Re: [PATCH bpf-next v2 5/6] bpf: specify the old and new poke_type for bpf_arch_text_poke

[kernel test robot <lkp@intel.com>]

Hi Menglong,

kernel test robot noticed the following build errors:

[auto build test ERROR on bpf-next/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Menglong-Dong/ftrace-introduce-FTRACE_OPS_FL_JMP/20251117-115243
base:   https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master
patch link:    https://lore.kernel.org/r/20251117034906.32036-6-dongml2%40chinatelecom.cn
patch subject: [PATCH bpf-next v2 5/6] bpf: specify the old and new poke_type for bpf_arch_text_poke
config: powerpc64-randconfig-002-20251118 (https://download.01.org/0day-ci/archive/20251118/202511180431.JVOEm6SO-lkp@intel.com/config)
compiler: powerpc64-linux-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251118/202511180431.JVOEm6SO-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511180431.JVOEm6SO-lkp@intel.com/

All errors (new ones prefixed by >>):

   arch/powerpc/net/bpf_jit_comp.c: In function 'bpf_arch_text_poke':
>> arch/powerpc/net/bpf_jit_comp.c:1135:7: error: 'poke_type' undeclared (first use in this function); did you mean 'probe_type'?
      if (poke_type != BPF_MOD_JUMP) {
          ^~~~~~~~~
          probe_type
   arch/powerpc/net/bpf_jit_comp.c:1135:7: note: each undeclared identifier is reported only once for each function it appears in


vim +1135 arch/powerpc/net/bpf_jit_comp.c

d243b62b7bd3d5 Naveen N Rao  2024-10-30  1070  
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1071  /*
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1072   * A 3-step process for bpf prog entry:
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1073   * 1. At bpf prog entry, a single nop/b:
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1074   * bpf_func:
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1075   *	[nop|b]	ool_stub
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1076   * 2. Out-of-line stub:
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1077   * ool_stub:
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1078   *	mflr	r0
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1079   *	[b|bl]	<bpf_prog>/<long_branch_stub>
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1080   *	mtlr	r0 // CONFIG_PPC_FTRACE_OUT_OF_LINE only
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1081   *	b	bpf_func + 4
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1082   * 3. Long branch stub:
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1083   * long_branch_stub:
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1084   *	.long	<branch_addr>/<dummy_tramp>
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1085   *	mflr	r11
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1086   *	bcl	20,31,$+4
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1087   *	mflr	r12
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1088   *	ld	r12, -16(r12)
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1089   *	mtctr	r12
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1090   *	mtlr	r11 // needed to retain ftrace ABI
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1091   *	bctr
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1092   *
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1093   * dummy_tramp is used to reduce synchronization requirements.
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1094   *
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1095   * When attaching a bpf trampoline to a bpf prog, we do not need any
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1096   * synchronization here since we always have a valid branch target regardless
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1097   * of the order in which the above stores are seen. dummy_tramp ensures that
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1098   * the long_branch stub goes to a valid destination on other cpus, even when
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1099   * the branch to the long_branch stub is seen before the updated trampoline
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1100   * address.
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1101   *
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1102   * However, when detaching a bpf trampoline from a bpf prog, or if changing
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1103   * the bpf trampoline address, we need synchronization to ensure that other
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1104   * cpus can no longer branch into the older trampoline so that it can be
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1105   * safely freed. bpf_tramp_image_put() uses rcu_tasks to ensure all cpus
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1106   * make forward progress, but we still need to ensure that other cpus
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1107   * execute isync (or some CSI) so that they don't go back into the
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1108   * trampoline again.
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1109   */
7cc5910294285d Menglong Dong 2025-11-17  1110  int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
7cc5910294285d Menglong Dong 2025-11-17  1111  		       enum bpf_text_poke_type new_t, void *old_addr,
7cc5910294285d Menglong Dong 2025-11-17  1112  		       void *new_addr)
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1113  {
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1114  	unsigned long bpf_func, bpf_func_end, size, offset;
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1115  	ppc_inst_t old_inst, new_inst;
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1116  	int ret = 0, branch_flags;
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1117  	char name[KSYM_NAME_LEN];
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1118  
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1119  	if (IS_ENABLED(CONFIG_PPC32))
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1120  		return -EOPNOTSUPP;
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1121  
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1122  	bpf_func = (unsigned long)ip;
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1123  
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1124  	/* We currently only support poking bpf programs */
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1125  	if (!__bpf_address_lookup(bpf_func, &size, &offset, name)) {
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1126  		pr_err("%s (0x%lx): kernel/modules are not supported\n", __func__, bpf_func);
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1127  		return -EOPNOTSUPP;
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1128  	}
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1129  
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1130  	/*
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1131  	 * If we are not poking at bpf prog entry, then we are simply patching in/out
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1132  	 * an unconditional branch instruction at im->ip_after_call
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1133  	 */
d243b62b7bd3d5 Naveen N Rao  2024-10-30  1134  	if (offset) {
d243b62b7bd3d5 Naveen N Rao  2024-10-30 @1135  		if (poke_type != BPF_MOD_JUMP) {

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki