Bug 238596

Created attachment 456214 [details] Patch

Comment on attachment 456214 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=456214&action=review > Source/WebKit/Platform/IPC/unix/IPCSemaphoreUnix.cpp:40 > + m_fd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK | EFD_SEMAPHORE); TIL eventfd() can be used as a semaphore, and the functionality is actually there since Linux 2.6.30 🤯️, and also supported since NetBSD 10. This might be an issue at some point for other BSDs which provide WebKitGTK packages in their ports collections; but I say let's not worry about that for now--surely their developers will find a way, and/or we can help them out a bit when the time comes. > Source/WebKit/Platform/IPC/unix/IPCSemaphoreUnix.cpp:73 > + return; IIUC, reaching this with an invalid file descriptor means that the caller is trying to use a destroyed semaphore, or an old one which was deinitialized after moving it into a new instance. I think we should assert inside OS(LINUX) that the file descriptor is valid: void Semaphore::signal() { #if OS(LINUX) RELEASE_ASSERT_WITH_MESSAGE(m_fd >= 0, "signalled destroyed semaphore"); // ... rest of the code #endif } (or maybe ASSERT_WITH_MESSAGE, and skip the check in release builds) > Source/WebKit/Platform/IPC/unix/IPCSemaphoreUnix.cpp:116 > + return false; Same comment as above regarding this check. > Source/WebKit/Platform/IPC/unix/IPCSemaphoreUnix.cpp:128 > + return false; ...and here, too.

Created attachment 456346 [details] Patch With asserts for valid semaphores.

Committed r292225 (249128@main): <https://commits.webkit.org/249128@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 456346 [details].

<rdar://problem/91170895>