Target descriptions are allocated lazily, that is fine in GDBserver,
but it is not safe to call malloc in gdb_collect in IPA, because we
can set a fast tracepoint in malloc, and when the tracepoint is hit,
gdb_collect/malloc is called, deadlock or memory corruption may be
triggered.
#0 0xf7cfc200 in malloc ()
#1 0xf7efdc07 in operator new(unsigned int) ()
#2 0xf7ef7636 in allocate_target_description() ()
#3 0xf7efcbe1 in i386_create_target_description(unsigned long long, bool) ()
#4 0xf7efb474 in i386_linux_read_description(unsigned long long) ()
#5 0xf7efb190 in get_ipa_tdesc(int) ()
#6 0xf7ef9baa in gdb_collect ()
The fix is to initialize all target descriptions earlier, when the
IPA is loaded. In order to guarantee malloc is not called in IPA
in gdb_collect, I change the test to set a breakpoint on malloc, if
IPA gdb_collect calls malloc, program will hit the breakpoint, and
test fail.
continue
Continuing.
Thread 1 "" hit Breakpoint 5, 0xf7cfc200 in malloc ()
(gdb) FAIL: gdb.trace/ftrace.exp: advance through tracing
gdb/gdbserver:
2017-12-07 Yao Qi <yao.qi@linaro.org>
* linux-aarch64-ipa.c (initialize_low_tracepoint): Call
aarch64_linux_read_description.
* linux-amd64-ipa.c (idx2mask): New array.
(get_ipa_tdesc): Move idx2mask out.
(initialize_low_tracepoint): Initialize target descriptions.
* linux-i386-ipa.c (idx2mask): New array.
(get_ipa_tdesc): Move idx2mask out.
(initialize_low_tracepoint): Initialize target descriptions.
gdb/testsuite:
2017-12-07 Yao Qi <yao.qi@linaro.org>
* gdb.trace/ftrace.exp (run_trace_experiment): Set breakpoint on
malloc and catch syscall.
a880623024