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++) {
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
=======================================
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