opensnoop: Monitor both sys_exit_open and sys_exit_openat.

In glibc 2.26 and above the open() wrapper function uses the sys_openat syscall
instead of sys_open(), which (for code linked with libc) breaks opensnoop unless
openat is monitored.
This commit is contained in:
Bastian Beischer
2019-06-03 15:32:46 +02:00
parent 98d42a2a14
commit e54f006e8c

View File

@@ -88,9 +88,11 @@ function end {
cd $tracing
warn "echo 0 > events/kprobes/getnameprobe/enable"
warn "echo 0 > events/syscalls/sys_exit_open/enable"
warn "echo 0 > events/syscalls/sys_exit_openat/enable"
if (( opt_pid || opt_tid )); then
warn "echo 0 > events/kprobes/getnameprobe/filter"
warn "echo 0 > events/syscalls/sys_exit_open/filter"
warn "echo 0 > events/syscalls/sys_exit_openat/filter"
fi
warn "echo -:getnameprobe >> kprobe_events"
warn "echo > trace"
@@ -177,14 +179,16 @@ if (( opt_pid )); then
done
filter=${filter:3} # trim leading ' || ' (four characters)
if ! echo $filter > events/kprobes/getnameprobe/filter || \
! echo $filter > events/syscalls/sys_exit_open/filter
! echo $filter > events/syscalls/sys_exit_open/filter || \
! echo $filter > events/syscalls/sys_exit_openat/filter
then
edie "ERROR: setting -p $pid. Exiting."
fi
fi
if (( opt_tid )); then
if ! echo "common_pid == $tid" > events/kprobes/getnameprobe/filter || \
! echo "common_pid == $tid" > events/syscalls/sys_exit_open/filter
! echo "common_pid == $tid" > events/syscalls/sys_exit_open/filter || \
! echo "common_pid == $tid" > events/syscalls/sys_exit_openat/filter
then
edie "ERROR: setting -L $tid. Exiting."
fi
@@ -195,6 +199,9 @@ fi
if ! echo 1 > events/syscalls/sys_exit_open/enable; then
edie "ERROR: enabling open() exit tracepoint. Exiting."
fi
if ! echo 1 > events/syscalls/sys_exit_openat/enable; then
edie "ERROR: enabling openat() exit tracepoint. Exiting."
fi
(( opt_time )) && printf "%-16s " "TIMEs"
printf "%-16.16s %-6s %4s %s\n" "COMM" "PID" "FD" "FILE"
@@ -242,8 +249,8 @@ fi ) | $awk -v o=$offset -v opt_name=$opt_name -v name=$name \
lastfile[pid] = m[1]
}
# sys_open()
$1 != "#" && $(4+o) == "sys_open" {
# sys_open() / sys_openat()
$1 != "#" && ($(4+o) == "sys_open" || $(4+o) == "sys_openat") {
filename = lastfile[pid]
delete lastfile[pid]
if (opt_file && filename !~ file)