On Mon, Apr 29, 2024 at 12:33 AM Jiri Olsa <olsajiri@xxxxxxxxx> wrote:
>
> On Fri, Apr 26, 2024 at 11:03:29AM -0700, Andrii Nakryiko wrote:
> > On Sun, Apr 21, 2024 at 12:43 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> > >
> > > Adding test to verify that when called from outside of the
> > > trampoline provided by kernel, the uretprobe syscall will cause
> > > calling process to receive SIGILL signal and the attached bpf
> > > program is no executed.
> > >
> > > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> > > ---
> > > .../selftests/bpf/prog_tests/uprobe_syscall.c | 92 +++++++++++++++++++
> > > .../selftests/bpf/progs/uprobe_syscall_call.c | 15 +++
> > > 2 files changed, 107 insertions(+)
> > > create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall_call.c
> > >
> >
> > See nits below, but overall LGTM
> >
> > Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> >
> > [...]
> >
> > > @@ -219,6 +301,11 @@ static void test_uretprobe_regs_change(void)
> > > {
> > > test__skip();
> > > }
> > > +
> > > +static void test_uretprobe_syscall_call(void)
> > > +{
> > > + test__skip();
> > > +}
> > > #endif
> > >
> > > void test_uprobe_syscall(void)
> > > @@ -228,3 +315,8 @@ void test_uprobe_syscall(void)
> > > if (test__start_subtest("uretprobe_regs_change"))
> > > test_uretprobe_regs_change();
> > > }
> > > +
> > > +void serial_test_uprobe_syscall_call(void)
> >
> > does it need to be serial? non-serial are still run sequentially
> > within a process (there is no multi-threading), it's more about some
> > global effects on system.
>
> plz see below
>
> >
> > > +{
> > > + test_uretprobe_syscall_call();
> > > +}
> > > diff --git a/tools/testing/selftests/bpf/progs/uprobe_syscall_call.c b/tools/testing/selftests/bpf/progs/uprobe_syscall_call.c
> > > new file mode 100644
> > > index 000000000000..5ea03bb47198
> > > --- /dev/null
> > > +++ b/tools/testing/selftests/bpf/progs/uprobe_syscall_call.c
> > > @@ -0,0 +1,15 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +#include "vmlinux.h"
> > > +#include <bpf/bpf_helpers.h>
> > > +#include <string.h>
> > > +
> > > +struct pt_regs regs;
> > > +
> > > +char _license[] SEC("license") = "GPL";
> > > +
> > > +SEC("uretprobe//proc/self/exe:uretprobe_syscall_call")
> > > +int uretprobe(struct pt_regs *regs)
> > > +{
> > > + bpf_printk("uretprobe called");
> >
> > debugging leftover? we probably don't want to pollute trace_pipe from test
>
> the reason for this is to make sure the bpf program was not executed,
>
> the test makes sure the child gets killed with SIGILL and also that
> the bpf program was not executed by checking the trace_pipe and
> making sure nothing was received
>
> the trace_pipe reading is also why it's serial
you could have attached BPF program from parent process and use a
global variable (and thus eliminate all the trace_pipe system-wide
dependency), but ok, it's fine by me the way this is done
>
> jirka
>
> >
> > > + return 0;
> > > +}
> > > --
> > > 2.44.0
> > >
