tests/regression/kernel/test_callstack

   1 #!/bin/bash
   2 #
   3 # Copyright (C) 2017 Francis Deslauriers <francis.deslauriers@efficios.com>
   4 #
   5 # SPDX-License-Identifier: GPL-2.0-only
   6 #
   7
   8 TEST_DESC="Kernel tracer - Callstack context"
   9
  10 CURDIR=$(dirname "$0")/
  11 TESTDIR=$CURDIR/../..
  12 NUM_TESTS=11
  13 TEST_APP_USERSPACE="$TESTDIR/utils/testapp/gen-syscall-events-callstack/gen-syscall-events-callstack"
  14 TEST_APP_KERNELSPACE="$TESTDIR/utils/testapp/gen-syscall-events/gen-syscall-events"
  15 PARSE_CALLSTACK="$TESTDIR/utils/parse-callstack.py"
  16
  17 SESSION_NAME="callstack"
  18 CHANNEL_NAME="chan0"
  19
  20 source "$TESTDIR/utils/utils.sh"
  21
  22 function lttng_untrack_all()
  23 {
  24         lttng_untrack 0 "-s $SESSION_NAME --all --pid -k"
  25 }
  26
  27 function lttng_track_pid()
  28 {
  29         local PID=$1
  30         lttng_track 0 "-s $SESSION_NAME -k --pid=$PID"
  31 }
  32
  33 function run_workload()
  34 {
  35         local TEST_APP=$1
  36         # shift the first argument, passing along the other args if any to the
  37         # test app.
  38         shift
  39         local start_file_sync=$(mktemp --tmpdir -u "tmp.${FUNCNAME[0]}_sync_before_first.XXXXXX")
  40
  41         lttng_untrack_all
  42
  43         ./"$TEST_APP" "$start_file_sync" "$@" &
  44         PID=$!
  45         lttng_track_pid $PID
  46
  47         start_lttng_tracing_ok
  48
  49         # Create start file to launch the execution of the syscall call by the
  50         # test app.
  51         touch "$start_file_sync"
  52
  53         wait $PID
  54
  55         stop_lttng_tracing_ok
  56
  57         # Clean up the synchronization file.
  58         rm -f "$start_file_sync"
  59 }
  60
  61 function test_user_callstack()
  62 {
  63         TRACE_PATH=$(mktemp --tmpdir -d "tmp.${FUNCNAME[0]}_trace_path.XXXXXX")
  64         # This is the expected userspace callstack. (see gen-syscall-events-callstack.c)
  65         USER_CS_EXPECTED="main fct_a fct_b fct_c my_gettid"
  66         EVENT_NAME="gettid"
  67
  68         diag "Userspace callstack test"
  69         create_lttng_session_ok $SESSION_NAME "$TRACE_PATH"
  70         lttng_enable_kernel_channel_ok "$SESSION_NAME" "$CHANNEL_NAME"
  71
  72         lttng_enable_kernel_syscall_ok "$SESSION_NAME" "$EVENT_NAME" "$CHANNEL_NAME"
  73         add_context_kernel_ok "$SESSION_NAME" "$CHANNEL_NAME" "callstack-user"
  74
  75         run_workload $TEST_APP_USERSPACE
  76
  77         destroy_lttng_session_ok "$SESSION_NAME"
  78
  79         "$BABELTRACE_BIN" "$TRACE_PATH" | grep $EVENT_NAME | ./"$PARSE_CALLSTACK" --user "$TEST_APP_USERSPACE" $USER_CS_EXPECTED
  80         ok $? "Validate userspace callstack"
  81
  82         rm -rf "$TRACE_PATH"
  83 }
  84
  85 function test_kernel_callstack()
  86 {
  87         TRACE_PATH=$(mktemp --tmpdir -d "tmp.${FUNCNAME[0]}_trace_path.XXXXXX")
  88         # Those are symbol expected to be present in the kernel callstack. This
  89         # is not an exhaustive list since it's kernel dependent.
  90
  91         # FIXME: we used to test for the following symbols as well:
  92         # save_stack_trace, lttng_callstack_get_size, but they were removed
  93         # because:
  94         #       1. kernel commit 77072f09 make it so that save_stack_trace is
  95         #        omitted from the callstack itself, and
  96         #
  97         #       2. the code (of this commit) can trigger Tail Call Optimization
  98         #       which mess up with the stacktrace by omiting the wrong address
  99         #       from the stacktrace.
 100         # When this is fixed, we should add both save_stack_trace and
 101         # lttng_callstack_get_size symbols back in the list of expected
 102         # addresses.
 103         KERNEL_CS_EXPECTED="lttng_event_reserve"
 104         EVENT_NAME="read"
 105
 106         diag "Kernel callstack test"
 107         create_lttng_session_ok $SESSION_NAME "$TRACE_PATH"
 108         lttng_enable_kernel_channel_ok "$SESSION_NAME" "$CHANNEL_NAME"
 109
 110         lttng_enable_kernel_syscall_ok "$SESSION_NAME" "$EVENT_NAME" "$CHANNEL_NAME"
 111         add_context_kernel_ok "$SESSION_NAME" "$CHANNEL_NAME" "callstack-kernel"
 112
 113         run_workload "$TEST_APP_KERNELSPACE" "/proc/cpuinfo" "/proc/cmdline"
 114
 115         destroy_lttng_session_ok "$SESSION_NAME"
 116
 117         "$BABELTRACE_BIN" "$TRACE_PATH" | grep $EVENT_NAME | ./"$PARSE_CALLSTACK" --kernel $KERNEL_CS_EXPECTED
 118         ok $? "Validate kernel callstack"
 119
 120         rm -rf "$TRACE_PATH"
 121 }
 122
 123 # Only run userspace callstack test on x86
 124 uname -m | grep -E "x86" >/dev/null 2>&1
 125 if test $? == 0; then
 126         NUM_TESTS=$((NUM_TESTS+11))
 127         RUN_USERSPACE_TEST=1
 128 else
 129         RUN_USERSPACE_TEST=0
 130 fi
 131
 132 # MUST set TESTDIR before calling those functions
 133 plan_tests $NUM_TESTS
 134
 135 print_test_banner "$TEST_DESC"
 136
 137 if [ "$(id -u)" == "0" ]; then
 138         isroot=1
 139 else
 140         isroot=0
 141 fi
 142
 143 skip $isroot "Root access is needed. Skipping all tests." "$NUM_TESTS" ||
 144 {
 145         which "$BABELTRACE_BIN" > /dev/null
 146         test $? -ne 0
 147         skip $? "Babeltrace binary not found. Skipping callstack tests" "$NUM_TESTS" ||
 148         {
 149                 start_lttng_sessiond
 150
 151                 if test $RUN_USERSPACE_TEST == 1; then
 152                         test_user_callstack
 153                 fi
 154
 155                 test_kernel_callstack
 156
 157                 stop_lttng_sessiond
 158         }
 159 }