From: naruse@... Date: 2014-03-06T10:27:37+00:00 Subject: [ruby-core:61328] [ruby-trunk - Bug #9600] sysconf(_SC_GETGR_R_SIZE_MAX) is just a hint for getgrnam_r() Issue #9600 has been updated by Yui NARUSE. Rei Odaira wrote: > but actually this value is just a hint, so obj2gid() should gradually extend the buffer until getgrnam_r() no longer throws ERANGE. SuSv7 changes it. * http://pubs.opengroup.org/onlinepubs/009695399/functions/getgrnam.html v6's getgrnam_r * http://pubs.opengroup.org/onlinepubs/9699919799/functions/getgrnam.html v7's getgrnam_r * http://pubs.opengroup.org/onlinepubs/9699919799/functions/sysconf.html v7's sysconf > SD5-XSH-ERN-166 is applied, changing "Maximum size" to "Initial size" for the "Maximum size of ..." entries in the table in the DESCRIPTION. But I didn't find SD5-XSH-ERN-166 itself. ---------------------------------------- Bug #9600: sysconf(_SC_GETGR_R_SIZE_MAX) is just a hint for getgrnam_r() https://bugs.ruby-lang.org/issues/9600#change-45653 * Author: Rei Odaira * Status: Open * Priority: Normal * Assignee: * Category: * Target version: * ruby -v: ruby 2.2.0dev (2014-03-05) [powerpc64-linux] * Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN, 2.1: UNKNOWN ---------------------------------------- When there is a group that has a lot of members, TestProcess#test_execopts_gid fails. Following is a more simple example: $ ruby -e 'system("true", gid: "largegroup")' -e:1:in `system': Numerical result out of range - getgrnam_r (Errno::ERANGE) from -e:1:in `
' This wrong exception happens because obj2gid() in process.c calls getgrnam_r() with a buffer that was allocated based on the size returned by sysconf(_SC_GETGR_R_SIZE_MAX). In Linux, sysconf(_SC_GETGR_R_SIZE_MAX) returns 1024, but actually this value is just a hint, so obj2gid() should gradually extend the buffer until getgrnam_r() no longer throws ERANGE. The same issue was reported in the following page: http://tomlee.co/2012/10/problems-with-large-linux-unix-groups-and-getgrgid_r-getgrnam_r/ -- http://bugs.ruby-lang.org/