switch to using user_ptr for pointers coming from userland

this avoid accidental dereferences, and now it's easy to tell apart
which pointers are safe to directly read and which aren't.

cons:
- const is completely discarded

1 files changed, 8 insertions, 6 deletions

diff --git a/src/shared/syscalls.h b/src/shared/syscalls.h
index 9eb3fa5..d0c6640 100644
--- a/src/shared/syscalls.h
+++ b/src/shared/syscalls.h
@@ -1,3 +1,5 @@
+// requires the user_ptr type from kernel/types.h or init/types.h
+
 #pragma once
 #include <stddef.h>
 
@@ -21,12 +23,12 @@ enum {
 /** Kills the current process.
  * TODO: what happens to the children?
  */
-_Noreturn void _syscall_exit(const char *msg, size_t len);
+_Noreturn void _syscall_exit(const user_ptr msg, size_t len);
 
 /** Waits for a child to exit, putting its exit message into *buf.
  * @return the length of the message
  */
-int _syscall_await(char *buf, int len);
+int _syscall_await(user_ptr buf, int len);
 
 /** Creates a copy of the current process, and executes it.
  * All user memory pages get copied too.
@@ -34,9 +36,9 @@ int _syscall_await(char *buf, int len);
  */
 int _syscall_fork(void);
 
-fd_t _syscall_fs_open(const char *path, int len);
-int _syscall_mount(const char *path, int len, fd_t fd);
+fd_t _syscall_fs_open(const user_ptr path, int len);
+int _syscall_mount(const user_ptr path, int len, fd_t fd);
 
-int _syscall_fd_read(fd_t fd, char *buf, int len);
-int _syscall_fd_write(fd_t fd, char *buf, int len);
+int _syscall_fd_read(fd_t fd, user_ptr buf, int len);
+int _syscall_fd_write(fd_t fd, user_ptr buf, int len);
 int _syscall_fd_close(fd_t fd);