Messages in this thread | | | Date | Mon, 6 May 2019 15:57:11 -0400 | From | Joel Fernandes <> | Subject | Re: [PATCH v2 1/4] bpf: Add support for reading user pointers |
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On Mon, May 06, 2019 at 09:11:19PM +0200, Daniel Borkmann wrote: > On 05/06/2019 08:31 PM, Joel Fernandes (Google) wrote: > > The eBPF based opensnoop tool fails to read the file path string passed > > to the do_sys_open function. This is because it is a pointer to > > userspace address and causes an -EFAULT when read with > > probe_kernel_read. This is not an issue when running the tool on x86 but > > is an issue on arm64. This patch adds a new bpf function call based > > which calls the recently proposed probe_user_read function [1]. > > Using this function call from opensnoop fixes the issue on arm64. > > > > [1] https://lore.kernel.org/patchwork/patch/1051588/ > > > > Cc: Michal Gregorczyk <michalgr@live.com> > > Cc: Adrian Ratiu <adrian.ratiu@collabora.com> > > Cc: Mohammad Husain <russoue@gmail.com> > > Cc: Qais Yousef <qais.yousef@arm.com> > > Cc: Srinivas Ramana <sramana@codeaurora.org> > > Cc: duyuchao <yuchao.du@unisoc.com> > > Cc: Manjo Raja Rao <linux@manojrajarao.com> > > Cc: Karim Yaghmour <karim.yaghmour@opersys.com> > > Cc: Tamir Carmeli <carmeli.tamir@gmail.com> > > Cc: Yonghong Song <yhs@fb.com> > > Cc: Alexei Starovoitov <ast@kernel.org> > > Cc: Brendan Gregg <brendan.d.gregg@gmail.com> > > Cc: Masami Hiramatsu <mhiramat@kernel.org> > > Cc: Peter Ziljstra <peterz@infradead.org> > > Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> > > Cc: Steven Rostedt <rostedt@goodmis.org> > > Cc: Kees Cook <keescook@chromium.org> > > Cc: kernel-team@android.com > > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> > > --- > > Masami, could you carry these patches in the series where are you add > > probe_user_read function? > > > > Previous submissions is here: > > https://lore.kernel.org/patchwork/patch/1069552/ > > v1->v2: split tools uapi sync into separate commit, added deprecation > > warning for old bpf_probe_read function. > > Please properly submit this series to bpf tree once the base > infrastructure from Masami is upstream.
Could you clarify what do you mean by "properly submit this series to bpf tree" mean? bpf@vger.kernel.org is CC'd.
> This series here should > also fix up all current probe read usage under samples/bpf/ and > tools/testing/selftests/bpf/.
Ok. Agreed, will do that.
thanks,
- Joel
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