From 4571fb8fe64644c79d91a8f76c148a05b7088ea8 Mon Sep 17 00:00:00 2001 From: Flavio Cruz Date: Thu, 4 May 2023 00:08:12 -0400 Subject: Update hurd/intr-msg.c to be more portable Summary of the changes: - Introduce BAD_TYPECHECK from MiG to make it simpler to do type checking. - Replace int type with mach_msg_type_t. This assumes that mach_msg_type_t is always the same size as int which is not true for x86_64. - Calculate the size and align using PTR_ALIGN_UP, which is a bit cleaner and similar to what we do elsewhere. - Define mach_msg_type_t to check using designated initializers. Message-Id: --- hurd/intr-msg.c | 34 +++++++++++++++++++++------------- 1 file changed, 21 insertions(+), 13 deletions(-) (limited to 'hurd') diff --git a/hurd/intr-msg.c b/hurd/intr-msg.c index 716d87ab6a..b535397bfb 100644 --- a/hurd/intr-msg.c +++ b/hurd/intr-msg.c @@ -28,6 +28,11 @@ # define mig_reply_header_t mig_reply_error_t #endif +/* Macro used by MIG to cleanly check the type. */ +#define BAD_TYPECHECK(type, check) __glibc_unlikely (({ \ + union { mach_msg_type_t t; uint32_t w; } _t, _c; \ + _t.t = *(type); _c.t = *(check);_t.w != _c.w; })) + error_t _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg, mach_msg_option_t option, @@ -61,7 +66,7 @@ _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg, #ifdef NDR_CHAR_ASCII NDR_record_t ndr; #else - int type; + mach_msg_type_t type; #endif int code; } check; @@ -222,11 +227,12 @@ _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg, if (ty->msgtl_header.msgt_inline) { + /* Calculate length of data in bytes. */ + const vm_size_t length = ((number * size) + 7) >> 3; clean_ports ((void *) ty, 0); - /* calculate length of data in bytes, rounding up */ - ty = (void *) ty + (((((number * size) + 7) >> 3) - + sizeof (mach_msg_type_t) - 1) - &~ (sizeof (mach_msg_type_t) - 1)); + /* Move to the next argument. */ + ty = (void *) PTR_ALIGN_UP ((char *) ty + length, + __alignof__ (uintptr_t)); } else { @@ -354,19 +360,21 @@ _hurd_intr_rpc_mach_msg (mach_msg_header_t *msg, { /* We got a reply. Was it EINTR? */ #ifdef MACH_MSG_TYPE_BIT - const union - { - mach_msg_type_t t; - int i; - } check = - { t: { MACH_MSG_TYPE_INTEGER_T, sizeof (integer_t) * 8, - 1, TRUE, FALSE, FALSE, 0 } }; + static const mach_msg_type_t type_check = { + .msgt_name = MACH_MSG_TYPE_INTEGER_T, + .msgt_size = sizeof (integer_t) * 8, + .msgt_number = 1, + .msgt_inline = TRUE, + .msgt_longform = FALSE, + .msgt_deallocate = FALSE, + .msgt_unused = 0 + }; #endif if (m->reply.RetCode == EINTR && m->header.msgh_size == sizeof m->reply #ifdef MACH_MSG_TYPE_BIT - && m->check.type == check.i + && !BAD_TYPECHECK(&m->check.type, &type_check) #endif && !(m->header.msgh_bits & MACH_MSGH_BITS_COMPLEX)) { -- cgit 1.4.1