On Mon, Mar 09, 2020 at 12:01:51PM +0000, Chris Wilson wrote:
[ 1715.899800] BUG: KCSAN: data-race in drm_gem_handle_create_tail / drm_gem_object_handle_put_unlocked [ 1715.899838] [ 1715.899861] write to 0xffff8881830f3604 of 4 bytes by task 7834 on cpu 1: [ 1715.899896] drm_gem_handle_create_tail+0x62/0x250 [ 1715.899927] drm_gem_open_ioctl+0xc1/0x160 [ 1715.899956] drm_ioctl_kernel+0xe4/0x120 [ 1715.899981] drm_ioctl+0x297/0x4c7 [ 1715.900003] ksys_ioctl+0x89/0xb0 [ 1715.900027] __x64_sys_ioctl+0x42/0x60 [ 1715.900052] do_syscall_64+0x6e/0x2c0 [ 1715.900079] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1715.900100] [ 1715.900119] read to 0xffff8881830f3604 of 4 bytes by task 8137 on cpu 0: [ 1715.900149] drm_gem_object_handle_put_unlocked+0x31/0x130 [ 1715.900180] drm_gem_object_release_handle+0x93/0xe0 [ 1715.900208] drm_gem_handle_delete+0x7b/0xe0 [ 1715.900235] drm_gem_close_ioctl+0x61/0x80 [ 1715.900264] drm_ioctl_kernel+0xe4/0x120 [ 1715.900291] drm_ioctl+0x297/0x4c7 [ 1715.900316] ksys_ioctl+0x89/0xb0 [ 1715.900340] __x64_sys_ioctl+0x42/0x60 [ 1715.900363] do_syscall_64+0x6e/0x2c0 [ 1715.900388] entry_SYSCALL_64_after_hwframe+0x44/0xa9
I'm impressed. The dream that we all get replaced by some scripts might be real :-)
Signed-off-by: Chris Wilson chris@chris-wilson.co.uk
Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch
drivers/gpu/drm/drm_gem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index a9e4a610445a..37627d06fb06 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -218,7 +218,7 @@ drm_gem_object_handle_put_unlocked(struct drm_gem_object *obj) struct drm_device *dev = obj->dev; bool final = false;
- if (WARN_ON(obj->handle_count == 0))
if (WARN_ON(READ_ONCE(obj->handle_count) == 0)) return;
/*
-- 2.20.1
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