| Message ID | 20220329212946.2861648-1-ndesaulniers@google.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | net, uapi: remove inclusion of arpa/inet.h | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
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? > > 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 >
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
On Tue, Mar 29, 2022 at 3:09 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > 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 think the answer is yes; in addition to the diff in this patch, the following seems to be working: ``` diff --git a/include/uapi/linux/byteorder/little_endian.h b/include/uapi/linux/byteorder/little_endian.h index cd98982e7523..c14f2c3728e2 100644 --- a/include/uapi/linux/byteorder/little_endian.h +++ b/include/uapi/linux/byteorder/little_endian.h @@ -103,5 +103,8 @@ static __always_inline __u16 __be16_to_cpup(const __be16 *p) #define __cpu_to_be16s(x) __swab16s((x)) #define __be16_to_cpus(x) __swab16s((x)) +#define htonl(x) __cpu_to_be32(x) +#define htons(x) __cpu_to_be16(x) +#define ntohs(x) __be16_to_cpu(x) #endif /* _UAPI_LINUX_BYTEORDER_LITTLE_ENDIAN_H */ ``` I think if I flush out the rest for both endiannesses, then we should be in good shape? > > (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
On Tue, Mar 29, 2022 at 3:09 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > 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...) I also think that Documentation/kbuild/headers_install.rst should probably include text from https://lore.kernel.org/all/Pine.LNX.4.58.0411281710490.22796@ppc970.osdl.org/ or something along the lines of "kernel headers MUST NOT depend on userspace headers; any instance of that in tree is a bug that should be fixed." For people I just cc'ed, here's the lore link to this thread: https://lore.kernel.org/lkml/20220329212946.2861648-1-ndesaulniers@google.com/ > > > > > > > > > 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
On Wed, Mar 30, 2022 at 12:26 AM Nick Desaulniers <ndesaulniers@google.com> wrote: > On Tue, Mar 29, 2022 at 3:09 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > ``` > diff --git a/include/uapi/linux/byteorder/little_endian.h > b/include/uapi/linux/byteorder/little_endian.h > index cd98982e7523..c14f2c3728e2 100644 > --- a/include/uapi/linux/byteorder/little_endian.h > +++ b/include/uapi/linux/byteorder/little_endian.h > @@ -103,5 +103,8 @@ static __always_inline __u16 __be16_to_cpup(const __be16 *p) > #define __cpu_to_be16s(x) __swab16s((x)) > #define __be16_to_cpus(x) __swab16s((x)) > > +#define htonl(x) __cpu_to_be32(x) > +#define htons(x) __cpu_to_be16(x) > +#define ntohs(x) __be16_to_cpu(x) > This is unfortunately a namespace violation, you can't define things in uapi headers that conflict with standard library interfaces. Arnd
On Wed, Mar 30, 2022 at 8:08 AM Arnd Bergmann <arnd@arndb.de> wrote: > On Wed, Mar 30, 2022 at 12:26 AM Nick Desaulniers > <ndesaulniers@google.com> wrote: > > On Tue, Mar 29, 2022 at 3:09 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > ``` > > diff --git a/include/uapi/linux/byteorder/little_endian.h > > b/include/uapi/linux/byteorder/little_endian.h > > index cd98982e7523..c14f2c3728e2 100644 > > --- a/include/uapi/linux/byteorder/little_endian.h > > +++ b/include/uapi/linux/byteorder/little_endian.h > > @@ -103,5 +103,8 @@ static __always_inline __u16 __be16_to_cpup(const __be16 *p) > > #define __cpu_to_be16s(x) __swab16s((x)) > > #define __be16_to_cpus(x) __swab16s((x)) > > > > +#define htonl(x) __cpu_to_be32(x) > > +#define htons(x) __cpu_to_be16(x) > > +#define ntohs(x) __be16_to_cpu(x) > > > > This is unfortunately a namespace violation, you can't define things in uapi > headers that conflict with standard library interfaces. nevermind, I just saw the thread continues and you arrived at a good solution withusing the __cpu_to_be16() etc directly. Arnd
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 *
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); ^ 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(-) base-commit: 5efabdadcf4a5b9a37847ecc85ba71cf2eff0fcf prerequisite-patch-id: 0c2abf2af8051f4b37a70ef11b7d2fc2a3ec7181