|
 |
01917d |
commit 9e0aa64f5510861b2517c5841b59adde8e423540
|
|
|
01917d |
Author: Jan Kratochvil <jan.kratochvil@redhat.com>
|
|
|
01917d |
Date: Mon May 19 20:20:27 2014 +0200
|
|
|
01917d |
|
|
|
01917d |
Fix gdbserver qGetTLSAddr for x86_64 -m32
|
|
|
01917d |
|
|
|
01917d |
gdbserver makes libthread_db to access uninitialized memory. Surprisingly it
|
|
|
01917d |
does not harm normally, even -fsanitize=address works with current gdbserver.
|
|
|
01917d |
I have found just valgrind detects it as a very first warning for gdbserver:
|
|
|
01917d |
|
|
|
01917d |
Syscall param ptrace(addr) contains uninitialised byte(s)
|
|
|
01917d |
at 0x3721EECEBE: ptrace (ptrace.c:45)
|
|
|
01917d |
by 0x436EE5: ps_get_thread_area (linux-x86-low.c:252)
|
|
|
01917d |
by 0x5559D02: __td_ta_lookup_th_unique (td_ta_map_lwp2thr.c:157)
|
|
|
01917d |
by 0x5559EC3: td_ta_map_lwp2thr (td_ta_map_lwp2thr.c:207)
|
|
|
01917d |
by 0x43F87D: find_one_thread (thread-db.c:281)
|
|
|
01917d |
by 0x440038: thread_db_get_tls_address (thread-db.c:505)
|
|
|
01917d |
by 0x40F6D0: handle_query (server.c:2004)
|
|
|
01917d |
by 0x4124CF: process_serial_event (server.c:3445)
|
|
|
01917d |
by 0x4136B6: handle_serial_event (server.c:3889)
|
|
|
01917d |
by 0x419571: handle_file_event (event-loop.c:434)
|
|
|
01917d |
by 0x418D38: process_event (event-loop.c:189)
|
|
|
01917d |
by 0x419AB7: start_event_loop (event-loop.c:552)
|
|
|
01917d |
|
|
|
01917d |
Reproducible with:
|
|
|
01917d |
cd gdb/testsuite
|
|
|
01917d |
g++ -o gdb.threads/tls gdb.threads/tls{,2}.c -m32 -pthread
|
|
|
01917d |
../gdbserver/gdbserver :1234 gdb.threads/tls
|
|
|
01917d |
../gdb -batch gdb.threads/tls -ex 'target remote :1234' -ex 'b spin' -ex c -ex 'p a_thread_local'
|
|
|
01917d |
|
|
|
01917d |
It is more easily reproducible even without valgrind using s/0x00/0xff/ in the
|
|
|
01917d |
attached patch. It will then turn the output of reproducer above:
|
|
|
01917d |
$1 = 0
|
|
|
01917d |
->
|
|
|
01917d |
Cannot find thread-local storage for Thread 29044, executable file .../gdb/testsuite/gdb.threads/tls:
|
|
|
01917d |
Remote target failed to process qGetTLSAddr request
|
|
|
01917d |
|
|
|
01917d |
gdb/gdbserver/
|
|
|
01917d |
2014-05-19 Jan Kratochvil <jan.kratochvil@redhat.com>
|
|
|
01917d |
|
|
|
01917d |
Fix gdbserver qGetTLSAddr for x86_64 -m32.
|
|
|
01917d |
* linux-x86-low.c (X86_64_USER_REGS): New.
|
|
|
01917d |
(x86_fill_gregset): Call memset for BUF first in x86_64 -m32 case.
|
|
|
01917d |
|
|
|
01917d |
Message-ID: <20140410114901.GA16411@host2.jankratochvil.net>
|
|
|
01917d |
|
|
|
01917d |
Index: gdb-7.6.1/gdb/gdbserver/linux-x86-low.c
|
|
|
01917d |
===================================================================
|
|
|
01917d |
--- gdb-7.6.1.orig/gdb/gdbserver/linux-x86-low.c
|
|
|
01917d |
+++ gdb-7.6.1/gdb/gdbserver/linux-x86-low.c
|
|
|
01917d |
@@ -144,6 +144,7 @@ static const int x86_64_regmap[] =
|
|
|
01917d |
};
|
|
|
01917d |
|
|
|
01917d |
#define X86_64_NUM_REGS (sizeof (x86_64_regmap) / sizeof (x86_64_regmap[0]))
|
|
|
01917d |
+#define X86_64_USER_REGS (GS + 1)
|
|
|
01917d |
|
|
|
01917d |
#else /* ! __x86_64__ */
|
|
|
01917d |
|
|
|
01917d |
@@ -275,6 +276,10 @@ x86_fill_gregset (struct regcache *regca
|
|
|
01917d |
collect_register (regcache, i, ((char *) buf) + x86_64_regmap[i]);
|
|
|
01917d |
return;
|
|
|
01917d |
}
|
|
|
01917d |
+
|
|
|
01917d |
+ /* 32-bit inferior registers need to be zero-extended.
|
|
|
01917d |
+ Callers would read uninitialized memory otherwise. */
|
|
|
01917d |
+ memset (buf, 0x00, X86_64_USER_REGS * 8);
|
|
|
01917d |
#endif
|
|
|
01917d |
|
|
|
01917d |
for (i = 0; i < I386_NUM_REGS; i++)
|