From 59b087e3954402c487e0abb4ad9bd05f43669436 Mon Sep 17 00:00:00 2001 From: Julien Grall Date: Mon, 30 Mar 2020 15:14:23 +0100 Subject: [PATCH] tools/ocaml: Fix stubs build when OCaml has been compiled with -safe-string The OCaml code has been fixed to handle properly -safe-string in Xen 4.11, however the stubs part were missed. On OCaml newer than 4.06.1, String_Val() will return a const char * when using -safe-string leading to build failure when this is used in place where char * is expected. The main use in Xen code base is when a new string is allocated. The suggested approach by the OCaml community [1] is to use the helper caml_alloc_initialized_string() but it was introduced by OCaml 4.06.1. The next best approach is to cast String_val() to (char *) as the helper would have done. So use it when we need to update the new string using memcpy(). Take the opportunity to remove the unnecessary cast of the source as mempcy() is expecting a void *. [1] https://github.com/ocaml/ocaml/pull/1274 Reported-by: Dario Faggioli Signed-off-by: Julien Grall Acked-by: Christian Lindig --- tools/ocaml/libs/xb/xenbus_stubs.c | 2 +- tools/ocaml/libs/xc/xenctrl_stubs.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/ocaml/libs/xb/xenbus_stubs.c b/tools/ocaml/libs/xb/xenbus_stubs.c index 001bb0337109..3065181a55e6 100644 --- a/tools/ocaml/libs/xb/xenbus_stubs.c +++ b/tools/ocaml/libs/xb/xenbus_stubs.c @@ -65,7 +65,7 @@ CAMLprim value stub_string_of_header(value tid, value rid, value ty, value len) }; ret = caml_alloc_string(sizeof(struct xsd_sockmsg)); - memcpy(String_val(ret), &xsd, sizeof(struct xsd_sockmsg)); + memcpy((char *) String_val(ret), &xsd, sizeof(struct xsd_sockmsg)); CAMLreturn(ret); } diff --git a/tools/ocaml/libs/xc/xenctrl_stubs.c b/tools/ocaml/libs/xc/xenctrl_stubs.c index 0fdbeac158b8..94aba38a4211 100644 --- a/tools/ocaml/libs/xc/xenctrl_stubs.c +++ b/tools/ocaml/libs/xc/xenctrl_stubs.c @@ -501,7 +501,7 @@ CAMLprim value stub_xc_vcpu_context_get(value xch, value domid, failwith_xc(_H(xch)); context = caml_alloc_string(sizeof(ctxt)); - memcpy(String_val(context), (char *) &ctxt.c, sizeof(ctxt.c)); + memcpy((char *) String_val(context), &ctxt.c, sizeof(ctxt.c)); CAMLreturn(context); } @@ -680,7 +680,7 @@ CAMLprim value stub_xc_readconsolering(value xch) conring_size = size; ring = caml_alloc_string(count); - memcpy(String_val(ring), str, count); + memcpy((char *) String_val(ring), str, count); free(str); CAMLreturn(ring);