From 0590c94c3596d6c1a3d549ae611366f2ad4e1d8d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adri=C3=A1n=20Larumbe?= <adrian.larumbe@collabora.com>
Date: Thu, 30 Jan 2025 17:28:13 +0000
Subject: [PATCH] drm/panthor: Fix race condition when gathering fdinfo group
samples
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Commit e16635d88fa0 ("drm/panthor: add DRM fdinfo support") failed to
protect access to groups with an xarray lock, which could lead to
use-after-free errors.
Fixes: e16635d88fa0 ("drm/panthor: add DRM fdinfo support")
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250130172851.941597-6-adrian.larumbe@collabora.com
Link: https://patchwork.freedesktop.org/patch/msgid/20250107173310.88329-1-florent.tomasin@arm.com
---
drivers/gpu/drm/panthor/panthor_sched.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index da87e6e819387..0b93bf83a9b21 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -2878,6 +2878,7 @@ void panthor_fdinfo_gather_group_samples(struct panthor_file *pfile)
if (IS_ERR_OR_NULL(gpool))
return;
+ xa_lock(&gpool->xa);
xa_for_each(&gpool->xa, i, group) {
mutex_lock(&group->fdinfo.lock);
pfile->stats.cycles += group->fdinfo.data.cycles;
@@ -2886,6 +2887,7 @@ void panthor_fdinfo_gather_group_samples(struct panthor_file *pfile)
group->fdinfo.data.time = 0;
mutex_unlock(&group->fdinfo.lock);
}
+ xa_unlock(&gpool->xa);
}
static void group_sync_upd_work(struct work_struct *work)
--
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