Kumar Kartikeya Dwivedi b239da3420 bpf: Add helper macro bpf_for_each_reg_in_vstate
For a lot of use cases in future patches, we will want to modify the
state of registers part of some same 'group' (e.g. same ref_obj_id). It
won't just be limited to releasing reference state, but setting a type
flag dynamically based on certain actions, etc.

Hence, we need a way to easily pass a callback to the function that
iterates over all registers in current bpf_verifier_state in all frames
upto (and including) the curframe.

While in C++ we would be able to easily use a lambda to pass state and
the callback together, sadly we aren't using C++ in the kernel. The next
best thing to avoid defining a function for each case seems like
statement expressions in GNU C. The kernel already uses them heavily,
hence they can passed to the macro in the style of a lambda. The
statement expression will then be substituted in the for loop bodies.

Variables __state and __reg are set to current bpf_func_state and reg
for each invocation of the expression inside the passed in verifier
state.

Then, convert mark_ptr_or_null_regs, clear_all_pkt_pointers,
release_reference, find_good_pkt_pointers, find_equal_scalars to
use bpf_for_each_reg_in_vstate.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220904204145.3089-16-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-07 16:42:23 -07:00
..
2022-08-14 09:28:54 -07:00
2022-05-26 17:13:43 -07:00
2022-08-08 15:16:29 -07:00
2022-05-25 16:18:27 -07:00
2021-12-02 17:25:21 +09:00
2022-07-28 12:36:35 +02:00
2022-06-02 08:55:01 -07:00
2022-01-11 13:08:21 -08:00
2021-09-08 15:32:35 -07:00
2022-05-23 17:51:12 -07:00
2022-03-15 10:32:44 +01:00
2022-08-05 09:41:12 -07:00
2021-09-08 15:32:34 -07:00
2022-08-02 19:34:45 -07:00
2021-10-14 13:29:18 +02:00
2022-02-25 09:36:06 +01:00
2022-08-06 16:38:17 -07:00
2022-08-03 19:52:08 -07:00