From: Masami Hiramatsu (Google) <[email protected]> In predicate_parse(), 'ptr' has already been advanced past 'next', shifting 'pos' passed to parse_pred() one character to the right.
In parse_pred(), several error paths report 'pos + i' after 'i' has already been advanced to subsequent tokens: - When a field is not found (FILT_ERR_FIELD_NOT_FOUND) or when a function event field is not "ip" (FILT_ERR_IP_FIELD_ONLY), 'pos + i' points past the field name or to the operand instead of the field. - In operator validation checks for string and numeric operands, and when select_comparison_fn() returns NOP, 'pos + i' points to the operand or past it instead of the unsupported operator. Fix these by passing 'next - str' in predicate_parse(), saving the field position in 'field_pos' and the operator position in 'op_pos', and passing 'pos + field_pos' or 'pos + op_pos' accordingly. Also update the tracing-error-log.tc selftest to reflect the corrected error position. Signed-off-by: Masami Hiramatsu (Google) <[email protected]> --- Changes in v4: - Drop Fixes and Cc: stable tags since this error position fix is a cleanup. Changes in v3: - Group all error position fixes for commit 80765597bc58 together into a single patch for ease of backporting. --- kernel/trace/trace_events_filter.c | 19 ++++++++++++------- .../ftrace/test.d/ftrace/tracing-error-log.tc | 2 +- 2 files changed, 13 insertions(+), 8 deletions(-) diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index e91ec41bfd2a..6ff208f0e033 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -537,7 +537,7 @@ predicate_parse(const char *str, int nr_parens, int nr_preds, inverts[N] = invert; /* #4 */ prog[N].target = N-1; - len = parse_pred(next, data, ptr - str, pe, &prog[N].pred); + len = parse_pred(next, data, next - str, pe, &prog[N].pred); if (len < 0) { ret = len; goto out_free; @@ -1700,12 +1700,15 @@ static int parse_pred(const char *str, void *data, int ret; int op; int s; + int field_pos = 0; + int op_pos = 0; int i = 0; /* First find the field to associate to */ while (isspace(str[i])) i++; s = i; + field_pos = i; while (isalnum(str[i]) || str[i] == '_') i++; @@ -1726,7 +1729,7 @@ static int parse_pred(const char *str, void *data, field = trace_find_event_field(call, field_name); kfree(field_name); if (!field) { - parse_error(pe, FILT_ERR_FIELD_NOT_FOUND, pos + i); + parse_error(pe, FILT_ERR_FIELD_NOT_FOUND, pos + field_pos); return -EINVAL; } @@ -1745,6 +1748,8 @@ static int parse_pred(const char *str, void *data, while (isspace(str[i])) i++; + op_pos = i; + /* Make sure this op is supported */ for (op = 0; ops[op]; op++) { /* This is why '<=' must come before '<' in ops[] */ @@ -1753,7 +1758,7 @@ static int parse_pred(const char *str, void *data, } if (!ops[op]) { - parse_error(pe, FILT_ERR_INVALID_OP, pos + i); + parse_error(pe, FILT_ERR_INVALID_OP, pos + op_pos); goto err_free; } @@ -1850,7 +1855,7 @@ static int parse_pred(const char *str, void *data, * (perf doesn't use it) and grab everything. */ if (strcmp(field->name, "ip") != 0) { - parse_error(pe, FILT_ERR_IP_FIELD_ONLY, pos + i); + parse_error(pe, FILT_ERR_IP_FIELD_ONLY, pos + field_pos); goto err_free; } pred->fn_num = FILTER_PRED_FN_NOP; @@ -2039,7 +2044,7 @@ static int parse_pred(const char *str, void *data, case OP_EQ: break; default: - parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i); + parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + op_pos); goto err_free; } @@ -2140,7 +2145,7 @@ static int parse_pred(const char *str, void *data, } if (op == OP_GLOB) { - parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i); + parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + op_pos); goto err_free; } @@ -2179,7 +2184,7 @@ static int parse_pred(const char *str, void *data, pred->fn_num = select_comparison_fn(pred->op, field->size, field->is_signed); if (pred->fn_num == FILTER_PRED_FN_NOP) { - parse_error(pe, FILT_ERR_INVALID_OP, pos + i); + parse_error(pe, FILT_ERR_INVALID_OP, pos + op_pos); goto err_free; } if (pred->op == OP_NE) diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/tracing-error-log.tc b/tools/testing/selftests/ftrace/test.d/ftrace/tracing-error-log.tc index 6c190620db47..2c900873ce3c 100644 --- a/tools/testing/selftests/ftrace/test.d/ftrace/tracing-error-log.tc +++ b/tools/testing/selftests/ftrace/test.d/ftrace/tracing-error-log.tc @@ -10,6 +10,6 @@ fail() { #msg exit_fail } -ftrace_errlog_check 'event filter parse error' '((sig >= 10 && sig < 15) || dsig ^== 17) && comm != bash' 'events/signal/signal_generate/filter' +ftrace_errlog_check 'event filter parse error' '((sig >= 10 && sig < 15) || ^dsig == 17) && comm != bash' 'events/signal/signal_generate/filter' exit 0
