| Message ID | 20201001085641.51130-1-colin.king@canonical.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | selftests/ftrace: check for do_sys_openat2 in user-memory test | expand |
On Thu, 1 Oct 2020 09:56:41 +0100 Colin King <colin.king@canonical.com> wrote: > From: Colin Ian King <colin.king@canonical.com> > > More recent libc implementations are now using openat/openat2 system > calls so also add do_sys_openat2 to the tracing so that the test > passes on these systems because do_sys_open may not be called. > > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > .../testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc > index a30a9c07290d..cf1b4c3e9e6b 100644 > --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc > +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc > @@ -9,6 +9,8 @@ grep -A10 "fetcharg:" README | grep -q '\[u\]<offset>' || exit_unsupported > :;: "user-memory access syntax and ustring working on user memory";: > echo 'p:myevent do_sys_open path=+0($arg2):ustring path2=+u0($arg2):string' \ > > kprobe_events > +echo 'p:myevent2 do_sys_openat2 path=+0($arg2):ustring path2=+u0($arg2):string' \ > + > kprobe_events > This still wont work, because the rest of the code only enables the myevent event, and not the one you just added. Did you see this broken before, and this patch fixes it? -- Steve > grep myevent kprobe_events | \ > grep -q 'path=+0($arg2):ustring path2=+u0($arg2):string'
On 01/10/2020 15:44, Steven Rostedt wrote: > On Thu, 1 Oct 2020 09:56:41 +0100 > Colin King <colin.king@canonical.com> wrote: > >> From: Colin Ian King <colin.king@canonical.com> >> >> More recent libc implementations are now using openat/openat2 system >> calls so also add do_sys_openat2 to the tracing so that the test >> passes on these systems because do_sys_open may not be called. >> >> Signed-off-by: Colin Ian King <colin.king@canonical.com> >> --- >> .../testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc >> index a30a9c07290d..cf1b4c3e9e6b 100644 >> --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc >> +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc >> @@ -9,6 +9,8 @@ grep -A10 "fetcharg:" README | grep -q '\[u\]<offset>' || exit_unsupported >> :;: "user-memory access syntax and ustring working on user memory";: >> echo 'p:myevent do_sys_open path=+0($arg2):ustring path2=+u0($arg2):string' \ >> > kprobe_events >> +echo 'p:myevent2 do_sys_openat2 path=+0($arg2):ustring path2=+u0($arg2):string' \ >> + > kprobe_events >> > > This still wont work, because the rest of the code only enables the myevent > event, and not the one you just added. Yep, I botched this and tested the wrong fix. > > Did you see this broken before, and this patch fixes it? So this test breaks with a recent libc and support tools built against libc. I believe the do_sys_open is not being detected because do_sys_openat2 is being called instead. Not sure now of the correct way to fix this. > > -- Steve > > >> grep myevent kprobe_events | \ >> grep -q 'path=+0($arg2):ustring path2=+u0($arg2):string' >
On Thu, 1 Oct 2020 16:40:33 +0100 Colin Ian King <colin.king@canonical.com> wrote: > So this test breaks with a recent libc and support tools built against > libc. I believe the do_sys_open is not being detected because > do_sys_openat2 is being called instead. > > Not sure now of the correct way to fix this. Perhaps by enabling both events? -- Steve
On Thu, 1 Oct 2020 16:40:33 +0100 Colin Ian King <colin.king@canonical.com> wrote: > On 01/10/2020 15:44, Steven Rostedt wrote: > > On Thu, 1 Oct 2020 09:56:41 +0100 > > Colin King <colin.king@canonical.com> wrote: > > > >> From: Colin Ian King <colin.king@canonical.com> > >> > >> More recent libc implementations are now using openat/openat2 system > >> calls so also add do_sys_openat2 to the tracing so that the test > >> passes on these systems because do_sys_open may not be called. > >> > >> Signed-off-by: Colin Ian King <colin.king@canonical.com> > >> --- > >> .../testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc | 2 ++ > >> 1 file changed, 2 insertions(+) > >> > >> diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc > >> index a30a9c07290d..cf1b4c3e9e6b 100644 > >> --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc > >> +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc > >> @@ -9,6 +9,8 @@ grep -A10 "fetcharg:" README | grep -q '\[u\]<offset>' || exit_unsupported > >> :;: "user-memory access syntax and ustring working on user memory";: > >> echo 'p:myevent do_sys_open path=+0($arg2):ustring path2=+u0($arg2):string' \ > >> > kprobe_events > >> +echo 'p:myevent2 do_sys_openat2 path=+0($arg2):ustring path2=+u0($arg2):string' \ > >> + > kprobe_events > >> > > > > This still wont work, because the rest of the code only enables the myevent > > event, and not the one you just added. > > Yep, I botched this and tested the wrong fix. > > > > > Did you see this broken before, and this patch fixes it? > > So this test breaks with a recent libc and support tools built against > libc. I believe the do_sys_open is not being detected because > do_sys_openat2 is being called instead. > > Not sure now of the correct way to fix this. Hmm, this actually just try to catch the user-string. So the another function which accepts any user-string, is OK. Let me try to use another one. Thank you for reporting! > > > > > -- Steve > > > > > >> grep myevent kprobe_events | \ > >> grep -q 'path=+0($arg2):ustring path2=+u0($arg2):string' > > >
On Thu, 1 Oct 2020 09:56:41 +0100 Colin King <colin.king@canonical.com> wrote: > From: Colin Ian King <colin.king@canonical.com> > > More recent libc implementations are now using openat/openat2 system > calls so also add do_sys_openat2 to the tracing so that the test > passes on these systems because do_sys_open may not be called. > > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > .../testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc > index a30a9c07290d..cf1b4c3e9e6b 100644 > --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc > +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc > @@ -9,6 +9,8 @@ grep -A10 "fetcharg:" README | grep -q '\[u\]<offset>' || exit_unsupported > :;: "user-memory access syntax and ustring working on user memory";: > echo 'p:myevent do_sys_open path=+0($arg2):ustring path2=+u0($arg2):string' \ > > kprobe_events OK, at first, you need to check the kernel has do_sys_openat2 from /proc/kallsyms (grep -qw will help you), because it is new syscall. > +echo 'p:myevent2 do_sys_openat2 path=+0($arg2):ustring path2=+u0($arg2):string' \ > + > kprobe_events Also, you need to append (">>") it instead overwrite (">") to kprobe_events. > > grep myevent kprobe_events | \ > grep -q 'path=+0($arg2):ustring path2=+u0($arg2):string' And also you have to enable both myevent and myevent2 (if exists) after this. Then I think your patch will work correctly. Thank you!
On 02/10/2020 14:07, Masami Hiramatsu wrote: > On Thu, 1 Oct 2020 09:56:41 +0100 > Colin King <colin.king@canonical.com> wrote: > >> From: Colin Ian King <colin.king@canonical.com> >> >> More recent libc implementations are now using openat/openat2 system >> calls so also add do_sys_openat2 to the tracing so that the test >> passes on these systems because do_sys_open may not be called. >> >> Signed-off-by: Colin Ian King <colin.king@canonical.com> >> --- >> .../testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc >> index a30a9c07290d..cf1b4c3e9e6b 100644 >> --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc >> +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc >> @@ -9,6 +9,8 @@ grep -A10 "fetcharg:" README | grep -q '\[u\]<offset>' || exit_unsupported >> :;: "user-memory access syntax and ustring working on user memory";: >> echo 'p:myevent do_sys_open path=+0($arg2):ustring path2=+u0($arg2):string' \ >> > kprobe_events > > OK, at first, you need to check the kernel has do_sys_openat2 from > /proc/kallsyms (grep -qw will help you), because it is new syscall. > >> +echo 'p:myevent2 do_sys_openat2 path=+0($arg2):ustring path2=+u0($arg2):string' \ >> + > kprobe_events > > Also, you need to append (">>") it instead overwrite (">") to kprobe_events. > >> >> grep myevent kprobe_events | \ >> grep -q 'path=+0($arg2):ustring path2=+u0($arg2):string' > > And also you have to enable both myevent and myevent2 (if exists) after > this. > > Then I think your patch will work correctly. Indeed, thanks. I'll send a V2 shortly. > > Thank you! >
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc index a30a9c07290d..cf1b4c3e9e6b 100644 --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_user.tc @@ -9,6 +9,8 @@ grep -A10 "fetcharg:" README | grep -q '\[u\]<offset>' || exit_unsupported :;: "user-memory access syntax and ustring working on user memory";: echo 'p:myevent do_sys_open path=+0($arg2):ustring path2=+u0($arg2):string' \ > kprobe_events +echo 'p:myevent2 do_sys_openat2 path=+0($arg2):ustring path2=+u0($arg2):string' \ + > kprobe_events grep myevent kprobe_events | \ grep -q 'path=+0($arg2):ustring path2=+u0($arg2):string'