1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __TRACE_PROBE_KERNEL_H_ 3 #define __TRACE_PROBE_KERNEL_H_ 4 5 /* 6 * This depends on trace_probe.h, but can not include it due to 7 * the way trace_probe_tmpl.h is used by trace_kprobe.c and trace_eprobe.c. 8 * Which means that any other user must include trace_probe.h before including 9 * this file. 10 */ 11 /* Return the length of string -- including null terminal byte */ 12 static nokprobe_inline int 13 fetch_store_strlen_user(unsigned long addr) 14 { 15 const void __user *uaddr = (__force const void __user *)addr; 16 17 return strnlen_user_nofault(uaddr, MAX_STRING_SIZE); 18 } 19 20 /* Return the length of string -- including null terminal byte */ 21 static nokprobe_inline int 22 fetch_store_strlen(unsigned long addr) 23 { 24 int ret, len = 0; 25 u8 c; 26 27 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 28 if (addr < TASK_SIZE) 29 return fetch_store_strlen_user(addr); 30 #endif 31 32 do { 33 ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1); 34 len++; 35 } while (c && ret == 0 && len < MAX_STRING_SIZE); 36 37 return (ret < 0) ? ret : len; 38 } 39 40 static nokprobe_inline void set_data_loc(int ret, void *dest, void *__dest, void *base) 41 { 42 if (ret < 0) 43 ret = 0; 44 *(u32 *)dest = make_data_loc(ret, __dest - base); 45 } 46 47 /* 48 * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf 49 * with max length and relative data location. 50 */ 51 static nokprobe_inline int 52 fetch_store_string_user(unsigned long addr, void *dest, void *base) 53 { 54 const void __user *uaddr = (__force const void __user *)addr; 55 int maxlen = get_loc_len(*(u32 *)dest); 56 void *__dest; 57 long ret; 58 59 if (unlikely(!maxlen)) 60 return -ENOMEM; 61 62 __dest = get_loc_data(dest, base); 63 64 ret = strncpy_from_user_nofault(__dest, uaddr, maxlen); 65 set_data_loc(ret, dest, __dest, base); 66 67 return ret; 68 } 69 70 /* 71 * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max 72 * length and relative data location. 73 */ 74 static nokprobe_inline int 75 fetch_store_string(unsigned long addr, void *dest, void *base) 76 { 77 int maxlen = get_loc_len(*(u32 *)dest); 78 void *__dest; 79 long ret; 80 81 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 82 if ((unsigned long)addr < TASK_SIZE) 83 return fetch_store_string_user(addr, dest, base); 84 #endif 85 86 if (unlikely(!maxlen)) 87 return -ENOMEM; 88 89 __dest = get_loc_data(dest, base); 90 91 /* 92 * Try to get string again, since the string can be changed while 93 * probing. 94 */ 95 ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen); 96 set_data_loc(ret, dest, __dest, base); 97 98 return ret; 99 } 100 101 static nokprobe_inline int 102 probe_mem_read_user(void *dest, void *src, size_t size) 103 { 104 const void __user *uaddr = (__force const void __user *)src; 105 106 return copy_from_user_nofault(dest, uaddr, size); 107 } 108 109 static nokprobe_inline int 110 probe_mem_read(void *dest, void *src, size_t size) 111 { 112 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 113 if ((unsigned long)src < TASK_SIZE) 114 return probe_mem_read_user(dest, src, size); 115 #endif 116 return copy_from_kernel_nofault(dest, src, size); 117 } 118 119 #endif /* __TRACE_PROBE_KERNEL_H_ */ 120