Arnaldo Carvalho de Melo 1836480429 perf bpf_skel augmented_raw_syscalls: Cap the socklen parameter using &= sizeof(saddr)
This works with:

  $ clang -v
  clang version 14.0.5 (Fedora 14.0.5-2.fc36)
  $

But not with:

  $ clang -v
  clang version 16.0.6 (Fedora 16.0.6-2.fc38)
  $

  [root@quaco ~]# perf trace -e connect*,sendto* ping -c 10 localhost
  libbpf: prog 'sys_enter_sendto': BPF program load failed: Permission denied
  libbpf: prog 'sys_enter_sendto': -- BEGIN PROG LOAD LOG --
  reg type unsupported for arg#0 function sys_enter_sendto#59
  0: R1=ctx(off=0,imm=0) R10=fp0
  ; int sys_enter_sendto(struct syscall_enter_args *args)
  0: (bf) r6 = r1                       ; R1=ctx(off=0,imm=0) R6_w=ctx(off=0,imm=0)
  1: (b7) r1 = 0                        ; R1_w=0
  ; int key = 0;
  2: (63) *(u32 *)(r10 -4) = r1         ; R1_w=0 R10=fp0 fp-8=0000????
  3: (bf) r2 = r10                      ; R2_w=fp0 R10=fp0
  ;
  4: (07) r2 += -4                      ; R2_w=fp-4
  ; return bpf_map_lookup_elem(&augmented_args_tmp, &key);
  5: (18) r1 = 0xffff8de5a5b8bc00       ; R1_w=map_ptr(off=0,ks=4,vs=8272,imm=0)
  7: (85) call bpf_map_lookup_elem#1    ; R0_w=map_value_or_null(id=1,off=0,ks=4,vs=8272,imm=0)
  8: (bf) r7 = r0                       ; R0_w=map_value_or_null(id=1,off=0,ks=4,vs=8272,imm=0) R7_w=map_value_or_null(id=1,off=0,ks=4,vs=8272,imm=0)
  9: (b7) r0 = 1                        ; R0_w=1
  ; if (augmented_args == NULL)
  10: (15) if r7 == 0x0 goto pc+25      ; R7_w=map_value(off=0,ks=4,vs=8272,imm=0)
  ; unsigned int socklen = args->args[5];
  11: (79) r1 = *(u64 *)(r6 +56)        ; R1_w=scalar() R6_w=ctx(off=0,imm=0)
  ;
  12: (bf) r2 = r1                      ; R1_w=scalar(id=2) R2_w=scalar(id=2)
  13: (67) r2 <<= 32                    ; R2_w=scalar(smax=9223372032559808512,umax=18446744069414584320,var_off=(0x0; 0xffffffff00000000),s32_min=0,s32_max=0,u32_max=0)
  14: (77) r2 >>= 32                    ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
  15: (b7) r8 = 128                     ; R8=128
  ; if (socklen > sizeof(augmented_args->saddr))
  16: (25) if r2 > 0x80 goto pc+1       ; R2=scalar(umax=128,var_off=(0x0; 0xff))
  17: (bf) r8 = r1                      ; R1=scalar(id=2) R8_w=scalar(id=2)
  ; const void *sockaddr_arg = (const void *)args->args[4];
  18: (79) r3 = *(u64 *)(r6 +48)        ; R3_w=scalar() R6=ctx(off=0,imm=0)
  ; bpf_probe_read(&augmented_args->saddr, socklen, sockaddr_arg);
  19: (bf) r1 = r7                      ; R1_w=map_value(off=0,ks=4,vs=8272,imm=0) R7=map_value(off=0,ks=4,vs=8272,imm=0)
  20: (07) r1 += 64                     ; R1_w=map_value(off=64,ks=4,vs=8272,imm=0)
  ; bpf_probe_read(&augmented_args->saddr, socklen, sockaddr_arg);
  21: (bf) r2 = r8                      ; R2_w=scalar(id=2) R8_w=scalar(id=2)
  22: (85) call bpf_probe_read#4
  R2 min value is negative, either use unsigned or 'var &= const'
  processed 22 insns (limit 1000000) max_states_per_insn 0 total_states 1 peak_states 1 mark_read 1
  -- END PROG LOAD LOG --
  libbpf: prog 'sys_enter_sendto': failed to load: -13
  libbpf: failed to load object 'augmented_raw_syscalls_bpf'
  libbpf: failed to load BPF skeleton 'augmented_raw_syscalls_bpf': -13

So use the suggested &= variant since sizeof(saddr) == 128 bytes.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-08-16 14:02:38 -03:00
..
2023-04-04 16:41:57 -03:00
2022-01-12 17:01:38 -08:00
2023-04-04 16:41:57 -03:00
2022-06-28 12:05:25 -03:00
2023-03-14 08:29:46 -03:00
2022-10-04 08:55:21 -03:00
2023-05-27 09:38:25 -03:00
2023-05-27 09:38:25 -03:00
2023-06-12 18:18:13 -03:00
2021-04-29 10:30:58 -03:00
2023-08-15 16:41:49 -03:00
2021-08-11 09:35:44 -03:00
2023-06-23 21:47:20 -07:00
2023-06-23 21:47:20 -07:00
2023-05-27 09:41:39 -03:00
2023-07-01 17:57:43 -07:00
2023-01-23 10:00:47 -03:00
2023-06-29 22:13:15 -07:00
2023-06-29 22:13:15 -07:00
2023-06-12 15:57:54 -03:00
2023-03-20 19:28:21 -03:00
2021-02-03 13:10:44 -03:00
2023-06-12 15:57:54 -03:00
2021-07-15 17:30:22 -03:00
2023-06-23 21:47:20 -07:00
2023-06-23 21:47:20 -07:00
2023-06-12 15:57:54 -03:00
2023-04-06 21:40:28 -03:00
2023-08-03 17:01:24 -03:00
2022-12-14 15:28:18 -03:00
2023-03-20 19:28:21 -03:00
2020-10-14 13:34:26 -03:00
2021-02-17 15:15:06 -03:00
2022-06-23 11:54:22 -03:00
2022-10-04 08:55:20 -03:00
2023-04-10 19:20:53 -03:00
2023-04-10 19:21:31 -03:00