[PATCH] RISC-V/bpf: Enable bpf_probe_read{, str}()

From: Yixun Lan
Date: Sun Jul 03 2022 - 09:09:50 EST


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>
---
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
--
2.35.1