Re: [PATCH v3] batman-adv: Add flex array to struct batadv_tvlv_tt_data
From: Kees Cook <hidden>
Date: 2024-05-06 16:27:47
Also in:
batman, linux-hardening, lkml, llvm
On Sat, May 04, 2024 at 07:08:39PM +0200, Erick Archer wrote:
quoted hunk ↗ jump to hunk
Hi Sven, On Sat, May 04, 2024 at 11:35:38AM +0200, Sven Eckelmann wrote:quoted
On Wednesday, 1 May 2024 17:02:42 CEST Erick Archer wrote:quoted
diff --git a/include/uapi/linux/batadv_packet.h b/include/uapi/linux/batadv_packet.h index 6e25753015df..dfbe30536995 100644 --- a/include/uapi/linux/batadv_packet.h +++ b/include/uapi/linux/batadv_packet.h[...]quoted
+/** + * struct batadv_tvlv_tt_data - tt data propagated through the tt tvlv container + * @flags: translation table flags (see batadv_tt_data_flags) + * @ttvn: translation table version number + * @num_vlan: number of announced VLANs. In the TVLV this struct is followed by + * one batadv_tvlv_tt_vlan_data object per announced vlan + * @vlan_data: array of batadv_tvlv_tt_vlan_data objects + */ +struct batadv_tvlv_tt_data { + __u8 flags; + __u8 ttvn; + __be16 num_vlan; + struct batadv_tvlv_tt_vlan_data vlan_data[] __counted_by_be(num_vlan); +};Thanks for the updates. But I can't accept this at the moment because __counted_by_be is used in an uapi header without it being defined include/uapi/linux/stddef.h (and this file is also not included in this header). See commit c8248faf3ca2 ("Compiler Attributes: counted_by: Adjust name and identifier expansion") as an example for the similar __counted_by macro.If I understand correctly, the following changes are also needed because the annotated struct is defined in a "uapi" header. Sorry if it's a stupid question, but I'm new to these topics.diff --git a/include/uapi/linux/batadv_packet.h b/include/uapi/linux/batadv_packet.h index 6e25753015df..41f39d7661c9 100644 --- a/include/uapi/linux/batadv_packet.h +++ b/include/uapi/linux/batadv_packet.h@@ -9,6 +9,7 @@ #include <asm/byteorder.h> #include <linux/if_ether.h> +#include <linux/stddef.h> #include <linux/types.h> /**diff --git a/include/uapi/linux/stddef.h b/include/uapi/linux/stddef.h index 2ec6f35cda32..58154117d9b0 100644 --- a/include/uapi/linux/stddef.h +++ b/include/uapi/linux/stddef.h@@ -55,4 +55,12 @@ #define __counted_by(m) #endif +#ifndef __counted_by_le +#define __counted_by_le(m) +#endif + +#ifndef __counted_by_be +#define __counted_by_be(m) +#endif + #endif /* _UAPI_LINUX_STDDEF_H */
Yup, this is needed for UAPI as you have it. Thanks! I should have noticed
the need for this when I reviewed commit ca7e324e8ad3 ("compiler_types:
add Endianness-dependent __counted_by_{le,be}").
If this is the right path, can these changes be merged into a
single patch or is it better to add a previous patch to define
__counted_by{le,be}?We're almost on top of the merge window, so how about this: send me a patch for just the UAPI addition, and I'll include it in this coming (next week expected) merge window. Once -rc2 is out, re-send this batman-adv patch since then netdev will be merged with -rc2 and the UAPI change will be there. -Kees -- Kees Cook