system/serenity
system/serenity
1
0
Fork 0
mirror of https://github.com/SerenityOS/serenity synced 2024-09-20 00:12:20 +00:00
Code Issues Packages Projects Releases Wiki Activity

Kernel: Allocate signal trampoline before committing to a sys$execve()

Browse source 
Once we commit to a new executable image in sys$execve(), we can no
longer return with an error to whoever called us from userspace.
We must make sure to surface any potential errors before that point.

This patch moves signal trampoline allocation before the commit.
A number of other things remain to be moved.
This commit is contained in:
Andreas Kling 2021-09-06 17:07:00 +02:00
parent 6863d015ec
commit 298cd57fe7
1 changed files with 4 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

12
Kernel/Syscalls/execve.cpp
View file

@ -482,7 +482,10 @@ KResult Process::do_exec(NonnullRefPtr<FileDescription> main_program_description
auto main_program_metadata = main_program_description->metadata();
auto load_result = TRY(load(main_program_description, interpreter_description, main_program_header));
auto signal_trampoline_range = TRY(load_result.space->try_allocate_range({}, PAGE_SIZE));
auto signal_trampoline_region = TRY(load_result.space->allocate_region_with_vmobject(signal_trampoline_range, g_signal_trampoline_region->vmobject(), 0, "Signal trampoline", PROT_READ | PROT_EXEC, true));
signal_trampoline_region->set_syscall_region(true);
// We commit to the new executable at this point. There is no turning back!
@ -523,13 +526,6 @@ KResult Process::do_exec(NonnullRefPtr<FileDescription> main_program_description
}
Memory::MemoryManager::enter_space(*m_space);
auto signal_trampoline_region = m_space->allocate_region_with_vmobject(signal_trampoline_range, g_signal_trampoline_region->vmobject(), 0, "Signal trampoline", PROT_READ | PROT_EXEC, true);
if (signal_trampoline_region.is_error()) {
VERIFY_NOT_REACHED();
}
signal_trampoline_region.value()->set_syscall_region(true);
m_executable = main_program_description->custody();
m_arguments = arguments;
m_environment = environment;
@ -612,7 +608,7 @@ KResult Process::do_exec(NonnullRefPtr<FileDescription> main_program_description
m_protected_values.execpromises = 0;
m_protected_values.has_execpromises = false;
m_protected_values.signal_trampoline = signal_trampoline_region.value()->vaddr();
m_protected_values.signal_trampoline = signal_trampoline_region->vaddr();
// FIXME: PID/TID ISSUE
m_protected_values.pid = new_main_thread->tid().value();