Messages in this thread Patch in this message | | | From | Chen Guokai <> | Subject | [PATCH v6 13/13] selftest/kprobes: Add testcase for kprobe SYM[+offs] | Date | Fri, 27 Jan 2023 21:05:41 +0800 |
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From: Liao Chang <liaochang1@huawei.com>
This testcase set multiple kprobes to the function that contains a series of complex opcode pattern, it helps discover some subtle bugs in the instruction decoder and kprobe jump optimization.
Signed-off-by: Liao Chang <liaochang1@huawei.com> --- .../ftrace/test.d/kprobe/kprobe_sym_offs.tc | 49 +++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_sym_offs.tc
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_sym_offs.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_sym_offs.tc new file mode 100644 index 000000000000..0007bec48308 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_sym_offs.tc @@ -0,0 +1,49 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# description: Kprobe dynamic event with offset +# requires: kprobe_events +TARGET_FUNC=vfs_write + +dec_addr() { # hexaddr + printf "%d" "0x"`echo $1 | tail -c 8` +} + +set_offs() { # target next + SYMADDR=$1 + ENDADDR=$2 + A1=`dec_addr $SYMADDR` + A2=`dec_addr $ENDADDR` + NEXT=`expr $A2 - $A1` # offset to previous symbol +} + +# Get the instruction number between two contiguous symbols +set_offs `grep -A1 -w ${TARGET_FUNC} /proc/kallsyms | cut -f 1 -d " " | xargs` + +# Instruction length depends on the machine architecute. +case `uname -m` in + arm64) LEN=4;; + riscv32|riscv64) LEN=2;; + *) LEN=2;; +esac + +N=0 +OFFS=0 +echo "Setup up kprobes on each instruction in function $TARGET_FUNC" +while true; do + N=$(($N+1)) + ! echo p ${TARGET_FUNC}+${OFFS} >> kprobe_events + OFFS=$(($OFFS+$LEN)) + test $OFFS -eq $NEXT && break +done + +L=`cat kprobe_events | wc -l` +echo "The number of kprobes events ($L) not $N in function $TARGET_FUNC" + +echo 1 > events/kprobes/enable +# Trigger vfs_write to test kprobes +cat kprobe_events >> $testlog +echo 0 > events/kprobes/enable +echo > kprobe_events +echo "Waiting for unoptimizing & freeing" +sleep 5 +echo "Done" -- 2.34.1
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