linux/tools/perf/tests/shell/lib/probe_vfs_getname.sh

25 lines
808 B
Bash
Raw Normal View History

# Arnaldo Carvalho de Melo <acme@kernel.org>, 2017
perf probe -l 2>&1 | grep -q probe:vfs_getname
had_vfs_getname=$?
cleanup_probe_vfs_getname() {
if [ $had_vfs_getname -eq 1 ] ; then
perf probe -q -d probe:vfs_getname*
fi
}
add_probe_vfs_getname() {
local verbose=$1
if [ $had_vfs_getname -eq 1 ] ; then
line=$(perf probe -L getname_flags 2>&1 | egrep 'result.*=.*filename;' | sed -r 's/[[:space:]]+([[:digit:]]+)[[:space:]]+result->uptr.*/\1/')
perf probe -q "vfs_getname=getname_flags:${line} pathname=result->name:string" || \
perf test: Fix test trace+probe_vfs_getname.sh on s390 This test places a kprobe to function getname_flags() in the kernel which has the following prototype: struct filename *getname_flags(const char __user *filename, int flags, int *empty) The 'filename' argument points to a filename located in user space memory. Looking at commit 88903c464321c ("tracing/probe: Add ustring type for user-space string") the kprobe should indicate that user space memory is accessed. Output before: [root@m35lp76 perf]# ./perf test 66 67 66: Use vfs_getname probe to get syscall args filenames : FAILED! 67: Check open filename arg using perf trace + vfs_getname: FAILED! [root@m35lp76 perf]# Output after: [root@m35lp76 perf]# ./perf test 66 67 66: Use vfs_getname probe to get syscall args filenames : Ok 67: Check open filename arg using perf trace + vfs_getname: Ok [root@m35lp76 perf]# Comments from Masami Hiramatsu: This bug doesn't happen on x86 or other archs on which user address space and kernel address space is the same. On some arches (ppc64 in this case?) user address space is partially or completely the same as kernel address space. (Yes, they switch the world when running into the kernel) In this case, we need to use different data access functions for each space. That is why I introduced the "ustring" type for kprobe events. As far as I can see, Thomas's patch is sane. Thomas, could you show us your result on your test environment? Comments from Thomas Richter: Test results for s/390 included above. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Link: http://lore.kernel.org/lkml/20200217102111.61137-1-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-02-17 11:21:11 +01:00
perf probe $verbose "vfs_getname=getname_flags:${line} pathname=filename:ustring"
fi
}
skip_if_no_debuginfo() {
perf test shell vfs_getname: Skip for tools built with NO_LIBDWARF=1 If that is the case, or if the required lib is not present, e.g. elfutils-devel in Fedora systems, then just skip the tests requiring DWARF analysis. Before: # rpm -e elfutils-devel # perf test ping vfs_getname 60: Use vfs_getname probe to get syscall args filenames : FAILED! 61: probe libc's inet_pton & backtrace it with ping : Ok 62: Check open filename arg using perf trace + vfs_getname: FAILED! 63: Add vfs_getname probe to get syscall args filenames : FAILED! # After: # perf test vfs_getname 60: Use vfs_getname probe to get syscall args filenames : Skip 62: Check open filename arg using perf trace + vfs_getname: Skip 63: Add vfs_getname probe to get syscall args filenames : Skip # Then, reinstalling elfutils-devel, rebuilding the tool and running again: # perf test vfs_getname 60: Use vfs_getname probe to get syscall args filenames : Ok 62: Check open filename arg using perf trace + vfs_getname: Ok 63: Add vfs_getname probe to get syscall args filenames : Ok # Reported-by: Kim Phillips <kim.phillips@arm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Thomas Richter <tmricht@linux.vnet.ibm.com> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-d67tvn401fxrwr97pu5ihfb1@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-08-14 14:40:58 -03:00
add_probe_vfs_getname -v 2>&1 | egrep -q "^(Failed to find the path for kernel|Debuginfo-analysis is not supported)" && return 2
return 1
}