Sinipelto/banan-os
1
0
Fork 0
forked from Bananymous/banan-os
Code Pull Requests Activity

Kernel: Fix most of mutex + block race conditions

Browse Source 
All block functions now take an optional mutex parameter that is
atomically unlocked instead of having the user unlock it before hand.
This prevents a ton of race conditions everywhere in the code!
This commit is contained in:
Bananymous
2025-06-06 03:59:22 +03:00
parent 96d5ed9cc7
commit eecdad50a6
36 changed files with 374 additions and 322 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
kernel/kernel/Epoll.cpp
View File

@@ -1,5 +1,6 @@
#include <kernel/Epoll.h>
#include <kernel/Lock/LockGuard.h>
#include <kernel/Lock/SpinLockAsMutex.h>
#include <kernel/Timer/Timer.h>
namespace Kernel
@@ -45,10 +46,12 @@ namespace Kernel
TRY(inode->add_epoll(this));
it->value.add_fd(fd, event);
auto processing_it = m_processing_events.find(inode);
if (processing_it == m_processing_events.end())
processing_it = MUST(m_processing_events.insert(inode, 0));
processing_it->value |= event.events;
SpinLockGuard _(m_ready_lock);
auto ready_it = m_ready_events.find(inode);
if (ready_it == m_ready_events.end())
ready_it = MUST(m_ready_events.insert(inode, 0));
ready_it->value |= event.events;
m_thread_blocker.unblock();
return {};
}
@@ -61,10 +64,12 @@ namespace Kernel
it->value.events[fd] = event;
auto processing_it = m_processing_events.find(inode);
if (processing_it == m_processing_events.end())
processing_it = MUST(m_processing_events.insert(inode, 0));
processing_it->value |= event.events;
SpinLockGuard _(m_ready_lock);
auto ready_it = m_ready_events.find(inode);
if (ready_it == m_ready_events.end())
ready_it = MUST(m_ready_events.insert(inode, 0));
ready_it->value |= event.events;
m_thread_blocker.unblock();
return {};
}
@@ -196,8 +201,14 @@ namespace Kernel
const uint64_t current_ns = SystemTimer::get().ns_since_boot();
if (current_ns >= waketime_ns)
break;
SpinLockGuard guard(m_ready_lock);
if (!m_ready_events.empty())
continue;
SpinLockGuardAsMutex smutex(guard);
const uint64_t timeout_ns = BAN::Math::min<uint64_t>(100'000'000, waketime_ns - current_ns);
TRY(Thread::current().block_or_eintr_or_timeout_ns(m_thread_blocker, timeout_ns, false));
TRY(Thread::current().block_or_eintr_or_timeout_ns(m_thread_blocker, timeout_ns, false, &smutex));
}
return event_count;