1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ 3 4 #include <vmlinux.h> 5 #include <bpf/bpf_tracing.h> 6 #include "bpf_misc.h" 7 #include "../bpf_testmod/bpf_testmod.h" 8 #include "../bpf_testmod/bpf_testmod_kfunc.h" 9 10 char _license[] SEC("license") = "GPL"; 11 12 __success 13 /* save __u64 *ctx to stack */ 14 __xlated("0: *(u64 *)(r10 -8) = r1") 15 /* main prog */ 16 __xlated("1: r1 = *(u64 *)(r1 +0)") 17 __xlated("2: r2 = *(u64 *)(r1 +0)") 18 __xlated("3: r3 = 0") 19 __xlated("4: r4 = 1") 20 __xlated("5: if r2 == 0x0 goto pc+10") 21 __xlated("6: r0 = 0") 22 __xlated("7: *(u64 *)(r1 +0) = r3") 23 /* epilogue */ 24 __xlated("8: r1 = *(u64 *)(r10 -8)") 25 __xlated("9: r1 = *(u64 *)(r1 +0)") 26 __xlated("10: r6 = *(u64 *)(r1 +0)") 27 __xlated("11: r6 += 10000") 28 __xlated("12: *(u64 *)(r1 +0) = r6") 29 __xlated("13: r0 = r6") 30 __xlated("14: r0 *= 2") 31 __xlated("15: exit") 32 /* 2nd part of the main prog after the first exit */ 33 __xlated("16: *(u64 *)(r1 +0) = r4") 34 __xlated("17: r0 = 1") 35 /* Clear the r1 to ensure it does not have 36 * off-by-1 error and ensure it jumps back to the 37 * beginning of epilogue which initializes 38 * the r1 with the ctx ptr. 39 */ 40 __xlated("18: r1 = 0") 41 __xlated("19: gotol pc-12") 42 SEC("struct_ops/test_epilogue_exit") test_epilogue_exit(void)43__naked int test_epilogue_exit(void) 44 { 45 asm volatile ( 46 "r1 = *(u64 *)(r1 +0);" 47 "r2 = *(u64 *)(r1 +0);" 48 "r3 = 0;" 49 "r4 = 1;" 50 "if r2 == 0 goto +3;" 51 "r0 = 0;" 52 "*(u64 *)(r1 + 0) = r3;" 53 "exit;" 54 "*(u64 *)(r1 + 0) = r4;" 55 "r0 = 1;" 56 "r1 = 0;" 57 "exit;" 58 ::: __clobber_all); 59 } 60 61 SEC(".struct_ops.link") 62 struct bpf_testmod_st_ops epilogue_exit = { 63 .test_epilogue = (void *)test_epilogue_exit, 64 }; 65 66 SEC("syscall") 67 __retval(20000) syscall_epilogue_exit0(void * ctx)68int syscall_epilogue_exit0(void *ctx) 69 { 70 struct st_ops_args args = { .a = 1 }; 71 72 return bpf_kfunc_st_ops_test_epilogue(&args); 73 } 74 75 SEC("syscall") 76 __retval(20002) syscall_epilogue_exit1(void * ctx)77int syscall_epilogue_exit1(void *ctx) 78 { 79 struct st_ops_args args = {}; 80 81 return bpf_kfunc_st_ops_test_epilogue(&args); 82 } 83