Messages in this thread Patch in this message | | | From | Nick Desaulniers <> | Date | Tue, 29 Mar 2022 15:09:59 -0700 | Subject | Re: [PATCH] net, uapi: remove inclusion of arpa/inet.h |
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On Tue, Mar 29, 2022 at 2:50 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > On Tue, Mar 29, 2022 at 2:29 PM Nick Desaulniers > <ndesaulniers@google.com> wrote: > > > > Testing out CONFIG_UAPI_HEADER_TEST=y with a prebuilt Bionic sysroot > > from Android's SDK, I encountered an error: > > > > HDRTEST usr/include/linux/fsi.h > > In file included from <built-in>:1: > > In file included from ./usr/include/linux/tipc_config.h:46: > > prebuilts/ndk/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include/arpa/inet.h:39:1: > > error: unknown type name 'in_addr_t' > > in_addr_t inet_addr(const char* __s); > > ^ > > Oh, this might not quite be the correct fix for this particular issue. > > Cherry picking this diff back into my Android kernel tree, I now observe: > HDRTEST usr/include/linux/tipc_config.h > In file included from <built-in>:1: > ./usr/include/linux/tipc_config.h:268:4: error: implicit declaration > of function 'ntohs' [-Werror,-Wimplicit-function-declaration] > (ntohs(((struct tlv_desc *)tlv)->tlv_len) <= space); > ^ > > Is there more than one byteorder.h? Oh, I see what I did; ntohs is defined in > linux/byteorder/generic.h > not > usr/include/asm/byteorder.h > Sorry, I saw `byteorder` and mixed up the path with the filename. > > So rather than just remove the latter, I should additionally be adding > the former. Though that then produces > > common/include/linux/byteorder/generic.h:146:9: error: implicit > declaration of function '__cpu_to_le16' > [-Werror,-Wimplicit-function-declaration] > *var = cpu_to_le16(le16_to_cpu(*var) + val); > ^ > > Oh?
Should there be a definition of ntohs (and friends) under include/uapi/linux/ somewhere, rather than have the kernel header include/uapi/linux/tipc_config.h depend on the libc header arpa/inet.h?
It looks like we already have include/uapi/linux/byteorder/{big|little}_endian.h to define __be16_to_cpu and friends, just no definition of ntohs under include/uapi/linux/.
Also, it looks like include/uapi/linux/ has definitions for __constant_ntohs in include/uapi/linux/byteorder/{big|little}_endian.h. Should those 2 headers also define ntohs (and friends) unprefixed, i.e. the versions that don't depend on constant expressions?
(I wish there was an entry in MAINTAINERS for UAPI questions like this...)
> > > > > This is because Bionic has a bug in its inclusion chain. I sent a patch > > to fix that, but looking closer at include/uapi/linux/tipc_config.h, > > there's a comment that it includes arpa/inet.h for ntohs; but ntohs is > > already defined in include/linux/byteorder/generic.h which is already > > included in include/uapi/linux/tipc_config.h. There are no __KERNEL__ > > guards on include/linux/byteorder/generic.h's definition of ntohs. So > > besides fixing Bionic, it looks like we can additionally remove this > > unnecessary header inclusion. > > > > Link: https://android-review.googlesource.com/c/platform/bionic/+/2048127 > > Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> > > --- > > include/uapi/linux/tipc_config.h | 4 ---- > > 1 file changed, 4 deletions(-) > > > > diff --git a/include/uapi/linux/tipc_config.h b/include/uapi/linux/tipc_config.h > > index 4dfc05651c98..b38374d5f192 100644 > > --- a/include/uapi/linux/tipc_config.h > > +++ b/include/uapi/linux/tipc_config.h > > @@ -43,10 +43,6 @@ > > #include <linux/tipc.h> > > #include <asm/byteorder.h> > > > > -#ifndef __KERNEL__ > > -#include <arpa/inet.h> /* for ntohs etc. */ > > -#endif > > - > > /* > > * Configuration > > * > > > > base-commit: 5efabdadcf4a5b9a37847ecc85ba71cf2eff0fcf > > prerequisite-patch-id: 0c2abf2af8051f4b37a70ef11b7d2fc2a3ec7181 > > -- > > 2.35.1.1021.g381101b075-goog > > > > > -- > Thanks, > ~Nick Desaulniers
-- Thanks, ~Nick Desaulniers
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