7 Oct
2018
7 Oct
'18
2:12 p.m.
Hello,
On Sat, Oct 06, 2018 at 12:00:02PM +0200, devel-request(a)uclibc-ng.org wrote:
Message: 1
Date: Fri, 5 Oct 2018 07:48:40 -0600
From: Lance Fredrickson <lancethepants(a)gmail.com>
To: devel(a)uclibc-ng.org
Subject: [uclibc-ng-devel] Fwd: recvmmsg/sendmmsg not in kernel <
Linux 2.6.33
Message-ID: <fc65bbd1-8cfa-f4cb-9a5b-25e21a273494(a)gmail.com>
Content-Type: text/plain; charset="utf-8"; Format="flowed"
Hi,
I'm having an issue where it seems recvmmsg/sendmmsg is being included
into the c library regardless of kernel version. I work with kernel
versions < 2.6.33 before this feature was included. When compiling
applications, autoconf is then mistakenly told from the c-library that
recvmmsg/sendmmsg is supported by the kernel, resulting in runtime
errors. I use buildroot to compile my toolchains.
Looking through uclibc-ng git, it looks like this feature was added with
this commit.
https://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/commit/?id=6e15fafa200666…
+# ifdef __NR_recvmmsg
^^^^^^^^^^^^^
+ return (ssize_t)INLINE_SYSCALL(recvmmsg, 5, sockfd, msg, vlen, flags, tmo);
+# else
......
+ return (ssize_t)__socketcall(SYS_RECVMMSG, args);
+# endif
+}
You kernel define __NR_recvmmsg in unistd.h ?
Best Regards
Guo Ren
8 Oct
8 Oct
5:47 p.m.
New subject: devel Digest, Vol 52, Issue 2
On 10/7/2018 8:12 AM, Guo Ren wrote:
https://cgit.uclibc-ng.org/cgi/cgit/uclibc-ng.git/commit/?id=6e15fafa200666…
+# ifdef __NR_recvmmsg
^^^^^^^^^^^^^
+ return (ssize_t)INLINE_SYSCALL(recvmmsg, 5, sockfd, msg, vlen, flags, tmo);
+# else
......
+ return (ssize_t)__socketcall(SYS_RECVMMSG, args);
+# endif
+}
You kernel define __NR_recvmmsg in unistd.h ?
Grepping through my toolchain the only occurrence of "__NR_recvmmsg" is
the following.
/* #define __NR_recvmmsg (__NR_Linux + 298) */
Which appears to be commented out, in include/asm/unistd.h
include/sys/socket.h does contain some code referring to recvmmsg.
I've linked both files here, the only place where such references are found.
https://files.lancethepants.com/files/unistd.h
https://files.lancethepants.com/files/socket.h
This is the actual toolchain + libraries I use to natively compile apps
on mipsel router with old kernel if you like to look at it.
https://files.lancethepants.com/Tomatoware/v1.6/
This is a autoconf example bit that is detecting recvmmsg present.
for ac_func in asprintf daemon fchmod flock fork gettimeofday mlockall
putenv recvmmsg strsignal nanosleep unsetenv vsyslog devname fdevname
do :
as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
cat >>confdefs.h <<_ACEOF
#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
Lance
2237
days inactive
2238
days old
1 comments
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Guo Ren -
Lance Fredrickson