diff options
| -rw-r--r-- | Documentation/trace/kprobetrace.rst | 9 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace_kprobe.c | 42 | ||||
| -rw-r--r-- | kernel/trace/trace_probe.c | 14 | ||||
| -rw-r--r-- | kernel/trace/trace_probe.h | 1 | ||||
| -rw-r--r-- | kernel/trace/trace_probe_tmpl.h | 14 | ||||
| -rw-r--r-- | kernel/trace/trace_uprobe.c | 12 |
7 files changed, 84 insertions, 10 deletions
diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst index 235ce2ab131a..a3ac7c9ac242 100644 --- a/Documentation/trace/kprobetrace.rst +++ b/Documentation/trace/kprobetrace.rst @@ -55,7 +55,8 @@ Synopsis of kprobe_events NAME=FETCHARG : Set NAME as the argument name of FETCHARG. FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types (u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types - (x8/x16/x32/x64), "string" and bitfield are supported. + (x8/x16/x32/x64), "string", "ustring" and bitfield + are supported. (\*1) only for the probe on function entry (offs == 0). (\*2) only for return probe. @@ -77,7 +78,11 @@ apply it to registers/stack-entries etc. (for example, '$stack1:x8[8]' is wrong, but '+8($stack):x8[8]' is OK.) String type is a special type, which fetches a "null-terminated" string from kernel space. This means it will fail and store NULL if the string container -has been paged out. +has been paged out. "ustring" type is an alternative of string for user-space. +Note that kprobe-event provides string/ustring types, but doesn't change it +automatically. So user has to decide if the targe string in kernel or in user +space carefully. On some arch, if you choose wrong one, it always fails to +record string data. The string array type is a bit different from other types. For other base types, <base-type>[1] is equal to <base-type> (e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not equal to string. The string type itself diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 1c80521fd436..d3a477a16e70 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4847,7 +4847,7 @@ static const char readme_msg[] = "\t $stack<index>, $stack, $retval, $comm\n" #endif "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" - "\t b<bit-width>@<bit-offset>/<container-size>,\n" + "\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n" "\t <type>\\[<array-size>\\]\n" #ifdef CONFIG_HIST_TRIGGERS "\t field: <stype> <name>;\n" diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 7d736248a070..439bf04d14ce 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -886,6 +886,15 @@ fetch_store_strlen(unsigned long addr) return (ret < 0) ? ret : len; } +/* Return the length of string -- including null terminal byte */ +static nokprobe_inline int +fetch_store_strlen_user(unsigned long addr) +{ + const void __user *uaddr = (__force const void __user *)addr; + + return strnlen_unsafe_user(uaddr, MAX_STRING_SIZE); +} + /* * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max * length and relative data location. @@ -894,19 +903,46 @@ static nokprobe_inline int fetch_store_string(unsigned long addr, void *dest, void *base) { int maxlen = get_loc_len(*(u32 *)dest); - u8 *dst = get_loc_data(dest, base); + void *__dest; long ret; if (unlikely(!maxlen)) return -ENOMEM; + + __dest = get_loc_data(dest, base); + /* * Try to get string again, since the string can be changed while * probing. */ - ret = strncpy_from_unsafe(dst, (void *)addr, maxlen); + ret = strncpy_from_unsafe(__dest, (void *)addr, maxlen); + if (ret >= 0) + *(u32 *)dest = make_data_loc(ret, __dest - base); + + return ret; +} +/* + * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf + * with max length and relative data location. + */ +static nokprobe_inline int +fetch_store_string_user(unsigned long addr, void *dest, void *base) +{ + const void __user *uaddr = (__force const void __user *)addr; + int maxlen = get_loc_len(*(u32 *)dest); + void *__dest; + long ret; + + if (unlikely(!maxlen)) + return -ENOMEM; + + __dest = get_loc_data(dest, base); + + ret = strncpy_from_unsafe_user(__dest, uaddr, maxlen); if (ret >= 0) - *(u32 *)dest = make_data_loc(ret, (void *)dst - base); + *(u32 *)dest = make_data_loc(ret, __dest - base); + return ret; } diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index a347faced959..5a0470f7b9de 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -78,6 +78,8 @@ static const struct fetch_type probe_fetch_types[] = { /* Special types */ __ASSIGN_FETCH_TYPE("string", string, string, sizeof(u32), 1, "__data_loc char[]"), + __ASSIGN_FETCH_TYPE("ustring", string, string, sizeof(u32), 1, + "__data_loc char[]"), /* Basic types */ ASSIGN_FETCH_TYPE(u8, u8, 0), ASSIGN_FETCH_TYPE(u16, u16, 0), @@ -569,7 +571,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, goto fail; /* Store operation */ - if (!strcmp(parg->type->name, "string")) { + if (!strcmp(parg->type->name, "string") || + !strcmp(parg->type->name, "ustring")) { if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM) { trace_probe_log_err(offset + (t ? (t - arg) : 0), @@ -590,7 +593,11 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, goto fail; } } - code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */ + /* If op == DEREF, replace it with STRING */ + if (!strcmp(parg->type->name, "ustring")) + code->op = FETCH_OP_ST_USTRING; + else + code->op = FETCH_OP_ST_STRING; code->size = parg->type->size; parg->dynamic = true; } else if (code->op == FETCH_OP_DEREF) { @@ -618,7 +625,8 @@ static int traceprobe_parse_probe_arg_body(char *arg, ssize_t *size, /* Loop(Array) operation */ if (parg->count) { if (scode->op != FETCH_OP_ST_MEM && - scode->op != FETCH_OP_ST_STRING) { + scode->op != FETCH_OP_ST_STRING && + scode->op != FETCH_OP_ST_USTRING) { trace_probe_log_err(offset + (t ? (t - arg) : 0), BAD_STRING); ret = -EINVAL; diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index f9a8c632188b..c7546e7ff8e2 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -96,6 +96,7 @@ enum fetch_op { FETCH_OP_ST_RAW, /* Raw: .size */ FETCH_OP_ST_MEM, /* Mem: .offset, .size */ FETCH_OP_ST_STRING, /* String: .offset, .size */ + FETCH_OP_ST_USTRING, /* User String: .offset, .size */ // Stage 4 (modify) op FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */ // Stage 5 (loop) op diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h index c30c61f12ddd..2e9e4dae8839 100644 --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -59,6 +59,9 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, static nokprobe_inline int fetch_store_strlen(unsigned long addr); static nokprobe_inline int fetch_store_string(unsigned long addr, void *dest, void *base); +static nokprobe_inline int fetch_store_strlen_user(unsigned long addr); +static nokprobe_inline int +fetch_store_string_user(unsigned long addr, void *dest, void *base); static nokprobe_inline int probe_mem_read(void *dest, void *src, size_t size); @@ -91,6 +94,10 @@ stage3: ret = fetch_store_strlen(val + code->offset); code++; goto array; + } else if (code->op == FETCH_OP_ST_USTRING) { + ret += fetch_store_strlen_user(val + code->offset); + code++; + goto array; } else return -EILSEQ; } @@ -106,6 +113,10 @@ stage3: loc = *(u32 *)dest; ret = fetch_store_string(val + code->offset, dest, base); break; + case FETCH_OP_ST_USTRING: + loc = *(u32 *)dest; + ret = fetch_store_string_user(val + code->offset, dest, base); + break; default: return -EILSEQ; } @@ -123,7 +134,8 @@ array: total += ret; if (++i < code->param) { code = s3; - if (s3->op != FETCH_OP_ST_STRING) { + if (s3->op != FETCH_OP_ST_STRING && + s3->op != FETCH_OP_ST_USTRING) { dest += s3->size; val += s3->size; goto stage3; diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index eb7e06b54741..852e998051f6 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -176,6 +176,12 @@ fetch_store_string(unsigned long addr, void *dest, void *base) return ret; } +static nokprobe_inline int +fetch_store_string_user(unsigned long addr, void *dest, void *base) +{ + return fetch_store_string(addr, dest, base); +} + /* Return the length of string -- including null terminal byte */ static nokprobe_inline int fetch_store_strlen(unsigned long addr) @@ -191,6 +197,12 @@ fetch_store_strlen(unsigned long addr) return (len > MAX_STRING_SIZE) ? 0 : len; } +static nokprobe_inline int +fetch_store_strlen_user(unsigned long addr) +{ + return fetch_store_strlen(addr); +} + static unsigned long translate_user_vaddr(unsigned long file_offset) { unsigned long base_addr; |