| Message ID | 20240916091712.2929279-1-eddyz87@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | 'bpf_fastcall' attribute in vmlinux.h and bpf_helper_defs.h | expand |
On Mon, 2024-09-16 at 02:17 -0700, Eduard Zingerman wrote:
> Modifications to pahole are submitted separately.
Note, corresponding pahole changes are submitted here:
https://lore.kernel.org/bpf/20240916091921.2929615-1-eddyz87@gmail.com/
[...]
Hello: This series was applied to bpf/bpf-next.git (master) by Andrii Nakryiko <andrii@kernel.org>: On Mon, 16 Sep 2024 02:17:08 -0700 you wrote: > The goal of this patch-set is to reflect attribute bpf_fastcall > for supported helpers and kfuncs in generated header files. > For helpers this requires a tweak for scripts/bpf_doc.py and an update > to uapi/linux/bpf.h doc-comment. > For kfuncs this requires: > - introduction of a new KF_FASTCALL flag; > - modification to pahole to read kfunc flags and generate > DECL_TAG "bpf_fastcall" for marked kfuncs; > - modification to bpftool to scan for DECL_TAG "bpf_fastcall" > presence. > > [...] Here is the summary with links: - [bpf-next,v1,1/4] bpf: allow specifying bpf_fastcall attribute for BPF helpers https://git.kernel.org/bpf/bpf-next/c/8143f960d915 - [bpf-next,v1,2/4] bpf: __bpf_fastcall for bpf_get_smp_processor_id in uapi https://git.kernel.org/bpf/bpf-next/c/f399d418c5f2 - [bpf-next,v1,3/4] bpf: use KF_FASTCALL to mark kfuncs supporting fastcall contract https://git.kernel.org/bpf/bpf-next/c/f49520133c3a - [bpf-next,v1,4/4] bpftool: __bpf_fastcall for kfuncs marked with special decl_tag https://git.kernel.org/bpf/bpf-next/c/00df87ce7eac You are awesome, thank you!
The goal of this patch-set is to reflect attribute bpf_fastcall for supported helpers and kfuncs in generated header files. For helpers this requires a tweak for scripts/bpf_doc.py and an update to uapi/linux/bpf.h doc-comment. For kfuncs this requires: - introduction of a new KF_FASTCALL flag; - modification to pahole to read kfunc flags and generate DECL_TAG "bpf_fastcall" for marked kfuncs; - modification to bpftool to scan for DECL_TAG "bpf_fastcall" presence. In both cases the following helper macro is defined in the generated header: #ifndef __bpf_fastcall #if __has_attribute(bpf_fastcall) #define __bpf_fastcall __attribute__((bpf_fastcall)) #else #define __bpf_fastcall #endif #endif And is used to mark appropriate function prototypes. More information about bpf_fastcall attribute could be found in [1] and [2]. Modifications to pahole are submitted separately. [1] LLVM source tree commit: 64e464349bfc ("[BPF] introduce __attribute__((bpf_fastcall))") [2] Linux kernel tree commit (note: feature was renamed from no_caller_saved_registers to bpf_fastcall after this commit): 52839f31cece ("Merge branch 'no_caller_saved_registers-attribute-for-helper-calls'") Eduard Zingerman (4): bpf: allow specifying bpf_fastcall attribute for BPF helpers bpf: __bpf_fastcall for bpf_get_smp_processor_id in uapi bpf: use KF_FASTCALL to mark kfuncs supporting fastcall contract bpftool: __bpf_fastcall for kfuncs marked with special decl_tag include/linux/btf.h | 1 + include/uapi/linux/bpf.h | 2 + kernel/bpf/helpers.c | 4 +- kernel/bpf/verifier.c | 5 +- scripts/bpf_doc.py | 50 ++++++++++++++++- tools/bpf/bpftool/btf.c | 98 ++++++++++++++++++++++++++++++---- tools/include/uapi/linux/bpf.h | 2 + 7 files changed, 144 insertions(+), 18 deletions(-)