V3.13 custom

Makefile

@@ -1,7 +1,7 @@
 VERSION = 3
 PATCHLEVEL = 13
 SUBLEVEL = 0
-EXTRAVERSION =
+EXTRAVERSION = -networkmmapv0.8
 NAME = One Giant Leap for Frogkind
 
 # *DOCUMENTATION*

arch/x86/syscalls/syscall_32.tbl

@@ -357,3 +357,5 @@
 348	i386	process_vm_writev	sys_process_vm_writev		compat_sys_process_vm_writev
 349	i386	kcmp			sys_kcmp
 350	i386	finit_module		sys_finit_module
+351 i386	network_mmap	sys_network_mmap_pgoff
+352	i386	network_msync	sys_network_msync

arch/x86/syscalls/syscall_64.tbl

@@ -320,6 +320,8 @@
 311	64	process_vm_writev	sys_process_vm_writev
 312	common	kcmp			sys_kcmp
 313	common	finit_module		sys_finit_module
+314 common	network_mmap	sys_network_mmap_pgoff
+315	common	network_msync	sys_network_msync
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact

include/linux/mm.h

@@ -2011,5 +2011,11 @@ void __init setup_nr_node_ids(void);
 static inline void setup_nr_node_ids(void) {}
 #endif
 
+typedef int (*network_mmap_fault_handler)(struct vm_area_struct *vma, struct vm_fault *vmf);
+extern void set_kmod_network_mmap_fault_handler(network_mmap_fault_handler func);
+
+typedef int (*network_msync)(unsigned long start, size_t len, int flags);
+extern void set_kmod_network_msync(network_msync func);
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_MM_H */

include/linux/syscalls.h

@@ -847,4 +847,10 @@ asmlinkage long sys_process_vm_writev(pid_t pid,
 asmlinkage long sys_kcmp(pid_t pid1, pid_t pid2, int type,
 			 unsigned long idx1, unsigned long idx2);
 asmlinkage long sys_finit_module(int fd, const char __user *uargs, int flags);
+
+asmlinkage long sys_network_mmap_pgoff(unsigned long addr, unsigned long len,
+			unsigned long prot, unsigned long flags,
+			unsigned long fd, unsigned long pgoff);
+
+asmlinkage long sys_network_msync(unsigned long start, size_t len, int flags);
 #endif

mm/mmap.c

@@ -1400,6 +1400,65 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
 	return retval;
 }
 
+network_mmap_fault_handler network_mmap_fault_handler_ptr = NULL;
+
+static int default_network_mmap_fault_handler(struct vm_area_struct *vma, struct vm_fault *vmf) {
+	int retval = VM_FAULT_SIGBUS;
+	printk(KERN_INFO "1. Calling default_network_mmap_fault_handler: %016llX\n", (uint64_t)network_mmap_fault_handler_ptr);
+	if (network_mmap_fault_handler_ptr) {
+		printk(KERN_INFO "2. Calling network_mmap_fault_handler_ptr\n");
+		retval = network_mmap_fault_handler_ptr(vma, vmf);
+		printk(KERN_INFO "3. Done calling network_mmap_fault_handler_ptr: %d\n", retval);
+	}
+	printk(KERN_INFO "4. default_network_mmap_fault_handler: %d\n", retval);
+
+	return retval;
+}
+
+static const struct vm_operations_struct network_mmap_vm_ops = {
+	.fault = default_network_mmap_fault_handler,
+};
+
+SYSCALL_DEFINE6(network_mmap_pgoff, unsigned long, addr, unsigned long, len,
+		unsigned long, prot, unsigned long, flags,
+		unsigned long, fd, unsigned long, pgoff)
+{
+	unsigned long retval;
+	struct vm_area_struct *vma;
+	struct mm_struct *mm = current->mm;
+
+	printk(KERN_INFO "network_mmap_pgoff: 1. Entering network_mmap_pgoff\n");
+
+	printk(KERN_INFO "network_mmap_pgoff: 2. Calling sys_mmap_pgoff\n");
+	retval = sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
+	printk(KERN_INFO "network_mmap_pgoff: 3. Completed sys_mmap_pgoff: %lu\n", retval);
+
+	// Was there an error? Just return the error code
+	if ((signed long)retval < 0 && (signed long)retval >= -133) {
+		return retval;
+	}
+
+	printk(KERN_INFO "network_mmap_pgoff: 4. Getting vma\n");
+	// Override the fault handler with our own!
+	vma = find_vma(mm, retval); // retval contains our address at the start of our mmaped region
+	if (!vma) {
+		retval = -ENOMEM;
+	}
+	printk(KERN_INFO "network_mmap_pgoff: 5. Completed getting vma: %016llX\n", (uint64_t)vma);
+	printk(KERN_INFO "network_mmap_pgoff: 6. Overriding fault handler to: %016llX\n", (uint64_t)&network_mmap_vm_ops);
+	vma->vm_ops = &network_mmap_vm_ops;
+	printk(KERN_INFO "network_mmap_pgoff: 7. Completed overriding fault handler\n");
+
+	return retval;
+}
+
+void set_kmod_network_mmap_fault_handler(network_mmap_fault_handler func) {
+	printk(KERN_INFO "set_kmod_network_mmap_fault_handler: 1. Entering set_kmod_network_mmap_fault_handler: %016llX\n", (uint64_t)func);
+	network_mmap_fault_handler_ptr = func;
+	printk(KERN_INFO "set_kmod_network_mmap_fault_handler: 2. Completed setting set_kmod_network_mmap_fault_handler: %016llX\n", (uint64_t)network_mmap_fault_handler_ptr);
+}
+EXPORT_SYMBOL(set_kmod_network_mmap_fault_handler);
+
 #ifdef __ARCH_WANT_SYS_OLD_MMAP
 struct mmap_arg_struct {
 	unsigned long addr;

mm/msync.c

@@ -101,3 +101,26 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
 out:
 	return error ? : unmapped_error;
 }
+
+network_msync network_msync_ptr = NULL;
+
+SYSCALL_DEFINE3(network_msync, unsigned long, start, size_t, len, int, flags)
+{
+	int retval = -EINVAL;
+	printk(KERN_INFO "1. Calling default_network_msync: %016llX\n", (uint64_t)network_msync_ptr);
+	if (network_msync_ptr) {
+		printk(KERN_INFO "2. Calling network_msync_ptr\n");
+		retval = network_msync_ptr(start, len, flags);
+		printk(KERN_INFO "3. Done calling network_msync_ptr: %d\n", retval);
+	}
+	printk(KERN_INFO "4. default_network_msync: %d\n", retval);
+
+	return retval;
+}
+
+void set_kmod_network_msync(network_msync func) {
+	printk(KERN_INFO "set_kmod_network_msync: 1. Entering set_kmod_network_msync: %016llX\n", (uint64_t)func);
+	network_msync_ptr = func;
+	printk(KERN_INFO "set_kmod_network_msync: 2. Completed setting set_kmod_network_msync: %016llX\n", (uint64_t)network_msync_ptr);
+}
+EXPORT_SYMBOL(set_kmod_network_msync);