From d10de37498f5b09f98fef135da4927456f9e11e3 Mon Sep 17 00:00:00 2001
From: Matheus <matheusuky@gmail.com>
Date: Sat, 20 Apr 2024 15:46:17 -0300
Subject: [PATCH] mouse: fix deadlock

---
 kernel-src/include/kernel/abi.h   |  1 +
 kernel-src/include/kernel/mouse.h |  2 ++
 kernel-src/include/kernel/sock.h  |  1 +
 kernel-src/include/kernel/vfs.h   |  4 ++--
 kernel-src/io/mouse.c             | 27 +++++++++++++++++++--------
 5 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/kernel-src/include/kernel/abi.h b/kernel-src/include/kernel/abi.h
index cf18e0f6..d877e6ea 100644
--- a/kernel-src/include/kernel/abi.h
+++ b/kernel-src/include/kernel/abi.h
@@ -137,6 +137,7 @@ typedef struct {
 #define SIOCGIFHWADDR 0x8927
 #define SIOCADDRT 0x890b
 #define SIOCSIFADDR	0x8916
+#define FIONREAD 0x541B
 
 typedef struct {
 	char name[IFNAMSIZ];
diff --git a/kernel-src/include/kernel/mouse.h b/kernel-src/include/kernel/mouse.h
index 834abaa0..3a4bbcb6 100644
--- a/kernel-src/include/kernel/mouse.h
+++ b/kernel-src/include/kernel/mouse.h
@@ -3,6 +3,7 @@
 
 #include <ringbuffer.h>
 #include <kernel/poll.h>
+#include <mutex.h>
 
 #define MOUSE_FLAG_RB 1
 #define MOUSE_FLAG_MB 2
@@ -20,6 +21,7 @@ typedef struct {
 	spinlock_t lock;
 	pollheader_t pollheader;
 	int flags;
+	mutex_t readmutex;
 } mouse_t;
 
 void mouse_init();
diff --git a/kernel-src/include/kernel/sock.h b/kernel-src/include/kernel/sock.h
index a93bf458..a1cb4880 100644
--- a/kernel-src/include/kernel/sock.h
+++ b/kernel-src/include/kernel/sock.h
@@ -36,6 +36,7 @@ typedef struct socketops_t {
 	int (*connect)(socket_t *socket, sockaddr_t *addr, uintmax_t data);
 	int (*listen)(socket_t *socket, int backlog);
 	int (*accept)(socket_t *server, socket_t *client, sockaddr_t *addr, uintmax_t flags);
+	size_t (*datacount)(socket_t *socket);
 	void (*destroy)(socket_t *socket);
 } socketops_t;
 
diff --git a/kernel-src/include/kernel/vfs.h b/kernel-src/include/kernel/vfs.h
index fab974ad..b3fee378 100644
--- a/kernel-src/include/kernel/vfs.h
+++ b/kernel-src/include/kernel/vfs.h
@@ -172,8 +172,8 @@ int vfs_unlink(vnode_t *ref, char *path);
 int vfs_pollstub(vnode_t *node, struct polldata *, int events);
 void vfs_inactive(vnode_t *node);
 
-#define VFS_LOOKUP_PARENT 1
-#define VFS_LOOKUP_NOLINK 2
+#define VFS_LOOKUP_PARENT 0x20000000
+#define VFS_LOOKUP_NOLINK 0x40000000
 #define VFS_LOOKUP_INTERNAL 0x80000000
 int vfs_lookup(vnode_t **result, vnode_t *start, char *path, char *lastcomp, int flags);
 
diff --git a/kernel-src/io/mouse.c b/kernel-src/io/mouse.c
index ed5b0d1d..d846daa5 100644
--- a/kernel-src/io/mouse.c
+++ b/kernel-src/io/mouse.c
@@ -23,6 +23,7 @@ static mouse_t *newmouse() {
 
 	POLL_INITHEADER(&mouse->pollheader);
 	SPINLOCK_INIT(mouse->lock);
+	MUTEX_INIT(&mouse->readmutex);
 
 	return mouse;
 }
@@ -77,11 +78,7 @@ static int read(int minor, void *buffer, size_t size, uintmax_t offset, int flag
 	if (packetcount == 0)
 		return error;
 
-	// disable interrupts here as to not lose any interrupts
-	// and because we cannot sleep with a raised ipl
-	bool oldintstatus = interrupt_set(false);
-	spinlock_acquire(&mouse->lock);
-
+	MUTEX_ACQUIRE(&mouse->readmutex, false);
 	// wait until there is data to read or return if nonblock
 	for (;;) {
 		polldesc_t desc = {0};
@@ -89,22 +86,33 @@ static int read(int minor, void *buffer, size_t size, uintmax_t offset, int flag
 		if (error)
 			goto leave;
 
+		// disable interrupts here as to not lose any interrupts
+		// and because we cannot sleep with a raised ipl
+		bool oldintstatus = interrupt_set(false);
+		spinlock_acquire(&mouse->lock);
+
 		int revents = internalpoll(mouse, &desc.data[0], POLLIN);
 
 		if (revents) {
+			spinlock_release(&mouse->lock);
+			interrupt_set(oldintstatus);
 			poll_leave(&desc);
 			poll_destroydesc(&desc);
 			break;
 		}
 
 		if (revents == 0 && flags & V_FFLAGS_NONBLOCKING) {
+			spinlock_release(&mouse->lock);
+			interrupt_set(oldintstatus);
+			poll_leave(&desc);
+			poll_destroydesc(&desc);
 			error = EAGAIN;
 			goto leave;
 		}
 
 		spinlock_release(&mouse->lock);
 		error = poll_dowait(&desc, 0);
-		spinlock_acquire(&mouse->lock);
+		interrupt_set(oldintstatus);
 
 		poll_leave(&desc);
 		poll_destroydesc(&desc);
@@ -117,8 +125,7 @@ static int read(int minor, void *buffer, size_t size, uintmax_t offset, int flag
 	__assert(*readc);
 
 	leave:
-	spinlock_release(&mouse->lock);
-	interrupt_set(oldintstatus);
+	MUTEX_RELEASE(&mouse->readmutex);
 
 	return error;
 }
@@ -128,12 +135,16 @@ static int poll(int minor, polldata_t *data, int events) {
 	if (mouse == NULL)
 		return POLLERR;
 
+	MUTEX_ACQUIRE(&mouse->readmutex, false);
+
 	long ipl = interrupt_raiseipl(IPL_MOUSE);
 	spinlock_acquire(&mouse->lock);
 	int revents = internalpoll(mouse, data, events);
 	spinlock_release(&mouse->lock);
 	interrupt_loweripl(ipl);
 
+	MUTEX_RELEASE(&mouse->readmutex);
+
 	return revents;
 }