@@ -27,7 +27,7 @@
struct mmap_interface
{
void *addr;
- int len;
+ size_t len;
};
#ifndef Data_abstract_val
@@ -37,4 +37,6 @@ struct mmap_interface
#define Intf_val(a) ((struct mmap_interface *) Data_abstract_val(a))
#define Intf_data_val(a) (Intf_val(a)->addr)
+value stub_mmap_alloc(void *addr, size_t len);
+
#endif
@@ -27,16 +27,18 @@
#include <caml/custom.h>
#include <caml/fail.h>
#include <caml/callback.h>
+#include <caml/unixsupport.h>
#define Wsize_bsize_round(n) (Wsize_bsize( (n) + sizeof(value) - 1 ))
-static int mmap_interface_init(struct mmap_interface *intf,
- int fd, int pflag, int mflag,
- int len, int offset)
+value stub_mmap_alloc(void *addr, size_t len)
{
- intf->len = len;
- intf->addr = mmap(NULL, len, pflag, mflag, fd, offset);
- return (intf->addr == MAP_FAILED) ? errno : 0;
+ CAMLparam0();
+ CAMLlocal1(result);
+ result = caml_alloc(Wsize_bsize_round(sizeof(struct mmap_interface)), Abstract_tag);
+ Intf_val(result)->addr = addr;
+ Intf_val(result)->len = len;
+ CAMLreturn(result);
}
CAMLprim value stub_mmap_init(value fd, value pflag, value mflag,
@@ -45,6 +47,8 @@ CAMLprim value stub_mmap_init(value fd, value pflag, value mflag,
CAMLparam5(fd, pflag, mflag, len, offset);
CAMLlocal1(result);
int c_pflag, c_mflag;
+ void* addr;
+ size_t length;
switch (Int_val(pflag)) {
case 0: c_pflag = PROT_READ; break;
@@ -59,12 +63,17 @@ CAMLprim value stub_mmap_init(value fd, value pflag, value mflag,
default: caml_invalid_argument("maptype");
}
- result = caml_alloc(Wsize_bsize_round(sizeof(struct mmap_interface)), Abstract_tag);
+ if (Int_val(len) < 0)
+ caml_invalid_argument("negative size");
+ if (Int_val(offset) < 0)
+ caml_invalid_argument("negative offset");
+ length = Int_val(len);
- if (mmap_interface_init(Intf_val(result), Int_val(fd),
- c_pflag, c_mflag,
- Int_val(len), Int_val(offset)))
- caml_failwith("mmap");
+ addr = mmap(NULL, length, c_pflag, c_mflag, fd, Int_val(offset));
+ if (MAP_FAILED == addr)
+ uerror("mmap", Nothing);
+
+ result = stub_mmap_alloc(addr, length);
CAMLreturn(result);
}
This also handles mmap errors better by using the `uerror` helper to raise a proper exception using `errno`. Changed type of `len` from `int` to `size_t`: at construction time we ensure the length is >= 0, so we can reflect this by using an unsigned type. The type is unsigned at the C API level, and a negative integer would just get translated to a very large unsigned number otherwise. mmap also takes off_t and size_t, so using int64 would be more generic here, however we only ever use this interface to map rings, so keeping the `int` sizes is fine. OCaml itself only uses `ints` for mapping bigarrays, and int64 for just the offset. Signed-off-by: Edwin Török <edvin.torok@citrix.com> --- tools/ocaml/libs/mmap/mmap_stubs.h | 4 +++- tools/ocaml/libs/mmap/xenmmap_stubs.c | 31 +++++++++++++++++---------- 2 files changed, 23 insertions(+), 12 deletions(-)