This patch is to use standard_testfile in i386-bp_permanent.exp to replace
existing setting to testfile, srcfile and binfile. So it fixes a problem
in i386-bp_permanent.exp in parallel testing.
$ make -j3 check TESTS='gdb.guile/scm-section-script.exp gdb.arch/i386-bp_permanent.exp'
....
gdb compile failed, /usr/bin/ld: cannot open output file x86/gdb/testsuite/gdb.arch/i386-bp_permanent: No such file or directory
collect2: error: ld returned 1 exit status
gdb/testsuite:
2014-12-05 Yao Qi <yao@codesourcery.com>
* gdb.arch/i386-bp_permanent.exp: Use standard_testfile.
The gdb.arch/i386-bp_permanent.exp test is currently failing an
assertion recently added:
(gdb) stepi
../../src/gdb/infrun.c:2237: internal-error: resume: Assertion `sig != GDB_SIGNAL_0' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
FAIL: gdb.arch/i386-bp_permanent.exp: Single stepping past permanent breakpoint. (GDB internal error)
The assertion expects that the only reason we currently need to step a
breakpoint instruction is when we have a signal to deliver. But when
stepping a permanent breakpoint (with or without a signal) we also
reach this code.
The assertion is correct and the permanent breakpoints skipping code
is wrong.
Consider the case of the user doing "step/stepi" when stopped at a
permanent breakpoint. GDB's `resume' calls the
gdbarch_skip_permanent_breakpoint hook and then happily continues
stepping:
/* Normally, by the time we reach `resume', the breakpoints are either
removed or inserted, as appropriate. The exception is if we're sitting
at a permanent breakpoint; we need to step over it, but permanent
breakpoints can't be removed. So we have to test for it here. */
if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
{
gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
}
But since gdbarch_skip_permanent_breakpoint already advanced the PC
manually, this ends up executing the instruction that is _after_ the
breakpoint instruction. The user-visible result is that a single-step
steps two instructions.
The gdb.arch/i386-bp_permanent.exp test is actually ensuring that
that's indeed how things work. It runs to an int3 instruction, does
"stepi", and checks that "leave" was executed with that "stepi". Like
this:
(gdb) b *0x0804848c
Breakpoint 2 at 0x804848c
(gdb) c
Continuing.
Breakpoint 2, 0x0804848c in standard ()
(gdb) disassemble
Dump of assembler code for function standard:
0x08048488 <+0>: push %ebp
0x08048489 <+1>: mov %esp,%ebp
0x0804848b <+3>: push %edi
=> 0x0804848c <+4>: int3
0x0804848d <+5>: leave
0x0804848e <+6>: ret
0x0804848f <+7>: nop
(gdb) si
0x0804848e in standard ()
(gdb) disassemble
Dump of assembler code for function standard:
0x08048488 <+0>: push %ebp
0x08048489 <+1>: mov %esp,%ebp
0x0804848b <+3>: push %edi
0x0804848c <+4>: int3
0x0804848d <+5>: leave
=> 0x0804848e <+6>: ret
0x0804848f <+7>: nop
End of assembler dump.
(gdb)
One would instead expect that a stepi at 0x0804848c stops at
0x0804848d, _before_ the "leave" is executed. This commit changes GDB
this way. Care is taken to make stepping into a signal handler when
the step starts at a permanent breakpoint instruction work correctly.
The patch adjusts gdb.arch/i386-bp_permanent.exp in this direction,
and also makes it work on x86_64 (currently it only works on i*86).
The patch also adds a new gdb.base/bp-permanent.exp test that
exercises many different code paths related to stepping permanent
breakpoints, including the stepping with signals cases. The test uses
"hack/trick" to make it work on all (or most) platforms -- it doesn't
really hard code a breakpoint instruction.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/
2014-11-12 Pedro Alves <palves@redhat.com>
* infrun.c (resume): Clear the thread's 'stepped_breakpoint' flag.
Rewrite stepping over a permanent breakpoint.
(thread_still_needs_step_over, proceed): Don't set
stepping_over_breakpoint for permanent breakpoints.
(handle_signal_stop): Don't clear stepped_breakpoint. Also pull
single-step breakpoints out of the target on hardware step
targets.
(process_event_stop_test): If stepping a permanent breakpoint
doesn't hit the step-resume breakpoint, delete the step-resume
breakpoint.
(switch_back_to_stepped_thread): Also check if the stepped thread
has advanced already on hardware step targets.
(currently_stepping): Return true if the thread stepped a
breakpoint.
gdb/testsuite/
2014-11-12 Pedro Alves <palves@redhat.com>
* gdb.arch/i386-bp_permanent.c: New file.
* gdb.arch/i386-bp_permanent.exp: Don't skip on x86_64.
(srcfile): Set to i386-bp_permanent.c.
(top level): Adjust to work in both 32-bit and 64-bit modes. Test
that stepi does not execute the 'leave' instruction, instead of
testing it does execute.
* gdb.base/bp-permanent.c: New file.
* gdb.base/bp-permanent.exp: New file.
Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
gdb/testsuite/
* gdb.ada/start.exp: Call untested with the correct test filename.
* gdb.arch/i386-bp_permanent.exp: Call untested with the correct
test filename. Make the test's binary unique.
* gdb.arch/i386-signal.exp: Call untested with the correct test
filename.
* gdb.arch/i386-size-overlap.exp: Ditto.
* gdb.arch/Makefile.in (EXECUTABLES): Update.
* gdb.base/gcore-buffer-overflow.exp: Ditto.
* gdb.cp/call-c.exp: Ditto.
* gdb.mi/mi-reverse.exp: Call untested with the correct test
filename. Make the test's binary unique.
* gdb.mi/Makefile.in (EXECUTABLES): Update.
* gdb.python/py-mi.exp: Ditto.
* gdb.python/Makefile.in (EXECUTABLES): Update.
* gdb.reverse/i386-precsave.exp: Ditto.
* gdb.reverse/i387-env-reverse.exp: Call untested with the correct
test filename.
* gdb.reverse/i387-stack-reverse.exp: Ditto.
* gdb.reverse/sigall-precsave.exp: Ditto. Make the test's binary
unique.
* gdb.reverse/sigall-reverse.exp: Call untested with the correct
test filename.
* gdb.reverse/Makefile.in (EXECUTABLES): Update.
* gdb.trace/tfile.exp: Ditto.
non-permanent breakpoints.
(bpstat_stop_status): Change enable_state to bp_disabled only for
non-permanent breakpoints.
(bp_loc_is_permanent): New function.
(create_breakpoint): Check if the location points to a permanent
breakpoint and if it does, make breakpoint permanent.
(update_breakpoint_locations): Make sure new locations of permanent
breakpoints are properly initialized.
* i386-tdep.c (i386_skip_permanent_breakpoint): New function.
(i386_gdbarch_init): Set gdbarch_skip_permanent_breakpoint.
* gdb.arch/i386-bp_permanent.exp: New test.
