binutils-gdb/gdb/testsuite/gdb.base/disp-step-syscall.exp

# This testcase is part of GDB, the GNU debugger.

# Copyright 2011-2016 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/>.

set syscall_insn ""

# Define the syscall instruction for each target.

if { [istarget "i\[34567\]86-*-linux*"] || [istarget "x86_64-*-linux*"] } {
    set syscall_insn "\[ \t\](int|syscall|sysenter)\[ \t\]"
} elseif { [istarget "aarch64*-*-linux*"] || [istarget "arm*-*-linux*"] } {
    set syscall_insn "\[ \t\](swi|svc)\[ \t\]"
} else {
    return -1
}

proc check_pc_after_cross_syscall { syscall syscall_insn_next_addr } {
    set syscall_insn_next_addr_found [get_hexadecimal_valueof "\$pc" "0"]

    set test "single step over $syscall final pc"
    if {$syscall_insn_next_addr != 0
	&& $syscall_insn_next_addr == $syscall_insn_next_addr_found} {
	pass $test
    } else {
	fail $test
    }
}

# Restart GDB and set up the test.  Return a list in which the first one
# is the address of syscall instruction and the second one is the address
# of the next instruction address of syscall instruction.  If anything
# wrong, the two elements of list are -1.

proc setup { syscall } {
    global gdb_prompt syscall_insn

    set testfile "disp-step-$syscall"

    clean_restart $testfile

    if { ![runto main] } then {
	fail "run to main ($syscall)"
	return -1
    }

    # Delete the breakpoint on main.
    gdb_test_no_output "delete break 1"

    gdb_test_no_output "set displaced-stepping off"

    gdb_test "break $syscall" "Breakpoint \[0-9\]* at .*"

    gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, (.* in |__libc_|)$syscall \\(\\).*" \
	"continue to $syscall (1st time)"
    # Hit the breakpoint on $syscall for the first time.  In this time,
    # we will let PLT resolution done, and the number single steps we will
    # do later will be reduced.

    gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, (.* in |__libc_|)$syscall \\(\\).*" \
	"continue to $syscall (2nd time)"
    # Hit the breakpoint on $syscall for the second time.  In this time,
    # the address of syscall insn and next insn of syscall are recorded.

    gdb_test "display/i \$pc" ".*"

    # Single step until we see a syscall insn or we reach the
    # upper bound of loop iterations.
    set msg "find syscall insn in $syscall"
    set steps 0
    set max_steps 1000
    gdb_test_multiple "stepi" $msg {
	-re ".*$syscall_insn.*$gdb_prompt $" {
	    pass $msg
	}
	-re "x/i .*=>.*\r\n$gdb_prompt $" {
	    incr steps
	    if {$steps == $max_steps} {
		fail $msg
	    } else {
		send_gdb "stepi\n"
		exp_continue
	    }
	}
    }

    if {$steps == $max_steps} {
	return { -1, -1 }
    }

    set syscall_insn_addr [get_hexadecimal_valueof "\$pc" "0"]
    if {[gdb_test "stepi" "x/i .*=>.*" "stepi $syscall insn"] != 0} {
	return { -1, -1 }
    }
    return [list $syscall_insn_addr [get_hexadecimal_valueof "\$pc" "0"]]
}

proc disp_step_cross_syscall { syscall } {
    with_test_prefix "$syscall" {
	global syscall_insn
	global gdb_prompt

	set testfile "disp-step-$syscall"

	if [build_executable ${testfile}.exp ${testfile} ${testfile}.c {debug}] {
	    untested ${testfile}.exp
	    return -1
	}

	foreach_with_prefix displaced {"off" "on"} {
	    if {$displaced == "on" && ![support_displaced_stepping]} {
		continue
	    }

	set ret [setup $syscall]

	set syscall_insn_addr [lindex $ret 0]
	set syscall_insn_next_addr [lindex $ret 1]
	if { $syscall_insn_addr == -1 } {
	    return -1
	}

	gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, (.* in |__libc_|)$syscall \\(\\).*" \
	    "continue to $syscall (3rd time)"

	# Hit the breakpoint on $syscall for the third time.  In this time, we'll set
	# breakpoint on the syscall insn we recorded previously, and single step over it.

	set syscall_insn_bp 0
	gdb_test_multiple "break \*$syscall_insn_addr"  "break on syscall insn" {
	    -re "Breakpoint (\[0-9\]*) at .*$gdb_prompt $" {
		set syscall_insn_bp $expect_out(1,string)
		pass "break on syscall insns"
	    }
	}

	gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, .*" \
	    "continue to syscall insn $syscall"

	gdb_test_no_output "set displaced-stepping $displaced"

	# Check the address of next instruction of syscall.
	if {[gdb_test "stepi" "x/i .*=>.*" "single step over $syscall"] != 0} {
	    return -1
	}

	check_pc_after_cross_syscall $syscall $syscall_insn_next_addr

	# Delete breakpoint syscall insns to avoid interference to other syscalls.
	delete_breakpoints

	gdb_test "break marker" "Breakpoint.*at.* file .*${testfile}.c, line.*"
	gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, marker \\(\\) at.*" \
	    "continue to marker ($syscall)"
	}
    }
}

disp_step_cross_syscall "fork"
disp_step_cross_syscall "vfork"