Messages in this thread Patch in this message | | | Date | Fri, 12 Sep 2008 13:06:39 +0200 | From | Adam Tkac <> | Subject | [PATCH 2.6.27-rc5] Allow set RLIMIT_NOFILE to RLIM_INFINITY |
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When a process wants to set the limit of open files to RLIM_INFINITY it gets EPERM even if it has CAP_SYS_RESOURCE capability.
For example, BIND does:
... #elif defined(NR_OPEN) && defined(__linux__) /* * Some Linux kernels don't accept RLIM_INFINIT; the maximum * possible value is the NR_OPEN defined in linux/fs.h. */ if (resource == isc_resource_openfiles && rlim_value == RLIM_INFINITY) { rl.rlim_cur = rl.rlim_max = NR_OPEN; unixresult = setrlimit(unixresource, &rl); if (unixresult == 0) return (ISC_R_SUCCESS); } #elif ...
If we allow setting RLIMIT_NOFILE to RLIM_INFINITY we increase portability - you don't have to check if OS is linux and then use different schema for limits.
The spec says "Specifying RLIM_INFINITY as any resource limit value on a successful call to setrlimit() shall inhibit enforcement of that resource limit." and we're presently not doing that.
Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Signed-off-by: Adam Tkac <vonsch@gmail.com> Tested-by: Adam Tkac <vonsch@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> ---
kernel/sys.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff -puN kernel/sys.c~rlimit-permit-setting-rlimit_nofile-to-rlim_infinity kernel/sys.c --- a/kernel/sys.c~rlimit-permit-setting-rlimit_nofile-to-rlim_infinity +++ a/kernel/sys.c @@ -1532,8 +1532,14 @@ asmlinkage long sys_setrlimit(unsigned i if ((new_rlim.rlim_max > old_rlim->rlim_max) && !capable(CAP_SYS_RESOURCE)) return -EPERM; - if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open) - return -EPERM; + if (resource == RLIMIT_NOFILE) { + if (new_rlim.rlim_max == RLIM_INFINITY) + new_rlim.rlim_max = sysctl_nr_open; + if (new_rlim.rlim_cur == RLIM_INFINITY) + new_rlim.rlim_cur = sysctl_nr_open; + if (new_rlim.rlim_max > sysctl_nr_open) + return -EPERM; + } retval = security_task_setrlimit(resource, &new_rlim); if (retval)
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