>Synopsis: Emulated tls is broken if the binary use glib2 functions
>Category: library
>Environment:
System : OpenBSD 6.5
Details : OpenBSD 6.5 (GENERIC.MP) #3: Sat Apr 13 14:48:43 MDT 2019
[email protected]:/usr/src/sys/arch/amd64/compile/GENERIC.MP
Architecture: OpenBSD.amd64
Machine : amd64
>Description:
A .so export a thread local variable, and has a function to modify its
value.
Then call that function in main, and also call glib2 function there,
this
cause the variable valus seen by main differ from expected.
>How-To-Repeat:
Source code to repeat:
### foo.h ###
----
#include <signal.h>
extern _Thread_local volatile sig_atomic_t foo_thread_events;
extern void set_thread_events(int bit);
----
### foo.c ###
----
#include "foo.h"
_Thread_local volatile sig_atomic_t foo_thread_events = 0;
void set_thread_events(int bit)
{
foo_thread_events |= bit;
}
----
### bar.c ###
----
#include "foo.h"
#include <stdio.h>
#include <glib.h>
int main(void)
{
g_log("test", G_LOG_LEVEL_CRITICAL, "...");
set_thread_events(0x01);
if (foo_thread_events & 0x01) {
fprintf(stdout, "set OK\n");
} else {
fprintf(stdout, "set Failed\n");
}
return 0;
}
----
### Commands to compile ###
----
cc -shared -fPIC -o foo.so foo.c
cc -o bar bar.c foo.so `pkg-config --cflags --libs glib-2.0`
export LD_LIBRARY_PATH=.
./bar
----
>Fix:
