sys/openbsd: add missing padding arguments

Due to missing padding arguments, stack garbage could end up being used as
actual arguments. More reading for the curious[1].

While here, add missing descriptions for pread and pwrite.

[1] https://flak.tedunangst.com/post/syzkaller-found-a-bug

4 files changed, 31 insertions, 6 deletions

diff --git a/sys/openbsd/fs.txt b/sys/openbsd/fs.txt
index dd687dce4..18a6cf757 100644
--- a/sys/openbsd/fs.txt
+++ b/sys/openbsd/fs.txt
@@ -20,11 +20,13 @@ openat(fd fd_dir, file ptr[in, filename], flags flags[open_flags], mode flags[op
 close(fd fd)
 read(fd fd, buf buffer[out], count len[buf])
 readv(fd fd, vec ptr[in, array[iovec_out]], vlen len[vec])
-preadv(fd fd, vec ptr[in, array[iovec_out]], vlen len[vec], off fileoff)
+pread(fd fd, buf buffer[in], nbyte len[buf], pad const[0], off fileoff)
+preadv(fd fd, vec ptr[in, array[iovec_out]], vlen len[vec], pad const[0], off fileoff)
 write(fd fd, buf buffer[in], count len[buf])
 writev(fd fd, vec ptr[in, array[iovec_in]], vlen len[vec])
-pwritev(fd fd, vec ptr[in, array[iovec_in]], vlen len[vec], off fileoff)
-lseek(fd fd, offset fileoff, whence flags[seek_whence])
+pwrite(fd fd, buf buffer[in], nbyte len[buf], pad const[0], off fileoff)
+pwritev(fd fd, vec ptr[in, array[iovec_in]], vlen len[vec], pad const[0], off fileoff)
+lseek(fd fd, pad const[0], offset fileoff, whence flags[seek_whence])
 dup(oldfd fd) fd
 dup2(oldfd fd, newfd fd) fd
 pipe2(pipefd ptr[out, pipefd], flags flags[pipe_flags])
diff --git a/sys/openbsd/fs_amd64.const b/sys/openbsd/fs_amd64.const
index 5f39ed6f8..a18c647f0 100644
--- a/sys/openbsd/fs_amd64.const
+++ b/sys/openbsd/fs_amd64.const
@@ -28,7 +28,9 @@ SYS_lseek = 199
 SYS_open = 5
 SYS_openat = 321
 SYS_pipe2 = 101
+SYS_pread = 173
 SYS_preadv = 267
+SYS_pwrite = 174
 SYS_pwritev = 268
 SYS_read = 3
 SYS_readv = 120
diff --git a/sys/openbsd/gen/amd64.go b/sys/openbsd/gen/amd64.go
index fb9797c9a..2ddd4c293 100644
--- a/sys/openbsd/gen/amd64.go
+++ b/sys/openbsd/gen/amd64.go
@@ -916,6 +916,7 @@ var syscalls_amd64 = []*Syscall{
 	}},
 	{NR: 201, Name: "ftruncate", CallName: "ftruncate", Args: []Type{
 		&ResourceType{TypeCommon: TypeCommon{TypeName: "fd", FldName: "fd", TypeSize: 4}},
+		&ConstType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "const", FldName: "pad", TypeSize: 8}}},
 		&IntType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "intptr", FldName: "len", TypeSize: 8}}},
 	}},
 	{NR: 99, Name: "getdents", CallName: "getdents", Args: []Type{
@@ -1624,6 +1625,7 @@ var syscalls_amd64 = []*Syscall{
 	}},
 	{NR: 199, Name: "lseek", CallName: "lseek", Args: []Type{
 		&ResourceType{TypeCommon: TypeCommon{TypeName: "fd", FldName: "fd", TypeSize: 4}},
+		&ConstType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "const", FldName: "pad", TypeSize: 8}}},
 		&IntType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "fileoff", FldName: "offset", TypeSize: 8}}, Kind: 1},
 		&FlagsType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "seek_whence", FldName: "whence", TypeSize: 8}}, Vals: []uint64{0, 1, 2}, BitMask: true},
 	}},
@@ -1833,16 +1835,32 @@ var syscalls_amd64 = []*Syscall{
 		&LenType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "len", FldName: "nfds", TypeSize: 8}}, Buf: "fds"},
 		&IntType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "int32", FldName: "timeout", TypeSize: 4}}},
 	}},
+	{NR: 173, Name: "pread", CallName: "pread", Args: []Type{
+		&ResourceType{TypeCommon: TypeCommon{TypeName: "fd", FldName: "fd", TypeSize: 4}},
+		&PtrType{TypeCommon: TypeCommon{TypeName: "ptr", FldName: "buf", TypeSize: 8}, Type: &BufferType{TypeCommon: TypeCommon{TypeName: "array", IsVarlen: true}}},
+		&LenType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "len", FldName: "nbyte", TypeSize: 8}}, Buf: "buf"},
+		&ConstType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "const", FldName: "pad", TypeSize: 8}}},
+		&IntType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "fileoff", FldName: "off", TypeSize: 8}}, Kind: 1},
+	}},
 	{NR: 267, Name: "preadv", CallName: "preadv", Args: []Type{
 		&ResourceType{TypeCommon: TypeCommon{TypeName: "fd", FldName: "fd", TypeSize: 4}},
 		&PtrType{TypeCommon: TypeCommon{TypeName: "ptr", FldName: "vec", TypeSize: 8}, Type: &ArrayType{TypeCommon: TypeCommon{TypeName: "array", IsVarlen: true}, Type: &StructType{Key: StructKey{Name: "iovec_out"}}}},
 		&LenType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "len", FldName: "vlen", TypeSize: 8}}, Buf: "vec"},
+		&ConstType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "const", FldName: "pad", TypeSize: 8}}},
+		&IntType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "fileoff", FldName: "off", TypeSize: 8}}, Kind: 1},
+	}},
+	{NR: 174, Name: "pwrite", CallName: "pwrite", Args: []Type{
+		&ResourceType{TypeCommon: TypeCommon{TypeName: "fd", FldName: "fd", TypeSize: 4}},
+		&PtrType{TypeCommon: TypeCommon{TypeName: "ptr", FldName: "buf", TypeSize: 8}, Type: &BufferType{TypeCommon: TypeCommon{TypeName: "array", IsVarlen: true}}},
+		&LenType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "len", FldName: "nbyte", TypeSize: 8}}, Buf: "buf"},
+		&ConstType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "const", FldName: "pad", TypeSize: 8}}},
 		&IntType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "fileoff", FldName: "off", TypeSize: 8}}, Kind: 1},
 	}},
 	{NR: 268, Name: "pwritev", CallName: "pwritev", Args: []Type{
 		&ResourceType{TypeCommon: TypeCommon{TypeName: "fd", FldName: "fd", TypeSize: 4}},
 		&PtrType{TypeCommon: TypeCommon{TypeName: "ptr", FldName: "vec", TypeSize: 8}, Type: &ArrayType{TypeCommon: TypeCommon{TypeName: "array", IsVarlen: true}, Type: &StructType{Key: StructKey{Name: "iovec_in"}}}},
 		&LenType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "len", FldName: "vlen", TypeSize: 8}}, Buf: "vec"},
+		&ConstType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "const", FldName: "pad", TypeSize: 8}}},
 		&IntType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "fileoff", FldName: "off", TypeSize: 8}}, Kind: 1},
 	}},
 	{NR: 3, Name: "read", CallName: "read", Args: []Type{
@@ -2251,6 +2269,7 @@ var syscalls_amd64 = []*Syscall{
 	{Name: "syz_open_pts", CallName: "syz_open_pts", Ret: &ResourceType{TypeCommon: TypeCommon{TypeName: "fd_tty", FldName: "ret", TypeSize: 4, ArgDir: 1}}},
 	{NR: 200, Name: "truncate", CallName: "truncate", Args: []Type{
 		&PtrType{TypeCommon: TypeCommon{TypeName: "ptr", FldName: "file", TypeSize: 8}, Type: &BufferType{TypeCommon: TypeCommon{TypeName: "filename", IsVarlen: true}, Kind: 3}},
+		&ConstType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "const", FldName: "pad", TypeSize: 8}}},
 		&IntType{IntTypeCommon: IntTypeCommon{TypeCommon: TypeCommon{TypeName: "intptr", FldName: "len", TypeSize: 8}}},
 	}},
 	{NR: 10, Name: "unlink", CallName: "unlink", Args: []Type{
@@ -2626,7 +2645,9 @@ var consts_amd64 = []ConstValue{
 	{Name: "SYS_pipe2", Value: 101},
 	{Name: "SYS_pledge", Value: 108},
 	{Name: "SYS_poll", Value: 252},
+	{Name: "SYS_pread", Value: 173},
 	{Name: "SYS_preadv", Value: 267},
+	{Name: "SYS_pwrite", Value: 174},
 	{Name: "SYS_pwritev", Value: 268},
 	{Name: "SYS_read", Value: 3},
 	{Name: "SYS_readlink", Value: 58},
@@ -2853,4 +2874,4 @@ var consts_amd64 = []ConstValue{
 	{Name: "__MAP_NOREPLACE", Value: 2048},
 }
 
-const revision_amd64 = "216c98ad3498631ce9d36fbfa6fa8f98d1f2c5cb"
+const revision_amd64 = "1b6671ad8d712ebbd04cdedcec2c7d0d224996b9"
diff --git a/sys/openbsd/sys.txt b/sys/openbsd/sys.txt
index b23b88429..d95198130 100644
--- a/sys/openbsd/sys.txt
+++ b/sys/openbsd/sys.txt
@@ -92,8 +92,8 @@ renameat(oldfd fd_dir, old ptr[in, filename], newfd fd_dir, new ptr[in, filename
 mkdir(path ptr[in, filename], mode flags[open_mode])
 mkdirat(fd fd_dir, path ptr[in, filename], mode flags[open_mode])
 rmdir(path ptr[in, filename])
-truncate(file ptr[in, filename], len intptr)
-ftruncate(fd fd, len intptr)
+truncate(file ptr[in, filename], pad const[0], len intptr)
+ftruncate(fd fd, pad const[0], len intptr)
 flock(fd fd, op flags[flock_op])
 fsync(fd fd)
 # fdatasync(fd fd)