drm/amdgpu: Replace one-element array with flexible-array member

One-element arrays are deprecated, and we are replacing them with
flexible array members instead. So, replace one-element array with
flexible-array member in struct _ATOM_FAKE_EDID_PATCH_RECORD and
refactor the rest of the code accordingly.

Important to mention is that doing a build before/after this patch
results in no binary output differences.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/238
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836
Signed-off-by: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
index 6be9ac2..18ae943 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
+++ b/drivers/gpu/drm/amd/amdgpu/atombios_encoders.c
@@ -2081,8 +2081,11 @@ amdgpu_atombios_encoder_get_lcd_info(struct amdgpu_encoder *encoder)
                                                }
                                        }
                                        record += fake_edid_record->ucFakeEDIDLength ?
-                                               fake_edid_record->ucFakeEDIDLength + 2 :
-                                               sizeof(ATOM_FAKE_EDID_PATCH_RECORD);
+                                                 struct_size(fake_edid_record,
+                                                             ucFakeEDIDString,
+                                                             fake_edid_record->ucFakeEDIDLength) :
+                                                 /* empty fake edid record must be 3 bytes long */
+                                                 sizeof(ATOM_FAKE_EDID_PATCH_RECORD) + 1;
                                        break;
                                case LCD_PANEL_RESOLUTION_RECORD_TYPE:
                                        panel_res_record = (ATOM_PANEL_RESOLUTION_PATCH_RECORD *)record;

diff --git a/drivers/gpu/drm/amd/include/atombios.h b/drivers/gpu/drm/amd/include/atombios.h
index 15943bc..b5b1d07 100644 (file)
--- a/drivers/gpu/drm/amd/include/atombios.h
+++ b/drivers/gpu/drm/amd/include/atombios.h
@@ -4107,7 +4107,7 @@ typedef struct _ATOM_FAKE_EDID_PATCH_RECORD
 {
   UCHAR ucRecordType;
   UCHAR ucFakeEDIDLength;       // = 128 means EDID length is 128 bytes, otherwise the EDID length = ucFakeEDIDLength*128
-  UCHAR ucFakeEDIDString[1];    // This actually has ucFakeEdidLength elements.
+  UCHAR ucFakeEDIDString[];     // This actually has ucFakeEdidLength elements.
 } ATOM_FAKE_EDID_PATCH_RECORD;
 
 typedef struct  _ATOM_PANEL_RESOLUTION_PATCH_RECORD