Remove the to_supports_btrace target method and instead rely on detecting errors
when trying to enable recording. This will also provide a suitable error
message explaining why recording is not possible.
For remote debugging, gdbserver will now always advertise branch tracing related
packets. When talking to an older GDB, this will cause GDB to try to enable
branch tracing and gdbserver to report a suitable error message every time.
An older gdbserver will not advertise branch tracing related packets if the
one-time check failed, so a newer GDB with this patch will fail to enable branch
tracing at remote_enable_btrace() rather than at btrace_enable(). The error
message is the same in both cases so there should be no user-visible change.
gdb/
* btrace.c (btrace_enable): Remove target_supports_btrace call.
* nat/linux-btrace.c (perf_event_pt_event_type): Move.
(kernel_supports_bts, kernel_supports_pt, linux_supports_bts)
(linux_supports_pt, linux_supports_btrace): Remove.
(linux_enable_bts): Call cpu_supports_bts.
* nat/linux-btrace.h (linux_supports_btrace): Remove.
* remote.c (remote_supports_btrace): Remove.
(init_remote_ops): Remove remote_supports_btrace.
* target-delegates.c: Regenerated.
* target.c (target_supports_btrace): Remove.
* target.h (target_ops) <to_supports_btrace>: Remove
(target_supports_btrace): Remove.
* x86-linux-nat.c (x86_linux_create_target): Remove
linux_supports_btrace.
gdbserver/
* linux-low.c (linux_target_ops): Remove linux_supports_btrace.
* nto-low.c (nto_target_ops): Remove NULL for supports_btrace.
* spu-low.c (spu_target_ops): Likewise.
* win32-low.c (win32_target_ops): Likewise.
* server.c (supported_btrace_packets): Report packets unconditionally.
* target.h (target_ops) <supports_btrace>: Remove.
(target_supports_btrace): Remove.
Change error reporting to use exceptions and be prepared to catch them in
gdbserver. We use the exception message in our error reply to GDB.
This may remove some detail from the error message in the native case since
errno is no longer printed. Later patches will improve that.
We're still using error strings on the RSP level. This patch does not affect
the interoperability of older/newer GDB/gdbserver.
gdbserver/
* server.c (handle_btrace_enable_bts, handle_btrace_enable_pt)
(handle_btrace_disable): Change return type to void. Use exceptions
to report errors.
(handle_btrace_general_set): Catch exception and copy message to
return message.
gdb/
* nat/linux-btrace.c (linux_enable_btrace): Throw exception if enabling
btrace failed.
* x86-linux-nat.c (x86_linux_enable_btrace): Catch btrace enabling
exception and use message in own exception.
I have the goal of "poisoning" the XNEW/xfree-family of functions, so
that we catch their usages with non-POD types. A few things need to be
fixed in the mean time, this is one.
The common lwp code in linux-nat.c and gdbserver/linux-low.c xfrees the
private lwp data of type arch_lwp_info. However, that type is opaque
from its point of view, as its defined differently in each arch-specific
implementation. This trips on the std::is_pod<T> check, since the
compiler can't tell whether the type is POD or not if it doesn't know
about it.
My initial patch [1] made a class hierarchy with a virtual destructor.
However, as Pedro pointed out, we only have one native architecture at
the time built in gdb and gdbserver, so that's overkill. Instead, we
can move the responsibility of free'ing arch_lwp_info to the arch code
(which is also the one that allocated it in the first place). This is
what this patch does.
Also, I had the concern that if we wanted to use C++ features in these
structures, we would have a problem with the one-definition rule.
However, since a build will only have one version of arch_lwp_info,
that's not a problem.
There are changes in arch-specific files, I was only able to built-test
this patch with the following cross-compilers:
aarch64-linux-gnu
alpha-linux-gnu
arm-linux-gnueabihf
hppa-linux-gnu
m68k-linux-gnu
mips64el-linux-gnuabi64
powerpc64-linux-gnu
s390x-linux-gnu
sh4-linux-gnu
sparc64-linux-gnu
x86_64-linux-gnu
x86_64-w64-mingw32
A buildbot run didn't find any regression.
[1] https://sourceware.org/ml/gdb-patches/2017-08/msg00255.html
gdb/ChangeLog:
* linux-nat.h (linux_nat_set_delete_thread): New declaration.
* linux-nat.c (linux_nat_delete_thread): New variable.
(lwp_free): Invoke linux_nat_delete_thread if set.
(linux_nat_set_delete_thread): New function.
* aarch64-linux-nat.c (_initialize_aarch64_linux_nat): Assign
thread delete callback.
* arm-linux-nat.c (arm_linux_delete_thread): New function.
(_initialize_arm_linux_nat): Assign thread delete callback.
* s390-linux-nat.c (s390_delete_thread): New function.
(_initialize_s390_nat): Assign thread delete callback.
* x86-linux-nat.c (x86_linux_add_target): Likewise.
* nat/aarch64-linux.c (aarch64_linux_delete_thread): New
function.
* nat/aarch64-linux.h (aarch64_linux_delete_thread): New
declaration.
* nat/x86-linux.c (x86_linux_delete_thread): New function.
* nat/x86-linux.h (x86_linux_delete_thread): New declaration.
gdb/gdbserver/ChangeLog:
* linux-aarch64-low.c (the_low_target): Add thread delete
callback.
* linux-arm-low.c (arm_delete_thread): New function.
(the_low_target): Add thread delete callback.
* linux-bfin-low.c (the_low_target): Likewise.
* linux-crisv32-low.c (the_low_target): Likewise.
* linux-low.c (delete_lwp): Invoke delete_thread callback if
set.
* linux-low.h (struct linux_target_ops) <delete_thread>: New
field.
* linux-m32r-low.c (the_low_target): Add thread delete callback.
* linux-mips-low.c (mips_linux_delete_thread): New function.
(the_low_target): Add thread delete callback.
* linux-ppc-low.c (the_low_target): Likewise.
* linux-s390-low.c (the_low_target): Likewise.
* linux-sh-low.c (the_low_target): Likewise.
* linux-tic6x-low.c (the_low_target): Likewise.
* linux-tile-low.c (the_low_target): Likewise.
* linux-x86-low.c (the_low_target): Likewise.
* linux-xtensa-low.c (the_low_target): Likewise.
This patch adds a new function amd64_linux_read_description, which
creates amd64-linux target descriptions according to its two
arguments, xcr0 and is_x32.
gdb:
2017-09-05 Yao Qi <yao.qi@linaro.org>
* amd64-linux-tdep.c (amd64_linux_read_description): New
function.
(amd64_linux_core_read_description): Call
amd64_linux_read_description.
(amd64_linux_init_abi): Likewise.
(amd64_x32_linux_init_abi): Likewise.
* amd64-linux-tdep.h (amd64_linux_read_description): Declare.
* x86-linux-nat.c (x86_linux_read_description): Call
amd64_linux_read_description.
This patch moves all the tdesc_i386*_linux target descriptions to a
function i386_linux_read_description, which returns the right target
description according to xcr0. This also remove the duplication in
getting target descriptions in corefile and native target.
gdb:
2017-07-26 Yao Qi <yao.qi@linaro.org>
* i386-linux-tdep.c (i386_linux_read_description): New function.
(i386_linux_core_read_description): Call
i386_linux_read_description.
* i386-linux-tdep.h (i386_linux_read_description): Declare.
(tdesc_i386_linux, tdesc_i386_mmx_linux): Remove declarations.
(tdesc_i386_avx_linux, tdesc_i386_mpx_linux): Likewise
(tdesc_i386_avx_mpx_linux, tdesc_i386_avx_avx512_linux): Likewise.
(tdesc_i386_avx_mpx_avx512_pku_linux): Likewise.
* x86-linux-nat.c (x86_linux_read_description): Call
i386_linux_read_description.
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
The current MPX target descriptions assume that MPX is always combined
with AVX, however that's not correct. We can have machines with MPX
and without AVX; or machines with AVX and without MPX.
This patch adds new target descriptions for machines that support
both MPX and AVX, as duplicates of the existing MPX descriptions.
The following commit will remove AVX from the MPX-only descriptions.
2016-04-16 Walfred Tedeschi <walfred.tedeschi@intel.com>
gdb/ChangeLog:
* amd64-linux-tdep.c (features/i386/amd64-avx-mpx-linux.c):
New include.
(amd64_linux_core_read_description): Add case for
X86_XSTATE_AVX_MPX_MASK.
(_initialize_amd64_linux_tdep): Call initialize_tdesc_amd64_avx_mpx_linux.
* amd64-linux-tdep.h (tdesc_amd64_avx_mpx_linux): New definition.
* amd64-tdep.c (features/i386/amd64-avx-mpx.c): New include.
(amd64_target_description): Add case for X86_XSTATE_AVX_MPX_MASK.
(_initialize_amd64_tdep): Call initialize_tdesc_amd64_avx_mpx.
* common/x86-xstate.h (X86_XSTATE_MPX_MASK): Remove AVX bits.
(X86_XSTATE_AVX_MPX_MASK): New case.
* features/Makefile (i386/i386-avx-mpx, i386/i386-avx-mpx-linux)
(i386/amd64-avx-mpx, i386/amd64-avx-mpx-linux): New rules.
(i386/i386-avx-mpx-expedite, i386/i386-avx-mpx-linux-expedite)
(i386/amd64-avx-mpx-expedite, i386/amd64-avx-mpx-linux-expedite):
New expedites.
* i386-linux-tdep.c (features/i386/i386-avx-mpx-linux.c): New
include.
(i386_linux_core_read_description): Add case
X86_XSTATE_AVX_MPX_MASK.
(_initialize_i386_linux_tdep): Call
initialize_tdesc_i386_avx_mpx_linux.
* i386-linux-tdep.h (tdesc_i386_avx_mpx_linux): New include.
* i386-tdep.c (features/i386/i386-avx-mpx.c): New include.
(i386_target_description): Add case for X86_XSTATE_AVX_MPX_MASK.
* x86-linux-nat.c (x86_linux_read_description): Add case for
X86_XSTATE_AVX_MPX_MASK.
* features/i386/amd64-avx-mpx-linux.xml: New file.
* features/i386/i386-avx-mpx-linux.xml: New file.
* features/i386/i386-avx-mpx.xml: New file.
* features/i386/amd64-avx-mpx.xml: New file.
* features/i386/amd64-avx-mpx-linux.c: Generated.
* features/i386/amd64-avx-mpx.c: Generated.
* features/i386/i386-avx-mpx-linux.c: Generated.
* features/i386/i386-avx-mpx.c: Generated.
* regformats/i386/amd64-avx-mpx-linux.dat: Generated.
* regformats/i386/amd64-avx-mpx.dat: Generated.
* regformats/i386/i386-avx-mpx-linux.dat: Generated.
* regformats/i386/i386-avx-mpx.dat: Generated.
gdb/gdbserver/ChangeLog:
* Makefile.in (clean): Add removal for i386-avx-mpx.c,
i386-avx-mpx-linux.c, amd64-avx-mpx.c and amd64-avx-mpx-linux.c.
(i386-avx-mpx.c, i386-avx-mpx-linux.c, amd64-avx-mpx.c)
(amd64-avx-mpx-linux.c): New rules.
(amd64-avx-mpx-linux-ipa.o, i386-avx-mpx-linux-ipa.o): New rule.
* configure.srv (srv_i386_regobj): Add i386-avx-mpx.o.
(srv_i386_linux_regobj): Add i386-avx-mpx-linux.o.
(srv_amd64_regobj): Add amd64-avx-mpx.o.
(srv_amd64_linux_regobj): Add amd64-avx-mpx-linux.o.
(srv_i386_xmlfiles): Add i386/i386-avx-mpx.xml.
(srv_amd64_xmlfiles): Add i386/amd64-avx-mpx.xml.
(srv_i386_linux_xmlfiles): Add i386/i386-avx-mpx-linux.xml.
(srv_amd64_linux_xmlfiles): Add i386/amd64-avx-mpx-linux.xml.
(ipa_i386_linux_regobj): Add i386-avx-mpx-linux-ipa.o.
(ipa_amd64_linux_regobj): Add amd64-avx-mpx-linux-ipa.o.
* linux-x86-low.c (x86_linux_read_description): Add case for
X86_XSTATE_AVX_MPX_MASK.
(x86_get_ipa_tdesc_idx): Add cases for avx_mpx.
(initialize_low_arch): Call init_registers_amd64_avx_mpx_linux and
init_registers_i386_avx_mpx_linux.
* linux-i386-ipa.c (get_ipa_tdesc): Add case for avx_mpx.
(initialize_low_tracepoint): Call
init_registers_i386_avx_mpx_linux.
* linux-amd64-ipa.c (get_ipa_tdesc): Add case for avx_mpx.
(initialize_low_tracepoint): Call
init_registers_amd64_avx_mpx_linux.
* linux-x86-tdesc.h (X86_TDESC_AVX_MPX): New enum value.
(init_registers_amd64_avx_mpx_linux, tdesc_amd64_avx_mpx_linux)
(init_registers_i386_avx_mpx_linux, tdesc_i386_avx_mpx_linux): New
declarations.
Since the record-btrace target now supports non-stop mode, we no
longer need to force-disable as-ns on x86.
gdb/ChangeLog:
2015-09-30 Pedro Alves <palves@redhat.com>
* linux-nat.c (linux_nat_always_non_stop_p): Always return 1.
* x86-linux-nat.c (x86_linux_always_non_stop_p): Delete.
(x86_linux_create_target): Don't install
x86_linux_always_non_stop_p.
For the BTS recording format, we sometimes get a FROM->TO record where the
FROM address lies in the kernel and the TO address lies in user space at
whatever address the user process was resumed.
GDB has a heuristic to filter out such records based on looking at the most
significant bit in the PC. This works fine for 64-bit systems but it doesn't
always work for 32-bit systems. Libraries that are loaded at fairly high
addresses might be mistaken for kernel code and branches inside the library
are filtered out.
Change the heuristic to (again heuristically) try to determine the lowest
address in kernel space. Any PC that is smaller than that should be in
user space.
On today's systems, there should be a symbol "_text" at that address.
Read /proc/kallsyms and search for that symbol.
It is not guaranteed that /proc/kallsyms is readable on all systems. On
64-bit systems, we fall back to check the most significant bit. On 32-bit
systems, we refrain from filtering out addresses.
The filtering should really be done by the kernel. And it soon will be:
https://lkml.org/lkml/2015/8/31/212.
gdb/
* nat/linux-btrace.h (struct btrace_target_info) <ptr_bits>: Remove.
* nat/linux-btrace.c: Include filestuff.h and inttypes.h.
Remove include of sys/utsname.h.
(linux_determine_kernel_ptr_bits): Remove.
(linux_determine_kernel_start): New.
(perf_event_is_kernel_addr): Remove tinfo argument. Update users.
Update check.
(perf_event_skip_bts_record): Remove tinfo argument. Update users.
(linux_enable_bts, linux_enable_pt): Remove tinfo->ptr_bits
initialization.
* x86-linux-nat.c (x86_linux_enable_btrace): Remove ptr_bits
assignment.
gdbserver/
* linux-low.c (linux_low_enable_btrace): Remove.
(linux_target_ops): Replace linux_low_enable_btrace with
linux_enable_btrace.
Markus reported that ASNS breaks target record-btrace. In particular,
the gdb.btrace/multi-thread-step.exp test fails (both with BTS and PT
tracing) with a crash in py-inferior.c:
Program received signal SIGSEGV, Segmentation fault.
0x00000000006aa40d in add_thread_object (tp=0x27d32d0)
at /users/mmetzger/team/gdb/git/gdb/python/py-inferior.c:337
337 entry->next = inf_obj->threads;
My machine doesn't support BTS nor PT, so I missed this...
Disabling ASNS temporarily on x86 until this is addressed.
Tested on x86_64 Fedora 20.
gdb/ChangeLog:
2015-08-18 Pedro Alves <palves@redhat.com>
* linux-nat.c (linux_nat_always_non_stop_p): If the linux_ops
target implements to_always_non_stop_p, call it.
* x86-linux-nat.c (x86_linux_always_non_stop_p): New function.
(x86_linux_create_target): Install it as to_always_non_stop_p
method.
have_ptrace_getregset is a tri-state variable (-1, 0, 1), and we have
some conditions like "if (have_ptrace_getregset)", which is not correct.
I'll explain why it is not correct in the following example. This fix
to this problem to replace the test (have_ptrace_getregset) to test
(have_ptrace_getregset == 1) or (have_ptrace_getregset == -1) etc.
However Doug thinks it hinders readability
https://sourceware.org/ml/gdb-patches/2015-05/msg00692.html so I decide
to add a new enum tribool and change have_ptrace_getregset to it, in
order to make these tests more readable.
have_ptrace_getregset is initialised to -1, and is adjusted to 0 or 1 in
$ARCH_linux_read_description according to the capability of the kernel.
However, it is possible that have_ptrace_getregset is used before it is
set to 0 or 1, which means it is still -1. This is shown below.
(gdb) run
Starting program: gdb/testsuite/gdb.base/break
Breakpoint 2, amd64_linux_fetch_inferior_registers (ops=0xceaa80, regcache=0xe72000, regnum=16) at git/gdb/amd64-linux-nat.c:128
128 {
top?p have_ptrace_getregset
$1 = TRIBOOL_UNKNOWN
top?c
Continuing.
Breakpoint 2, amd64_linux_fetch_inferior_registers (ops=0xceaa80, regcache=0xe72000, regnum=16) at git/gdb/amd64-linux-nat.c:128
128 {
top?c
Continuing.
Breakpoint 1, x86_linux_read_description (ops=0xceaa80) at git/gdb/x86-linux-nat.c:117
117 {
PTRACE_GETREGSET command is used even GDB doesn't know whether
PTRACE_GETREGSET is supported or not. It is wrong, but works on x86.
However it doesn't work on arm-linux if the kernel doesn't support
PTRACE_GETREGSET at all. We'll get:
(gdb) run
Starting program: gdb/testsuite/gdb.base/break
warning: Unable to fetch general register.
PC register is not available
gdb:
2015-06-23 Yao Qi <yao.qi@linaro.org>
* amd64-linux-nat.c (amd64_linux_fetch_inferior_registers):
Check whether have_ptrace_getregset is TRIBOOL_TRUE explicitly.
(amd64_linux_store_inferior_registers): Likewise.
* arm-linux-nat.c (fetch_fpregister): Likewise.
(fetch_fpregs, store_fpregister): Likewise.
(store_fpregister, store_fpregs): Likewise.
(fetch_register, fetch_regs): Likewise.
(store_register, store_regs): Likewise.
(fetch_vfp_regs, store_vfp_regs): Likewise.
(arm_linux_read_description): Check have_ptrace_getregset is
TRIBOOL_UNKNOWN. Set have_ptrace_getregset to TRIBOOL_TRUE
or TRIBOOL_FALSE.
* i386-linux-nat.c (fetch_xstateregs): Check
have_ptrace_getregset is not TRIBOOL_TRUE.
(store_xstateregs): Likewise.
* linux-nat.c (have_ptrace_getregset): Change its type to
enum tribool.
* linux-nat.h (tribool): New enum.
* x86-linux-nat.c (x86_linux_read_description): Use enum tribool.
Check whether have_ptrace_getregset is TRIBOOL_TRUE.
I'll let arm-linux-nat.c to use PTRACE_GETREGSET if kernel supports,
so this patch is to move have_ptrace_getregset from x86-linux-nat.c
to linux-nat.c.
gdb:
2015-06-01 Yao Qi <yao.qi@linaro.org>
* x86-linux-nat.c (have_ptrace_getregset): Move it to ...
* linux-nat.c: ... here.
* x86-linux-nat.h (have_ptrace_getregset): Move the declaration
to ...
* linux-nat.h: ... here.
Macros PTRACE_GETREGSET and PTRACE_SETREGSET are defined locally in
some places in GDB and GDBserver. This patch is to move them to
nat/linux-ptrace.h to avoid duplication.
gdb:
2015-06-01 Yao Qi <yao.qi@linaro.org>
* amd64-linux-nat.c: Include "nat/linux-ptrace.h".
* i386-linux-nat.c: Likewise.
* nat/linux-ptrace.h (PTRACE_GETREGSET, PTRACE_SETREGSET): Define.
* s390-linux-nat.c: Include "nat/linux-ptrace.h".
(PTRACE_GETREGSET, PTRACE_SETREGSET): Remove.
* x86-linux-nat.c: Include "nat/linux-ptrace.h".
* x86-linux-nat.h (PTRACE_GETREGSET, PTRACE_SETREGSET): Remove.
gdb/gdbserver:
2015-06-01 Yao Qi <yao.qi@linaro.org>
* linux-s390-low.c (PTRACE_GETREGSET, PTRACE_SETREGSET): Remove.
* linux-x86-low.c: Likewise.
This commit moves two identical functions from gdb/x86-linux-nat.c and
gdb/gdbserver/linux-x86-low.c into the shared file gdb/nat/x86-linux.c.
gdb/ChangeLog:
* nat/x86-linux.h (x86_linux_new_thread): New declaration.
(x86_linux_prepare_to_resume): Likewise.
* x86-linux-nat.c (x86_linux_new_thread):
Moved to nat/x86-linux.c.
(x86_linux_prepare_to_resume): Likewise.
* nat/x86-linux.c (x86_linux_new_thread): New function.
(x86_linux_prepare_to_resume): Likewise.
gdb/gdbserver/ChangeLog:
* linux-x86-low.c (x86_linux_new_thread): Moved to
nat/x86-linux.c.
(x86_linux_prepare_to_resume): Likewise.
This commit moves the entire body of both GDB's and gdbserver's
x86_linux_prepare_to_resume functions into new functions,
x86_linux_update_debug_registers. This reorganisation allows
all Linux x86 low-level debug register code to be placed in one
shared file, separate from general Linux x86 shared code.
gdb/ChangeLog:
* x86-linux-nat.c (x86_linux_update_debug_registers):
New function, factored out from...
(x86_linux_prepare_to_resume): ...this.
gdb/gdbserver/ChangeLog:
* linux-x86-low.c (x86_linux_update_debug_registers):
New function, factored out from...
(x86_linux_prepare_to_resume): ...this.
This commit makes several small changes to the low-level debug
register code for Linux x86, making the code in the GDB and
gdbserver implementations identical.
gdb/ChangeLog:
* x86-linux-nat.c (x86_linux_dr_set_addr): Update assertion.
(x86_linux_new_thread): Rename argument.
gdb/gdbserver/ChangeLog:
* linux-x86-low.c (x86_linux_dr_get): Add assertion.
Use perror_with_name. Pass string through gettext.
(x86_linux_dr_set): Likewise.
This commit moves the code to handle lwp_info.arch_private for
Linux x86 into a new shared file, nat/x86-linux.c.
gdb/ChangeLog:
* nat/x86-linux.h: New file.
* nat/x86-linux.c: Likewise.
* Makefile.in (HFILES_NO_SRCDIR): Add nat/x86-linux.h.
(x86-linux.o): New rule.
* config/i386/linux.mh (NATDEPFILES): Add x86-linux.o.
* config/i386/linux64.mh (NATDEPFILES): Likewise.
* nat/linux-nat.h (struct arch_lwp_info): New forward declaration.
(lwp_set_arch_private_info): New declaration.
(lwp_arch_private_info): Likewise.
* linux-nat.c (lwp_set_arch_private_info): New function.
(lwp_arch_private_info): Likewise.
* x86-linux-nat.c: Include nat/x86-linux.h.
(arch_lwp_info): Removed structure.
(update_debug_registers_callback):
Use lwp_set_debug_registers_changed.
(x86_linux_prepare_to_resume): Use lwp_debug_registers_changed
and lwp_set_debug_registers_changed.
(x86_linux_new_thread): Use lwp_set_debug_registers_changed.
gdb/gdbserver/ChangeLog:
* Makefile.in (x86-linux.o): New rule.
* configure.srv: Add x86-linux.o to relevant targets.
* linux-low.c (lwp_set_arch_private_info): New function.
(lwp_arch_private_info): Likewise.
* linux-x86-low.c: Include nat/x86-linux.h.
(arch_lwp_info): Removed structure.
(update_debug_registers_callback):
Use lwp_set_debug_registers_changed.
(x86_linux_prepare_to_resume): Use lwp_debug_registers_changed
and lwp_set_debug_registers_changed.
(x86_linux_new_thread): Use lwp_set_debug_registers_changed.
This commit introduces three accessors that shared Linux code can
use to access fields of struct lwp_info. The GDB and gdbserver
Linux x86 code is modified to use them.
gdb/ChangeLog:
* nat/linux-nat.h (ptid_of_lwp): New declaration.
(lwp_is_stopped): Likewise.
(lwp_stop_reason): Likewise.
* linux-nat.c (ptid_of_lwp): New function.
(lwp_is_stopped): Likewise.
(lwp_is_stopped_by_watchpoint): Likewise.
* x86-linux-nat.c (update_debug_registers_callback):
Use lwp_is_stopped.
(x86_linux_prepare_to_resume): Use ptid_of_lwp and
lwp_stop_reason.
gdb/gdbserver/ChangeLog:
* linux-low.c (ptid_of_lwp): New function.
(lwp_is_stopped): Likewise.
(lwp_stop_reason): Likewise.
* linux-x86-low.c (update_debug_registers_callback):
Use lwp_is_stopped.
(x86_linux_prepare_to_resume): Use ptid_of_lwp and
lwp_stop_reason.
This commit introduces a new function, current_lwp_ptid, that
shared Linux code can use to obtain the ptid of the current
lightweight process.
gdb/ChangeLog:
* nat/linux-nat.h (current_lwp_ptid): New declaration.
* linux-nat.c (current_lwp_ptid): New function.
* x86-linux-nat.c: Include nat/linux-nat.h.
(x86_linux_dr_get_addr): Use current_lwp_ptid.
(x86_linux_dr_get_control): Likewise.
(x86_linux_dr_get_status): Likewise.
(x86_linux_dr_set_control): Likewise.
(x86_linux_dr_set_addr): Likewise.
gdb/gdbserver/ChangeLog:
* linux-low.c (current_lwp_ptid): New function.
* linux-x86-low.c: Include nat/linux-nat.h.
(x86_dr_low_get_addr): Use current_lwp_ptid.
(x86_dr_low_get_control): Likewise.
(x86_dr_low_get_status): Likewise.
The heuristic for filtering out kernel addressess in BTS trace checks the
most significant bit in each address. This works fine for 32-bit and 64-bit
mode.
For 32-bit compatibility mode, i.e. a 32-bit inferior running on 64-bit
host, we need to check bit 63 (or any bit bigger than 31), not bit 31.
Use the machine field in struct utsname provided by a uname call to
determine whether we are running on a 64-bit host.
Thanks to Jan Kratochvil for reporting the issue.
gdb/
* nat/linux-btrace.c: Include sys/utsname.h.
(linux_determine_kernel_ptr_bits): New.
(linux_enable_bts): Call linux_determine_kernel_ptr_bits.
* x86-linux-nat.c (x86_linux_enable_btrace): Do not overwrite non-zero
ptr_bits.
gdbserver/
* linux-low.c (linux_low_enable_btrace): Do not overwrite non-zero
ptr_bits.
In C++ mode, we get:
gdb/gdbserver/linux-x86-low.c: In function ‘void x86_linux_dr_set(ptid_t, int, long unsigned int)’:
gdb/gdbserver/linux-x86-low.c:558:38: error: ‘regnum’ cannot appear in a constant-expression
offsetof (struct user, u_debugreg[regnum]), value);
^
gdb/gdbserver/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* linux-x86-low.c (u_debugreg_offset): New function.
(x86_linux_dr_get, x86_linux_dr_set): Use it.
gdb/ChangeLog:
2015-02-27 Pedro Alves <palves@redhat.com>
* x86-linux-nat.c (u_debugreg_offset): New function.
(x86_linux_dr_get, x86_linux_dr_set): Use it.
Add a struct to describe the branch trace configuration and use it for
enabling branch tracing.
The user will be able to set configuration fields for each tracing format
to be used for new threads.
The actual configuration that is active for a given thread will be shown
in the "info record" command.
At the moment, the configuration struct only contains a format field
that is set to the only available format.
The format is the only configuration option that can not be set via set
commands. It is given as argument to the "record btrace" command when
starting recording.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* Makefile.in (XMLFILES): Add btrace-conf.dtd.
* x86-linux-nat.c (x86_linux_enable_btrace): Update parameters.
(x86_linux_btrace_conf): New.
(x86_linux_create_target): Initialize to_btrace_conf.
* nat/linux-btrace.c (linux_enable_btrace): Update parameters.
Check format. Split into this and ...
(linux_enable_bts): ... this.
(linux_btrace_conf): New.
(perf_event_skip_record): Renamed into ...
(perf_event_skip_bts_record): ... this. Updated users.
(linux_disable_btrace): Split into this and ...
(linux_disable_bts): ... this.
(linux_read_btrace): Check format.
* nat/linux-btrace.h (linux_enable_btrace): Update parameters.
(linux_btrace_conf): New.
(btrace_target_info)<ptid>: Moved.
(btrace_target_info)<conf>: New.
(btrace_target_info): Split into this and ...
(btrace_tinfo_bts): ... this. Updated users.
* btrace.c (btrace_enable): Update parameters.
(btrace_conf, parse_xml_btrace_conf_bts, parse_xml_btrace_conf)
(btrace_conf_children, btrace_conf_attributes)
(btrace_conf_elements): New.
* btrace.h (btrace_enable): Update parameters.
(btrace_conf, parse_xml_btrace_conf): New.
* common/btrace-common.h (btrace_config): New.
* feature/btrace-conf.dtd: New.
* record-btrace.c (record_btrace_conf): New.
(record_btrace_cmdlist): New.
(record_btrace_enable_warn, record_btrace_open): Pass
&record_btrace_conf.
(record_btrace_info): Print recording format.
(cmd_record_btrace_bts_start): New.
(cmd_record_btrace_start): Call cmd_record_btrace_bts_start.
(_initialize_record_btrace): Add "record btrace bts" subcommand.
Add "record bts" alias command.
* remote.c (remote_state)<btrace_config>: New.
(remote_btrace_reset, PACKET_qXfer_btrace_conf): New.
(remote_protocol_features): Add qXfer:btrace-conf:read.
(remote_open_1): Call remote_btrace_reset.
(remote_xfer_partial): Handle TARGET_OBJECT_BTRACE_CONF.
(btrace_target_info)<conf>: New.
(btrace_sync_conf, btrace_read_config): New.
(remote_enable_btrace): Update parameters. Call btrace_sync_conf and
btrace_read_conf.
(remote_btrace_conf): New.
(init_remote_ops): Initialize to_btrace_conf.
(_initialize_remote): Add qXfer:btrace-conf packet.
* target.c (target_enable_btrace): Update parameters.
(target_btrace_conf): New.
* target.h (target_enable_btrace): Update parameters.
(target_btrace_conf): New.
(target_object)<TARGET_OBJECT_BTRACE_CONF>: New.
(target_ops)<to_enable_btrace>: Update parameters and comment.
(target_ops)<to_btrace_conf>: New.
* target-delegates: Regenerate.
* target-debug.h (target_debug_print_const_struct_btrace_config_p)
(target_debug_print_const_struct_btrace_target_info_p): New.
NEWS: Announce new command and new packet.
doc/
* gdb.texinfo (Process Record and Replay): Describe the "record
btrace bts" command.
(General Query Packets): Describe qXfer:btrace-conf:read packet.
(Branch Trace Configuration Format): New.
gdbserver/
* linux-low.c (linux_low_enable_btrace): Update parameters.
(linux_low_btrace_conf): New.
(linux_target_ops)<to_btrace_conf>: Initialize.
* server.c (current_btrace_conf): New.
(handle_btrace_enable): Rename to ...
(handle_btrace_enable_bts): ... this. Pass ¤t_btrace_conf
to target_enable_btrace. Update comment. Update users.
(handle_qxfer_btrace_conf): New.
(qxfer_packets): Add btrace-conf entry.
(handle_query): Report qXfer:btrace-conf:read as supported packet.
* target.h (target_ops)<enable_btrace>: Update parameters and comment.
(target_ops)<read_btrace_conf>: New.
(target_enable_btrace): Update parameters.
(target_read_btrace_conf): New.
testsuite/
* gdb.btrace/delta.exp: Update "info record" output.
* gdb.btrace/enable.exp: Update "info record" output.
* gdb.btrace/finish.exp: Update "info record" output.
* gdb.btrace/instruction_history.exp: Update "info record" output.
* gdb.btrace/next.exp: Update "info record" output.
* gdb.btrace/nexti.exp: Update "info record" output.
* gdb.btrace/step.exp: Update "info record" output.
* gdb.btrace/stepi.exp: Update "info record" output.
* gdb.btrace/nohist.exp: Update "info record" output.
Add a structure to hold the branch trace data and an enum to describe
the format of that data. So far, only BTS is supported. Also added
a NONE format to indicate that no branch trace data is available.
This will make it easier to support different branch trace formats in
the future.
2015-02-09 Markus Metzger <markus.t.metzger@intel.com>
* Makefile.in (SFILES): Add common/btrace-common.c.
(COMMON_OBS): Add common/btrace-common.o.
(btrace-common.o): Add build rules.
* btrace.c (parse_xml_btrace): Update parameters.
(parse_xml_btrace_block): Set format field.
(btrace_add_pc, btrace_fetch): Use struct btrace_data.
(do_btrace_data_cleanup, make_cleanup_btrace_data): New.
(btrace_compute_ftrace): Split into this and...
(btrace_compute_ftrace_bts): ...this.
(btrace_stitch_trace): Split into this and...
(btrace_stitch_bts): ...this.
* btrace.h (parse_xml_btrace): Update parameters.
(make_cleanup_btrace_data): New.
* common/btrace-common.c: New.
* common/btrace-common.h: Include common-defs.h.
(btrace_block_s): Update comment.
(btrace_format): New.
(btrace_format_string): New.
(btrace_data_bts): New.
(btrace_data): New.
(btrace_data_init, btrace_data_fini, btrace_data_empty): New.
* remote.c (remote_read_btrace): Update parameters.
* target.c (target_read_btrace): Update parameters.
* target.h (target_read_btrace): Update parameters.
(target_ops)<to_read_btrace>: Update parameters.
* x86-linux-nat.c (x86_linux_read_btrace): Update parameters.
* target-delegates.c: Regenerate.
* target-debug (target_debug_print_struct_btrace_data_p): New.
* nat/linux-btrace.c (linux_read_btrace): Split into this and...
(linux_read_bts): ...this.
* nat/linux-btrace.h (linux_read_btrace): Update parameters.
gdbserver/
* Makefile.in (SFILES): Add common/btrace-common.c.
(OBS): Add common/btrace-common.o.
(btrace-common.o): Add build rules.
* linux-low: Include btrace-common.h.
(linux_low_read_btrace): Use struct btrace_data. Call
btrace_data_init and btrace_data_fini.
Running the testsuite with a series that reimplements user-visible
all-stop behavior on top of a target running in non-stop mode revealed
problems related to event starvation avoidance.
For example, I see
gdb.threads/signal-while-stepping-over-bp-other-thread.exp failing.
What happens is that GDB core never gets to see the signal event. It
ends up processing the events for the same threads over an over,
because Linux's waitpid(-1, ...) returns that first task in the task
list that has an event, starving threads on the tail of the task list.
So I wrote a non-stop mode test originally inspired by
signal-while-stepping-over-bp-other-thread.exp, to stress this
independently of all-stop on top of non-stop. Fixing it required the
changes described below. The test will be added in a following
commit.
1) linux-nat.c has code in place that picks an event LWP at random out
of all that have had events. This is because on the kernel side,
"waitpid(-1, ...)" just walks the task list linearly looking for the
first that had an event. But, this code is currently only used in
all-stop mode. So with a multi-threaded program that has multiple
events triggering debug events in parallel, GDB ends up starving some
threads.
To make the event randomization work in non-stop mode too, the patch
makes us pull out all the already pending events on the kernel side,
with waitpid, before deciding which LWP to report to the core.
There's some code in linux_wait that takes care of leaving events
pending if they were for LWPs the caller is not interested in. The
patch moves that to linux_nat_filter_event, so that we only have one
place that leaves events pending. With that in place, conceptually,
the flow is simpler and more normalized:
#1 - walk the LWP list looking for an LWP with a pending event to report.
#2 - if no pending event, pull events out of the kernel, and store
them in the LWP structures as pending.
#3- goto #1.
2) Then, currently the event randomization code only considers SIGTRAP
(or trap-like) events. That means that if e.g., have have multiple
threads stepping in parallel that hit a breakpoint that needs stepping
over, and one gets a signal, the signal may end up never getting
processed, because GDB will always be giving priority to the SIGTRAPs.
The patch fixes this by making the randomization code consider all
kinds of pending events.
3) If multiple threads hit a breakpoint, we report one of those, and
"cancel" the others. Cancelling means decrementing the PC, and
discarding the event. If the next time the LWP is resumed the
breakpoint is still installed, the LWP should hit it again, and we'll
report the hit then. The problem I found is that this delays threads
from advancing too much, with the kernel potentially ending up
scheduling the same threads over and over, and others not advancing.
So the patch switches away from cancelling the breakpoints, and
instead remembering that the LWP had stopped for a breakpoint. If on
resume the breakpoint is still installed, we report it. If it's no
longer installed, we discard the pending event then. This is actually
how GDBserver used to handle this before d50171e4 (Teach linux
gdbserver to step-over-breakpoints), but with the difference that back
then we'd delay adjusting the PC until resuming, which made it so that
"info threads" could wrongly see threads with unadjusted PCs.
gdb/
2015-01-09 Pedro Alves <palves@redhat.com>
* breakpoint.c (hardware_breakpoint_inserted_here_p): New
function.
* breakpoint.h (hardware_breakpoint_inserted_here_p): New
declaration.
* linux-nat.c (linux_nat_status_is_event): Move higher up in file.
(linux_resume_one_lwp): Store the thread's PC. Adjust to clear
stop_reason.
(check_stopped_by_watchpoint): New function.
(save_sigtrap): Reimplement.
(linux_nat_stopped_by_watchpoint): Adjust.
(linux_nat_lp_status_is_event): Delete.
(stop_wait_callback): Only call save_sigtrap after storing the
pending status.
(status_callback): If the thread had been stopped for a breakpoint
that has since been removed, discard the event and resume the LWP.
(count_events_callback, select_event_lwp_callback): Use
lwp_status_pending_p instead of linux_nat_lp_status_is_event.
(cancel_breakpoint): Rename to ...
(check_stopped_by_breakpoint): ... this. Record whether the LWP
stopped for a software breakpoint or hardware breakpoint.
(select_event_lwp): Only give preference to the stepping LWP in
all-stop mode. Adjust comments.
(stop_and_resume_callback): Remove references to new_pending_p.
(linux_nat_filter_event): Likewise. Leave exit events of the
leader thread pending here. Handle signal short circuiting here.
Only call save_sigtrap after storing the pending waitstatus.
(linux_nat_wait_1): Remove 'retry' label. Remove references to
new_pending. Don't handle leaving events the caller is not
interested in pending here, nor handle signal short-circuiting
here. Also give equal priority to all LWPs that have had events
in non-stop mode. If reporting a software breakpoint event,
unadjust the LWP's PC.
* linux-nat.h (enum lwp_stop_reason): New.
(struct lwp_info) <stop_pc>: New field.
(struct lwp_info) <stopped_by_watchpoint>: Delete field.
(struct lwp_info) <stop_reason>: New field.
* x86-linux-nat.c (x86_linux_prepare_to_resume): Adjust.
The following patch...
commit 3116063bd6
Date: Fri Jun 27 09:52:29 2014 +0100
Subject: Tidy #include lists
... introduced a build failure on certain x86 GNU/Linux distributions
(reproduced on SuSE 10 and RHES4) due to "struct iovec" not being
defined. This struct is defined in <sys/uio.h>, which used to be
explicitly included, but no longer is after the commit above was
applied.
[...]/i386-linux-nat.c: In function 'fetch_xstateregs':
[...]/i386-linux-nat.c:325:16: error: storage size of 'iov' isn't known
[...]/i386-linux-nat.c: In function 'store_xstateregs':
[...]/i386-linux-nat.c:348:16: error: storage size of 'iov' isn't known
make[2]: *** [i386-linux-nat.o] Error 1
It seems to be working on newer GNU/Linux distros thanks to indirect
inclusion of <sys/uio.h>, but it does not work on some other versions
of the same distros. This is why indirect includes of public APIs
should be avoided if at all possible.
This patch fixes the issue by adding the explicit include back.
gdb/ChangeLog:
* i386-linux-nat.c, x86-linux-nat.c: Add <sys/uio.h> #include.
Historically the Linux x86 watchpoint code did not cope with multi-
threaded processes and LWP IDs were passed to it wrapped as PIDs.
Not all entry points were converted when the Linux x86 watchpoint
code was made multi-thread-aware, so a handler was left in place to
cope with wrapped LWPs. Since then all such entry points have been
converted to pass regular LWPs and the handler is now redundant.
This commit removes the handler and adds assertions to ensure no
wrapped LWPs are passed in future.
gdb/ChangeLog:
* x86-linux-nat.c (x86_linux_dr_get, x86_linux_dr_set):
Remove code to cope with LWPs wrapped as PIDs.
Add assertions to ensure no wrapped LWPs are passed.
The loop macro ALL_DEBUG_REGISTERS does not iterate over the status or
control registers, so its name is misleading. This commit renames it
as ALL_DEBUG_ADDRESS_REGISTERS and updates all uses. This commit also
updates its loop conditions to an equivalent but better form, and
makes two functions use it that had previously hardwired the loop.
A comment on a related field in the x86_debug_reg_state structure is
also updated to reflect that the field refers specifically to address
registers only.
gdb/ChangeLog:
* nat/x86-dregs.h (ALL_DEBUG_REGISTERS): Renamed as...
(ALL_DEBUG_ADDRESS_REGISTERS): New macro. All uses updated.
Loop conditions changed to equivalent form.
(struct x86_debug_reg_state): Updated dr_ref_count comment.
* x86-linux-nat.c (x86_linux_prepare_to_resume): Use
ALL_DEBUG_ADDRESS_REGISTERS.
gdb/gdbserver/ChangeLog:
* linux-x86-low.c (x86_linux_prepare_to_resume): Use
ALL_DEBUG_ADDRESS_REGISTERS.
This commit renames nine files that contain code used by both 32- and
64-bit Intel ports such that their names are prefixed with "x86"
rather than "i386". All types, functions and variables within these
files are likewise renamed such that their names are prefixed with
"x86" rather than "i386". This makes GDB follow the convention used
by gdbserver such that 32-bit Intel code lives in files called
"i386-*", 64-bit Intel code lives in files called "amd64-*", and code
for both 32- and 64-bit Intel lives in files called "x86-*".
This commit only renames OS-independent files. The Linux ports of
both GDB and gdbserver now follow the i386/amd64/x86 convention fully.
Some ports still use the old convention where "i386" in file/function/
type/variable names can mean "32-bit only" or "32- and 64-bit" but I
don't want to touch ports I can't fully test except where absolutely
necessary.
gdb/ChangeLog:
* i386-nat.h: Renamed as...
* x86-nat.h: New file. All type, function and variable name
prefixes changed from "i386_" to "x86_". All references updated.
* i386-nat.c: Renamed as...
* x86-nat.c: New file. All type, function and variable name
prefixes changed from "i386_" to "x86_". All references updated.
* common/i386-xstate.h: Renamed as...
* common/x86-xstate.h: New file. All type, function and variable
name prefixes changed from "i386_" to "x86_". All references
updated.
* nat/i386-cpuid.h: Renamed as...
* nat/x86-cpuid.h: New file. All type, function and variable name
prefixes changed from "i386_" to "x86_". All references updated.
* nat/i386-gcc-cpuid.h: Renamed as...
* nat/x86-gcc-cpuid.h: New file. All type, function and variable
name prefixes changed from "i386_" to "x86_". All references
updated.
* nat/i386-dregs.h: Renamed as...
* nat/x86-dregs.h: New file. All type, function and variable name
prefixes changed from "i386_" to "x86_". All references updated.
* nat/i386-dregs.c: Renamed as...
* nat/x86-dregs.c: New file. All type, function and variable name
prefixes changed from "i386_" to "x86_". All references updated.
gdb/gdbserver/ChangeLog:
* i386-low.h: Renamed as...
* x86-low.h: New file. All type, function and variable name
prefixes changed from "i386_" to "x86_". All references updated.
* i386-low.c: Renamed as...
* x86-low.c: New file. All type, function and variable name
prefixes changed from "i386_" to "x86_". All references updated.
Markus Metzger
Joel Brobecker
Simon Marchi
Yao Qi
Michael Sturm
Trevor Saunders
Walfred Tedeschi
Pedro Alves
Gary Benson