[PATCH] drm/nouveau: Add __GFP_NOFAIL for DSM buffer allocation in r535_disp_oneinit()

[Li Qiang]

acpi_evaluate_dsm() expects a valid buffer pointer for the DSM argument.
The current code uses kmalloc() without checking its return value, which
may lead to a NULL pointer dereference under memory pressure.

Since this buffer is small and there is no recovery path available here,
use __GFP_NOFAIL to guarantee allocation success and avoid potential
kernel crashes.

Fixes: 9e99444490238 ("drm/nouveau/disp/r535: initial support")
Signed-off-by: Li Qiang <liqian...@kylinos.cn>
---
 drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c 
b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c
index 6e63df816d85..f55ff5dea1c5 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c
@@ -1585,7 +1585,8 @@ r535_disp_oneinit(struct nvkm_disp *disp)
                                        union acpi_object argv4 = {
                                                .buffer.type    = 
ACPI_TYPE_BUFFER,
                                                .buffer.length  = 
sizeof(ctrl->backLightData),
-                                               .buffer.pointer = 
kmalloc(argv4.buffer.length, GFP_KERNEL),
+                                               .buffer.pointer = 
kmalloc(argv4.buffer.length,
+                                                               GFP_KERNEL | 
__GFP_NOFAIL),
                                        }, *obj;
 
                                        obj = acpi_evaluate_dsm(handle, nbci ? 
&NBCI_DSM_GUID : &NVHG_DSM_GUID,
-- 
2.25.1