-- REDIR: 0x50e19b0 (free) redirected to 0x4c2d693 (free)
--10376-- REDIR: 0x4e4af60 (pthread_mutex_destroy) redirected to 0x4c313d0 (pthread_mutex_destroy)
==10376== Thread 5:
==10376== Conflicting load by thread 5 at 0x0505d3e0 size 4
==10376==    at 0x4E4FCF0: close (syscall-template.S:81)
==10376==    by 0x4007CB: thread (t.c:17)
==10376==    by 0x4C2ED74: vgDrd_thread_wrapper (drd_pthread_intercepts.c:355)
==10376==    by 0x4E48F8D: start_thread (pthread_create.c:311)
==10376==    by 0x5157E1C: clone (clone.S:113)
==10376== Location 0x505d3e0 is 0 bytes inside global var "__pthread_multiple_threads"
==10376== declared at vars.c:38
==10376== Other segment start (thread 1)
==10376==    at 0x4C2F301: pthread_create@* (drd_pthread_intercepts.c:483)
==10376==    by 0x4007FB: main (t.c:35)
==10376== Other segment end (thread 1)
==10376==    at 0x5157DE1: clone (clone.S:83)
==10376==    by 0x4E47F44: do_clone.constprop.4 (createthread.c:74)
==10376==    by 0x4E4966D: pthread_create@@GLIBC_2.2.5 (createthread.c:244)
==10376==    by 0x4C2F220: pthread_create@* (drd_pthread_intercepts.c:473)
==10376==    by 0x4007FB: main (t.c:35)
==10376== 
--10376-- REDIR: 0x4e4a160 (pthread_join) redirected to 0x4c2f660 (pthread_join)
==10376== 
==10376== ERROR SUMMARY: 21 errors from 1 contexts (suppressed: 279 from 25)
==10376== 
==10376== 21 errors in context 1 of 1:
==10376== Conflicting load by thread 5 at 0x0505d3e0 size 4
==10376==    at 0x4E4FCF0: close (syscall-template.S:81)
==10376==    by 0x4007CB: thread (t.c:17)
==10376==    by 0x4C2ED74: vgDrd_thread_wrapper (drd_pthread_intercepts.c:355)
==10376==    by 0x4E48F8D: start_thread (pthread_create.c:311)
==10376==    by 0x5157E1C: clone (clone.S:113)
==10376== Location 0x505d3e0 is 0 bytes inside global var "__pthread_multiple_threads"
==10376== declared at vars.c:38
==10376== 
--10376-- 
--10376-- used_suppression:     24 drd-ld /tmp/lib/valgrind/default.supp:584
--10376-- used_suppression:    255 drd-libpthread-pthread_create /tmp/lib/valgrind/default.supp:645
==10376== 
==10376== ERROR SUMMARY: 21 errors from 1 contexts (suppressed: 279 from 25)



HERE IS THE CODE:
================


#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <pthread.h>

/* Happens with two threads also */
#define THREAD_COUNT 256

void* thread(void* x)
{
    int fd;
    (void)x;
    /* Happens with any file, not just /dev/null */
    fd = open("/dev/null", O_RDONLY);
    if (fd < 0) {
        fprintf(stderr, "Error\n");
        return 0;
    }
    close(fd);
    return 0;
}

int main()
{
    size_t i;
    int r;
    pthread_t threads[THREAD_COUNT];

    for (i = 0; i < THREAD_COUNT; ++i) {
        r = pthread_create(&threads[i], 0, &thread, 0);
        if (r != 0) {
            fprintf(stderr, "Error\n");
            return 0;
        }
    }

    for (i = 0; i < THREAD_COUNT; ++i) {
        r = pthread_join(threads[i], 0);
        if (r != 0) {
            fprintf(stderr, "Error\n");
            return 0;
        }
    }
    return 0;
}



Reproducible: Always