kprobe_args_syntax.tc

  1#!/bin/sh
  2# SPDX-License-Identifier: GPL-2.0
  3# description: Kprobe event argument syntax
  4# requires: kprobe_events "x8/16/32/64":README
  5
  6PROBEFUNC="vfs_read"
  7GOODREG=
  8BADREG=
  9GOODSYM="_sdata"
 10if ! grep -qw ${GOODSYM} /proc/kallsyms ; then
 11  GOODSYM=$PROBEFUNC
 12fi
 13BADSYM="deaqswdefr"
 14SYMADDR=0x`grep -w ${GOODSYM} /proc/kallsyms | cut -f 1 -d " "`
 15GOODTYPE="x16"
 16BADTYPE="y16"
 17
 18case `uname -m` in
 19x86_64|i[3456]86)
 20  GOODREG=%ax
 21  BADREG=%ex
 22;;
 23aarch64)
 24  GOODREG=%x0
 25  BADREG=%ax
 26;;
 27arm*)
 28  GOODREG=%r0
 29  BADREG=%ax
 30;;
 31ppc*)
 32  GOODREG=%r3
 33  BADREG=%msr
 34;;
 35s390*)
 36  GOODREG=%r2
 37  BADREG=%s2
 38;;
 39mips*)
 40  GOODREG=%r4
 41  BADREG=%r12
 42;;
 43loongarch*)
 44  GOODREG=%r4
 45  BADREG=%r12
 46;;
 47riscv*)
 48  GOODREG=%a0
 49  BADREG=%a8
 50;;
 51*)
 52  echo "Please implement other architecture here"
 53  exit_untested
 54esac
 55
 56test_goodarg() # Good-args
 57{
 58  while [ "$1" ]; do
 59    echo "p ${PROBEFUNC} $1" > kprobe_events
 60    shift 1
 61  done;
 62}
 63
 64test_badarg() # Bad-args
 65{
 66  while [ "$1" ]; do
 67    ! echo "p ${PROBEFUNC} $1" > kprobe_events
 68    shift 1
 69  done;
 70}
 71
 72echo > kprobe_events
 73
 74: "Register access"
 75test_goodarg ${GOODREG}
 76test_badarg ${BADREG}
 77
 78: "Symbol access"
 79test_goodarg "@${GOODSYM}" "@${SYMADDR}" "@${GOODSYM}+10" "@${GOODSYM}-10"
 80test_badarg "@" "@${BADSYM}" "@${GOODSYM}*10" "@${GOODSYM}/10" \
 81	    "@${GOODSYM}%10" "@${GOODSYM}&10" "@${GOODSYM}|10"
 82
 83: "Stack access"
 84test_goodarg "\$stack" "\$stack0" "\$stack1"
 85test_badarg "\$stackp" "\$stack0+10" "\$stack1-10"
 86
 87: "Retval access"
 88echo "r ${PROBEFUNC} \$retval" > kprobe_events
 89! echo "p ${PROBEFUNC} \$retval" > kprobe_events
 90
 91# $comm was introduced in 4.8, older kernels reject it.
 92if grep -A1 "fetcharg:" README | grep -q '\$comm' ; then
 93: "Comm access"
 94test_goodarg "\$comm"
 95fi
 96
 97: "Indirect memory access"
 98test_goodarg "+0(${GOODREG})" "-0(${GOODREG})" "+10(\$stack)" \
 99	"+0(\$stack1)" "+10(@${GOODSYM}-10)" "+0(+10(+20(\$stack)))"
100test_badarg "+(${GOODREG})" "(${GOODREG}+10)" "-(${GOODREG})" "(${GOODREG})" \
101	"+10(\$comm)" "+0(${GOODREG})+10"
102
103: "Name assignment"
104test_goodarg "varname=${GOODREG}"
105test_badarg "varname=varname2=${GOODREG}"
106
107: "Type syntax"
108test_goodarg "${GOODREG}:${GOODTYPE}"
109test_badarg "${GOODREG}::${GOODTYPE}" "${GOODREG}:${BADTYPE}" \
110	"${GOODTYPE}:${GOODREG}"
111
112: "Combination check"
113
114test_goodarg "\$comm:string" "+0(\$stack):string"
115test_badarg "\$comm:x64" "\$stack:string" "${GOODREG}:string"