From 0e03c7a811ef477eae4465ffb3ff443e1b6e1e87 Mon Sep 17 00:00:00 2001
From: Christian Fillion <contact@cfillion.ca>
Date: Wed, 16 Oct 2024 02:12:06 -0400
Subject: [PATCH 1/2] fix a segfault on signals received after main returns

The waybar process does not exit instantaneously.
Signals may be recevied after main has started freeing resources.

When a worker thread is in `fgets` this time window can last forever.
An easy way to duplicate the crash is pressing ^C twice with a Hyprland module.

    Thread 1 "waybar" received signal SIGSEGV, Segmentation fault.
    spdlog::sinks::sink::should_log (this=0x5f620b542ca5,
        msg_level=spdlog::level::info)
        at /usr/src/debug/spdlog/spdlog-1.14.1/include/spdlog/sinks/sink-inl.h:13
    13	  return msg_level >= level_.load(std::memory_order_relaxed);
    (gdb) p $_siginfo._sifields._sigfault.si_addr
    $1 = (void *) 0x5f620b542cad
---
 src/main.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/main.cpp b/src/main.cpp
index 679c66d6..442c530c 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -107,6 +107,10 @@ int main(int argc, char* argv[]) {
       ret = client->main(argc, argv);
     } while (reload);
 
+    std::signal(SIGUSR1, SIG_IGN);
+    std::signal(SIGUSR2, SIG_IGN);
+    std::signal(SIGINT,  SIG_IGN);
+
     delete client;
     return ret;
   } catch (const std::exception& e) {

From 92242f0b9d7f37f4ccf87f03b0c0ce30255d2d54 Mon Sep 17 00:00:00 2001
From: Christian Fillion <contact@cfillion.ca>
Date: Wed, 16 Oct 2024 09:56:05 -0400
Subject: [PATCH 2/2] hyprland: fix a data race at startup between sockets 1
 and 2

`Workspaces::*` and `IPC::startIPC` may both call `getSocketFolder` at the same time.

This randomly causes crashes and/or corruption of the socket path.

Typical crash A:

    [2024-10-16 07:42:09.987] [info] Hyprland IPC starting
    malloc(): unaligned tcache chunk detected
    [2024-10-16 07:42:09.987] [error] Hyprland IPC: Unable to connect?
    Thread 1 "waybar" received signal SIGABRT, Aborted.
    (gdb) bt
    #0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
    (omitted for brievety)
    #9  0x00007ffff64ae745 in operator new (sz=sz@entry=296) at /usr/src/debug/gcc/gcc/libstdc++-v3/libsupc++/new_op.cc:50
    #10 0x00007ffff65ab1f1 in std::filesystem::__cxx11::path::_List::_Impl::copy (this=0x555555a23350) at /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++17/fs_path.cc:249
    #11 0x00007ffff65ab3bd in std::filesystem::__cxx11::path::_List::_List (this=0x7fffffff9d30, other=<optimized out>) at /usr/src/debug/gcc/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/unique_ptr.h:454
    #12 0x00005555556f4ab1 in waybar::modules::hyprland::IPC::getSocket1Reply(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) ()
    #13 0x00005555556f5e3d in waybar::modules::hyprland::IPC::getSocket1JsonReply(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) ()
    #14 0x000055555571289c in waybar::modules::hyprland::Workspaces::setCurrentMonitorId() ()

Typical crash B:

    [2024-10-16 10:01:15.859] [info] Hyprland IPC starting
    [2024-10-16 10:01:15.859] [info] Loading persistent workspaces from Hyprland workspace rules
    Thread 8 "waybar" received signal SIGSEGV, Segmentation fault.
    (gdb) bt
    #0  std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_S_copy
        (__d=0x5555558fbca8 "/", __s=0x2973961a26d35726 <error: Cannot access memory at address 0x2973961a26d35726>, __n=1)
        at /usr/src/debug/gcc/gcc-build/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:433
    (omitted for brievety)
    #15 waybar::modules::hyprland::IPC::getSocketFolder[abi:cxx11](char const*)
        (instanceSig=0x7fffffffe604 "4520b30d498daca8079365bdb909a8dea38e8d55_1729051218_1982280648") at ../src/modules/hyprland/backend.cpp:41
    #16 0x000055555564230f in waybar::modules::hyprland::IPC::startIPC()::{lambda()#1}::operator()() const ()
        at ../src/modules/hyprland/backend.cpp:70
    #17 0x00007ffff64e1c34 in std::execute_native_thread_routine (__p=0x5555558119c0) at /usr/src/debug/gcc/gcc/libstdc++-v3/src/c++11/thread.cc:104
    #18 0x00007ffff62a339d in start_thread (arg=<optimized out>) at pthread_create.c:447
---
 src/modules/hyprland/backend.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/modules/hyprland/backend.cpp b/src/modules/hyprland/backend.cpp
index 77f534e0..39341a14 100644
--- a/src/modules/hyprland/backend.cpp
+++ b/src/modules/hyprland/backend.cpp
@@ -18,6 +18,9 @@ namespace waybar::modules::hyprland {
 std::filesystem::path IPC::socketFolder_;
 
 std::filesystem::path IPC::getSocketFolder(const char* instanceSig) {
+  static std::mutex folderMutex;
+  std::unique_lock lock(folderMutex);
+
   // socket path, specified by EventManager of Hyprland
   if (!socketFolder_.empty()) {
     return socketFolder_;