Hi, wt., 23 mar 2021 o 18:36 Willy Tarreau <w...@1wt.eu> napisał(a):
> > It is most probably because of compiler optimizations. Some compiler > > barriers are necessary to avoid instructions reordering. It is the > purpose > > of attached patches. Sorry to ask you it again, but could you make some > > tests ? > Sure, I'll verify! I don't believe in it at all. free(), malloc() etc are free to manipulate > global variables so the compiler cannot reorder these operations around > them. We're probably facing other corner cases (or the same but not > totally addressed maybe). > After reading I wasn't sure anymore I even tested properly patched package. :) Fortunately I have a core file so I verified if hlua_not_dumpable variable exists. I don't know how it is possible that hlua_not_dumpable is 0 in this state (bt), if Christopher theory about lacking compiler barriers is wrong. (gdb) p hlua_not_dumpable $1 = 0 (gdb) bt #0 __lll_lock_wait_private () at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:95 #1 0x00007f52fb16c34b in __GI___libc_malloc (bytes=bytes@entry=41) at malloc.c:3063 #2 0x000055d94949e9a9 in hlua_alloc (ud=0x55d9498e90d0 <hlua_global_allocator>, ptr=<optimized out>, osize=4, nsize=41) at src/hlua.c:8210 #3 0x000055d949622271 in luaM_realloc_ () #4 0x000055d949621dbe in luaC_newobj () #5 0x000055d949626f4d in internshrstr () #6 0x000055d9496271fc in luaS_new () #7 0x000055d94961bd03 in lua_pushstring () #8 0x000055d94962d48a in luaL_traceback () #9 0x000055d9495a1b62 in ha_task_dump (buf=buf@entry=0x7f5247c7f628, task=0x7f5234057ba0, pfx=pfx@entry=0x55d949672f19 ' ' <repeats 13 times>) at src/debug.c:227 #10 0x000055d9495a1fd7 in ha_thread_dump (buf=0x7f5247c7f628, thr=<optimized out>, calling_tid=7) at src/debug.c:91 #11 0x000055d9495a2236 in debug_handler (sig=<optimized out>, si=<optimized out>, arg=<optimized out>) at src/debug.c:847 #12 <signal handler called> #13 _int_malloc (av=av@entry=0x7f5234000020, bytes=bytes@entry=56) at malloc.c:4100 #14 0x00007f52fb16c35d in __GI___libc_malloc (bytes=bytes@entry=56) at malloc.c:3065 #15 0x000055d94949e9a9 in hlua_alloc (ud=0x55d9498e90d0 <hlua_global_allocator>, ptr=<optimized out>, osize=5, nsize=56) at src/hlua.c:8210
