testsuite/gdb.trace/ftrace.exp

# Copyright 2011-2019 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/>.

load_lib "trace-support.exp"

if {[skip_shlib_tests]} {
    return 0
}

standard_testfile
set executable $testfile
set expfile $testfile.exp

# Some targets have leading underscores on assembly symbols.
set additional_flags [gdb_target_symbol_prefix_flags]

if ![gdb_trace_common_supports_arch] {
    unsupported "no trace-common.h support for arch"
    return -1
}

if [prepare_for_testing "failed to prepare" $executable $srcfile \
	[list debug $additional_flags]] {
    return -1
}

if ![runto_main] {
    fail "can't run to main to check for trace support"
    return -1
}

if ![gdb_target_supports_trace] {
    unsupported "target does not support trace"
    return -1
}

set libipa [get_in_proc_agent]
set remote_libipa [gdb_load_shlib $libipa]

# Can't use prepare_for_testing, because that splits compiling into
# building objects and then linking, and we'd fail with "linker input
# file unused because linking not done" when building the object.

if { [gdb_compile "$srcdir/$subdir/$srcfile" $binfile \
	  executable [list debug $additional_flags shlib=$libipa] ] != "" } {
    untested "failed to compile"
    return -1
}
clean_restart ${executable}

if ![runto_main] {
    fail "can't run to main for ftrace tests"
    return 0
}

proc run_trace_experiment {} {

    gdb_test "continue" \
	".*Breakpoint \[0-9\]+, begin .*" \
	"advance to trace begin"

    gdb_test_no_output "tstart" "start trace experiment"

    # Fast tracepoint can be set in signal handler, so gdb_collect in
    # IPA shouldn't call any non-async-signal-safe functions.  It is
    # impractical to list all non-async-signal-safe functions, and set
    # breakpoints on them, so choose malloc only in this test.
    gdb_test "b -q malloc"

    # Performance-wise, gdb_collect in IPA shouldn't call any syscall
    # in order to keep fast tracepoint fast enough.
    global gdb_prompt
    set test "catch syscall"
    gdb_test_multiple $test $test {
	-re "The feature \'catch syscall\' is not supported.*\r\n$gdb_prompt $" {
	}
	-re ".*$gdb_prompt $" {
	    pass $test
	}
    }

    global decimal
    set test "advance through tracing"
    gdb_test_multiple "continue" $test {
	-re "Thread 2 .* hit Catchpoint $decimal \\(call to syscall .*\\).*\r\n$gdb_prompt $" {
	    # IPA starts a helper thread, which calls accept.  Ignore it.
	    send_gdb "continue\n"
	    exp_continue
	}
	-re "Breakpoint $decimal, end .*$gdb_prompt $" {
	    pass $test
	}
    }

    gdb_test "tstatus" ".*Trace .*" "check on trace status"

    gdb_test "tstop" "" ""
}

proc test_fast_tracepoints {} {
    global gdb_prompt

    set fourgood 0

    gdb_breakpoint "begin" qualified

    gdb_breakpoint "end" qualified

    gdb_test "print gdb_agent_gdb_trampoline_buffer_error" ".*" ""

    gdb_test "ftrace set_point" "Fast tracepoint .*" \
        "fast tracepoint at a long insn"

    gdb_trace_setactions "collect at set_point: define actions" \
        "" \
        "collect globvar, anarg" "^$"

    # Make a test of shorter fast tracepoints, 32-bit x86 only

    if { [istarget "i?86-*-*"] } {

        # A Linux target needs to be able to allocate trampolines in the
        # 16-bit range, check mmap_min_addr so we can warn testers.
        if { [istarget "i?86-*-linux*"] } {

            set minaddr [exec sh -c "cat /proc/sys/vm/mmap_min_addr"]

            if { [expr $minaddr > 64512] } {
                warning "mmap_min_addr > 64512, fast tracepoint will fail"
                warning "do \"sudo sysctl -w vm.mmap_min_addr=32768\" to adjust"
            }
        }

        gdb_test_multiple "ftrace four_byter" "set 4-byte fast tracepoint" {
            -re "May not have a fast tracepoint at .*\r\n$gdb_prompt $" {
                pass "4-byte fast tracepoint could not be set"
            }
            -re "Fast tracepoint .*\r\n$gdb_prompt $" {
                pass "4-byte fast tracepoint is set"
                set fourgood 1
            }
        }

        if { $fourgood } {

            gdb_trace_setactions "collect at four_byter: define actions" \
            "" \
            "collect globvar, anarg" "^$"
        }
    }

    run_trace_experiment

    gdb_test "tfind pc *set_point" "Found trace frame .*" \
        "tfind set_point frame, first time"

    gdb_test "print globvar" " = 1"

    gdb_test "tfind pc *set_point" "Found trace frame .*" \
        "tfind set_point frame, second time"

    setup_kfail "gdb/13808" "x86_64-*-linux*"
    gdb_test "print anarg" " = 200"

    gdb_test "tfind start" "Found trace frame .*" \
        "reset tfinding"

    if { $fourgood } {

        gdb_test "tfind pc *four_byter" "Found trace frame .*" \
            "tfind four_byter frame, first time"

        gdb_test "print anarg" " = 101" \
            "look at collected local, first time"

        gdb_test "tfind pc *four_byter" "Found trace frame .*" \
            "tfind four_byter frame, second time"

        gdb_test "print anarg" " = 201" \
            "look at collected local, second time"

    }

    # If debugging with the remote target, try force disabling the
    # fast tracepoints RSP feature, and confirm fast tracepoints
    # can no longer be downloaded.
    set test "fast tracepoint could not be downloaded with the feature disabled"
    if [gdb_is_target_remote] {
        gdb_test "set remote fast-tracepoints-packet off"

        gdb_test_multiple "tstart" $test {
            -re "warning: Target does not support fast tracepoints, downloading .* as regular tracepoint.*\r\n$gdb_prompt $" {
                pass $test
            }
        }
    } else {
        unsupported $test
    }
}

gdb_reinitialize_dir $srcdir/$subdir

if { [gdb_test "info sharedlibrary" ".*${remote_libipa}.*" "IPA loaded"] != 0 } {
    untested "could not find IPA lib loaded"
    return 1
}

test_fast_tracepoints