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grep-2.27-1 fails when >/dev/null 2>&1

From Lars Bro@21:1/5 to All on Tue Jan 3 21:50:02 2017

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Hi list,

I am using Debian Stretch, obtained with debootstrap (as of Jan 02 2017).
Linux kernel of the host is 4.4.6, and the following is run in a chroot.
File system is ext4.

When I try to run "./configure" of one of the applications I use, it fails, claiming that gmake is not present.

When looking into the "configure script" I find this construct:

/bin/sh -c 'make --version | grep GNU' >/dev/null 2>&1

And when I test it, I see this:

root@mini:/# /bin/sh -c 'make --version | grep GNU' >/dev/null 2>&1 root@mini:/# echo $?
2
root@mini:/# /bin/sh -c 'make --version | grep GNU' >/dev/null 2>/dev/null root@mini:/# echo $?

0
root@mini:/#

There is apparently something that goes wrong when "dup(2)" is used as in

&1

I did an strace of the two constructs:
This is the failing:

"/bin/sh -c 'make --version | gre"..., 8192) = 55
open("/dev/null", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3
fcntl(1, F_DUPFD, 10) = 11
close(1) = 0
fcntl(11, F_SETFD, FD_CLOEXEC) = 0
dup2(3, 1) = 1
close(3) = 0
fcntl(2, F_DUPFD, 10) = 12
close(2) = 0
fcntl(12, F_SETFD, FD_CLOEXEC) = 0
dup2(1, 2)

[pid 11678] read(0, "GNU Make 4.1\nBuilt for x86_64-pc"..., 32768) =
297
[pid 11678] splice(0, NULL, 1, NULL, 32768, SPLICE_F_MOVE) = -1
EINVAL
(Invalid argument)

And this one works

read(0, /bin/sh -c 'make --version | grep GNU' > /dev/null

/dev/null

" /bin/sh -c 'make --version | gr"..., 8192) = 64
open("/dev/null", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3
fcntl(1, F_DUPFD, 10) = 11
close(1) = 0
fcntl(11, F_SETFD, FD_CLOEXEC) = 0
dup2(3, 1) = 1
close(3) = 0
open("/dev/null", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3
fcntl(2, F_DUPFD, 10) = 12
close(2) = 0
fcntl(12, F_SETFD, FD_CLOEXEC) = 0
dup2(3, 2) = 2
close(3)

[pid 11689] read(0, "GNU Make 4.1\nBuilt for x86_64-pc"..., 32768) =
297
[pid 11689] splice(0, NULL, 1, NULL, 32768, SPLICE_F_MOVE) = 0

This suggests that there is something with the "splice(2)" system call.

I tried with grep_2.25-6 wich was in Stretch before. It works as below:

[pid 11821] <... read resumed> "GNU Make 4.1\nBuilt for x86_64-
pc"...,
32768) = 297
...
[pid 11821] read(0, "", 32768) = 0
[pid 11821] write(1, "GNU Make 4.1\nLicense GPLv3+: GNU"..., 91) = 91

It seems to work because it uses read(0,...) and write(1,...) instead of splice().

I could temporarily downgrade grep to that version, but I fear that the
problem may be of a more general nature.

yours,

Lars Bro

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<div dir="ltr">Hi list, I am using Debian Stretch, obtained with debootstrap (as of Jan 02 2017). Linux kernel of the host is 4.4.6, and the following is run in a chroot. File system is ext4. When I try to run "./configure" of one
of the applications I use, it fails, claiming that gmake is not present. When looking into the "configure script" I find this construct: /bin/sh -c 'make --version | grep GNU' >/dev/null 2>&1 And when I
test it, I see this: root@mini:/# /bin/sh -c 'make --version | grep GNU' >/dev/null 2>&1 root@mini:/# echo $? 2 root@mini:/# /bin/sh -c 'make --version | grep GNU' >/dev/null 2>/dev/null root@mini:/#
echo $? 0 root@mini:/# There is apparently something that goes wrong when "dup(2)" is used as in 2>&1 I did an strace of the two constructs: This is the failing: "/bin/sh -c 'make --version | gre&
quot;..., 8192) = 55 open("/dev/null", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3 fcntl(1, F_DUPFD, 10) = 11 close(1) = 0 fcntl(11, F_SETFD, FD_CLOEXEC) �
�= 0 dup2(3, 1) = 1 close(3) = 0 fcntl(2, F_DUPFD, 10) = 12 close(2) = 0 
fcntl(12, F_SETFD, FD_CLOEXEC) = 0 dup2(1, 2) [pid 11678] read(0, "GNU Make 4.1\nBuilt for x86_64-pc"..., 32768) = 297 [pid 11678] splice(0, NULL, 1, NULL, 32768, SPLICE_F_MOVE) = -1 EINVAL (Invalid argument)
 And this one works read(0, /bin/sh -c 'make --version | grep GNU' > /dev/null 2>/dev/null " /bin/sh -c 'make --version | gr"..., 8192) = 64 open("/dev/null", O_WRONLY|O_CREAT|O_TRUNC,
0666) = 3 fcntl(1, F_DUPFD, 10) = 11 close(1) = 0 fcntl(11, F_SETFD, FD_CLOEXEC) = 0 dup2(3, 1) = 1 close(3)
= 0 open("/dev/null", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 3 fcntl(2, F_DUPFD, 10) = 12 close(2) = 0 fcntl(12, F_
SETFD, FD_CLOEXEC) = 0 dup2(3, 2) = 2 close(3) [pid 11689] read(0, "GNU Make 4.1\nBuilt for x86_64-pc"..., 32768) = 297 [pid 11689] splice(0, NULL, 1, NULL, 32768,
SPLICE_F_MOVE) = 0 This suggests that there is something with the "splice(2)" system call. I tried with grep_2.25-6 wich was in Stretch before. It works as below: [pid 11821] <... read resumed> "GNU Make 4.1\
nBuilt for x86_64- pc"..., 32768) = 297 ... [pid 11821] read(0, "", 32768) = 0 [pid 11821] write(1, "GNU Make 4.1\nLicense GPLv3+: GNU"..., 91) = 91 It seems to work because it uses read(0,
...) and write(1,...) instead of splice(). I could temporarily downgrade grep to that version, but I fear that the problem may be of a more general nature. yours, Lars Bro </div>

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From Adrian Bunk@21:1/5 to Lars Bro on Sun Jan 15 23:10:02 2017

On Tue, Jan 03, 2017 at 09:39:59PM +0100, Lars Bro wrote:

Hi list,

Hi Lars,

I am using Debian Stretch, obtained with debootstrap (as of Jan 02 2017). Linux kernel of the host is 4.4.6, and the following is run in a chroot.
File system is ext4.

When I try to run "./configure" of one of the applications I use, it fails, claiming that gmake is not present.

When looking into the "configure script" I find this construct:

/bin/sh -c 'make --version | grep GNU' >/dev/null 2>&1

And when I test it, I see this:

root@mini:/# /bin/sh -c 'make --version | grep GNU' >/dev/null 2>&1 root@mini:/# echo $?
2
root@mini:/# /bin/sh -c 'make --version | grep GNU' >/dev/null 2>/dev/null root@mini:/# echo $?
0
root@mini:/#
...

thanks for your report, can you submit it as a bug report against the
grep package?

Upstream bug report and patch for this issue are at
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=25283

yours,

Lars Bro

Thanks
Adrian

--

"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed

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grep-2.27-1 fails when >/dev/null 2>&1

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