aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--gdb/ChangeLog22
-rw-r--r--gdb/Makefile.in5
-rw-r--r--gdb/amd64-tdep.c14
-rw-r--r--gdb/arch-utils.c8
-rw-r--r--gdb/arch-utils.h5
-rw-r--r--gdb/gdbarch.c23
-rw-r--r--gdb/gdbarch.h6
-rwxr-xr-xgdb/gdbarch.sh3
-rw-r--r--gdb/i386-tdep.c13
-rw-r--r--gdb/infrun.c11
-rw-r--r--gdb/testsuite/ChangeLog7
-rw-r--r--gdb/testsuite/gdb.base/step-indirect-call-thunk.c42
-rw-r--r--gdb/testsuite/gdb.base/step-indirect-call-thunk.exp73
-rw-r--r--gdb/testsuite/gdb.reverse/step-indirect-call-thunk.c36
-rw-r--r--gdb/testsuite/gdb.reverse/step-indirect-call-thunk.exp100
-rw-r--r--gdb/x86-tdep.c76
-rw-r--r--gdb/x86-tdep.h30
17 files changed, 473 insertions, 1 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 1141a1d..f379680 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,25 @@
+2018-04-13 Markus Metzger <markus.t.metzger@intel.com>
+
+ * infrun.c (process_event_stop_test): Call
+ gdbarch_in_indirect_branch_thunk.
+ * gdbarch.sh (in_indirect_branch_thunk): New.
+ * gdbarch.c: Regenerated.
+ * gdbarch.h: Regenerated.
+ * x86-tdep.h: New.
+ * x86-tdep.c: New.
+ * Makefile.in (ALL_TARGET_OBS): Add x86-tdep.o.
+ (HFILES_NO_SRCDIR): Add x86-tdep.h.
+ (ALLDEPFILES): Add x86-tdep.c.
+ * arch-utils.h (default_in_indirect_branch_thunk): New.
+ * arch-utils.c (default_in_indirect_branch_thunk): New.
+ * i386-tdep: Include x86-tdep.h.
+ (i386_in_indirect_branch_thunk): New.
+ (i386_elf_init_abi): Set in_indirect_branch_thunk gdbarch
+ function.
+ * amd64-tdep: Include x86-tdep.h.
+ (amd64_in_indirect_branch_thunk): New.
+ (amd64_init_abi): Set in_indirect_branch_thunk gdbarch function.
+
2018-04-12 Jan Kratochvil <jan.kratochvil@redhat.com>
PR gdb/23053
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index e885dca..40c9f89 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -793,6 +793,7 @@ ALL_TARGET_OBS = \
vax-nbsd-tdep.o \
vax-tdep.o \
windows-tdep.o \
+ x86-tdep.o \
xcoffread.o \
xstormy16-tdep.o \
xtensa-config.o \
@@ -1521,7 +1522,8 @@ HFILES_NO_SRCDIR = \
tui/tui-win.h \
tui/tui-windata.h \
tui/tui-wingeneral.h \
- tui/tui-winsource.h
+ tui/tui-winsource.h \
+ x86-tdep.h
# Header files that already have srcdir in them, or which are in objdir.
@@ -2363,6 +2365,7 @@ ALLDEPFILES = \
windows-nat.c \
windows-tdep.c \
x86-nat.c \
+ x86-tdep.c \
xcoffread.c \
xstormy16-tdep.c \
xtensa-config.c \
diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c
index bceb6e1..1fea264 100644
--- a/gdb/amd64-tdep.c
+++ b/gdb/amd64-tdep.c
@@ -48,6 +48,7 @@
#include "ax-gdb.h"
#include "common/byte-vector.h"
#include "osabi.h"
+#include "x86-tdep.h"
/* Note that the AMD64 architecture was previously known as x86-64.
The latter is (forever) engraved into the canonical system name as
@@ -3034,6 +3035,16 @@ static const int amd64_record_regmap[] =
AMD64_DS_REGNUM, AMD64_ES_REGNUM, AMD64_FS_REGNUM, AMD64_GS_REGNUM
};
+/* Implement the "in_indirect_branch_thunk" gdbarch function. */
+
+static bool
+amd64_in_indirect_branch_thunk (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ return x86_in_indirect_branch_thunk (pc, amd64_register_names,
+ AMD64_RAX_REGNUM,
+ AMD64_RIP_REGNUM);
+}
+
void
amd64_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch,
const target_desc *default_tdesc)
@@ -3206,6 +3217,9 @@ amd64_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch,
set_gdbarch_insn_is_call (gdbarch, amd64_insn_is_call);
set_gdbarch_insn_is_ret (gdbarch, amd64_insn_is_ret);
set_gdbarch_insn_is_jump (gdbarch, amd64_insn_is_jump);
+
+ set_gdbarch_in_indirect_branch_thunk (gdbarch,
+ amd64_in_indirect_branch_thunk);
}
/* Initialize ARCH for x86-64, no osabi. */
diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c
index 5986ed6..cd9bd66 100644
--- a/gdb/arch-utils.c
+++ b/gdb/arch-utils.c
@@ -979,6 +979,14 @@ gdbarch_skip_prologue_noexcept (gdbarch *gdbarch, CORE_ADDR pc) noexcept
return new_pc;
}
+/* See arch-utils.h. */
+
+bool
+default_in_indirect_branch_thunk (gdbarch *gdbarch, CORE_ADDR pc)
+{
+ return false;
+}
+
void
_initialize_gdbarch_utils (void)
{
diff --git a/gdb/arch-utils.h b/gdb/arch-utils.h
index 3407a16..b785b24 100644
--- a/gdb/arch-utils.h
+++ b/gdb/arch-utils.h
@@ -262,4 +262,9 @@ extern int default_print_insn (bfd_vma memaddr, disassemble_info *info);
extern CORE_ADDR gdbarch_skip_prologue_noexcept (gdbarch *gdbarch,
CORE_ADDR pc) noexcept;
+/* Default implementation of gdbarch_in_indirect_branch_thunk that returns
+ false. */
+extern bool default_in_indirect_branch_thunk (gdbarch *gdbarch,
+ CORE_ADDR pc);
+
#endif
diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c
index ddafe25..1359c2f 100644
--- a/gdb/gdbarch.c
+++ b/gdb/gdbarch.c
@@ -266,6 +266,7 @@ struct gdbarch
gdbarch_skip_trampoline_code_ftype *skip_trampoline_code;
gdbarch_skip_solib_resolver_ftype *skip_solib_resolver;
gdbarch_in_solib_return_trampoline_ftype *in_solib_return_trampoline;
+ gdbarch_in_indirect_branch_thunk_ftype *in_indirect_branch_thunk;
gdbarch_stack_frame_destroyed_p_ftype *stack_frame_destroyed_p;
gdbarch_elf_make_msymbol_special_ftype *elf_make_msymbol_special;
gdbarch_coff_make_msymbol_special_ftype *coff_make_msymbol_special;
@@ -433,6 +434,7 @@ gdbarch_alloc (const struct gdbarch_info *info,
gdbarch->skip_trampoline_code = generic_skip_trampoline_code;
gdbarch->skip_solib_resolver = generic_skip_solib_resolver;
gdbarch->in_solib_return_trampoline = generic_in_solib_return_trampoline;
+ gdbarch->in_indirect_branch_thunk = default_in_indirect_branch_thunk;
gdbarch->stack_frame_destroyed_p = generic_stack_frame_destroyed_p;
gdbarch->coff_make_msymbol_special = default_coff_make_msymbol_special;
gdbarch->make_symbol_special = default_make_symbol_special;
@@ -627,6 +629,7 @@ verify_gdbarch (struct gdbarch *gdbarch)
/* Skip verify of skip_trampoline_code, invalid_p == 0 */
/* Skip verify of skip_solib_resolver, invalid_p == 0 */
/* Skip verify of in_solib_return_trampoline, invalid_p == 0 */
+ /* Skip verify of in_indirect_branch_thunk, invalid_p == 0 */
/* Skip verify of stack_frame_destroyed_p, invalid_p == 0 */
/* Skip verify of elf_make_msymbol_special, has predicate. */
/* Skip verify of coff_make_msymbol_special, invalid_p == 0 */
@@ -1103,6 +1106,9 @@ gdbarch_dump (struct gdbarch *gdbarch, struct ui_file *file)
"gdbarch_dump: have_nonsteppable_watchpoint = %s\n",
plongest (gdbarch->have_nonsteppable_watchpoint));
fprintf_unfiltered (file,
+ "gdbarch_dump: in_indirect_branch_thunk = <%s>\n",
+ host_address_to_string (gdbarch->in_indirect_branch_thunk));
+ fprintf_unfiltered (file,
"gdbarch_dump: in_solib_return_trampoline = <%s>\n",
host_address_to_string (gdbarch->in_solib_return_trampoline));
fprintf_unfiltered (file,
@@ -3353,6 +3359,23 @@ set_gdbarch_in_solib_return_trampoline (struct gdbarch *gdbarch,
gdbarch->in_solib_return_trampoline = in_solib_return_trampoline;
}
+bool
+gdbarch_in_indirect_branch_thunk (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ gdb_assert (gdbarch != NULL);
+ gdb_assert (gdbarch->in_indirect_branch_thunk != NULL);
+ if (gdbarch_debug >= 2)
+ fprintf_unfiltered (gdb_stdlog, "gdbarch_in_indirect_branch_thunk called\n");
+ return gdbarch->in_indirect_branch_thunk (gdbarch, pc);
+}
+
+void
+set_gdbarch_in_indirect_branch_thunk (struct gdbarch *gdbarch,
+ gdbarch_in_indirect_branch_thunk_ftype in_indirect_branch_thunk)
+{
+ gdbarch->in_indirect_branch_thunk = in_indirect_branch_thunk;
+}
+
int
gdbarch_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR addr)
{
diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index 5cb131d..0084f19 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -741,6 +741,12 @@ typedef int (gdbarch_in_solib_return_trampoline_ftype) (struct gdbarch *gdbarch,
extern int gdbarch_in_solib_return_trampoline (struct gdbarch *gdbarch, CORE_ADDR pc, const char *name);
extern void set_gdbarch_in_solib_return_trampoline (struct gdbarch *gdbarch, gdbarch_in_solib_return_trampoline_ftype *in_solib_return_trampoline);
+/* Return true if PC lies inside an indirect branch thunk. */
+
+typedef bool (gdbarch_in_indirect_branch_thunk_ftype) (struct gdbarch *gdbarch, CORE_ADDR pc);
+extern bool gdbarch_in_indirect_branch_thunk (struct gdbarch *gdbarch, CORE_ADDR pc);
+extern void set_gdbarch_in_indirect_branch_thunk (struct gdbarch *gdbarch, gdbarch_in_indirect_branch_thunk_ftype *in_indirect_branch_thunk);
+
/* A target might have problems with watchpoints as soon as the stack
frame of the current function has been destroyed. This mostly happens
as the first action in a function's epilogue. stack_frame_destroyed_p()
diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh
index 0923029..4fc54cb 100755
--- a/gdb/gdbarch.sh
+++ b/gdb/gdbarch.sh
@@ -660,6 +660,9 @@ m;CORE_ADDR;skip_solib_resolver;CORE_ADDR pc;pc;;generic_skip_solib_resolver;;0
# Some systems also have trampoline code for returning from shared libs.
m;int;in_solib_return_trampoline;CORE_ADDR pc, const char *name;pc, name;;generic_in_solib_return_trampoline;;0
+# Return true if PC lies inside an indirect branch thunk.
+m;bool;in_indirect_branch_thunk;CORE_ADDR pc;pc;;default_in_indirect_branch_thunk;;0
+
# A target might have problems with watchpoints as soon as the stack
# frame of the current function has been destroyed. This mostly happens
# as the first action in a function's epilogue. stack_frame_destroyed_p()
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 60dc801..bf4ca54 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -47,6 +47,7 @@
#include "i386-tdep.h"
#include "i387-tdep.h"
#include "x86-xstate.h"
+#include "x86-tdep.h"
#include "record.h"
#include "record-full.h"
@@ -4421,6 +4422,15 @@ i386_gnu_triplet_regexp (struct gdbarch *gdbarch)
+/* Implement the "in_indirect_branch_thunk" gdbarch function. */
+
+static bool
+i386_in_indirect_branch_thunk (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ return x86_in_indirect_branch_thunk (pc, i386_register_names,
+ I386_EAX_REGNUM, I386_EIP_REGNUM);
+}
+
/* Generic ELF. */
void
@@ -4447,6 +4457,9 @@ i386_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
i386_stap_is_single_operand);
set_gdbarch_stap_parse_special_token (gdbarch,
i386_stap_parse_special_token);
+
+ set_gdbarch_in_indirect_branch_thunk (gdbarch,
+ i386_in_indirect_branch_thunk);
}
/* System V Release 4 (SVR4). */
diff --git a/gdb/infrun.c b/gdb/infrun.c
index c1db689..9e5e063 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -6565,6 +6565,17 @@ process_event_stop_test (struct execution_control_state *ecs)
return;
}
+ /* Step through an indirect branch thunk. */
+ if (ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
+ && gdbarch_in_indirect_branch_thunk (gdbarch, stop_pc))
+ {
+ if (debug_infrun)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: stepped into indirect branch thunk\n");
+ keep_going (ecs);
+ return;
+ }
+
if (ecs->event_thread->control.step_range_end != 1
&& (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
|| ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index d7722a8..0dc05dd 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2018-04-13 Markus Metzger <markus.t.metzger@intel.com>
+
+ * gdb.base/step-indirect-call-thunk.exp: New.
+ * gdb.base/step-indirect-call-thunk.c: New.
+ * gdb.reverse/step-indirect-call-thunk.exp: New.
+ * gdb.reverse/step-indirect-call-thunk.c: New.
+
2018-04-11 Simon Marchi <simon.marchi@ericsson.com>
* gdb.base/pie-fork.c: New file.
diff --git a/gdb/testsuite/gdb.base/step-indirect-call-thunk.c b/gdb/testsuite/gdb.base/step-indirect-call-thunk.c
new file mode 100644
index 0000000..bd22ea6
--- /dev/null
+++ b/gdb/testsuite/gdb.base/step-indirect-call-thunk.c
@@ -0,0 +1,42 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2018 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+static int
+inc (int x)
+{ /* inc.1 */
+ return x + 1; /* inc.2 */
+} /* inc.3 */
+
+static int
+thrice (int (*op)(int), int x)
+{ /* thrice.1 */
+ x = op (x); /* thrice.2 */
+ x = op (x); /* thrice.3 */
+ return op (x); /* thrice.4 */
+} /* thrice.5 */
+
+int
+main ()
+{
+ int x;
+
+ x = thrice (inc, 40);
+
+ return x;
+}
diff --git a/gdb/testsuite/gdb.base/step-indirect-call-thunk.exp b/gdb/testsuite/gdb.base/step-indirect-call-thunk.exp
new file mode 100644
index 0000000..baeb6d6
--- /dev/null
+++ b/gdb/testsuite/gdb.base/step-indirect-call-thunk.exp
@@ -0,0 +1,73 @@
+# Copyright 2018 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+standard_testfile
+
+set cflags "-mindirect-branch=thunk -mfunction-return=thunk"
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile \
+ [list debug "additional_flags=$cflags"]] } {
+ return -1
+}
+
+if { ![runto_main] } {
+ untested "failed to run to main"
+ return -1
+}
+
+# Do repeated instruction steps in order to reach TARGET from CURRENT
+#
+# CURRENT is a string matching the current location
+# TARGET is a string matching the target location
+# TEST is the test name
+#
+# The function issues repeated "stepi" commands as long as the location
+# matches CURRENT up to a maximum of 100 steps.
+#
+# TEST passes if the resulting location matches TARGET and fails
+# otherwise.
+#
+proc stepi_until { current target test } {
+ global gdb_prompt
+
+ set count 0
+ gdb_test_multiple "stepi" "$test" {
+ -re "$current.*$gdb_prompt $" {
+ incr count
+ if { $count < 100 } {
+ send_gdb "stepi\n"
+ exp_continue
+ } else {
+ fail "$test"
+ }
+ }
+ -re "$target.*$gdb_prompt $" {
+ pass "$test"
+ }
+ }
+}
+
+# Normal stepping steps through all thunks.
+gdb_test "step" "thrice\.2.*" "step into thrice"
+gdb_test "next" "thrice\.3.*" "step through thunks and over inc"
+gdb_test "step" "inc\.2.*" "step through call thunk into inc"
+gdb_test "step" "inc\.3.*" "step inside inc"
+gdb_test "step" "thrice\.4.*" "step through return thunk back into thrice"
+
+# We can use instruction stepping to step into thunks.
+stepi_until "thrice" "indirect_thunk" "stepi into call thunk"
+stepi_until "indirect_thunk" "inc." "stepi out of call thunk into inc"
+stepi_until "inc" "return_thunk" "stepi into return thunk"
+stepi_until "return_thunk" "thrice" \
+ "stepi out of return thunk back into thrice"
diff --git a/gdb/testsuite/gdb.reverse/step-indirect-call-thunk.c b/gdb/testsuite/gdb.reverse/step-indirect-call-thunk.c
new file mode 100644
index 0000000..85464c3
--- /dev/null
+++ b/gdb/testsuite/gdb.reverse/step-indirect-call-thunk.c
@@ -0,0 +1,36 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2018 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+static int
+inc (int x)
+{ /* inc.1 */
+ return x + 1; /* inc.2 */
+} /* inc.3 */
+
+static int
+apply (int (*op)(int), int x)
+{ /* apply.1 */
+ return op (x); /* apply.2 */
+} /* apply.3 */
+
+int
+main ()
+{ /* main.1 */
+ return apply (inc, 41); /* main.2 */
+} /* main.3 */
diff --git a/gdb/testsuite/gdb.reverse/step-indirect-call-thunk.exp b/gdb/testsuite/gdb.reverse/step-indirect-call-thunk.exp
new file mode 100644
index 0000000..bb7fbf6
--- /dev/null
+++ b/gdb/testsuite/gdb.reverse/step-indirect-call-thunk.exp
@@ -0,0 +1,100 @@
+# Copyright 2018 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+if { ![supports_reverse] } {
+ untested "target does not support record"
+ return -1
+}
+
+standard_testfile
+
+set cflags "-mindirect-branch=thunk -mfunction-return=thunk"
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile \
+ [list debug "additional_flags=$cflags"]] } {
+ return -1
+}
+
+if { ![runto_main] } {
+ untested "failed to run to main"
+ return -1
+}
+
+# Do repeated stepping COMMANDs in order to reach TARGET from CURRENT
+#
+# COMMAND is a stepping command
+# CURRENT is a string matching the current location
+# TARGET is a string matching the target location
+# TEST is the test name
+#
+# The function issues repeated COMMANDs as long as the location matches
+# CURRENT up to a maximum of 100 steps.
+#
+# TEST passes if the resulting location matches TARGET and fails
+# otherwise.
+#
+proc step_until { command current target test } {
+ global gdb_prompt
+
+ set count 0
+ gdb_test_multiple "$command" "$test" {
+ -re "$current.*$gdb_prompt $" {
+ incr count
+ if { $count < 100 } {
+ send_gdb "$command\n"
+ exp_continue
+ } else {
+ fail "$test"
+ }
+ }
+ -re "$target.*$gdb_prompt $" {
+ pass "$test"
+ }
+ }
+}
+
+gdb_test_no_output "record"
+gdb_test "next" ".*" "record trace"
+
+# Normal stepping steps through all thunks.
+gdb_test "reverse-step" "apply\.3.*" "reverse-step into apply"
+gdb_test "reverse-step" "inc\.3.*" "reverse-step into inc"
+gdb_test "reverse-step" "inc\.2.*" "reverse-step inside inc"
+gdb_test "reverse-step" "apply\.2.*" \
+ "reverse-step through call thunk into apply"
+gdb_test "reverse-step" "main\.2.*" "reverse-step into main"
+gdb_test "step" "apply\.2.*" "step into apply"
+gdb_test "step" "inc\.2.*" "step through call thunk into inc"
+gdb_test "reverse-step" "apply\.2.*" \
+ "reverse-step through call thunk into apply"
+gdb_test "next" "apply\.3.*" "step through thunks and over inc"
+gdb_test "reverse-next" "apply\.2.*" \
+ "reverse-step through thunks and over inc"
+
+# We can use instruction stepping to step into thunks.
+step_until "stepi" "apply\.2" "indirect_thunk" "stepi into call thunk"
+step_until "stepi" "indirect_thunk" "inc" \
+ "stepi out of call thunk into inc"
+step_until "stepi" "inc" "return_thunk" "stepi into return thunk"
+step_until "stepi" "return_thunk" "apply" \
+ "stepi out of return thunk back into apply"
+
+step_until "reverse-stepi" "apply" "return_thunk" \
+ "reverse-stepi into return thunk"
+step_until "reverse-stepi" "return_thunk" "inc" \
+ "reverse-stepi out of return thunk into inc"
+step_until "reverse-stepi" "inc" "indirect_thunk" \
+ "reverse-stepi into call thunk"
+step_until "reverse-stepi" "indirect_thunk" "apply" \
+ "reverse-stepi out of call thunk into apply"
diff --git a/gdb/x86-tdep.c b/gdb/x86-tdep.c
new file mode 100644
index 0000000..3e665c2
--- /dev/null
+++ b/gdb/x86-tdep.c
@@ -0,0 +1,76 @@
+/* Target-dependent code for X86-based targets.
+
+ Copyright (C) 2018 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include "defs.h"
+#include "x86-tdep.h"
+
+
+/* Check whether NAME is included in NAMES[LO] (inclusive) to NAMES[HI]
+ (exclusive). */
+
+static bool
+x86_is_thunk_register_name (const char *name, const char **names, int lo,
+ int hi)
+{
+ int reg;
+ for (reg = lo; reg < hi; ++reg)
+ if (strcmp (name, names[reg]) == 0)
+ return true;
+
+ return false;
+}
+
+/* See x86-tdep.h. */
+
+bool
+x86_in_indirect_branch_thunk (CORE_ADDR pc, const char **register_names,
+ int lo, int hi)
+{
+ struct bound_minimal_symbol bmfun = lookup_minimal_symbol_by_pc (pc);
+ if (bmfun.minsym == nullptr)
+ return false;
+
+ const char *name = MSYMBOL_LINKAGE_NAME (bmfun.minsym);
+ if (name == nullptr)
+ return false;
+
+ /* Check the indirect return thunk first. */
+ if (strcmp (name, "__x86_return_thunk") == 0)
+ return true;
+
+ /* Then check a family of indirect call/jump thunks. */
+ static const char thunk[] = "__x86_indirect_thunk";
+ static const size_t length = sizeof (thunk) - 1;
+ if (strncmp (name, thunk, length) != 0)
+ return false;
+
+ /* If that's the complete name, we're in the memory thunk. */
+ name += length;
+ if (*name == '\0')
+ return true;
+
+ /* Check for suffixes. */
+ if (*name++ != '_')
+ return false;
+
+ if (x86_is_thunk_register_name (name, register_names, lo, hi))
+ return true;
+
+ return false;
+}
diff --git a/gdb/x86-tdep.h b/gdb/x86-tdep.h
new file mode 100644
index 0000000..807ad1d
--- /dev/null
+++ b/gdb/x86-tdep.h
@@ -0,0 +1,30 @@
+/* Target-dependent code for X86-based targets.
+
+ Copyright (C) 2018 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#ifndef X86_TDEP_H
+#define X86_TDEP_H
+
+/* Checks whether PC lies in an indirect branch thunk using registers
+ REGISTER_NAMES[LO] (inclusive) to REGISTER_NAMES[HI] (exclusive). */
+
+extern bool x86_in_indirect_branch_thunk (CORE_ADDR pc,
+ const char **register_names,
+ int lo, int hi);
+
+#endif /* x86-tdep.h */