Date: Mon, 24 Aug 2020 12:49:51 +0000 (UTC) From: Edward Tomasz Napierala <trasz@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r364666 - in stable/12: share/man/man4 sys/compat/linux Message-ID: <202008241249.07OCnpOq034763@repo.freebsd.org>
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Author: trasz Date: Mon Aug 24 12:49:51 2020 New Revision: 364666 URL: https://svnweb.freebsd.org/changeset/base/364666 Log: MFC r362015: Make linux(4) set the openfiles soft resource limit to 1024 for Linux applications, which often depend on this being the case. There's a new sysctl, compat.linux.default_openfiles, to control this behaviour. Sponsored by: The FreeBSD Foundation Modified: stable/12/share/man/man4/linux.4 stable/12/sys/compat/linux/linux_emul.c stable/12/sys/compat/linux/linux_mib.c stable/12/sys/compat/linux/linux_mib.h Directory Properties: stable/12/ (props changed) Modified: stable/12/share/man/man4/linux.4 ============================================================================== --- stable/12/share/man/man4/linux.4 Mon Aug 24 12:47:20 2020 (r364665) +++ stable/12/share/man/man4/linux.4 Mon Aug 24 12:49:51 2020 (r364666) @@ -24,7 +24,7 @@ .\" .\" $FreeBSD$ .\" -.Dd December 16, 2019 +.Dd June 10, 2020 .Dt LINUX 4 .Os .Sh NAME @@ -95,6 +95,10 @@ variables and .Xr loader 8 tunables: .Bl -tag -width indent +.It Va compat.linux.default_openfiles +Default soft openfiles resource limit for Linux applications. +Set to -1 to disable the limit. +Defaults to 1024. .It Va compat.linux.emul_path Path to the Linux run-time environment. Defaults to Modified: stable/12/sys/compat/linux/linux_emul.c ============================================================================== --- stable/12/sys/compat/linux/linux_emul.c Mon Aug 24 12:47:20 2020 (r364665) +++ stable/12/sys/compat/linux/linux_emul.c Mon Aug 24 12:49:51 2020 (r364666) @@ -42,10 +42,12 @@ __FBSDID("$FreeBSD$"); #include <sys/mutex.h> #include <sys/sx.h> #include <sys/proc.h> +#include <sys/resourcevar.h> #include <sys/syscallsubr.h> #include <sys/sysent.h> #include <compat/linux/linux_emul.h> +#include <compat/linux/linux_mib.h> #include <compat/linux/linux_misc.h> #include <compat/linux/linux_persona.h> #include <compat/linux/linux_util.h> @@ -87,6 +89,32 @@ pem_find(struct proc *p) return (pem); } +/* + * Linux apps generally expect the soft open file limit to be set + * to 1024, often iterating over all the file descriptors up to that + * limit instead of using closefrom(2). Give them what they want, + * unless there already is a resource limit in place. + */ +static void +linux_set_default_openfiles(struct thread *td, struct proc *p) +{ + struct rlimit rlim; + int error; + + if (linux_default_openfiles < 0) + return; + + PROC_LOCK(p); + lim_rlimit_proc(p, RLIMIT_NOFILE, &rlim); + PROC_UNLOCK(p); + if (rlim.rlim_cur != rlim.rlim_max || + rlim.rlim_cur <= linux_default_openfiles) + return; + rlim.rlim_cur = linux_default_openfiles; + error = kern_proc_setrlimit(td, p, RLIMIT_NOFILE, &rlim); + KASSERT(error == 0, ("kern_proc_setrlimit failed")); +} + void linux_proc_init(struct thread *td, struct thread *newtd, int flags) { @@ -115,6 +143,8 @@ linux_proc_init(struct thread *td, struct thread *newt p->p_emuldata = pem; } newtd->td_emuldata = em; + + linux_set_default_openfiles(td, p); } else { p = td->td_proc; Modified: stable/12/sys/compat/linux/linux_mib.c ============================================================================== --- stable/12/sys/compat/linux/linux_mib.c Mon Aug 24 12:47:20 2020 (r364665) +++ stable/12/sys/compat/linux/linux_mib.c Mon Aug 24 12:49:51 2020 (r364666) @@ -62,6 +62,11 @@ static unsigned linux_osd_jail_slot; SYSCTL_NODE(_compat, OID_AUTO, linux, CTLFLAG_RW, 0, "Linux mode"); +int linux_default_openfiles = 1024; +SYSCTL_INT(_compat_linux, OID_AUTO, default_openfiles, CTLFLAG_RWTUN, + &linux_default_openfiles, 0, + "Default soft openfiles resource limit, or -1 for unlimited"); + int linux_ignore_ip_recverr = 1; SYSCTL_INT(_compat_linux, OID_AUTO, ignore_ip_recverr, CTLFLAG_RWTUN, &linux_ignore_ip_recverr, 0, "Ignore enabling IP_RECVERR"); Modified: stable/12/sys/compat/linux/linux_mib.h ============================================================================== --- stable/12/sys/compat/linux/linux_mib.h Mon Aug 24 12:47:20 2020 (r364665) +++ stable/12/sys/compat/linux/linux_mib.h Mon Aug 24 12:49:51 2020 (r364666) @@ -62,6 +62,7 @@ int linux_kernver(struct thread *td); #define linux_use26(t) (linux_kernver(t) >= LINUX_KERNVER_2006000) +extern int linux_default_openfiles; extern int linux_ignore_ip_recverr; extern int linux_preserve_vstatus; extern bool linux_map_sched_prio;
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