Bug #71219 [Fbk->Opn]: php's configure script incorrectly checks for ttyname_r availability

Edit report at https://bugs.php.net/bug.php?id=71219&edit=1

 ID:                 71219
 User updated by:    atoth at atoth dot sote dot hu
 Reported by:        atoth at atoth dot sote dot hu
 Summary:            php's configure script incorrectly checks for
                     ttyname_r availability
-Status:             Feedback
+Status:             Open
 Type:               Bug
 Package:            *Compile Issues
 Operating System:   Linux (Gentoo Hardened)
 PHP Version:        5.6.16
 Block user comment: N
 Private report:     N

 New Comment:

Your logic is right, however the test still returns false.

"checking for working ttyname_r() implementation... no, posix_ttyname() will be thread-unsafe"

configure.log show this:
"configure:79083: checking for working ttyname_r() implementation
configure:79104: x86_64-pc-linux-gnu-gcc -o conftest -I/usr/include -O2 -march=native -pipe -pthread  -D_REENTRANT -L/usr/lib64 -Wl,-O1 -Wl,--as-needed conftest.c -liodbc -lmcrypt -lltdl -lonig -lstdc++ -lcrypto -lssl -lcrypto -lcrypt -lpam -lgmp -lt1 -lX11 -lXpm -lpng -lz -ljpeg -lvpx -lcrypto -lssl -lcrypto -lenchant -ldb-5.1 -lgdbm -lcurl -lbz2 -lz -lpcre -lcrypto -lssl -lcrypto -lrt -lm -ldl -lnsl  -lxml2 -lz -lm -ldl -lcurl -lnghttp2 -lidn -lrtmp -lz -lgmp -lgnutls -lhogweed -lnettle -lssh2 -lssh2 -lssl3 -lsmime3 -lnss3 -lnssutil3 -lplds4 -lplc4 -lnspr4 -lz -lxml2 -lz -lm -ldl -lfreetype -licui18n -licuuc -licudata -licuio -liodbc -liodbcinst -ldl -lodbc >&5
configure:79104: $? = 0
configure:79104: ./conftest
configure:79104: $? = 1
configure: program exited with status 1
configure: failed program was:
| /* confdefs.h */
| #define PACKAGE_NAME ""
| #define PACKAGE_TARNAME ""
| #define PACKAGE_VERSION ""
--
| #define HAVE_GETPWUID_R 1
| #define HAVE_GETGRGID_R 1
| /* end confdefs.h.  */
|
| #include <unistd.h>
|
| int main(int argc, char *argv[])
| {
|       char buf[64];
|
|       return ttyname_r(0, buf, 64) ? 1 : 0;
| }
|
configure:79114: result: no, posix_ttyname() will be thread-unsafe"

I modified the check to output the return value, which was turned out to be: 25.
Errno #25 means: ENOTTY.

I modified the test program like this:
"
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>

int main(int argc, char *argv[])
{
        char buf[64];
        int retval;

        retval = ttyname_r(0, buf, 64);
        printf("\nretval 0: %s, fd path 0: %s.\n", strerror(retval), buf);
        retval = ttyname_r(1, buf, 64);
        printf("retval 1: %s, fd path 1: %s.\n", strerror(retval), buf);
        retval = ttyname_r(2, buf, 64);
        printf("retval 2: %s, fd path 2: %s.\n", strerror(retval), buf);

        return ttyname_r(0, buf, 64) ? 1 : 0;
}
"

This is the output I got:
checking for working ttyname_r() implementation...
retval 0: Inappropriate ioctl for device, fd path 0: H1gB?.
retval 1: Success, fd path 1: /dev/pts/2.
retval 2: Inappropriate ioctl for device, fd path 2: /dev/pts/2.

So my logic was wrong, but checking for fd 0 is inappropriate.
I guess ti would be better to check for fd 1, instead!

What's your opinion?


Previous Comments:
------------------------------------------------------------------------
[2015-12-26 05:11:46] [email protected]

I don't understant the problem here,

if ttyname_r() return 0; it mean success, then:

 return ttyname_r(0, buf, 64) ? 1 : 0;

return 0, action-if-true is evaluated. seems correct to me.

------------------------------------------------------------------------
[2015-12-25 18:34:19] atoth at atoth dot sote dot hu

Description:
------------
While PHP's configure script checks for ttyname_r it uses this code snippet:
return ttyname_r(0, buf, 64) ? 1 : 0;
Although ttyname returns a pointer to the fd's null-terminated pathname or NULL on error - ttyname_r behaves differently: it stores the pathname in a buffer and returns 0 on success or an error number.
http://linux.die.net/man/3/ttyname_r
Therefore the above cited check will report a failure upon success.
Configure emits a messages about posix_ttyname being thread unsafe, despite ttyname_r is available.

I suggest to change the test logic by taking into account the return values. I attach a trivial example patch below.

Please note, that this minor issue affects both 5.6* and the new 7.0* branches. I could not select both branches for the report...



------------------------------------------------------------------------



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Edit this bug report at https://bugs.php.net/bug.php?id=71219&edit=1