Recognize int3 instructions in trace parser

Not quite sure why we'd be seeing this, but let's not crash when we do. For now, treat a software interrupt as a jump. Ref janestreet#257
Xyene · Nov 14, 2022 · df87ec5 · df87ec5
1 parent 923eaef
commit df87ec5
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Showing 4 changed files with 15 additions and 4 deletions.
diff --git a/core/event.ml b/core/event.ml
@@ -7,6 +7,7 @@ module Kind = struct
     | Syscall
     | Sysret
     | Hardware_interrupt
+    | Interrupt
     | Iret
     | Jump
   [@@deriving sexp, compare, bin_io]

diff --git a/core/event.mli b/core/event.mli
@@ -7,6 +7,7 @@ module Kind : sig
     | Syscall
     | Sysret
     | Hardware_interrupt
+    | Interrupt
     | Iret
     | Jump
   [@@deriving sexp, compare]

diff --git a/src/perf_decode.ml b/src/perf_decode.ml
@@ -22,7 +22,7 @@ let perf_callstack_entry_re = Re.Perl.re "^\t *([0-9a-f]+) (.*)$" |> Re.compile
 
 let perf_branches_event_re =
   Re.Perl.re
-    {|^ *(call|return|tr strt|syscall|sysret|hw int|iret|tr end|tr strt tr end|tr end  (?:call|return|syscall|sysret|iret)|jmp|jcc) +([0-9a-f]+) (.*) => +([0-9a-f]+) (.*)$|}
+    {|^ *(int|call|return|tr strt|syscall|sysret|hw int|iret|tr end|tr strt tr end|tr end  (?:call|return|syscall|sysret|iret)|jmp|jcc) +([0-9a-f]+) (.*) => +([0-9a-f]+) (.*)$|}
   |> Re.compile
 ;;
 
@@ -243,6 +243,7 @@ let parse_perf_branches_event ?perf_maps (thread : Event.Thread.t) time line : E
       match String.strip kind with
       | "call" -> Some Call
       | "return" -> Some Return
+      | "int" -> Some Interrupt
       | "jmp" -> Some Jump
       | "jcc" -> Some Jump
       | "syscall" -> Some Syscall
@@ -495,6 +496,14 @@ let%test_module _ =
            (data (Trace (kind Call) (src 0x56234f77576b) (dst 0x56234f4bc7a0)))))) |}]
     ;;
 
+    let%expect_test "257" =
+      check "1907478/1909463 457407.880965552:          1                                branches:uH:   int                      564aa58813d4 Builtins_RunMicrotasks+0x554 (/usr/local/bin/workload) =>     564aa584fa00 Builtins_Call_ReceiverIsNotNullOrUndefined+0x0 (/usr/local/bin/workload)";
+      [%expect{|
+        ((Ok
+          ((thread ((pid (1907478)) (tid (1909463)))) (time 5d7h3m27.880965552s)
+           (data (Trace (kind Interrupt) (src 0x564aa58813d4) (dst 0x564aa584fa00)))))) |}]
+    ;;
+
     let%expect_test "decode error with a timestamp" =
       check
         " instruction trace error type 1 time 47170.086912826 cpu -1 pid 293415 tid \

diff --git a/src/trace_writer.ml b/src/trace_writer.ml
@@ -1004,9 +1004,9 @@ let write_event (T t) ?events_writer event =
          ~time;
        (match kind, trace_state_change with
         | Some Call, (None | Some End) -> call t thread_info ~time ~location:dst
-        | ( Some (Call | Syscall | Return | Hardware_interrupt | Iret | Sysret | Jump)
+        | ( Some (Call | Syscall | Return | Hardware_interrupt | Iret | Interrupt | Sysret | Jump)
           , Some Start )
-        | Some (Hardware_interrupt | Jump), Some End ->
+        | Some (Hardware_interrupt | Jump | Interrupt), Some End ->
           raise_s
             [%message
               "BUG: magic-trace devs thought this event was impossible, but you just \
@@ -1093,7 +1093,7 @@ let write_event (T t) ?events_writer event =
                ~addr:dst.instruction_pointer
                ~time;
              check_current_symbol t thread_info ~time dst)
-        | Some Jump, None ->
+        | Some (Jump | Interrupt), None ->
           Ocaml_hacks.check_current_symbol_track_entertraps t thread_info ~time dst
         (* (None, _) comes up when perf spews something magic-trace doesn't recognize.
        Instead of crashing, ignore it and keep going. *)