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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /js/src/gdb/mozilla/asmjs.py | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/src/gdb/mozilla/asmjs.py')
-rw-r--r-- | js/src/gdb/mozilla/asmjs.py | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/js/src/gdb/mozilla/asmjs.py b/js/src/gdb/mozilla/asmjs.py new file mode 100644 index 0000000000..85a19a5cfc --- /dev/null +++ b/js/src/gdb/mozilla/asmjs.py @@ -0,0 +1,51 @@ +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this file, +# You can obtain one at http://mozilla.org/MPL/2.0/. + +""" +In asm code, out-of-bounds heap accesses cause segfaults, which the engine +handles internally. Make GDB ignore them. +""" + +import gdb + +SIGSEGV = 11 + +# A sigaction buffer for each inferior process. +sigaction_buffers = {} + + +def on_stop(event): + if isinstance(event, gdb.SignalEvent) and event.stop_signal == "SIGSEGV": + # Allocate memory for sigaction, once per js shell process. + process = gdb.selected_inferior() + buf = sigaction_buffers.get(process) + if buf is None: + buf = gdb.parse_and_eval( + "(struct sigaction *) malloc(sizeof(struct sigaction))" + ) + sigaction_buffers[process] = buf + + # See if WasmFaultHandler is installed as the SIGSEGV signal action. + sigaction_fn = gdb.parse_and_eval( + "(void(*)(int,void*,void*))__sigaction" + ).dereference() + sigaction_fn(SIGSEGV, 0, buf) + WasmTrapHandler = gdb.parse_and_eval("WasmTrapHandler") + if buf["__sigaction_handler"]["sa_handler"] == WasmTrapHandler: + # Advise the user that magic is happening. + print("js/src/gdb/mozilla/asmjs.py: Allowing WasmTrapHandler to run.") + + # If WasmTrapHandler doesn't handle this segfault, it will unhook + # itself and re-raise. + gdb.execute("continue") + + +def on_exited(event): + if event.inferior in sigaction_buffers: + del sigaction_buffers[event.inferior] + + +def install(): + gdb.events.stop.connect(on_stop) + gdb.events.exited.connect(on_exited) |