mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
eacaaed784
Implement two relocations of a new enumerator value-based CO-RE relocation kind: ENUMVAL_EXISTS and ENUMVAL_VALUE. First, ENUMVAL_EXISTS, allows to detect the presence of a named enumerator value in the target (kernel) BTF. This is useful to do BPF helper/map/program type support detection from BPF program side. bpf_core_enum_value_exists() macro helper is provided to simplify built-in usage. Second, ENUMVAL_VALUE, allows to capture enumerator integer value and relocate it according to the target BTF, if it changes. This is useful to have a guarantee against intentional or accidental re-ordering/re-numbering of some of the internal (non-UAPI) enumerations, where kernel developers don't care about UAPI backwards compatiblity concerns. bpf_core_enum_value() allows to capture this succinctly and use correct enum values in code. LLVM uses ldimm64 instruction to capture enumerator value-based relocations, so add support for ldimm64 instruction patching as well. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200819194519.3375898-5-andriin@fb.com |
||
---|---|---|
.. | ||
api | ||
bpf | ||
lockdep | ||
perf | ||
subcmd | ||
symbol | ||
traceevent | ||
argv_split.c | ||
bitmap.c | ||
ctype.c | ||
find_bit.c | ||
hweight.c | ||
rbtree.c | ||
str_error_r.c | ||
string.c | ||
vsprintf.c | ||
zalloc.c |