perf trace: Use the right bpf_probe_read(_str) variant for reading user data
Perf test case 111 Check open filename arg using perf trace + vfs_getname fails on s390. This is caused by a failing function bpf_probe_read() in file util/bpf_skel/augmented_raw_syscalls.bpf.c. The root cause is the lookup by address. Function bpf_probe_read() is used. This function works only for architectures with ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE. On s390 is not possible to determine from the address to which address space the address belongs to (user or kernel space). Replace bpf_probe_read() by bpf_probe_read_kernel() and bpf_probe_read_str() by bpf_probe_read_user_str() to explicity specify the address space the address refers to. Output before: # ./perf trace -eopen,openat -- touch /tmp/111 libbpf: prog 'sys_enter': BPF program load failed: Invalid argument libbpf: prog 'sys_enter': -- BEGIN PROG LOAD LOG -- reg type unsupported for arg#0 function sys_enter#75 0: R1=ctx(off=0,imm=0) R10=fp0 ; int sys_enter(struct syscall_enter_args *args) 0: (bf) r6 = r1 ; R1=ctx(off=0,imm=0) R6_w=ctx(off=0,imm=0) ; return bpf_get_current_pid_tgid(); 1: (85) call bpf_get_current_pid_tgid#14 ; R0_w=scalar() 2: (63) *(u32 *)(r10 -8) = r0 ; R0_w=scalar() R10=fp0 fp-8=????mmmm 3: (bf) r2 = r10 ; R2_w=fp0 R10=fp0 ; ..... lines deleted here ..... 23: (bf) r3 = r6 ; R3_w=ctx(off=0,imm=0) R6=ctx(off=0,imm=0) 24: (85) call bpf_probe_read#4 unknown func bpf_probe_read#4 processed 23 insns (limit 1000000) max_states_per_insn 0 \ total_states 2 peak_states 2 mark_read 2 -- END PROG LOAD LOG -- libbpf: prog 'sys_enter': failed to load: -22 libbpf: failed to load object 'augmented_raw_syscalls_bpf' libbpf: failed to load BPF skeleton 'augmented_raw_syscalls_bpf': -22 .... Output after: # ./perf test -Fv 111 111: Check open filename arg using perf trace + vfs_getname : --- start --- 1.085 ( 0.011 ms): touch/320753 openat(dfd: CWD, filename: \ "/tmp/temporary_file.SWH85", \ flags: CREAT|NOCTTY|NONBLOCK|WRONLY, mode: IRUGO|IWUGO) = 3 ---- end ---- Check open filename arg using perf trace + vfs_getname: Ok # Test with the sleep command shows: Output before: # ./perf trace -e *sleep sleep 1.234567890 0.000 (1234.681 ms): sleep/63114 clock_nanosleep(rqtp: \ { .tv_sec: 0, .tv_nsec: 0 }, rmtp: 0x3ffe0979720) = 0 # Output after: # ./perf trace -e *sleep sleep 1.234567890 0.000 (1234.686 ms): sleep/64277 clock_nanosleep(rqtp: \ { .tv_sec: 1, .tv_nsec: 234567890 }, rmtp: 0x3fff3df9ea0) = 0 # Fixes: 14e4b9f4 ("perf trace: Raw augmented syscalls fix libbpf 1.0+ compatibility") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Co-developed-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ian Rogers <irogers@google.com> Cc: gor@linux.ibm.com Cc: hca@linux.ibm.com Cc: sumanthk@linux.ibm.com Cc: svens@linux.ibm.com Link: https://lore.kernel.org/r/20231019082642.3286650-1-tmricht@linux.ibm.comSigned-off-by: Namhyung Kim <namhyung@kernel.org>
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