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

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

# Copyright 2011-2012 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 { ![support_displaced_stepping] } {
    unsupported "displaced stepping"
    return -1
}

set syscall_insn ""

# Define the syscall instruction for each target.

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

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

    set testfile "disp-step-$syscall"

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

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

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

    gdb_test "break marker" "Breakpoint.*at.* file .*${testfile}.c, line.*"
    gdb_test_no_output "set displaced-stepping off"

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

    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 sysall insn or we reach the upper bound of loop
    # iterations.
    set see_syscall_insn 0

    for {set i 0} {$i < 1000 && $see_syscall_insn == 0} {incr i} {
	send_gdb "stepi\n"
	gdb_expect {
	    -re ".*$syscall_insn.*$gdb_prompt $" {
		set see_syscall_insn 1
	    }
	    -re ".*$gdb_prompt $" {}
	}
    }

    if {$see_syscall_insn == 0} then {
	fail "find syscall insn in $syscall"
	return -1
    }

    set syscall_insn_addr [get_hexadecimal_valueof "\$pc" "0"]
    gdb_test "stepi" ".*" "stepi $syscall insn"
    set syscall_insn_next_addr [get_hexadecimal_valueof "\$pc" "0"]

    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_no_output "delete $syscall_bp" "delete break $syscall"

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

    gdb_test_no_output "set displaced-stepping on"

    # Check the address of next instruction of syscall.
    gdb_test "stepi" ".*$syscall_insn_next_addr.*" "single step over $syscall"

    # Delete breakpoint syscall insns to avoid interference to other syscalls.
    gdb_test_no_output "delete $syscall_insn_bp" "delete break $syscall insn"

    gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, marker \\(\\) at.*" \
	"continue to marker ($syscall)"
}}

disp_step_cross_syscall "fork"
disp_step_cross_syscall "vfork"