src/sys/compat/linux/linux_misc.c, branch releng/12.2

MFC r347538 by dchagin:

2020-08-24T17:06:34Z

Linuxulator depends on a fundamental kernel settings such as SMP. Many of them listed in opt_global.h which is not generated while building modules outside of a kernel and such modules never match real cofigured kernel. So, we should prevent our users from building obviously defective modules. Therefore, remove the root cause of the building of modules outside of a kernel - the possibility of building modules with DEBUG or KTR flags. And remove all of DEBUG printfs as it is incomplete and in threaded programms not informative, also a half of system call does not have DEBUG printf. For debuging Linux programms we have dtrace, ktr and ktrace ability. PR: 222861

MFC r356727:

2020-08-24T14:13:20Z

Make linux getcpu(2) report the domain. Submitted by: markj Sponsored by: The FreeBSD Foundation

MFC r349746:

2020-08-24T12:57:03Z

Fix linuxulator prlimit64(2) with pid == 0. This makes 'ulimit -a' return something reasonable, and helps linux binaries which attempt to close all the files, eg apt(8). Sponsored by: The FreeBSD Foundation

MFC r362205:

2020-08-24T12:54:19Z

Make Linux uname(2) return x86_64 to 32-bit apps. This helps Steam. PR: kern/240432 Analyzed by: Alex S Sponsored by: The FreeBSD Foundation

MFC r358673 by tijl:

2020-08-24T12:47:20Z

Move compat.linux.map_sched_prio sysctl definition to linux_mib.c so it is only defined by linux_common kernel module and not both linux and linux64 modules. Reported by: Yuri Pankov

MFC r358483 by tijl:

2020-08-24T12:43:54Z

linuxulator: Map scheduler priorities to Linux priorities. On Linux the valid range of priorities for the SCHED_FIFO and SCHED_RR scheduling policies is [1,99]. For SCHED_OTHER the single valid priority is 0. On FreeBSD it is [0,31] for all policies. Programs are supposed to query the valid range using sched_get_priority_(min|max), but of course some programs assume the Linux values are valid. This commit adds a tunable compat.linux.map_sched_prio. When enabled sched_get_priority_(min|max) return the Linux values and sched_setscheduler and sched_(get|set)param translate between FreeBSD and Linux values. Because there are more Linux levels than FreeBSD levels, multiple Linux levels map to a single FreeBSD level, which means pre-emption might not happen as it does on Linux, so the tunable allows to disable this behaviour. It is enabled by default because I think it is unlikely that anyone runs real-time software under Linux emulation on FreeBSD that critically relies on correct pre-emption. This fixes FMOD, a commercial sound library used by several games. PR: 240043 Tested by: Alex S

MFC r356241:

2020-08-23T20:12:07Z

Add basic getcpu(2) support to linuxulator. The purpose of this syscall is to query the CPU number and the NUMA domain the calling thread is currently running on. The third argument is ignored. It doesn't do anything regarding scheduling - it's literally just a way to query the current state, without any guarantees you won't get rescheduled an opcode later. This unbreaks Java from CentOS 8 (java-11-openjdk-11.0.5.10-0.el8_0.x86_64). Sponsored by: The FreeBSD Foundation

MFC r356177:

2020-08-23T19:59:38Z

Implement Linux syslog(2) syscall; just enough to make Linux dmesg(8) utility work. Sponsored by: The FreeBSD Foundation

MFC r347971:

2020-08-23T19:22:42Z

Implement PTRACE_O_TRACESYSGOOD. This makes Linux strace(1) work. Sponsored by: The FreeBSD Foundation

MFC r362037:

2020-06-17T13:46:05Z

Fix a couple of nits in Linux sysinfo(2) emulation.