linux_dsm_epyc7002/lib
Linus Torvalds 91f28da8c9 random32: make prandom_u32() less predictable
This is the cleanup of the latest series of prandom_u32 experimentations
 consisting in using SipHash instead of Tausworthe to produce the randoms
 used by the network stack. The changes to the files were kept minimal,
 and the controversial commit that used to take noise from the fast_pool
 (f227e3ec3b) was reverted. Instead, a dedicated "net_rand_noise" per_cpu
 variable is fed from various sources of activities (networking, scheduling)
 to perturb the SipHash state using fast, non-trivially predictable data,
 instead of keeping it fully deterministic. The goal is essentially to make
 any occasional memory leakage or brute-force attempt useless.
 
 The resulting code was verified to be very slightly faster on x86_64 than
 what is was with the controversial commit above, though this remains barely
 above measurement noise. It was also tested on i386 and arm, and build-
 tested only on arm64.
 
 The whole discussion around this is archived here:
   https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
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Merge tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom

Pull random32 updates from Willy Tarreau:
 "Make prandom_u32() less predictable.

  This is the cleanup of the latest series of prandom_u32
  experimentations consisting in using SipHash instead of Tausworthe to
  produce the randoms used by the network stack.

  The changes to the files were kept minimal, and the controversial
  commit that used to take noise from the fast_pool (f227e3ec3b) was
  reverted. Instead, a dedicated "net_rand_noise" per_cpu variable is
  fed from various sources of activities (networking, scheduling) to
  perturb the SipHash state using fast, non-trivially predictable data,
  instead of keeping it fully deterministic. The goal is essentially to
  make any occasional memory leakage or brute-force attempt useless.

  The resulting code was verified to be very slightly faster on x86_64
  than what is was with the controversial commit above, though this
  remains barely above measurement noise. It was also tested on i386 and
  arm, and build- tested only on arm64"

Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/

* tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom:
  random32: add a selftest for the prandom32 code
  random32: add noise from network and scheduling activity
  random32: make prandom_u32() output unpredictable
2020-10-25 10:40:08 -07:00
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.gitignore
argv_split.c
ashldi3.c
ashrdi3.c
asn1_decoder.c
assoc_array.c
atomic64_test.c
atomic64.c
audit.c
bcd.c
bch.c
bitfield_kunit.c
bitmap.c
bitrev.c
bootconfig.c
bsearch.c
btree.c
bucket_locks.c
bug.c
build_OID_registry
bust_spinlocks.c
check_signature.c
checksum.c
clz_ctz.c
clz_tab.c
cmdline.c
cmpdi2.c
compat_audit.c
cpu_rmap.c
cpumask.c
crc4.c
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crc8.c
crc16.c
crc32.c
crc32defs.h
crc32test.c
crc64.c
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
ctype.c
debug_info.c
debug_locks.c
debugobjects.c
dec_and_lock.c
decompress_bunzip2.c
decompress_inflate.c
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress_unzstd.c
decompress.c
devres.c
digsig.c
dump_stack.c
dynamic_debug.c
dynamic_queue_limits.c
earlycpio.c
errname.c
error-inject.c
errseq.c
extable.c
fault-inject-usercopy.c
fault-inject.c
fdt_addresses.c
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_bit_benchmark.c
find_bit.c
flex_proportions.c
gen_crc32table.c
gen_crc64table.c
genalloc.c
generic-radix-tree.c
glob.c
globtest.c
hexdump.c
hweight.c
idr.c
inflate.c
interval_tree_test.c
interval_tree.c
iomap_copy.c
iomap.c
iommu-helper.c
iov_iter.c
irq_poll.c
irq_regs.c
is_single_threaded.c
kasprintf.c
Kconfig
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Kconfig.kasan
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kfifo.c
klist.c
kobject_uevent.c
kobject.c
kstrtox.c
kstrtox.h
libcrc32c.c
linear_ranges.c
list_debug.c
list_sort.c
list-test.c
llist.c
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-rtmutex.h
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c
lockref.c
logic_pio.c
lru_cache.c
lshrdi3.c
Makefile
memcat_p.c
memory-notifier-error-inject.c
memregion.c
memweight.c
muldi3.c
net_utils.c
netdev-notifier-error-inject.c
nlattr.c
nmi_backtrace.c
nodemask.c
notifier-error-inject.c
notifier-error-inject.h
objagg.c
of-reconfig-notifier-error-inject.c
oid_registry.c
once.c
packing.c
parman.c
parser.c
pci_iomap.c
percpu_counter.c
percpu_test.c
percpu-refcount.c
plist.c
pm-notifier-error-inject.c
radix-tree.c
random32.c
ratelimit.c
rbtree_test.c
rbtree.c
refcount.c
rhashtable.c
sbitmap.c
scatterlist.c
seq_buf.c
sg_pool.c
sg_split.c
sha1.c
show_mem.c
siphash.c
smp_processor_id.c
sort.c
stackdepot.c
stmp_device.c
string_helpers.c
string.c
strncpy_from_user.c
strnlen_user.c
syscall.c
test_bitmap.c
test_bitops.c
test_bits.c
test_blackhole_dev.c
test_bpf.c
test_debug_virtual.c
test_firmware.c
test_fpu.c
test_free_pages.c
test_hash.c
test_hexdump.c
test_hmm_uapi.h
test_hmm.c
test_ida.c
test_kasan_module.c
test_kasan.c
test_kmod.c
test_linear_ranges.c
test_list_sort.c
test_lockup.c
test_memcat_p.c
test_meminit.c
test_min_heap.c
test_module.c
test_objagg.c
test_overflow.c
test_parman.c
test_printf.c
test_rhashtable.c
test_siphash.c
test_sort.c
test_stackinit.c
test_static_key_base.c
test_static_keys.c
test_string.c
test_strscpy.c
test_sysctl.c
test_ubsan.c
test_user_copy.c
test_uuid.c
test_vmalloc.c
test_xarray.c
test-kstrtox.c
test-string_helpers.c
textsearch.c
timerqueue.c
ts_bm.c
ts_fsm.c
ts_kmp.c
ubsan.c
ubsan.h
ucmpdi2.c
ucs2_string.c
usercopy.c
uuid.c
vsprintf.c
win_minmax.c
xarray.c
xxhash.c