On Fri, 2023-03-24 at 20:23 -0700, Stanislav Fomichev wrote: > On 03/25, Eduard Zingerman wrote: > > This is a follow up for RFC [1]. It migrates a first batch of 38 > > verifier/*.c tests to inline assembly and use of ./test_progs for > > actual execution. The migration is done by a python script (see [2]). > > Jesus Christ, 43 patches on a Friday night (^_^) > Unless I get bored on the weekend, will get to them Monday morning > (or unless Alexei/Andrii beat me to it; I see they were commenting > on the RFC). Alexei and Andrii wanted this to be organized like one patch-set with patch per migrated file. I actually found the side-by-side comparison process to be quite painful, took me ~1.5 days to go through all migrated files. So, I can split this in smaller batches if that would make others life easier. Also the last patch: selftests/bpf: verifier/xdp_direct_packet_access.c converted to inline assembly was blocked because it is too large. I'll split it in two in the v2 (but will wait for some feedback first). [...] > Are those '\' at the end required? Can we do regular string coalescing > like the following below? > > asm volatile( > "r2 = *(u32*)(r1 + %[xdp_md_data]);" > "r3 = *(u32*)(r1 + %[xdp_md_data_end]);" > "r1 = r2;" > ... > ); > > Or is asm directive somehow special? Strings coalescing would work, I updated the script to support both modes, here is an example of verifier/and.c converted this way (caution, that test missuses BPF_ST_MEM and has a wrong jump, the translation is fine): https://gist.github.com/eddyz87/8725b9140098e1311ca5186c6ee73855 It was my understanding from the RFC feedback that this "lighter" way is preferable and we already have some tests written like that. Don't have a strong opinion on this topic. Pros for '\': - it indeed looks lighter; - labels could be "inline", like in the example above "l0_%=: r0 = 0;". Cons for '\': - harder to edit (although, at-least for emacs, I plan to solve this using https://github.com/twlz0ne/separedit.el); - no syntax highlighting for comments. Pros for string coalescing: - easier to edit w/o special editor support; - syntax highlighting for comments. Cons for string coalescing: - a bit harder to read; - "inline" labels look super weird, so each labels takes a full line. [...]
