diff options
Diffstat (limited to 'kernel/trace/trace_probe.c')
| -rw-r--r-- | kernel/trace/trace_probe.c | 419 |
1 files changed, 302 insertions, 117 deletions
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 4dc74d73fc1d..217169de0920 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -594,6 +594,8 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type, return 0; } +static int __store_entry_arg(struct trace_probe *tp, int argnum); + static int parse_btf_arg(char *varname, struct fetch_insn **pcode, struct fetch_insn *end, struct traceprobe_parse_context *ctx) @@ -618,11 +620,7 @@ static int parse_btf_arg(char *varname, return -EOPNOTSUPP; } - if (ctx->flags & TPARG_FL_RETURN) { - if (strcmp(varname, "$retval") != 0) { - trace_probe_log_err(ctx->offset, NO_BTFARG); - return -ENOENT; - } + if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) { code->op = FETCH_OP_RETVAL; /* Check whether the function return type is not void */ if (query_btf_context(ctx) == 0) { @@ -654,11 +652,21 @@ static int parse_btf_arg(char *varname, const char *name = btf_name_by_offset(ctx->btf, params[i].name_off); if (name && !strcmp(name, varname)) { - code->op = FETCH_OP_ARG; - if (ctx->flags & TPARG_FL_TPOINT) - code->param = i + 1; - else - code->param = i; + if (tparg_is_function_entry(ctx->flags)) { + code->op = FETCH_OP_ARG; + if (ctx->flags & TPARG_FL_TPOINT) + code->param = i + 1; + else + code->param = i; + } else if (tparg_is_function_return(ctx->flags)) { + code->op = FETCH_OP_EDATA; + ret = __store_entry_arg(ctx->tp, i); + if (ret < 0) { + /* internal error */ + return ret; + } + code->offset = ret; + } tid = params[i].type; goto found; } @@ -755,6 +763,110 @@ static int check_prepare_btf_string_fetch(char *typename, #endif +#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API + +static int __store_entry_arg(struct trace_probe *tp, int argnum) +{ + struct probe_entry_arg *earg = tp->entry_arg; + bool match = false; + int i, offset; + + if (!earg) { + earg = kzalloc(sizeof(*tp->entry_arg), GFP_KERNEL); + if (!earg) + return -ENOMEM; + earg->size = 2 * tp->nr_args + 1; + earg->code = kcalloc(earg->size, sizeof(struct fetch_insn), + GFP_KERNEL); + if (!earg->code) { + kfree(earg); + return -ENOMEM; + } + /* Fill the code buffer with 'end' to simplify it */ + for (i = 0; i < earg->size; i++) + earg->code[i].op = FETCH_OP_END; + tp->entry_arg = earg; + } + + offset = 0; + for (i = 0; i < earg->size - 1; i++) { + switch (earg->code[i].op) { + case FETCH_OP_END: + earg->code[i].op = FETCH_OP_ARG; + earg->code[i].param = argnum; + earg->code[i + 1].op = FETCH_OP_ST_EDATA; + earg->code[i + 1].offset = offset; + return offset; + case FETCH_OP_ARG: + match = (earg->code[i].param == argnum); + break; + case FETCH_OP_ST_EDATA: + offset = earg->code[i].offset; + if (match) + return offset; + offset += sizeof(unsigned long); + break; + default: + break; + } + } + return -ENOSPC; +} + +int traceprobe_get_entry_data_size(struct trace_probe *tp) +{ + struct probe_entry_arg *earg = tp->entry_arg; + int i, size = 0; + + if (!earg) + return 0; + + for (i = 0; i < earg->size; i++) { + switch (earg->code[i].op) { + case FETCH_OP_END: + goto out; + case FETCH_OP_ST_EDATA: + size = earg->code[i].offset + sizeof(unsigned long); + break; + default: + break; + } + } +out: + return size; +} + +void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs) +{ + struct probe_entry_arg *earg = tp->entry_arg; + unsigned long val; + int i; + + if (!earg) + return; + + for (i = 0; i < earg->size; i++) { + struct fetch_insn *code = &earg->code[i]; + + switch (code->op) { + case FETCH_OP_ARG: + val = regs_get_kernel_argument(regs, code->param); + break; + case FETCH_OP_ST_EDATA: + *(unsigned long *)((unsigned long)edata + code->offset) = val; + break; + case FETCH_OP_END: + goto end; + default: + break; + } + } +end: + return; +} +NOKPROBE_SYMBOL(store_trace_entry_data) +#endif + #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long)) /* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */ @@ -830,7 +942,7 @@ static int parse_probe_vars(char *orig_arg, const struct fetch_type *t, #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API len = str_has_prefix(arg, "arg"); - if (len && tparg_is_function_entry(ctx->flags)) { + if (len) { ret = kstrtoul(arg + len, 10, ¶m); if (ret) goto inval; @@ -839,15 +951,29 @@ static int parse_probe_vars(char *orig_arg, const struct fetch_type *t, err = TP_ERR_BAD_ARG_NUM; goto inval; } + param--; /* argN starts from 1, but internal arg[N] starts from 0 */ - code->op = FETCH_OP_ARG; - code->param = (unsigned int)param - 1; - /* - * The tracepoint probe will probe a stub function, and the - * first parameter of the stub is a dummy and should be ignored. - */ - if (ctx->flags & TPARG_FL_TPOINT) - code->param++; + if (tparg_is_function_entry(ctx->flags)) { + code->op = FETCH_OP_ARG; + code->param = (unsigned int)param; + /* + * The tracepoint probe will probe a stub function, and the + * first parameter of the stub is a dummy and should be ignored. + */ + if (ctx->flags & TPARG_FL_TPOINT) + code->param++; + } else if (tparg_is_function_return(ctx->flags)) { + /* function entry argument access from return probe */ + ret = __store_entry_arg(ctx->tp, param); + if (ret < 0) /* This error should be an internal error */ + return ret; + + code->op = FETCH_OP_EDATA; + code->offset = ret; + } else { + err = TP_ERR_NOFENTRY_ARGS; + goto inval; + } return 0; } #endif @@ -1037,7 +1163,8 @@ parse_probe_arg(char *arg, const struct fetch_type *type, break; default: if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */ - if (!tparg_is_function_entry(ctx->flags)) { + if (!tparg_is_function_entry(ctx->flags) && + !tparg_is_function_return(ctx->flags)) { trace_probe_log_err(ctx->offset, NOSUP_BTFARG); return -EINVAL; } @@ -1090,67 +1217,45 @@ static int __parse_bitfield_probe_arg(const char *bf, return (BYTES_TO_BITS(t->size) < (bw + bo)) ? -EINVAL : 0; } -/* String length checking wrapper */ -static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, - struct probe_arg *parg, - struct traceprobe_parse_context *ctx) +/* Split type part from @arg and return it. */ +static char *parse_probe_arg_type(char *arg, struct probe_arg *parg, + struct traceprobe_parse_context *ctx) { - struct fetch_insn *code, *scode, *tmp = NULL; - char *t, *t2, *t3; - int ret, len; - char *arg; - - arg = kstrdup(argv, GFP_KERNEL); - if (!arg) - return -ENOMEM; - - ret = -EINVAL; - len = strlen(arg); - if (len > MAX_ARGSTR_LEN) { - trace_probe_log_err(ctx->offset, ARG_TOO_LONG); - goto out; - } else if (len == 0) { - trace_probe_log_err(ctx->offset, NO_ARG_BODY); - goto out; - } - - ret = -ENOMEM; - parg->comm = kstrdup(arg, GFP_KERNEL); - if (!parg->comm) - goto out; + char *t = NULL, *t2, *t3; + int offs; - ret = -EINVAL; t = strchr(arg, ':'); if (t) { - *t = '\0'; - t2 = strchr(++t, '['); + *t++ = '\0'; + t2 = strchr(t, '['); if (t2) { *t2++ = '\0'; t3 = strchr(t2, ']'); if (!t3) { - int offs = t2 + strlen(t2) - arg; + offs = t2 + strlen(t2) - arg; trace_probe_log_err(ctx->offset + offs, ARRAY_NO_CLOSE); - goto out; + return ERR_PTR(-EINVAL); } else if (t3[1] != '\0') { trace_probe_log_err(ctx->offset + t3 + 1 - arg, BAD_ARRAY_SUFFIX); - goto out; + return ERR_PTR(-EINVAL); } *t3 = '\0'; if (kstrtouint(t2, 0, &parg->count) || !parg->count) { trace_probe_log_err(ctx->offset + t2 - arg, BAD_ARRAY_NUM); - goto out; + return ERR_PTR(-EINVAL); } if (parg->count > MAX_ARRAY_LEN) { trace_probe_log_err(ctx->offset + t2 - arg, ARRAY_TOO_BIG); - goto out; + return ERR_PTR(-EINVAL); } } } + offs = t ? t - arg : 0; /* * Since $comm and immediate string can not be dereferenced, @@ -1159,72 +1264,54 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, if (!(ctx->flags & TPARG_FL_TEVENT) && (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 || strncmp(arg, "\\\"", 2) == 0)) { - /* The type of $comm must be "string", and not an array. */ - if (parg->count || (t && strcmp(t, "string"))) - goto out; + /* The type of $comm must be "string", and not an array type. */ + if (parg->count || (t && strcmp(t, "string"))) { + trace_probe_log_err(ctx->offset + offs, NEED_STRING_TYPE); + return ERR_PTR(-EINVAL); + } parg->type = find_fetch_type("string", ctx->flags); } else parg->type = find_fetch_type(t, ctx->flags); - if (!parg->type) { - trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), BAD_TYPE); - goto out; - } - parg->offset = *size; - *size += parg->type->size * (parg->count ?: 1); - ret = -ENOMEM; - if (parg->count) { - len = strlen(parg->type->fmttype) + 6; - parg->fmt = kmalloc(len, GFP_KERNEL); - if (!parg->fmt) - goto out; - snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, - parg->count); + if (!parg->type) { + trace_probe_log_err(ctx->offset + offs, BAD_TYPE); + return ERR_PTR(-EINVAL); } - code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); - if (!code) - goto out; - code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; - - ctx->last_type = NULL; - ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], - ctx); - if (ret) - goto fail; + return t; +} - /* Update storing type if BTF is available */ - if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && - ctx->last_type) { - if (!t) { - parg->type = find_fetch_type_from_btf_type(ctx); - } else if (strstr(t, "string")) { - ret = check_prepare_btf_string_fetch(t, &code, ctx); - if (ret) - goto fail; - } - } +/* After parsing, adjust the fetch_insn according to the probe_arg */ +static int finalize_fetch_insn(struct fetch_insn *code, + struct probe_arg *parg, + char *type, + int type_offset, + struct traceprobe_parse_context *ctx) +{ + struct fetch_insn *scode; + int ret; - ret = -EINVAL; /* Store operation */ if (parg->type->is_string) { + /* Check bad combination of the type and the last fetch_insn. */ if (!strcmp(parg->type->name, "symstr")) { if (code->op != FETCH_OP_REG && code->op != FETCH_OP_STACK && code->op != FETCH_OP_RETVAL && code->op != FETCH_OP_ARG && code->op != FETCH_OP_DEREF && code->op != FETCH_OP_TP_ARG) { - trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), + trace_probe_log_err(ctx->offset + type_offset, BAD_SYMSTRING); - goto fail; + return -EINVAL; } } else { if (code->op != FETCH_OP_DEREF && code->op != FETCH_OP_UDEREF && code->op != FETCH_OP_IMM && code->op != FETCH_OP_COMM && code->op != FETCH_OP_DATA && code->op != FETCH_OP_TP_ARG) { - trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), + trace_probe_log_err(ctx->offset + type_offset, BAD_STRING); - goto fail; + return -EINVAL; } } + if (!strcmp(parg->type->name, "symstr") || (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM || code->op == FETCH_OP_DATA) || code->op == FETCH_OP_TP_ARG || @@ -1240,9 +1327,10 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, code++; if (code->op != FETCH_OP_NOP) { trace_probe_log_err(ctx->offset, TOO_MANY_OPS); - goto fail; + return -EINVAL; } } + /* If op == DEREF, replace it with STRING */ if (!strcmp(parg->type->name, "ustring") || code->op == FETCH_OP_UDEREF) @@ -1263,47 +1351,134 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, code++; if (code->op != FETCH_OP_NOP) { trace_probe_log_err(ctx->offset, TOO_MANY_OPS); - goto fail; + return -E2BIG; } code->op = FETCH_OP_ST_RAW; code->size = parg->type->size; } + + /* Save storing fetch_insn. */ scode = code; + /* Modify operation */ - if (t != NULL) { - ret = __parse_bitfield_probe_arg(t, parg->type, &code); + if (type != NULL) { + /* Bitfield needs a special fetch_insn. */ + ret = __parse_bitfield_probe_arg(type, parg->type, &code); if (ret) { - trace_probe_log_err(ctx->offset + t - arg, BAD_BITFIELD); - goto fail; + trace_probe_log_err(ctx->offset + type_offset, BAD_BITFIELD); + return ret; } } else if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && ctx->last_type) { + /* If user not specified the type, try parsing BTF bitfield. */ ret = parse_btf_bitfield(&code, ctx); if (ret) - goto fail; + return ret; } - ret = -EINVAL; + /* Loop(Array) operation */ if (parg->count) { if (scode->op != FETCH_OP_ST_MEM && scode->op != FETCH_OP_ST_STRING && scode->op != FETCH_OP_ST_USTRING) { - trace_probe_log_err(ctx->offset + (t ? (t - arg) : 0), - BAD_STRING); - goto fail; + trace_probe_log_err(ctx->offset + type_offset, BAD_STRING); + return -EINVAL; } code++; if (code->op != FETCH_OP_NOP) { trace_probe_log_err(ctx->offset, TOO_MANY_OPS); - goto fail; + return -E2BIG; } code->op = FETCH_OP_LP_ARRAY; code->param = parg->count; } + + /* Finalize the fetch_insn array. */ code++; code->op = FETCH_OP_END; - ret = 0; + return 0; +} + +/* String length checking wrapper */ +static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, + struct probe_arg *parg, + struct traceprobe_parse_context *ctx) +{ + struct fetch_insn *code, *tmp = NULL; + char *type, *arg; + int ret, len; + + len = strlen(argv); + if (len > MAX_ARGSTR_LEN) { + trace_probe_log_err(ctx->offset, ARG_TOO_LONG); + return -E2BIG; + } else if (len == 0) { + trace_probe_log_err(ctx->offset, NO_ARG_BODY); + return -EINVAL; + } + + arg = kstrdup(argv, GFP_KERNEL); + if (!arg) + return -ENOMEM; + + parg->comm = kstrdup(arg, GFP_KERNEL); + if (!parg->comm) { + ret = -ENOMEM; + goto out; + } + + type = parse_probe_arg_type(arg, parg, ctx); + if (IS_ERR(type)) { + ret = PTR_ERR(type); + goto out; + } + + code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL); + if (!code) { + ret = -ENOMEM; + goto out; + } + code[FETCH_INSN_MAX - 1].op = FETCH_OP_END; + + ctx->last_type = NULL; + ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1], + ctx); + if (ret < 0) + goto fail; + + /* Update storing type if BTF is available */ + if (IS_ENABLED(CONFIG_PROBE_EVENTS_BTF_ARGS) && + ctx->last_type) { + if (!type) { + parg->type = find_fetch_type_from_btf_type(ctx); + } else if (strstr(type, "string")) { + ret = check_prepare_btf_string_fetch(type, &code, ctx); + if (ret) + goto fail; + } + } + parg->offset = *size; + *size += parg->type->size * (parg->count ?: 1); + + if (parg->count) { + len = strlen(parg->type->fmttype) + 6; + parg->fmt = kmalloc(len, GFP_KERNEL); + if (!parg->fmt) { + ret = -ENOMEM; + goto out; + } + snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype, + parg->count); + } + + ret = finalize_fetch_insn(code, parg, type, type ? type - arg : 0, ctx); + if (ret < 0) + goto fail; + + for (; code < tmp + FETCH_INSN_MAX; code++) + if (code->op == FETCH_OP_END) + break; /* Shrink down the code buffer */ parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL); if (!parg->code) @@ -1312,7 +1487,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, memcpy(parg->code, tmp, sizeof(*code) * (code - tmp + 1)); fail: - if (ret) { + if (ret < 0) { for (code = tmp; code < tmp + FETCH_INSN_MAX; code++) if (code->op == FETCH_NOP_SYMBOL || code->op == FETCH_OP_DATA) @@ -1375,9 +1550,7 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg, struct probe_arg *parg = &tp->args[i]; const char *body; - /* Increment count for freeing args in error case */ - tp->nr_args++; - + ctx->tp = tp; body = strchr(arg, '='); if (body) { if (body - arg > MAX_ARG_NAME_LEN) { @@ -1434,7 +1607,8 @@ static int argv_has_var_arg(int argc, const char *argv[], int *args_idx, if (str_has_prefix(argv[i], "$arg")) { trace_probe_log_set_index(i + 2); - if (!tparg_is_function_entry(ctx->flags)) { + if (!tparg_is_function_entry(ctx->flags) && + !tparg_is_function_return(ctx->flags)) { trace_probe_log_err(0, NOFENTRY_ARGS); return -EINVAL; } @@ -1757,12 +1931,18 @@ void trace_probe_cleanup(struct trace_probe *tp) for (i = 0; i < tp->nr_args; i++) traceprobe_free_probe_arg(&tp->args[i]); + if (tp->entry_arg) { + kfree(tp->entry_arg->code); + kfree(tp->entry_arg); + tp->entry_arg = NULL; + } + if (tp->event) trace_probe_unlink(tp); } int trace_probe_init(struct trace_probe *tp, const char *event, - const char *group, bool alloc_filter) + const char *group, bool alloc_filter, int nargs) { struct trace_event_call *call; size_t size = sizeof(struct trace_probe_event); @@ -1798,6 +1978,11 @@ int trace_probe_init(struct trace_probe *tp, const char *event, goto error; } + tp->nr_args = nargs; + /* Make sure pointers in args[] are NULL */ + if (nargs) + memset(tp->args, 0, sizeof(tp->args[0]) * nargs); + return 0; error: |