On 04/07/2022 03:20, Yixun Lan wrote: > [You don't often get email from dlan@xxxxxxxxxx. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] > > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > Hi Conor Dooley: > > On 14:12 Sun 03 Jul , Conor Dooley wrote: >> On 03/07/2022 14:09, Yixun Lan wrote: >>> Enable this option to fix a bcc error in RISC-V platform >>> >>> And, the error shows as follows: >>> >>> ~ # runqlen >>> WARNING: This target JIT is not designed for the host you are running. \ >>> If bad things happen, please choose a different -march switch. >>> bpf: Failed to load program: Invalid argument >>> 0: R1=ctx(off=0,imm=0) R10=fp0 >>> 0: (85) call bpf_get_current_task#35 ; R0_w=scalar() >>> 1: (b7) r6 = 0 ; R6_w=0 >>> 2: (7b) *(u64 *)(r10 -8) = r6 ; R6_w=P0 R10=fp0 fp-8_w=00000000 >>> 3: (07) r0 += 312 ; R0_w=scalar() >>> 4: (bf) r1 = r10 ; R1_w=fp0 R10=fp0 >>> 5: (07) r1 += -8 ; R1_w=fp-8 >>> 6: (b7) r2 = 8 ; R2_w=8 >>> 7: (bf) r3 = r0 ; R0_w=scalar(id=1) R3_w=scalar(id=1) >>> 8: (85) call bpf_probe_read#4 >>> unknown func bpf_probe_read#4 >>> processed 9 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 >>> >>> Traceback (most recent call last): >>> File "/usr/lib/python-exec/python3.9/runqlen", line 187, in <module> >>> b.attach_perf_event(ev_type=PerfType.SOFTWARE, >>> File "/usr/lib/python3.9/site-packages/bcc/__init__.py", line 1228, in attach_perf_event >>> fn = self.load_func(fn_name, BPF.PERF_EVENT) >>> File "/usr/lib/python3.9/site-packages/bcc/__init__.py", line 522, in load_func >>> raise Exception("Failed to load BPF program %s: %s" % >>> Exception: Failed to load BPF program b'do_perf_event': Invalid argument >>> >>> Signed-off-by: Yixun Lan <dlan@xxxxxxxxxx> >> >> Do you know what commit this fixes? >> Thanks, >> Conor. >> > > I think this is effectively broken for RISC-V 64 at the commit: > 0ebeea8ca8a4: bpf: Restrict bpf_probe_read{, str}() only to archs where they work > > However, the bcc tools haven't got BPF support for RISC-V at that time, > so no one noticed it > > I can add a Fixes tag if you think it's a proper way Hmm, I had a read of that commit and the breakage sounded intentional. I ran a git log --grep "0ebeea8ca8a4" & it seems like a mixed bag of fixes tags. Whether or not it deserves the explicit tag, mentioning the commit would be useful. The tag would be: Fixes: 0ebeea8ca8a4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work") Thanks, Conor. > >>> --- >>> arch/riscv/Kconfig | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >>> index 32ffef9f6e5b4..da0016f1be6ce 100644 >>> --- a/arch/riscv/Kconfig >>> +++ b/arch/riscv/Kconfig >>> @@ -25,6 +25,7 @@ config RISCV >>> select ARCH_HAS_GIGANTIC_PAGE >>> select ARCH_HAS_KCOV >>> select ARCH_HAS_MMIOWB >>> + select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE >>> select ARCH_HAS_PTE_SPECIAL >>> select ARCH_HAS_SET_DIRECT_MAP if MMU >>> select ARCH_HAS_SET_MEMORY if MMU > > -- > Yixun Lan (dlan) > Gentoo Linux Developer > GPG Key ID AABEFD55 > > _______________________________________________ > linux-riscv mailing list > linux-riscv@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-riscv
