116 lines · c
1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * Define struct user_exit_info which is shared between BPF and userspace parts4 * to communicate exit status and other information.5 *6 * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.7 * Copyright (c) 2022 Tejun Heo <tj@kernel.org>8 * Copyright (c) 2022 David Vernet <dvernet@meta.com>9 */10#ifndef __USER_EXIT_INFO_H11#define __USER_EXIT_INFO_H12 13enum uei_sizes {14 UEI_REASON_LEN = 128,15 UEI_MSG_LEN = 1024,16 UEI_DUMP_DFL_LEN = 32768,17};18 19struct user_exit_info {20 int kind;21 s64 exit_code;22 char reason[UEI_REASON_LEN];23 char msg[UEI_MSG_LEN];24};25 26#ifdef __bpf__27 28#ifdef LSP29#include "../vmlinux/vmlinux.h"30#else31#include "vmlinux.h"32#endif33#include <bpf/bpf_core_read.h>34 35#define UEI_DEFINE(__name) \36 char RESIZABLE_ARRAY(data, __name##_dump); \37 const volatile u32 __name##_dump_len; \38 struct user_exit_info __name SEC(".data")39 40#define UEI_RECORD(__uei_name, __ei) ({ \41 bpf_probe_read_kernel_str(__uei_name.reason, \42 sizeof(__uei_name.reason), (__ei)->reason); \43 bpf_probe_read_kernel_str(__uei_name.msg, \44 sizeof(__uei_name.msg), (__ei)->msg); \45 bpf_probe_read_kernel_str(__uei_name##_dump, \46 __uei_name##_dump_len, (__ei)->dump); \47 if (bpf_core_field_exists((__ei)->exit_code)) \48 __uei_name.exit_code = (__ei)->exit_code; \49 /* use __sync to force memory barrier */ \50 __sync_val_compare_and_swap(&__uei_name.kind, __uei_name.kind, \51 (__ei)->kind); \52})53 54#else /* !__bpf__ */55 56#include <stdio.h>57#include <stdbool.h>58 59/* no need to call the following explicitly if SCX_OPS_LOAD() is used */60#define UEI_SET_SIZE(__skel, __ops_name, __uei_name) ({ \61 u32 __len = (__skel)->struct_ops.__ops_name->exit_dump_len ?: UEI_DUMP_DFL_LEN; \62 (__skel)->rodata->__uei_name##_dump_len = __len; \63 RESIZE_ARRAY((__skel), data, __uei_name##_dump, __len); \64})65 66#define UEI_EXITED(__skel, __uei_name) ({ \67 /* use __sync to force memory barrier */ \68 __sync_val_compare_and_swap(&(__skel)->data->__uei_name.kind, -1, -1); \69})70 71#define UEI_REPORT(__skel, __uei_name) ({ \72 struct user_exit_info *__uei = &(__skel)->data->__uei_name; \73 char *__uei_dump = (__skel)->data_##__uei_name##_dump->__uei_name##_dump; \74 if (__uei_dump[0] != '\0') { \75 fputs("\nDEBUG DUMP\n", stderr); \76 fputs("================================================================================\n\n", stderr); \77 fputs(__uei_dump, stderr); \78 fputs("\n================================================================================\n\n", stderr); \79 } \80 fprintf(stderr, "EXIT: %s", __uei->reason); \81 if (__uei->msg[0] != '\0') \82 fprintf(stderr, " (%s)", __uei->msg); \83 fputs("\n", stderr); \84 __uei->exit_code; \85})86 87/*88 * We can't import vmlinux.h while compiling user C code. Let's duplicate89 * scx_exit_code definition.90 */91enum scx_exit_code {92 /* Reasons */93 SCX_ECODE_RSN_HOTPLUG = 1LLU << 32,94 95 /* Actions */96 SCX_ECODE_ACT_RESTART = 1LLU << 48,97};98 99enum uei_ecode_mask {100 UEI_ECODE_USER_MASK = ((1LLU << 32) - 1),101 UEI_ECODE_SYS_RSN_MASK = ((1LLU << 16) - 1) << 32,102 UEI_ECODE_SYS_ACT_MASK = ((1LLU << 16) - 1) << 48,103};104 105/*106 * These macro interpret the ecode returned from UEI_REPORT().107 */108#define UEI_ECODE_USER(__ecode) ((__ecode) & UEI_ECODE_USER_MASK)109#define UEI_ECODE_SYS_RSN(__ecode) ((__ecode) & UEI_ECODE_SYS_RSN_MASK)110#define UEI_ECODE_SYS_ACT(__ecode) ((__ecode) & UEI_ECODE_SYS_ACT_MASK)111 112#define UEI_ECODE_RESTART(__ecode) (UEI_ECODE_SYS_ACT((__ecode)) == SCX_ECODE_ACT_RESTART)113 114#endif /* __bpf__ */115#endif /* __USER_EXIT_INFO_H */116