From b7b7a48c66b56850b3ee8b5493f9964ef96859d2 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Thu, 11 Mar 2021 13:28:50 +0100
Subject: [PATCH] Kernel: Move process signal trampoline address into protected
 data

---
 Kernel/Process.h           | 2 +-
 Kernel/Syscalls/execve.cpp | 3 ++-
 Kernel/Syscalls/fork.cpp   | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/Kernel/Process.h b/Kernel/Process.h
index 6ff695547b7..0b6be73611a 100644
--- a/Kernel/Process.h
+++ b/Kernel/Process.h
@@ -118,6 +118,7 @@ protected:
     bool m_has_execpromises { false };
     u32 m_execpromises { 0 };
     mode_t m_umask { 022 };
+    VirtualAddress m_signal_trampoline;
 };
 
 class ProcessBase : public ProtectedProcessBase {
@@ -544,7 +545,6 @@ private:
     String m_name;
 
     OwnPtr<Space> m_space;
-    VirtualAddress m_signal_trampoline;
 
     RefPtr<ProcessGroup> m_pg;
 
diff --git a/Kernel/Syscalls/execve.cpp b/Kernel/Syscalls/execve.cpp
index 803f610746e..63fb04c5e67 100644
--- a/Kernel/Syscalls/execve.cpp
+++ b/Kernel/Syscalls/execve.cpp
@@ -530,7 +530,6 @@ KResult Process::do_exec(NonnullRefPtr<FileDescription> main_program_description
     }
 
     signal_trampoline_region.value()->set_syscall_region(true);
-    m_signal_trampoline = signal_trampoline_region.value()->vaddr();
 
     m_executable = main_program_description->custody();
     m_arguments = arguments;
@@ -605,6 +604,8 @@ KResult Process::do_exec(NonnullRefPtr<FileDescription> main_program_description
         m_execpromises = 0;
         m_has_execpromises = false;
 
+        m_signal_trampoline = signal_trampoline_region.value()->vaddr();
+
         // FIXME: PID/TID ISSUE
         m_pid = new_main_thread->tid().value();
     }
diff --git a/Kernel/Syscalls/fork.cpp b/Kernel/Syscalls/fork.cpp
index 4016206d182..102345800b3 100644
--- a/Kernel/Syscalls/fork.cpp
+++ b/Kernel/Syscalls/fork.cpp
@@ -44,7 +44,6 @@ KResultOr<pid_t> Process::sys$fork(RegisterState& regs)
     child->m_veil_state = m_veil_state;
     child->m_unveiled_paths = m_unveiled_paths.deep_copy();
     child->m_fds = m_fds;
-    child->m_signal_trampoline = m_signal_trampoline;
     child->m_pg = m_pg;
 
     {
@@ -56,6 +55,7 @@ KResultOr<pid_t> Process::sys$fork(RegisterState& regs)
         child->m_sid = m_sid;
         child->m_extra_gids = m_extra_gids;
         child->m_umask = m_umask;
+        child->m_signal_trampoline = m_signal_trampoline;
     }
 
     dbgln_if(FORK_DEBUG, "fork: child={}", child);