Kernel+LibC: Add stubs for POSIX shared memory API.

Specifically shm_open() and shm_unlink(). This patch just adds stubs.

Kernel/Process.cpp

@@ -2454,3 +2454,17 @@ int Process::sys$rename(const char* oldpath, const char* newpath)
         return -EFAULT;
     return VFS::the().rename(String(oldpath), String(newpath), cwd_inode());
 }
+
+int Process::sys$shm_open(const char* name, int flags, mode_t mode)
+{
+    if (!validate_read_str(name))
+        return -EFAULT;
+    return -ENOTIMPL;
+}
+
+int Process::sys$shm_unlink(const char* name)
+{
+    if (!validate_read_str(name))
+        return -EFAULT;
+    return -ENOTIMPL;
+}

Kernel/Process.h

@@ -99,6 +99,8 @@ public:
 
     int sys$gettid();
     int sys$donate(int tid);
+    int sys$shm_open(const char* name, int flags, mode_t);
+    int sys$shm_unlink(const char* name);
     pid_t sys$setsid();
     pid_t sys$getsid(pid_t);
     int sys$setpgid(pid_t pid, pid_t pgid);

Kernel/Syscall.cpp

@@ -243,6 +243,10 @@ static dword handle(RegisterDump& regs, dword function, dword arg1, dword arg2,
         return current->process().sys$create_thread((int(*)(void*))arg1, (void*)arg2);
     case Syscall::SC_rename:
         return current->process().sys$rename((const char*)arg1, (const char*)arg2);
+    case Syscall::SC_shm_open:
+        return current->process().sys$shm_open((const char*)arg1, (int)arg2, (mode_t)arg3);
+    case Syscall::SC_shm_close:
+        return current->process().sys$shm_unlink((const char*)arg1);
     default:
         kprintf("<%u> int0x82: Unknown function %u requested {%x, %x, %x}\n", current->process().pid(), function, arg1, arg2, arg3);
         break;

Kernel/Syscall.h

@@ -96,6 +96,8 @@
     __ENUMERATE_SYSCALL(gettid) \
     __ENUMERATE_SYSCALL(donate) \
     __ENUMERATE_SYSCALL(rename) \
+    __ENUMERATE_SYSCALL(shm_open) \
+    __ENUMERATE_SYSCALL(shm_close) \
 
 
 namespace Syscall {

LibC/mman.cpp

@@ -28,4 +28,16 @@ int set_mmap_name(void* addr, size_t size, const char* name)
     __RETURN_WITH_ERRNO(rc, rc, -1);
 }
 
+int shm_open(const char* name, int flags, mode_t mode)
+{
+    int rc = syscall(SC_shm_open, name, flags, mode);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
+
+int shm_unlink(const char* name)
+{
+    int rc = syscall(SC_unlink, name);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
+
 }

LibC/mman.h

@@ -21,6 +21,8 @@ __BEGIN_DECLS
 void* mmap(void* addr, size_t, int prot, int flags, int fd, off_t);
 int munmap(void*, size_t);
 int set_mmap_name(void*, size_t, const char*);
+int shm_open(const char* name, int flags, mode_t);
+int shm_unlink(const char* name);
 
 __END_DECLS