[PATCH 5.10 013/116] tracing: Propagate is_signed to expression

Greg Kroah-Hartman
2022-02-14T09:50:08Z

From: Tom Zanussi <zanussi@kernel.org>

commit 097f1eefedeab528cecbd35586dfe293853ffb17 upstream.

During expression parsing, a new expression field is created which
should inherit the properties of the operands, such as size and
is_signed.

is_signed propagation was missing, causing spurious errors with signed
operands. Add it in parse_expr() and parse_unary() to fix the problem.

Link: https://lkml.kernel.org/r/f4dac08742fd7a0920bf80a73c6c44042f5eaa40.1643319703.git.zanussi@kernel.org

Cc: stable@vger.kernel.org
Fixes: 100719dcef447 ("tracing: Add simple expression support to hist triggers")
Reported-by: Yordan Karadzhov <ykaradzhov@vmware.com>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215513
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/trace/trace_events_hist.c | 3 +++
1 file changed, 3 insertions(+)

--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2154,6 +2154,8 @@ static struct hist_field *parse_unary(st
(HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
expr->fn = hist_field_unary_minus;
expr->operands[0] = operand1;
+ expr->size = operand1->size;
+ expr->is_signed = operand1->is_signed;
expr->operator = FIELD_OP_UNARY_MINUS;
expr->name = expr_str(expr, 0);
expr->type = kstrdup(operand1->type, GFP_KERNEL);
@@ -2293,6 +2295,7 @@ static struct hist_field *parse_expr(str

/* The operand sizes should be the same, so just pick one */
expr->size = operand1->size;
+ expr->is_signed = operand1->is_signed;

expr->operator = field_op;
expr->name = expr_str(expr, 0);