Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#!/usr/bin/env bash
2
3set -euo pipefail
4
5TIMEOUT=10
6
7function do_one
8{
9 local mitigation="$1"
10 local orig
11 local start
12 local now
13
14 orig=$(cat "$mitigation")
15
16 start=$(date +%s)
17 now=$start
18
19 while [[ $((now-start)) -lt "$TIMEOUT" ]]
20 do
21 echo 0 > "$mitigation"
22 echo 1 > "$mitigation"
23
24 now=$(date +%s)
25 done
26
27 echo "$orig" > "$mitigation"
28}
29
30rc=0
31cd /sys/kernel/debug/powerpc || rc=1
32if [[ "$rc" -ne 0 ]]; then
33 echo "Error: couldn't cd to /sys/kernel/debug/powerpc" >&2
34 exit 1
35fi
36
37tainted=$(cat /proc/sys/kernel/tainted)
38if [[ "$tainted" -ne 0 ]]; then
39 echo "Warning: kernel already tainted! ($tainted)" >&2
40fi
41
42mitigations="barrier_nospec stf_barrier count_cache_flush rfi_flush entry_flush uaccess_flush"
43
44for m in $mitigations
45do
46 if [[ -f /sys/kernel/debug/powerpc/$m ]]
47 then
48 do_one "$m" &
49 fi
50done
51
52echo "Spawned threads enabling/disabling mitigations ..."
53
54if stress-ng > /dev/null 2>&1; then
55 stress="stress-ng"
56elif stress > /dev/null 2>&1; then
57 stress="stress"
58else
59 stress=""
60fi
61
62if [[ -n "$stress" ]]; then
63 "$stress" -m "$(nproc)" -t "$TIMEOUT" &
64 echo "Spawned VM stressors ..."
65fi
66
67echo "Waiting for timeout ..."
68wait
69
70orig_tainted=$tainted
71tainted=$(cat /proc/sys/kernel/tainted)
72if [[ "$tainted" != "$orig_tainted" ]]; then
73 echo "Error: kernel newly tainted, before ($orig_tainted) after ($tainted)" >&2
74 exit 1
75fi
76
77echo "OK"
78exit 0