Hi Yonghong! Thanks for looking at my patch! This is my first patch to the Linux kernel / first time using an email-based patch workflow, so I don't know what I'm doing. I hope to contribute more to BPF in the future, though. The patches apply fine to me on bpf-next master (am I supposed to be targeting a different branch?), and I've asked someone else to confirm too. I've tested with your exact git version. I have a theory about what might be going wrong for you, see below. Here's what I'm doing: # prove I'm on bpf-next master $ git show | head -n 5 commit 91b2db27d3ff9ad29e8b3108dfbf1e2f49fe9bd3 Author: Song Liu <songliubraving@xxxxxx> Date: Thu Nov 19 16:28:33 2020 -0800 bpf: Simplify task_file_seq_get_next() # Download the patches - these are the "raw" links published by lore.kernel.org for each of the two emails. $ curl https://lore.kernel.org/bpf/20201122022205.57229-1-andreimatei1@xxxxxxxxx/raw > p1.patch $ curl https://lore.kernel.org/bpf/20201122022205.57229-2-andreimatei1@xxxxxxxxx/raw > p2.patch $ git am p1.patch Applying: selftest/bpf: fix link in readme $ git am p2.patch Applying: selftest/bpf: fix rst formatting in readme So, it all "works for me". The patches were produced with `git format-patch` and sent with `git send-email`. Please let me know if I was supposed to do something else. With the risk of continuing to not know what I'm talking about, I perhaps have a guess about why the patches don't apply for you: if you simply copy-pasted the email into your p2.txt, that might not apply because a space might be lost from the end of one of the one lines that I'm deleting. The patch has a line that reads: "-This is due to a llvm BPF backend bug. The fix ". Notice the space at the end of the line. At least Gmail doesn't render that space, so if I simply copy-paste the patch from my browser, I end up with a corrupted line and so it doesn't apply. Perhaps that's your situation? Thanks Yonghong, I appreciate your time! - Andrei On Mon, Nov 23, 2020 at 2:22 AM Yonghong Song <yhs@xxxxxx> wrote: > > > > On 11/21/20 6:22 PM, Andrei Matei wrote: > > A couple of places in the readme had invalid rst formatting causing the > > rendering to be off. This patch fixes them with minimal edits. > > > > Signed-off-by: Andrei Matei <andreimatei1@xxxxxxxxx> > > --- > > tools/testing/selftests/bpf/README.rst | 28 ++++++++++++++------------ > > 1 file changed, 15 insertions(+), 13 deletions(-) > > I cannot apply patch #2 with my current bpf-next branch. > > -bash-4.4$ git apply ~/p1.txt > -bash-4.4$ git apply ~/p2.txt > /home/yhs/p2.txt:34: trailing whitespace. > __ > https://reviews.llvm.org/D85570 > > /home/yhs/p2.txt:52: trailing whitespace. > __ > https://reviews.llvm.org/D78466 > > /home/yhs/p2.txt:70: trailing whitespace. > .. _0: > https://reviews.llvm.org/D74572 > > /home/yhs/p2.txt:71: trailing whitespace. > .. _1: > https://reviews.llvm.org/D74668 > > /home/yhs/p2.txt:72: trailing whitespace. > .. _2: > https://reviews.llvm.org/D85174 > > error: patch failed: tools/testing/selftests/bpf/README.rst:33 > error: tools/testing/selftests/bpf/README.rst: patch does not apply > -bash-4.4$ git --version > git version 2.24.1 > -bash-4.4$ > > Could you help check what is the issue? Maybe the links are presented > differently in the patch vs. in the README.rst? > > > > > diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst > > index 3b8d8885892d..ca064180d4d0 100644 > > --- a/tools/testing/selftests/bpf/README.rst > > +++ b/tools/testing/selftests/bpf/README.rst > > @@ -33,11 +33,12 @@ The verifier will reject such code with above error. > > At insn 18 the r7 is indeed unbounded. The later insn 19 checks the bounds and > > the insn 20 undoes map_value addition. It is currently impossible for the > > verifier to understand such speculative pointer arithmetic. > > -Hence > > - https://reviews.llvm.org/D85570 > > -addresses it on the compiler side. It was committed on llvm 12. > > +Hence `this patch`__ addresses it on the compiler side. It was committed on llvm 12. > > + > > +__ https://reviews.llvm.org/D85570 > > > > The corresponding C code > > + > > .. code-block:: c > > > > for (int i = 0; i < MAX_CGROUPS_PATH_DEPTH; i++) { > > @@ -80,10 +81,11 @@ The symptom for ``bpf_iter/netlink`` looks like > > 17: (7b) *(u64 *)(r7 +0) = r2 > > only read is supported > > > > -This is due to a llvm BPF backend bug. The fix > > - https://reviews.llvm.org/D78466 > > +This is due to a llvm BPF backend bug. `The fix`__ > > has been pushed to llvm 10.x release branch and will be > > -available in 10.0.1. The fix is available in llvm 11.0.0 trunk. > > +available in 10.0.1. The patch is available in llvm 11.0.0 trunk. > > + > > +__ https://reviews.llvm.org/D78466 > > > > BPF CO-RE-based tests and Clang version > > ======================================= > > @@ -97,11 +99,11 @@ them to Clang/LLVM. These sub-tests are going to be skipped if Clang is too > > old to support them, they shouldn't cause build failures or runtime test > > failures: > > > > - - __builtin_btf_type_id() ([0], [1], [2]); > > - - __builtin_preserve_type_info(), __builtin_preserve_enum_value() ([3], [4]). > > +- __builtin_btf_type_id() [0_, 1_, 2_]; > > +- __builtin_preserve_type_info(), __builtin_preserve_enum_value() [3_, 4_]. > > > > - [0] https://reviews.llvm.org/D74572 > > - [1] https://reviews.llvm.org/D74668 > > - [2] https://reviews.llvm.org/D85174 > > - [3] https://reviews.llvm.org/D83878 > > - [4] https://reviews.llvm.org/D83242 > > +.. _0: https://reviews.llvm.org/D74572 > > +.. _1: https://reviews.llvm.org/D74668 > > +.. _2: https://reviews.llvm.org/D85174 > > +.. _3: https://reviews.llvm.org/D83878 > > +.. _4: https://reviews.llvm.org/D83242 > >