From 4420528254153189c70b6267593e445dc8654e37 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 29 May 2023 12:52:07 -0600 Subject: [PATCH] firewire: Replace zero-length array with flexible-array member MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Zero-length and one-element arrays are deprecated, and we are moving towards adopting C99 flexible-array members, instead. Address the following warnings found with GCC-13 and -fstrict-flex-arrays=3 enabled: sound/firewire/amdtp-stream.c: In function ‘build_it_pkt_header’: sound/firewire/amdtp-stream.c:694:17: warning: ‘generate_cip_header’ accessing 8 bytes in a region of size 0 [-Wstringop-overflow=] 694 | generate_cip_header(s, cip_header, data_block_counter, syt); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ sound/firewire/amdtp-stream.c:694:17: note: referencing argument 2 of type ‘__be32[2]’ {aka ‘unsigned int[2]’} sound/firewire/amdtp-stream.c:667:13: note: in a call to function ‘generate_cip_header’ 667 | static void generate_cip_header(struct amdtp_stream *s, __be32 cip_header[2], | ^~~~~~~~~~~~~~~~~~~ This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy() and help us make progress towards globally enabling -fstrict-flex-arrays=3 [1]. Link: https://github.com/KSPP/linux/issues/21 Link: https://github.com/KSPP/linux/issues/303 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1] Signed-off-by: Gustavo A. R. Silva Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/ZHT0V3SpvHyxCv5W@work Signed-off-by: Takashi Sakamoto --- include/linux/firewire.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/firewire.h b/include/linux/firewire.h index 1716c01c4e54..efb6e2cf2034 100644 --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -391,7 +391,7 @@ struct fw_iso_packet { u32 tag:2; /* tx: Tag in packet header */ u32 sy:4; /* tx: Sy in packet header */ u32 header_length:8; /* Length of immediate header */ - u32 header[0]; /* tx: Top of 1394 isoch. data_block */ + u32 header[]; /* tx: Top of 1394 isoch. data_block */ }; #define FW_ISO_CONTEXT_TRANSMIT 0