From: Julien Grall Date: Mon, 30 Mar 2020 14:14:23 +0000 (+0100) Subject: tools/ocaml: Fix stubs build when OCaml has been compiled with -safe-string X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=2e9e9e440f9257f7db12a744d0de0b7ab7746dfd;p=xen.git 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 (cherry picked from commit 59b087e3954402c487e0abb4ad9bd05f43669436) --- diff --git a/tools/ocaml/libs/xb/xenbus_stubs.c b/tools/ocaml/libs/xb/xenbus_stubs.c index 001bb03371..3065181a55 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 c4fdc58b2d..cae33a8cb2 100644 --- a/tools/ocaml/libs/xc/xenctrl_stubs.c +++ b/tools/ocaml/libs/xc/xenctrl_stubs.c @@ -436,7 +436,7 @@ CAMLprim value stub_xc_vcpu_context_get(value xch, value domid, ret = xc_vcpu_getcontext(_H(xch), _D(domid), Int_val(cpu), &ctxt); 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); } @@ -615,7 +615,7 @@ 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);