+2014-05-07 Kyle McMartin <kyle@redhat.com>
+
+ Pushed by Joel Brobecker <brobecker@adacore.com>.
+ * aarch64-tdep.c (aarch64_software_single_step): New function.
+ (aarch64_gdbarch_init): Handle single stepping of atomic sequences
+ with aarch64_software_single_step.
+
2014-05-05 Joel Brobecker <brobecker@adacore.com>
GDB 7.7.1 released.
}
\f
+/* Implement the "software_single_step" gdbarch method, needed to
+ single step through atomic sequences on AArch64. */
+
+static int
+aarch64_software_single_step (struct frame_info *frame)
+{
+ struct gdbarch *gdbarch = get_frame_arch (frame);
+ struct address_space *aspace = get_frame_address_space (frame);
+ enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch);
+ const int insn_size = 4;
+ const int atomic_sequence_length = 16; /* Instruction sequence length. */
+ CORE_ADDR pc = get_frame_pc (frame);
+ CORE_ADDR breaks[2] = { -1, -1 };
+ CORE_ADDR loc = pc;
+ CORE_ADDR closing_insn = 0;
+ uint32_t insn = read_memory_unsigned_integer (loc, insn_size,
+ byte_order_for_code);
+ int index;
+ int insn_count;
+ int bc_insn_count = 0; /* Conditional branch instruction count. */
+ int last_breakpoint = 0; /* Defaults to 0 (no breakpoints placed). */
+
+ /* Look for a Load Exclusive instruction which begins the sequence. */
+ if (!decode_masked_match (insn, 0x3fc00000, 0x08400000))
+ return 0;
+
+ for (insn_count = 0; insn_count < atomic_sequence_length; ++insn_count)
+ {
+ int32_t offset;
+ unsigned cond;
+
+ loc += insn_size;
+ insn = read_memory_unsigned_integer (loc, insn_size,
+ byte_order_for_code);
+
+ /* Check if the instruction is a conditional branch. */
+ if (decode_bcond (loc, insn, &cond, &offset))
+ {
+ if (bc_insn_count >= 1)
+ return 0;
+
+ /* It is, so we'll try to set a breakpoint at the destination. */
+ breaks[1] = loc + offset;
+
+ bc_insn_count++;
+ last_breakpoint++;
+ }
+
+ /* Look for the Store Exclusive which closes the atomic sequence. */
+ if (decode_masked_match (insn, 0x3fc00000, 0x08000000))
+ {
+ closing_insn = loc;
+ break;
+ }
+ }
+
+ /* We didn't find a closing Store Exclusive instruction, fall back. */
+ if (!closing_insn)
+ return 0;
+
+ /* Insert breakpoint after the end of the atomic sequence. */
+ breaks[0] = loc + insn_size;
+
+ /* Check for duplicated breakpoints, and also check that the second
+ breakpoint is not within the atomic sequence. */
+ if (last_breakpoint
+ && (breaks[1] == breaks[0]
+ || (breaks[1] >= pc && breaks[1] <= closing_insn)))
+ last_breakpoint = 0;
+
+ /* Insert the breakpoint at the end of the sequence, and one at the
+ destination of the conditional branch, if it exists. */
+ for (index = 0; index <= last_breakpoint; index++)
+ insert_single_step_breakpoint (gdbarch, aspace, breaks[index]);
+
+ return 1;
+}
+
/* Initialize the current architecture based on INFO. If possible,
re-use an architecture from ARCHES, which is a list of
architectures already created during this debugging session.
set_gdbarch_breakpoint_from_pc (gdbarch, aarch64_breakpoint_from_pc);
set_gdbarch_cannot_step_breakpoint (gdbarch, 1);
set_gdbarch_have_nonsteppable_watchpoint (gdbarch, 1);
+ set_gdbarch_software_single_step (gdbarch, aarch64_software_single_step);
/* Information about registers, etc. */
set_gdbarch_sp_regnum (gdbarch, AARCH64_SP_REGNUM);
+2014-05-07 Kyle McMartin <kyle@redhat.com>
+
+ Pushed by Joel Brobecker <brobecker@adacore.com>.
+ * gdb.arch/aarch64-atomic-inst.c: New file.
+ * gdb.arch/aarch64-atomic-inst.exp: New file.
+
2014-05-07 Yao Qi <yao@codesourcery.com>
* gdb.dwarf2/dwzbuildid.exp: Match output "No symbol "the_int"
--- /dev/null
+/* This file is part of GDB, the GNU debugger.
+
+ Copyright 2008-2014 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/>. */
+
+int main(void)
+{
+ unsigned long tmp, cond;
+ unsigned long dword = 0;
+
+ /* Test that we can step over ldxr/stxr. This sequence should step from
+ ldxr to the following __asm __volatile. */
+ __asm __volatile ("1: ldxr %0,%2\n" \
+ " cmp %0,#1\n" \
+ " b.eq out\n" \
+ " add %0,%0,1\n" \
+ " stxr %w1,%0,%2\n" \
+ " cbnz %w1,1b" \
+ : "=&r" (tmp), "=&r" (cond), "+Q" (dword) \
+ : : "memory");
+
+ /* This sequence should take the conditional branch and step from ldxr
+ to the return dword line. */
+ __asm __volatile ("1: ldxr %0,%2\n" \
+ " cmp %0,#1\n" \
+ " b.eq out\n" \
+ " add %0,%0,1\n" \
+ " stxr %w1,%0,%2\n" \
+ " cbnz %w1,1b\n" \
+ : "=&r" (tmp), "=&r" (cond), "+Q" (dword) \
+ : : "memory");
+
+ dword = -1;
+__asm __volatile ("out:\n");
+ return dword;
+}
--- /dev/null
+# Copyright 2008-2014 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, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+#
+# This file is part of the gdb testsuite.
+
+# Test single stepping through atomic sequences beginning with
+# a ldxr instruction and ending with a stxr instruction.
+
+if {![istarget "aarch64*"]} {
+ verbose "Skipping ${gdb_test_file_name}."
+ return
+}
+
+standard_testfile
+if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
+ return -1
+}
+
+if ![runto_main] {
+ untested "could not run to main"
+ return -1
+}
+
+gdb_breakpoint "[gdb_get_line_number "ldxr"]" \
+ "Breakpoint $decimal at $hex" \
+ "Set the breakpoint at the start of the sequence"
+
+gdb_test "continue" "Continuing.*Breakpoint $decimal.*" \
+ "Continue until breakpoint"
+
+gdb_test "next" ".*__asm __volatile.*" \
+ "Step through the ldxr/stxr sequence"
+
+gdb_test "next" ".*return dword.*" \
+ "Stepped through sequence through conditional branch"
projects / binutils-gdb.git / commitdiff