diff options
Diffstat (limited to 'kernel/trace/trace_events_filter.c')
-rw-r--r-- | kernel/trace/trace_events_filter.c | 93 |
1 files changed, 92 insertions, 1 deletions
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index e095c3b3a50d..1dad64267878 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -64,6 +64,7 @@ enum filter_pred_fn { FILTER_PRED_FN_PCHAR_USER, FILTER_PRED_FN_PCHAR, FILTER_PRED_FN_CPU, + FILTER_PRED_FN_FUNCTION, FILTER_PRED_FN_, FILTER_PRED_TEST_VISITED, }; @@ -71,6 +72,7 @@ enum filter_pred_fn { struct filter_pred { enum filter_pred_fn fn_num; u64 val; + u64 val2; struct regex regex; unsigned short *ops; struct ftrace_event_field *field; @@ -103,6 +105,7 @@ struct filter_pred { C(INVALID_FILTER, "Meaningless filter expression"), \ C(IP_FIELD_ONLY, "Only 'ip' field is supported for function trace"), \ C(INVALID_VALUE, "Invalid value (did you forget quotes)?"), \ + C(NO_FUNCTION, "Function not found"), \ C(ERRNO, "Error"), \ C(NO_FILTER, "No filter found") @@ -876,6 +879,17 @@ static int filter_pred_comm(struct filter_pred *pred, void *event) return cmp ^ pred->not; } +/* Filter predicate for functions. */ +static int filter_pred_function(struct filter_pred *pred, void *event) +{ + unsigned long *addr = (unsigned long *)(event + pred->offset); + unsigned long start = (unsigned long)pred->val; + unsigned long end = (unsigned long)pred->val2; + int ret = *addr >= start && *addr < end; + + return pred->op == OP_EQ ? ret : !ret; +} + /* * regex_match_foo - Basic regex callbacks * @@ -1335,6 +1349,8 @@ static int filter_pred_fn_call(struct filter_pred *pred, void *event) return filter_pred_pchar(pred, event); case FILTER_PRED_FN_CPU: return filter_pred_cpu(pred, event); + case FILTER_PRED_FN_FUNCTION: + return filter_pred_function(pred, event); case FILTER_PRED_TEST_VISITED: return test_pred_visited_fn(pred, event); default: @@ -1350,8 +1366,13 @@ static int parse_pred(const char *str, void *data, struct trace_event_call *call = data; struct ftrace_event_field *field; struct filter_pred *pred = NULL; + unsigned long offset; + unsigned long size; + unsigned long ip; char num_buf[24]; /* Big enough to hold an address */ char *field_name; + char *name; + bool function = false; bool ustring = false; char q; u64 val; @@ -1393,6 +1414,12 @@ static int parse_pred(const char *str, void *data, i += len; } + /* See if the field is a kernel function name */ + if ((len = str_has_prefix(str + i, ".function"))) { + function = true; + i += len; + } + while (isspace(str[i])) i++; @@ -1423,7 +1450,71 @@ static int parse_pred(const char *str, void *data, pred->offset = field->offset; pred->op = op; - if (ftrace_event_is_function(call)) { + if (function) { + /* The field must be the same size as long */ + if (field->size != sizeof(long)) { + parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i); + goto err_free; + } + + /* Function only works with '==' or '!=' and an unquoted string */ + switch (op) { + case OP_NE: + case OP_EQ: + break; + default: + parse_error(pe, FILT_ERR_INVALID_OP, pos + i); + goto err_free; + } + + if (isdigit(str[i])) { + /* We allow 0xDEADBEEF */ + while (isalnum(str[i])) + i++; + + len = i - s; + /* 0xfeedfacedeadbeef is 18 chars max */ + if (len >= sizeof(num_buf)) { + parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i); + goto err_free; + } + + strncpy(num_buf, str + s, len); + num_buf[len] = 0; + + ret = kstrtoul(num_buf, 0, &ip); + if (ret) { + parse_error(pe, FILT_ERR_INVALID_VALUE, pos + i); + goto err_free; + } + } else { + s = i; + for (; str[i] && !isspace(str[i]); i++) + ; + + len = i - s; + name = kmemdup_nul(str + s, len, GFP_KERNEL); + if (!name) + goto err_mem; + ip = kallsyms_lookup_name(name); + kfree(name); + if (!ip) { + parse_error(pe, FILT_ERR_NO_FUNCTION, pos + i); + goto err_free; + } + } + + /* Now find the function start and end address */ + if (!kallsyms_lookup_size_offset(ip, &size, &offset)) { + parse_error(pe, FILT_ERR_NO_FUNCTION, pos + i); + goto err_free; + } + + pred->fn_num = FILTER_PRED_FN_FUNCTION; + pred->val = ip - offset; + pred->val2 = pred->val + size; + + } else if (ftrace_event_is_function(call)) { /* * Perf does things different with function events. * It only allows an "ip" field, and expects a string. |