cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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short_splice_read.sh (2823B)

      1#!/bin/sh
      2# SPDX-License-Identifier: GPL-2.0
      3#
      4# Test for mishandling of splice() on pseudofilesystems, which should catch
      5# bugs like 11990a5bd7e5 ("module: Correctly truncate sysfs sections output")
      6#
      7# Since splice fallback was removed as part of the set_fs() rework, many of these
      8# tests expect to fail now. See https://lore.kernel.org/lkml/202009181443.C2179FB@keescook/
      9set -e
     10
     11DIR=$(dirname "$0")
     12
     13ret=0
     14
     15expect_success()
     16{
     17	title="$1"
     18	shift
     19
     20	echo "" >&2
     21	echo "$title ..." >&2
     22
     23	set +e
     24	"$@"
     25	rc=$?
     26	set -e
     27
     28	case "$rc" in
     29	0)
     30		echo "ok: $title succeeded" >&2
     31		;;
     32	1)
     33		echo "FAIL: $title should work" >&2
     34		ret=$(( ret + 1 ))
     35		;;
     36	*)
     37		echo "FAIL: something else went wrong" >&2
     38		ret=$(( ret + 1 ))
     39		;;
     40	esac
     41}
     42
     43expect_failure()
     44{
     45	title="$1"
     46	shift
     47
     48	echo "" >&2
     49	echo "$title ..." >&2
     50
     51	set +e
     52	"$@"
     53	rc=$?
     54	set -e
     55
     56	case "$rc" in
     57	0)
     58		echo "FAIL: $title unexpectedly worked" >&2
     59		ret=$(( ret + 1 ))
     60		;;
     61	1)
     62		echo "ok: $title correctly failed" >&2
     63		;;
     64	*)
     65		echo "FAIL: something else went wrong" >&2
     66		ret=$(( ret + 1 ))
     67		;;
     68	esac
     69}
     70
     71do_splice()
     72{
     73	filename="$1"
     74	bytes="$2"
     75	expected="$3"
     76	report="$4"
     77
     78	out=$("$DIR"/splice_read "$filename" "$bytes" | cat)
     79	if [ "$out" = "$expected" ] ; then
     80		echo "      matched $report" >&2
     81		return 0
     82	else
     83		echo "      no match: '$out' vs $report" >&2
     84		return 1
     85	fi
     86}
     87
     88test_splice()
     89{
     90	filename="$1"
     91
     92	echo "  checking $filename ..." >&2
     93
     94	full=$(cat "$filename")
     95	rc=$?
     96	if [ $rc -ne 0 ] ; then
     97		return 2
     98	fi
     99
    100	two=$(echo "$full" | grep -m1 . | cut -c-2)
    101
    102	# Make sure full splice has the same contents as a standard read.
    103	echo "    splicing 4096 bytes ..." >&2
    104	if ! do_splice "$filename" 4096 "$full" "full read" ; then
    105		return 1
    106	fi
    107
    108	# Make sure a partial splice see the first two characters.
    109	echo "    splicing 2 bytes ..." >&2
    110	if ! do_splice "$filename" 2 "$two" "'$two'" ; then
    111		return 1
    112	fi
    113
    114	return 0
    115}
    116
    117### /proc/$pid/ has no splice interface; these should all fail.
    118expect_failure "proc_single_open(), seq_read() splice" test_splice /proc/$$/limits
    119expect_failure "special open(), seq_read() splice" test_splice /proc/$$/comm
    120
    121### /proc/sys/ has a splice interface; these should all succeed.
    122expect_success "proc_handler: proc_dointvec_minmax() splice" test_splice /proc/sys/fs/nr_open
    123expect_success "proc_handler: proc_dostring() splice" test_splice /proc/sys/kernel/modprobe
    124expect_success "proc_handler: special read splice" test_splice /proc/sys/kernel/version
    125
    126### /sys/ has no splice interface; these should all fail.
    127if ! [ -d /sys/module/test_module/sections ] ; then
    128	expect_success "test_module kernel module load" modprobe test_module
    129fi
    130expect_failure "kernfs attr splice" test_splice /sys/module/test_module/coresize
    131expect_failure "kernfs binattr splice" test_splice /sys/module/test_module/sections/.init.text
    132
    133exit $ret