# \[PATCH v3 14/16\] tracing/filters: Fix error positions for CPUS mask parsing - From: Masami Hiramatsu (Google) \ - Date: 2026-10-28 00:45:38 - List: linux-trace-kernel - Page: https://ratatoskr.run/linux-trace-kernel/2026/10/17814025 - Thread: https://ratatoskr.run/linux-trace-kernel/2026/10/17814009/t.md ```text From: Masami Hiramatsu (Google) In parse_pred(), CPUS mask error paths report incorrect error positions: - Checking 'str[i++] != '\'{'\'' post-increments 'i' before calling parse_error(), shifting the error caret one character past the missing brace position. - In the CPUS operator check and comparison function selection check, 'pos + i' points to the CPUS operand or past it instead of the unsupported operator. Check 'str[i] != '\'{'\'' before incrementing 'i', and pass 'pos + op_pos' for the operator checks so the error caret points accurately. Fixes: 39f7c41c908b ("tracing/filters: Enable filtering a cpumask field by another cpumask") Fixes: 3cbec9d7b93d ("tracing/filters: Enable filtering a scalar field by a cpumask") Cc: Signed-off-by: Masami Hiramatsu (Google) --- Changes in v3: - Group error position fixes for CPUS mask parsing into a single patch targeting commit 39f7c41c908b and commit 3cbec9d7b93d. --- kernel/trace/trace_events_filter.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index b1b4f1a57dc9..291c9805e119 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -1926,16 +1926,17 @@ static int parse_pred(const char *str, void *data, case OP_BAND: 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; } /* Skip CPUS */ i += 4; - if (str[i++] != '{') { + if (str[i] != '{') { parse_error(pe, FILT_ERR_MISSING_BRACE_OPEN, pos + i); goto err_free; } + i++; maskstart = i; /* Walk the cpulist until closing } */ @@ -2023,7 +2024,7 @@ static int parse_pred(const char *str, void *data, } } 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; } ```