From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Desnoyers Subject: Re: [PATCH lttng-ust] Fix: address GCC unaligned pointer warnings Date: Mon, 29 Jul 2019 10:04:01 -0400 (EDT) Message-ID: <1204712857.1203.1564409041569.JavaMail.zimbra__28208.0635357246$1564409058$gmane$org@efficios.com> References: <20190726220007.21275-1-gabriel.pollo-guilbert@efficios.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail.efficios.com (mail.efficios.com [IPv6:2607:5300:60:7898::beef]) by lists.lttng.org (Postfix) with ESMTPS id 45y1dG5Znwz18Ff for ; Mon, 29 Jul 2019 10:04:02 -0400 (EDT) In-Reply-To: <20190726220007.21275-1-gabriel.pollo-guilbert@efficios.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: lttng-dev-bounces@lists.lttng.org Sender: "lttng-dev" To: Gabriel-Andrew Pollo-Guilbert Cc: lttng-dev List-Id: lttng-dev@lists.lttng.org Merged into master, 2.11, 2.10, 2.9, thanks! Mathieu ----- On Jul 26, 2019, at 6:00 PM, Gabriel-Andrew Pollo-Guilbert gabriel.pollo-guilbert@efficios.com wrote: > The release of GCC 9 added the following warning: > > -Waddress-of-packed-member, enabled by default, warns about an > unaligned pointer value from the address of a packed member of a > struct or union. > > The warning is triggered in some place in LTTng-UST in cases where we > pass a pointer to get a result. Rather than passing the pointer directly > from the struct member, we get the result into a local storage, then > write it in the struct. > > Signed-off-by: Gabriel-Andrew Pollo-Guilbert > > --- > liblttng-ust-comm/lttng-ust-comm.c | 26 +++++++++++++++++++------- > liblttng-ust/lttng-ust-comm.c | 6 +++++- > 2 files changed, 24 insertions(+), 8 deletions(-) > > diff --git a/liblttng-ust-comm/lttng-ust-comm.c > b/liblttng-ust-comm/lttng-ust-comm.c > index 679b40e6..92d86d4e 100644 > --- a/liblttng-ust-comm/lttng-ust-comm.c > +++ b/liblttng-ust-comm/lttng-ust-comm.c > @@ -853,12 +853,15 @@ static > int serialize_integer_type(struct ustctl_integer_type *uit, > const struct lttng_integer_type *lit) > { > + int32_t encoding; > + > uit->size = lit->size; > uit->signedness = lit->signedness; > uit->reverse_byte_order = lit->reverse_byte_order; > uit->base = lit->base; > - if (serialize_string_encoding(&uit->encoding, lit->encoding)) > + if (serialize_string_encoding(&encoding, lit->encoding)) > return -EINVAL; > + uit->encoding = encoding; > uit->alignment = lit->alignment; > return 0; > } > @@ -880,9 +883,11 @@ int serialize_basic_type(struct lttng_session *session, > } > case atype_string: > { > - if (serialize_string_encoding(&ubt->string.encoding, > - lbt->string.encoding)) > + int32_t encoding; > + > + if (serialize_string_encoding(&encoding, lbt->string.encoding)) > return -EINVAL; > + ubt->string.encoding = encoding; > *uatype = ustctl_atype_string; > break; > } > @@ -1007,13 +1012,15 @@ int serialize_one_field(struct lttng_session *session, > { > struct ustctl_field *uf = &fields[*iter_output]; > struct ustctl_type *ut = &uf->type; > + enum ustctl_abstract_types atype; > > strncpy(uf->name, lf->name, LTTNG_UST_SYM_NAME_LEN); > uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0'; > - ret = serialize_basic_type(session, &ut->atype, lt->atype, > + ret = serialize_basic_type(session, &atype, lt->atype, > &ut->u.basic, <->u.basic); > if (ret) > return ret; > + ut->atype = atype; > (*iter_output)++; > break; > } > @@ -1023,6 +1030,7 @@ int serialize_one_field(struct lttng_session *session, > struct ustctl_type *ut = &uf->type; > struct ustctl_basic_type *ubt; > const struct lttng_basic_type *lbt; > + enum ustctl_abstract_types atype; > > strncpy(uf->name, lf->name, LTTNG_UST_SYM_NAME_LEN); > uf->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0'; > @@ -1030,10 +1038,11 @@ int serialize_one_field(struct lttng_session *session, > ubt = &ut->u.array.elem_type; > lbt = <->u.array.elem_type; > ut->u.array.length = lt->u.array.length; > - ret = serialize_basic_type(session, &ubt->atype, lbt->atype, > + ret = serialize_basic_type(session, &atype, lbt->atype, > &ubt->u.basic, &lbt->u.basic); > if (ret) > return -EINVAL; > + ubt->atype = atype; > ut->atype = ustctl_atype_array; > (*iter_output)++; > break; > @@ -1044,6 +1053,7 @@ int serialize_one_field(struct lttng_session *session, > struct ustctl_type *ut = &uf->type; > struct ustctl_basic_type *ubt; > const struct lttng_basic_type *lbt; > + enum ustctl_abstract_types atype; > int ret; > > strncpy(uf->name, lf->name, LTTNG_UST_SYM_NAME_LEN); > @@ -1051,16 +1061,18 @@ int serialize_one_field(struct lttng_session *session, > uf->type.atype = ustctl_atype_sequence; > ubt = &ut->u.sequence.length_type; > lbt = <->u.sequence.length_type; > - ret = serialize_basic_type(session, &ubt->atype, lbt->atype, > + ret = serialize_basic_type(session, &atype, lbt->atype, > &ubt->u.basic, &lbt->u.basic); > if (ret) > return -EINVAL; > + ubt->atype = atype; > ubt = &ut->u.sequence.elem_type; > lbt = <->u.sequence.elem_type; > - ret = serialize_basic_type(session, &ubt->atype, lbt->atype, > + ret = serialize_basic_type(session, &atype, lbt->atype, > &ubt->u.basic, &lbt->u.basic); > if (ret) > return -EINVAL; > + ubt->atype = atype; > ut->atype = ustctl_atype_sequence; > (*iter_output)++; > break; > diff --git a/liblttng-ust/lttng-ust-comm.c b/liblttng-ust/lttng-ust-comm.c > index 61dbb41b..4bc350e2 100644 > --- a/liblttng-ust/lttng-ust-comm.c > +++ b/liblttng-ust/lttng-ust-comm.c > @@ -875,14 +875,18 @@ int handle_message(struct sock_info *sock_info, > } > case LTTNG_UST_STREAM: > { > + uint64_t memory_map_size; > + > /* Receive shm_fd, wakeup_fd */ > ret = ustcomm_recv_stream_from_sessiond(sock, > - &lum->u.stream.len, > + &memory_map_size, > &args.stream.shm_fd, > &args.stream.wakeup_fd); > if (ret) { > goto error; > } > + lum->u.stream.len = memory_map_size; > + > if (ops->cmd) > ret = ops->cmd(lum->handle, lum->cmd, > (unsigned long) &lum->u, > -- > 2.22.0 -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com