linux/arch/s390/kernel
Jason A. Donenfeld 9592eef7c1 random: remove CONFIG_ARCH_RANDOM
When RDRAND was introduced, there was much discussion on whether it
should be trusted and how the kernel should handle that. Initially, two
mechanisms cropped up, CONFIG_ARCH_RANDOM, a compile time switch, and
"nordrand", a boot-time switch.

Later the thinking evolved. With a properly designed RNG, using RDRAND
values alone won't harm anything, even if the outputs are malicious.
Rather, the issue is whether those values are being *trusted* to be good
or not. And so a new set of options were introduced as the real
ones that people use -- CONFIG_RANDOM_TRUST_CPU and "random.trust_cpu".
With these options, RDRAND is used, but it's not always credited. So in
the worst case, it does nothing, and in the best case, maybe it helps.

Along the way, CONFIG_ARCH_RANDOM's meaning got sort of pulled into the
center and became something certain platforms force-select.

The old options don't really help with much, and it's a bit odd to have
special handling for these instructions when the kernel can deal fine
with the existence or untrusted existence or broken existence or
non-existence of that CPU capability.

Simplify the situation by removing CONFIG_ARCH_RANDOM and using the
ordinary asm-generic fallback pattern instead, keeping the two options
that are actually used. For now it leaves "nordrand" for now, as the
removal of that will take a different route.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-07-18 15:03:37 +02:00
..
syscalls arch: syscalls: simplify uapi/kapi directory creation 2022-03-31 12:03:46 +09:00
vdso32 s390/vdso: remove -nostdlib compiler flag 2021-11-16 12:29:19 +01:00
vdso64 s390/vdso: filter out -mstack-guard and -mstack-size 2021-11-16 12:29:19 +01:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
alternative.c s390/alternatives: remove padding generation code 2022-05-17 15:16:28 +02:00
asm-offsets.c s390/stack: add union to reflect kvm stack slot usages 2022-06-01 12:03:17 +02:00
audit.c audit: add support for the openat2 syscall 2021-10-01 16:52:48 -04:00
audit.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cache.c s390: raise minimum supported machine generation to z10 2022-03-10 15:58:17 +01:00
compat_audit.c audit: add support for the openat2 syscall 2021-10-01 16:52:48 -04:00
compat_linux.c s390: use generic UID16 implementation 2019-01-18 09:33:18 +01:00
compat_linux.h s390/compat: cleanup compat_linux.h header file 2022-05-06 20:45:16 +02:00
compat_ptrace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat_signal.c s390/signal: fix typo in comments 2022-03-08 00:33:01 +01:00
cpcmd.c s390/cpcmd: use physical address for command and response 2021-10-26 15:21:28 +02:00
crash_dump.c s390/crash: make copy_oldmem_page() return number of bytes copied 2022-06-23 17:23:30 +02:00
debug.c s390/sclp: add tracing of SCLP interactions 2021-08-25 11:03:35 +02:00
diag.c s390/extable: move EX_TABLE define to asm-extable.h 2022-03-08 00:33:00 +01:00
dis.c s390/disassembler: update opcode table 2021-12-16 19:58:07 +01:00
dumpstack.c exit: Add and use make_task_dead. 2021-12-13 12:04:45 -06:00
early_printk.c s390/sclp: remove unused sclp_early_printk_forced 2020-09-21 08:08:44 +02:00
early.c s390: simplify early program check handler 2022-05-25 11:46:02 +02:00
earlypgm.S s390: generate register offsets into pt_regs automatically 2022-05-25 11:46:02 +02:00
ebcdic.c s390: ebcdic: convert comments to UTF-8 2018-08-23 18:48:43 -07:00
entry.h s390: simplify early program check handler 2022-05-25 11:46:02 +02:00
entry.S s390/mcck: isolate SIE instruction when setting CIF_MCCK_GUEST flag 2022-06-01 12:03:16 +02:00
fpu.c s390: convert to generic entry 2021-01-19 12:29:26 +01:00
ftrace.c ftrace: Remove return value of ftrace_arch_modify_*() 2022-05-26 21:13:00 -04:00
ftrace.h s390: raise minimum supported machine generation to z10 2022-03-10 15:58:17 +01:00
guarded_storage.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-11-13 11:47:01 -08:00
head64.S s390: remove invalid email address of Heiko Carstens 2022-02-06 23:31:29 +01:00
idle.c s390/time,idle: get rid of unsigned long long 2021-03-08 10:46:27 +01:00
ima_arch.c s390/kexec_file: Disable kexec_load when IPLed secure 2019-04-29 10:44:03 +02:00
ipl_vmparm.c s390/cio: remove unused include linux/spinlock.h from cio.h 2021-07-27 09:39:13 +02:00
ipl.c s390/maccess: rework absolute lowcore accessors 2022-03-27 22:18:39 +02:00
irq.c s390/irq: utilize RCU instead of irq_lock_sparse() in show_msi_interrupt() 2022-04-27 12:53:34 +02:00
jump_label.c s390/jump_label: add __init_or_module annotation 2021-10-11 20:55:58 +02:00
kdebugfs.c s390: no need to check return value of debugfs_create functions 2019-01-28 15:58:55 +01:00
kexec_elf.c kexec: Fix file verification on S390 2019-09-10 13:27:51 +01:00
kexec_image.c kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE 2019-08-19 21:54:15 -07:00
kprobes_insn_page.S s390/kprobes: move insn_page to text segment 2020-10-09 23:45:30 +02:00
kprobes.c s390/kprobes: enable kretprobes framepointer verification 2022-03-27 22:18:39 +02:00
lgr.c s390/lgr: use simple assignment instead of memcpy 2022-02-06 23:31:29 +01:00
machine_kexec_file.c s390/kexec: handle R_390_PLT32DBL rela in arch_kexec_apply_relocations_add() 2021-12-10 16:12:34 +01:00
machine_kexec_reloc.c s390/kaslr: add support for R_390_JMP_SLOT relocation type 2020-05-20 10:13:27 +02:00
machine_kexec.c s390/kexec: set end-of-ipl flag in last diag308 call 2022-04-25 13:54:12 +02:00
Makefile s390: simplify early program check handler 2022-05-25 11:46:02 +02:00
mcount.S s390/kprobes: Avoid additional kprobe in kretprobe handling 2022-03-10 15:58:17 +01:00
module.c Merge branch 'akpm' (patches from Andrew) 2022-03-25 10:21:20 -07:00
nmi.c s390/pai: add support for cryptography counters 2022-05-09 11:50:01 +02:00
nospec-branch.c s390: raise minimum supported machine generation to z10 2022-03-10 15:58:17 +01:00
nospec-sysfs.c s390: introduce nospec_uses_trampoline() 2021-10-26 15:21:29 +02:00
numa.c drivers/base/node: consolidate node device subsystem initialization in node_dev_init() 2022-03-22 15:57:10 -07:00
os_info.c s390/maccess: rework absolute lowcore accessors 2022-03-27 22:18:39 +02:00
perf_cpum_cf_common.c s390/cpumf: Support for CPU Measurement Facility CSVN 7 2022-01-17 14:13:08 +01:00
perf_cpum_cf_events.c s390/cpumf: add new extended counter set for IBM z16 2022-05-16 10:58:33 +02:00
perf_cpum_cf.c s390/cpumf: Handle events cycles and instructions identical 2022-06-23 17:23:59 +02:00
perf_cpum_sf.c s390/cpumf: Support for CPU Measurement Sampling Facility LS bit 2022-01-17 14:13:08 +01:00
perf_event.c s390/stack: add union to reflect kvm stack slot usages 2022-06-01 12:03:17 +02:00
perf_pai_crypto.c s390/pai: Fix multiple concurrent event installation 2022-06-23 17:24:00 +02:00
perf_regs.c perf/arch: Remove perf_sample_data::regs_user_copy 2020-11-09 18:12:34 +01:00
process.c fork: Generalize PF_IO_WORKER handling 2022-05-07 09:01:59 -05:00
processor.c s390: add z16 elf platform 2022-04-06 13:08:50 +02:00
ptrace.c ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
reipl.S s390: add missing ENDPROC statements to assembler functions 2019-05-02 13:54:11 +02:00
relocate_kernel.S s390/kexec: set end-of-ipl flag in last diag308 call 2022-04-25 13:54:12 +02:00
runtime_instr.c s390/runtime_instrumentation: fix storage key handling 2020-08-17 13:17:10 +02:00
setup.c random: remove CONFIG_ARCH_RANDOM 2022-07-18 15:03:37 +02:00
signal.c ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
smp.c s390/smp: use physical address for SIGP_SET_PREFIX command 2022-03-27 22:18:39 +02:00
stacktrace.c s390: remove invalid email address of Heiko Carstens 2022-02-06 23:31:29 +01:00
sthyi.c s390/sthyi: use register pair instead of register asm 2021-06-18 16:41:22 +02:00
syscall.c s390: add support for BEAR enhancement facility 2021-10-26 15:21:29 +02:00
sysinfo.c s390/extable: move EX_TABLE define to asm-extable.h 2022-03-08 00:33:00 +01:00
text_amode31.S s390/extable: move EX_TABLE define to asm-extable.h 2022-03-08 00:33:00 +01:00
time.c s390/stp: clock_delta should be signed 2022-05-11 14:40:57 +02:00
topology.c s390: remove invalid email address of Heiko Carstens 2022-02-06 23:31:29 +01:00
trace.c s390/ftrace: fix potential crashes when switching tracers 2020-04-22 16:20:55 +02:00
traps.c s390/traps: improve panic message for translation-specification exception 2022-03-27 22:18:38 +02:00
unwind_bc.c s390/unwind: avoid duplicated unwinding entries for kretprobes 2022-03-27 22:18:39 +02:00
uprobes.c s390: raise minimum supported machine generation to z10 2022-03-10 15:58:17 +01:00
uv.c s390/uv: fix memblock virtual vs physical address confusion 2021-12-16 19:58:07 +01:00
vdso.c s390/vdso: add vdso randomization 2022-04-25 13:54:15 +02:00
vmlinux.lds.S s390: remove .fixup section 2022-03-08 00:33:01 +01:00
vtime.c s390: assume stckf is always present 2022-03-10 15:58:17 +01:00