[tip: sched/core] rseq: Fix rseq unregistration regression

[tip-bot2 for Mathieu Desnoyers]

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     40724ecafccb1fb62b66264854e8c3ad394c8f3d
Gitweb:        https://git.kernel.org/tip/40724ecafccb1fb62b66264854e8c3ad394c8f3d
Author:        Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
AuthorDate:    Thu, 16 Jan 2025 15:59:56 -05:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 21 Jan 2025 08:10:51 +01:00

rseq: Fix rseq unregistration regression

A logic inversion in rseq_reset_rseq_cpu_node_id() causes the rseq
unregistration to fail when rseq_validate_ro_fields() succeeds rather
than the opposite.

This affects both CONFIG_DEBUG_RSEQ=y and CONFIG_DEBUG_RSEQ=n.

Fixes: 7d5265ffcd8b ("rseq: Validate read-only fields under DEBUG_RSEQ config")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20250116205956.836074-1-mathieu.desnoyers@xxxxxxxxxxxx
---
 kernel/rseq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rseq.c b/kernel/rseq.c
index e04bb30..442aba2 100644
--- a/kernel/rseq.c
+++ b/kernel/rseq.c
@@ -201,7 +201,7 @@ static int rseq_reset_rseq_cpu_node_id(struct task_struct *t)
 	/*
 	 * Validate read-only rseq fields.
 	 */
-	if (!rseq_validate_ro_fields(t))
+	if (rseq_validate_ro_fields(t))
 		return -EFAULT;
 	/*
 	 * Reset cpu_id_start to its initial state (0).