diff mbox

[1/1] package/zeromq: enable kernel-based feature flags

Message ID 1423214752-29779-1-git-send-email-lionel.orry@gmail.com
State Superseded
Headers show

Commit Message

Lionel Orry Feb. 6, 2015, 9:25 a.m. UTC 
The current configuration system does not check for cached variables for
these flags, and thus they are always disabled when cross-compiling.
This patch fixes the configuration system to use cached variables and
enables them at configuration time.

Signed-off-by: Lionel Orry <lionel.orry@gmail.com>
---
 ...e.m4-make-kernel-specific-flags-cacheable.patch | 204 +++++++++++++++++++++
 package/zeromq/zeromq.mk                           |  10 +
 2 files changed, 214 insertions(+)
 create mode 100644 package/zeromq/0002-acinclude.m4-make-kernel-specific-flags-cacheable.patch

Comments

Thomas Petazzoni March 15, 2015, 10:28 p.m. UTC | #1 
Dear Lionel Orry,

On Fri,  6 Feb 2015 10:25:52 +0100, Lionel Orry wrote:
> The current configuration system does not check for cached variables for
> these flags, and thus they are always disabled when cross-compiling.
> This patch fixes the configuration system to use cached variables and
> enables them at configuration time.
> 
> Signed-off-by: Lionel Orry <lionel.orry@gmail.com>
> ---
>  ...e.m4-make-kernel-specific-flags-cacheable.patch | 204 +++++++++++++++++++++
>  package/zeromq/zeromq.mk                           |  10 +
>  2 files changed, 214 insertions(+)
>  create mode 100644 package/zeromq/0002-acinclude.m4-make-kernel-specific-flags-cacheable.patch

Thanks for this patch, and sorry for the slow response.

However, I believe it would be a lot better to change the acinclude.m4
tests to not use AC_TRY_RUN, but instead to simply test if TCP_KEEPCNT,
TCP_KEEPIDLE, etc. exist at compile time. If they are defined in the
kernel headers, then you know the kernel supports them, since running a
kernel older than the kernel headers used in the toolchain cannot work.

So, replace AC_TRY_RUN with AC_TRY_LINK or something like that. Or
maybe there's even a simpler autoconf macro to test if a definition
exists or not.

Can you try this instead?

Also, did you submit your patch upstream?

Thanks a lot,

Thomas
Lionel Orry March 16, 2015, 6:43 a.m. UTC | #2 
Hi Thomas,

On Sun, Mar 15, 2015 at 11:28 PM, Thomas Petazzoni
<thomas.petazzoni@free-electrons.com> wrote:
> Dear Lionel Orry,
>
> On Fri,  6 Feb 2015 10:25:52 +0100, Lionel Orry wrote:
>> The current configuration system does not check for cached variables for
>> these flags, and thus they are always disabled when cross-compiling.
>> This patch fixes the configuration system to use cached variables and
>> enables them at configuration time.
>>
>> Signed-off-by: Lionel Orry <lionel.orry@gmail.com>
>> ---
>>  ...e.m4-make-kernel-specific-flags-cacheable.patch | 204 +++++++++++++++++++++
>>  package/zeromq/zeromq.mk                           |  10 +
>>  2 files changed, 214 insertions(+)
>>  create mode 100644 package/zeromq/0002-acinclude.m4-make-kernel-specific-flags-cacheable.patch
>
> Thanks for this patch, and sorry for the slow response.
>
> However, I believe it would be a lot better to change the acinclude.m4
> tests to not use AC_TRY_RUN, but instead to simply test if TCP_KEEPCNT,
> TCP_KEEPIDLE, etc. exist at compile time. If they are defined in the
> kernel headers, then you know the kernel supports them, since running a
> kernel older than the kernel headers used in the toolchain cannot work.
>
> So, replace AC_TRY_RUN with AC_TRY_LINK or something like that. Or
> maybe there's even a simpler autoconf macro to test if a definition
> exists or not.

the fact is, I was asked by Arnout to do it that way, and his opinion
was that it was needed to run the snippet on the target to be sure of
the resut. See:
http://article.gmane.org/gmane.comp.lib.uclibc.buildroot/106055

Is there something I misunderstood ? Who has the final call about this ?

>
> Can you try this instead?
>
> Also, did you submit your patch upstream?

Yes I did, it has been merged into the next branch of zeromq, v4.1.x.

>
> Thanks a lot,
>
> Thomas
> --
> Thomas Petazzoni, CTO, Free Electrons
> Embedded Linux, Kernel and Android engineering
> http://free-electrons.com

Best regards,
Lionel
Thomas Petazzoni March 16, 2015, 8:05 a.m. UTC | #3 
Dear Lionel Orry,

On Mon, 16 Mar 2015 07:43:11 +0100, Lionel Orry wrote:

> > So, replace AC_TRY_RUN with AC_TRY_LINK or something like that. Or
> > maybe there's even a simpler autoconf macro to test if a definition
> > exists or not.
> 
> the fact is, I was asked by Arnout to do it that way, and his opinion
> was that it was needed to run the snippet on the target to be sure of
> the resut. See:
> http://article.gmane.org/gmane.comp.lib.uclibc.buildroot/106055
> 
> Is there something I misunderstood ? Who has the final call about this ?

I am not sure I agree with Arnout suggestion, but...

> > Also, did you submit your patch upstream?
> 
> Yes I did, it has been merged into the next branch of zeromq, v4.1.x.

... since your patch has been merged upstream, I'm just fine with using
it as is.

Thanks!

Thomas
Arnout Vandecappelle March 18, 2015, 10:27 p.m. UTC | #4 
On 16/03/15 07:43, Lionel Orry wrote:
> Hi Thomas,
> 
> On Sun, Mar 15, 2015 at 11:28 PM, Thomas Petazzoni
> <thomas.petazzoni@free-electrons.com> wrote:
>> Dear Lionel Orry,
>>
>> On Fri,  6 Feb 2015 10:25:52 +0100, Lionel Orry wrote:
>>> The current configuration system does not check for cached variables for
>>> these flags, and thus they are always disabled when cross-compiling.
>>> This patch fixes the configuration system to use cached variables and
>>> enables them at configuration time.
>>>
>>> Signed-off-by: Lionel Orry <lionel.orry@gmail.com>
>>> ---
>>>  ...e.m4-make-kernel-specific-flags-cacheable.patch | 204 +++++++++++++++++++++
>>>  package/zeromq/zeromq.mk                           |  10 +
>>>  2 files changed, 214 insertions(+)
>>>  create mode 100644 package/zeromq/0002-acinclude.m4-make-kernel-specific-flags-cacheable.patch
>>
>> Thanks for this patch, and sorry for the slow response.
>>
>> However, I believe it would be a lot better to change the acinclude.m4
>> tests to not use AC_TRY_RUN, but instead to simply test if TCP_KEEPCNT,
>> TCP_KEEPIDLE, etc. exist at compile time. If they are defined in the
>> kernel headers, then you know the kernel supports them, since running a
>> kernel older than the kernel headers used in the toolchain cannot work.
>>
>> So, replace AC_TRY_RUN with AC_TRY_LINK or something like that. Or
>> maybe there's even a simpler autoconf macro to test if a definition
>> exists or not.
> 
> the fact is, I was asked by Arnout to do it that way, and his opinion
> was that it was needed to run the snippet on the target to be sure of
> the resut. See:
> http://article.gmane.org/gmane.comp.lib.uclibc.buildroot/106055
> 
> Is there something I misunderstood ? Who has the final call about this ?

 It's been a while ago, of course, but I think one problem was that the symbols
are also defined by the toolchain, so they exist even if the kernel doesn't
support them.

 Regards,
 Arnout
Thomas Petazzoni April 21, 2015, 8:47 p.m. UTC | #5 
Dear Arnout Vandecappelle,

On Wed, 18 Mar 2015 23:27:55 +0100, Arnout Vandecappelle wrote:

>  It's been a while ago, of course, but I think one problem was that the symbols
> are also defined by the toolchain, so they exist even if the kernel doesn't
> support them.

If the flags exist in the toolchain, then it means that the toolchain
is using a certain version of the kernel headers. Running with a kernel
older than that will anyway not work.

I mean, there are zillions of configure script that tests if the
toolchain has syscall foo() or bar() by simply doing a compile time
test. They don't actually check if the user is stupid enough to run on
a system that has a kernel older than the kernel headers + C library
combination used in the toolchain.

Or am I missing something specific to those flags?

Thanks,

Thomas
Arnout Vandecappelle April 21, 2015, 9:48 p.m. UTC | #6 
On 21/04/15 22:47, Thomas Petazzoni wrote:
> Dear Arnout Vandecappelle,
> 
> On Wed, 18 Mar 2015 23:27:55 +0100, Arnout Vandecappelle wrote:
> 
>>  It's been a while ago, of course, but I think one problem was that the symbols
>> are also defined by the toolchain, so they exist even if the kernel doesn't
>> support them.
> 
> If the flags exist in the toolchain, then it means that the toolchain
> is using a certain version of the kernel headers. Running with a kernel
> older than that will anyway not work.
> 
> I mean, there are zillions of configure script that tests if the
> toolchain has syscall foo() or bar() by simply doing a compile time
> test. They don't actually check if the user is stupid enough to run on
> a system that has a kernel older than the kernel headers + C library
> combination used in the toolchain.
> 
> Or am I missing something specific to those flags?

 They are not syscalls but flags which are defined in <netinet/tcp.h>, which (at
least for uClibc) is copied verbatim from libc to the sysroot. So AFAICS the
libc doesn't actually check if it is really available in the kernel. Possibly
the kernels that didn't support these flags already defined (and ignored) them.


 Regards,
 Arnout
diff mbox

Patch

diff --git a/package/zeromq/0002-acinclude.m4-make-kernel-specific-flags-cacheable.patch b/package/zeromq/0002-acinclude.m4-make-kernel-specific-flags-cacheable.patch
new file mode 100644
index 0000000..9b6e808
--- /dev/null
+++ b/package/zeromq/0002-acinclude.m4-make-kernel-specific-flags-cacheable.patch
@@ -0,0 +1,204 @@ 
+From 2eee4dd2b1668124f377f6da1d511249086a1449 Mon Sep 17 00:00:00 2001
+From: Lionel Orry <lionel.orry@gmail.com>
+Date: Fri, 6 Feb 2015 09:45:21 +0100
+Subject: [PATCH 1/1] acinclude.m4: make kernel-specific flags cacheable
+
+Specifically when cross-compiling, one can be willing to force these
+variable values using the environment of a config.cache file. This
+commit makes this possible.
+
+The affected variables are:
+
+* libzmq_cv_sock_cloexec
+* libzmq_cv_so_keepalive
+* libzmq_cv_tcp_keepcnt
+* libzmq_cv_tcp_keepidle
+* libzmq_cv_tcp_keepintvl
+* libzmq_cv_tcp_keepalive
+
+Signed-off-by: Lionel Orry <lionel.orry@gmail.com>
+---
+ acinclude.m4 | 84 ++++++++++++++++++++++++++++++++++--------------------------
+ 1 file changed, 48 insertions(+), 36 deletions(-)
+
+diff --git a/acinclude.m4 b/acinclude.m4
+index c5c2748..b40f0c1 100644
+--- a/acinclude.m4
++++ b/acinclude.m4
+@@ -586,8 +586,8 @@ dnl # LIBZMQ_CHECK_SOCK_CLOEXEC([action-if-found], [action-if-not-found])
+ dnl # Check if SOCK_CLOEXEC is supported                                           #
+ dnl ################################################################################
+ AC_DEFUN([LIBZMQ_CHECK_SOCK_CLOEXEC], [{
+-    AC_MSG_CHECKING(whether SOCK_CLOEXEC is supported)
+-    AC_TRY_RUN([/* SOCK_CLOEXEC test */
++    AC_CACHE_CHECK([whether SOCK_CLOEXEC is supported], [libzmq_cv_sock_cloexec],
++        [AC_TRY_RUN([/* SOCK_CLOEXEC test */
+ #include <sys/types.h>
+ #include <sys/socket.h>
+ 
+@@ -596,11 +596,13 @@ int main (int argc, char *argv [])
+     int s = socket (PF_INET, SOCK_STREAM | SOCK_CLOEXEC, 0);
+     return (s == -1);
+ }
+-    ],
+-    [AC_MSG_RESULT(yes) ; libzmq_cv_sock_cloexec="yes" ; $1],
+-    [AC_MSG_RESULT(no)  ; libzmq_cv_sock_cloexec="no"  ; $2],
+-    [AC_MSG_RESULT(not during cross-compile) ; libzmq_cv_sock_cloexec="no"]
++        ],
++        [libzmq_cv_sock_cloexec="yes"],
++        [libzmq_cv_sock_cloexec="no"],
++        [libzmq_cv_sock_cloexec="not during cross-compile"]
++        )]
+     )
++    AS_IF([test "x$libzmq_cv_sock_cloexec" = "xyes"], [$1], [$2])
+ }])
+ 
+ dnl ################################################################################
+@@ -608,8 +610,8 @@ dnl # LIBZMQ_CHECK_SO_KEEPALIVE([action-if-found], [action-if-not-found])
+ dnl # Check if SO_KEEPALIVE is supported                                           #
+ dnl ################################################################################
+ AC_DEFUN([LIBZMQ_CHECK_SO_KEEPALIVE], [{
+-    AC_MSG_CHECKING(whether SO_KEEPALIVE is supported)
+-    AC_TRY_RUN([/* SO_KEEPALIVE test */
++    AC_CACHE_CHECK([whether SO_KEEPALIVE is supported], [libzmq_cv_so_keepalive],
++        [AC_TRY_RUN([/* SO_KEEPALIVE test */
+ #include <sys/types.h>
+ #include <sys/socket.h>
+ 
+@@ -621,11 +623,13 @@ int main (int argc, char *argv [])
+         ((rc = setsockopt (s, SOL_SOCKET, SO_KEEPALIVE, (char*) &opt, sizeof (int))) == -1)
+     );
+ }
+-    ],
+-    [AC_MSG_RESULT(yes) ; libzmq_cv_so_keepalive="yes" ; $1],
+-    [AC_MSG_RESULT(no)  ; libzmq_cv_so_keepalive="no"  ; $2],
+-    [AC_MSG_RESULT(not during cross-compile) ; libzmq_cv_so_keepalive="no"]
++        ],
++        [libzmq_cv_so_keepalive="yes"],
++        [libzmq_cv_so_keepalive="no"],
++        [libzmq_cv_so_keepalive="not during cross-compile"]
++        )]
+     )
++    AS_IF([test "x$libzmq_cv_so_keepalive" = "xyes"], [$1], [$2])
+ }])
+ 
+ dnl ################################################################################
+@@ -633,8 +637,8 @@ dnl # LIBZMQ_CHECK_TCP_KEEPCNT([action-if-found], [action-if-not-found])
+ dnl # Check if TCP_KEEPCNT is supported                                            #
+ dnl ################################################################################
+ AC_DEFUN([LIBZMQ_CHECK_TCP_KEEPCNT], [{
+-    AC_MSG_CHECKING(whether TCP_KEEPCNT is supported)
+-    AC_TRY_RUN([/* TCP_KEEPCNT test */
++    AC_CACHE_CHECK([whether TCP_KEEPCNT is supported], [libzmq_cv_tcp_keepcnt],
++        [AC_TRY_RUN([/* TCP_KEEPCNT test */
+ #include <sys/types.h>
+ #include <sys/socket.h>
+ #include <netinet/in.h>
+@@ -649,11 +653,13 @@ int main (int argc, char *argv [])
+         ((rc = setsockopt (s, IPPROTO_TCP, TCP_KEEPCNT, (char*) &opt, sizeof (int))) == -1)
+     );
+ }
+-    ],
+-    [AC_MSG_RESULT(yes) ; libzmq_cv_tcp_keepcnt="yes" ; $1],
+-    [AC_MSG_RESULT(no)  ; libzmq_cv_tcp_keepcnt="no"  ; $2],
+-    [AC_MSG_RESULT(not during cross-compile) ; libzmq_cv_tcp_keepcnt="no"]
++        ],
++        [libzmq_cv_tcp_keepcnt="yes"],
++        [libzmq_cv_tcp_keepcnt="no"],
++        [libzmq_cv_tcp_keepcnt="not during cross-compile"]
++        )]
+     )
++    AS_IF([test "x$libzmq_cv_tcp_keepcnt" = "xyes"], [$1], [$2])
+ }])
+ 
+ dnl ################################################################################
+@@ -661,8 +667,8 @@ dnl # LIBZMQ_CHECK_TCP_KEEPIDLE([action-if-found], [action-if-not-found])
+ dnl # Check if TCP_KEEPIDLE is supported                                           #
+ dnl ################################################################################
+ AC_DEFUN([LIBZMQ_CHECK_TCP_KEEPIDLE], [{
+-    AC_MSG_CHECKING(whether TCP_KEEPIDLE is supported)
+-    AC_TRY_RUN([/* TCP_KEEPIDLE test */
++    AC_CACHE_CHECK([whether TCP_KEEPIDLE is supported], [libzmq_cv_tcp_keepidle],
++        [AC_TRY_RUN([/* TCP_KEEPIDLE test */
+ #include <sys/types.h>
+ #include <sys/socket.h>
+ #include <netinet/in.h>
+@@ -677,11 +683,13 @@ int main (int argc, char *argv [])
+         ((rc = setsockopt (s, IPPROTO_TCP, TCP_KEEPIDLE, (char*) &opt, sizeof (int))) == -1)
+     );
+ }
+-    ],
+-    [AC_MSG_RESULT(yes) ; libzmq_cv_tcp_keepidle="yes" ; $1],
+-    [AC_MSG_RESULT(no)  ; libzmq_cv_tcp_keepidle="no"  ; $2],
+-    [AC_MSG_RESULT(not during cross-compile) ; libzmq_cv_tcp_keepidle="no"]
++        ],
++        [libzmq_cv_tcp_keepidle="yes"],
++        [libzmq_cv_tcp_keepidle="no"],
++        [libzmq_cv_tcp_keepidle="not during cross-compile"]
++        )]
+     )
++    AS_IF([test "x$libzmq_cv_tcp_keepidle" = "xyes"], [$1], [$2])
+ }])
+ 
+ dnl ################################################################################
+@@ -689,8 +697,8 @@ dnl # LIBZMQ_CHECK_TCP_KEEPINTVL([action-if-found], [action-if-not-found])
+ dnl # Check if TCP_KEEPINTVL is supported                                           #
+ dnl ################################################################################
+ AC_DEFUN([LIBZMQ_CHECK_TCP_KEEPINTVL], [{
+-    AC_MSG_CHECKING(whether TCP_KEEPINTVL is supported)
+-    AC_TRY_RUN([/* TCP_KEEPINTVL test */
++    AC_CACHE_CHECK([whether TCP_KEEPINTVL is supported], [libzmq_cv_tcp_keepintvl],
++        [AC_TRY_RUN([/* TCP_KEEPINTVL test */
+ #include <sys/types.h>
+ #include <sys/socket.h>
+ #include <netinet/in.h>
+@@ -705,11 +713,13 @@ int main (int argc, char *argv [])
+         ((rc = setsockopt (s, IPPROTO_TCP, TCP_KEEPINTVL, (char*) &opt, sizeof (int))) == -1)
+     );
+ }
+-    ],
+-    [AC_MSG_RESULT(yes) ; libzmq_cv_tcp_keepintvl="yes" ; $1],
+-    [AC_MSG_RESULT(no)  ; libzmq_cv_tcp_keepintvl="no"  ; $2],
+-    [AC_MSG_RESULT(not during cross-compile) ; libzmq_cv_tcp_keepintvl="no"]
++        ],
++        [libzmq_cv_tcp_keepintvl="yes"],
++        [libzmq_cv_tcp_keepintvl="no"],
++        [libzmq_cv_tcp_keepintvl="not during cross-compile"]
++        )]
+     )
++    AS_IF([test "x$libzmq_cv_tcp_keepintvl" = "xyes"], [$1], [$2])
+ }])
+ 
+ dnl ################################################################################
+@@ -717,8 +727,8 @@ dnl # LIBZMQ_CHECK_TCP_KEEPALIVE([action-if-found], [action-if-not-found])
+ dnl # Check if TCP_KEEPALIVE is supported                                          #
+ dnl ################################################################################
+ AC_DEFUN([LIBZMQ_CHECK_TCP_KEEPALIVE], [{
+-    AC_MSG_CHECKING(whether TCP_KEEPALIVE is supported)
+-    AC_TRY_RUN([/* TCP_KEEPALIVE test */
++    AC_CACHE_CHECK([whether TCP_KEEPALIVE is supported], [libzmq_cv_tcp_keepalive],
++        [AC_TRY_RUN([/* TCP_KEEPALIVE test */
+ #include <sys/types.h>
+ #include <sys/socket.h>
+ #include <netinet/in.h>
+@@ -733,11 +743,13 @@ int main (int argc, char *argv [])
+         ((rc = setsockopt (s, IPPROTO_TCP, TCP_KEEPALIVE, (char*) &opt, sizeof (int))) == -1)
+     );
+ }
+-    ],
+-    [AC_MSG_RESULT(yes) ; libzmq_cv_tcp_keepalive="yes" ; $1],
+-    [AC_MSG_RESULT(no)  ; libzmq_cv_tcp_keepalive="no"  ; $2],
+-    [AC_MSG_RESULT(not during cross-compile) ; libzmq_cv_tcp_keepalive="no"]
++        ],
++        [libzmq_cv_tcp_keepalive="yes"],
++        [libzmq_cv_tcp_keepalive="no"],
++        [libzmq_cv_tcp_keepalive="not during cross-compile"]
++        )]
+     )
++    AS_IF([test "x$libzmq_cv_tcp_keepalive" = "xyes"], [$1], [$2])
+ }])
+ 
+ dnl ################################################################################
+-- 
+2.1.0
+
diff --git a/package/zeromq/zeromq.mk b/package/zeromq/zeromq.mk
index e8f7c57..ad41671 100644
--- a/package/zeromq/zeromq.mk
+++ b/package/zeromq/zeromq.mk
@@ -11,8 +11,18 @@  ZEROMQ_DEPENDENCIES = util-linux
 ZEROMQ_LICENSE = LGPLv3+ with exceptions
 ZEROMQ_LICENSE_FILES = COPYING COPYING.LESSER
 # For 0001-tests-disable-test_fork-if-fork-is-not-available.patch
+# and 0002-acinclude.m4-make-kernel-specific-flags-cacheable.patch
 ZEROMQ_AUTORECONF = YES
 
+# Assume these flags are always available. It is true, at least for
+# SOCK_CLOEXEC, since linux v2.6.27.
+# Note: the flag TCP_KEEPALIVE is NOT available so we do not include it.
+ZEROMQ_CONF_ENV = libzmq_cv_sock_cloexec=yes \
+				  libzmq_cv_so_keepalive=yes \
+				  libzmq_cv_tcp_keepcnt=yes \
+				  libzmq_cv_tcp_keepidle=yes \
+				  libzmq_cv_tcp_keepintvl=yes
+
 # Only tools/curve_keygen.c needs this, but it doesn't hurt to pass it
 # for the rest of the build as well (which automatically includes stdc++).
 ifeq ($(BR2_STATIC_LIBS),y)