Running break-interp.exp with the target always in non-stop mode trips
on PR13858, as enabling non-stop also enables displaced stepping.
The problem is that when GDB doesn't know where the entry point is, it
doesn't know where to put the displaced stepping scratch pad. The
test added by this commit exercises this. Without the fix, we get:
(gdb) PASS: gdb.base/step-over-no-symbols.exp: displaced=on: break *$pc
set displaced-stepping on
(gdb) PASS: gdb.base/step-over-no-symbols.exp: displaced=on: set displaced-stepping on
stepi
0x00000000004005be in ?? ()
Entry point address is not known.
(gdb) PASS: gdb.base/step-over-no-symbols.exp: displaced=on: stepi
p /x $pc
$2 = 0x4005be
(gdb) PASS: gdb.base/step-over-no-symbols.exp: displaced=on: get after PC
FAIL: gdb.base/step-over-no-symbols.exp: displaced=on: advanced
The fix switches all GNU/Linux ports to get the entry point from
AT_ENTRY in the target auxiliary vector instead of from symbols. This
is currently only done by PPC when Cell debugging is enabled, but I
think all archs should be able to do the same. Note that
ppc_linux_displaced_step_location cached the result, I'm guessing to
avoid constantly re-fetching the auxv out of remote targets, but
that's no longer necessary nowadays, as the auxv blob is itself cached
in the inferior object. The ppc_linux_entry_point_addr global is
obviously bad for multi-process too nowadays.
Tested on x86-64 (-m64/-m32), PPC64 (-m64/-m32) and S/390 GNU/Linux.
Yao tested the new test on ARM as well.
gdb/ChangeLog:
2015-04-10 Pedro Alves <palves@redhat.com>
PR gdb/13858
* amd64-linux-tdep.c (amd64_linux_init_abi_common): Install
linux_displaced_step_location as gdbarch_displaced_step_location
hook.
* arm-linux-tdep.c (arm_linux_init_abi): Likewise.
* i386-linux-tdep.c (i386_linux_init_abi): Likewise.
* linux-tdep.c (linux_displaced_step_location): New function,
based on ppc_linux_displaced_step_location.
* linux-tdep.h (linux_displaced_step_location): New declaration.
* ppc-linux-tdep.c (ppc_linux_entry_point_addr): Delete.
(ppc_linux_inferior_created, ppc_linux_displaced_step_location):
Delete.
(ppc_linux_init_abi): Install linux_displaced_step_location as
gdbarch_displaced_step_location hook, even without Cell/B.E..
(_initialize_ppc_linux_tdep): Don't install
ppc_linux_inferior_created as inferior_created observer.
* s390-linux-tdep.c (s390_gdbarch_init): Install
linux_displaced_step_location as gdbarch_displaced_step_location
hook.
gdb/testsuite/
2015-04-10 Pedro Alves <palves@redhat.com>
PR gdb/13858
* gdb.base/step-over-no-symbols.exp: New file.
Now that all Linux targets use the regset iterator, the fall back to
the deprecated target method is dropped.
gdb/ChangeLog:
* linux-nat.c (linux_nat_collect_thread_registers): Remove.
(linux_nat_make_corefile_notes): Remove.
(linux_target_install_ops): Do not set target method
'make_corefile_notes'.
* linux-tdep.c (struct linux_corefile_thread_data)<collect>:
Remove field.
(linux_corefile_thread_callback): Instead of args->collect, call
linux_collect_thread_registers.
(linux_make_corefile_notes): Remove 'collect' parameter. Return
NULL unless there is a regset iterator.
(linux_make_corefile_notes_1): Remove.
(linux_init_abi): Replace reference to linux_make_corefile_notes_1
by linux_make_corefile_notes.
* linux-tdep.h (linux_make_corefile_notes): Remove prototype.
It will be used when one wants to convert between the internal GDB signal
representation (enum gdb_signal) and the target's representation.
The idea of this patch came from a chat between Pedro and I on IRC, plus
the discussion of my patches to add the new $_exitsignal convenience
variable:
<http://sourceware.org/ml/gdb-patches/2013-06/msg00452.html>
<http://sourceware.org/ml/gdb-patches/2013-06/msg00352.html>
What I did was to investigate, on the Linux kernel, which targets shared
the signal numbers definition with the generic definition, present at
<include/uapi/asm-generic/signal.h>. For the record, I used linux-3.10-rc7
as the main source of information, always looking at
<arch/<ARCH_NAME>/include/uapi/asm/signal.h>. For SIGRTMAX (which defaults
to _NSIG in most cases), I had to look at different signal-related
files, but most of them (except MIPS) were defined to 64 anyway.
Then, with all the differences in hand, I implemented the bits on each
target.
2013-08-09 Sergio Durigan Junior <sergiodj@redhat.com>
* linux-tdep.c: Define enum with generic signal numbers.
(linux_gdb_signal_from_target): New function.
(linux_gdb_signal_to_target): Likewise.
(linux_init_abi): Set gdbarch_gdb_signal_{to,from}_target
methods to the functions above.
* linux-tdep.h (linux_gdb_signal_from_target): New prototype.
(linux_gdb_signal_to_target): Likewise.
* alpha-linux-tdep.c: Define new enum with signals different
from generic Linux kernel.
(alpha_linux_gdb_signal_from_target): New function.
(alpha_linux_gdb_signal_to_target): Likewise.
(alpha_linux_init_abi): Set gdbarch_gdb_signal_{to,from}_target
with the functions mentioned above.
* avr-tdep.c: Define enum with differences between Linux kernel
and AVR signals.
(avr_linux_gdb_signal_from_target): New function.
(avr_linux_gdb_signal_to_target): Likewise.
(avr_gdbarch_init): Set gdbarch_gdb_signal_{to,from}_target to
the functions mentioned above.
* sparc-linux-tdep.c: Define enum with differences between SPARC
and generic Linux kernel signal numbers.
(sparc32_linux_gdb_signal_from_target): New function.
(sparc32_linux_gdb_signal_to_target): Likewise.
(sparc32_linux_init_abi): Set gdbarch_gdb_signal_{to,from}_target
to the functions defined above.
* xtensa-linux-tdep.c: Define enum with differences between
Xtensa and Linux kernel generic signals.
(xtensa_linux_gdb_signal_from_target): New function.
(xtensa_linux_gdb_signal_to_target): Likewise.
(xtensa_linux_init_abi): Set gdbarch_gdb_signal_to_target
to the functions defined above.
* mips-linux-tdep.c: Define enum with differences between
signals in MIPS and Linux kernel generic ones.
(mips_gdb_signal_to_target): New function.
(mips_gdb_signal_from_target): Redefine to use new enum, handle
only different signals from the Linux kernel generic.
(mips_linux_init_abi): Set gdbarch_gdb_signal_{to,from}_target
the functions defined above.
* mips-linux-tdep.h (enum mips_signals): Remove.
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.