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Subject[PATCH] [next] drm/amdgpu: Replace 1-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 structs _ATOM_GPIO_PIN_ASSIGNMENT,
_ATOM_DISPLAY_OBJECT_PATH, _ATOM_DISPLAY_OBJECT_PATH_TABLE,
_ATOM_OBJECT_TABLE and refactor the rest of the code accordingly.

Important to mention is that doing a build before/after this patch results
in no functional 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 [1]

Signed-off-by: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@gmail.com>
---

Binary difference findings:

Some changes took more than a single line which changed the line
number parameter passed to the drm_dbg function (which leverages
kernel's dynamic debugging). Functionally-wise, nothing changed
after doing a before/after patch build.

Additional one-element arrays to be changed:

There are more instances of one-element arrays to be changed but
I will keep patches small so they are easy to review. [and I can
only dedicate a few hours per day on this :-) ]

---
.../gpu/drm/amd/display/dc/bios/bios_parser.c | 23 ++++++++++++-------
drivers/gpu/drm/amd/include/atombios.h | 8 +++----
2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/bios/bios_parser.c b/drivers/gpu/drm/amd/display/dc/bios/bios_parser.c
index 9b8ea6e9a2b9..39dd8b2dc254 100644
--- a/drivers/gpu/drm/amd/display/dc/bios/bios_parser.c
+++ b/drivers/gpu/drm/amd/display/dc/bios/bios_parser.c
@@ -138,7 +138,9 @@ static uint8_t get_number_of_objects(struct bios_parser *bp, uint32_t offset)

uint32_t object_table_offset = bp->object_info_tbl_offset + offset;

- table = GET_IMAGE(ATOM_OBJECT_TABLE, object_table_offset);
+ table = ((ATOM_OBJECT_TABLE *) bios_get_image(&bp->base,
+ object_table_offset,
+ struct_size(table, asObjects, 1)));

if (!table)
return 0;
@@ -166,8 +168,9 @@ static struct graphics_object_id bios_parser_get_connector_id(
uint32_t connector_table_offset = bp->object_info_tbl_offset
+ le16_to_cpu(bp->object_info_tbl.v1_1->usConnectorObjectTableOffset);

- ATOM_OBJECT_TABLE *tbl =
- GET_IMAGE(ATOM_OBJECT_TABLE, connector_table_offset);
+ ATOM_OBJECT_TABLE *tbl = ((ATOM_OBJECT_TABLE *) bios_get_image(&bp->base,
+ connector_table_offset,
+ struct_size(tbl, asObjects, 1)));

if (!tbl) {
dm_error("Can't get connector table from atom bios.\n");
@@ -1789,11 +1792,13 @@ static enum bp_result bios_parser_get_gpio_pin_info(
if (!DATA_TABLES(GPIO_Pin_LUT))
return BP_RESULT_BADBIOSTABLE;

- header = GET_IMAGE(ATOM_GPIO_PIN_LUT, DATA_TABLES(GPIO_Pin_LUT));
+ header = ((ATOM_GPIO_PIN_LUT *) bios_get_image(&bp->base,
+ DATA_TABLES(GPIO_Pin_LUT),
+ struct_size(header, asGPIO_Pin, 1)));
if (!header)
return BP_RESULT_BADBIOSTABLE;

- if (sizeof(ATOM_COMMON_TABLE_HEADER) + sizeof(ATOM_GPIO_PIN_LUT)
+ if (sizeof(ATOM_COMMON_TABLE_HEADER) + struct_size(header, asGPIO_Pin, 1)
> le16_to_cpu(header->sHeader.usStructureSize))
return BP_RESULT_BADBIOSTABLE;

@@ -1978,7 +1983,8 @@ static ATOM_OBJECT *get_bios_object(struct bios_parser *bp,

offset += bp->object_info_tbl_offset;

- tbl = GET_IMAGE(ATOM_OBJECT_TABLE, offset);
+ tbl = ((ATOM_OBJECT_TABLE *) bios_get_image(&bp->base, offset,
+ struct_size(tbl, asObjects, 1)));
if (!tbl)
return NULL;

@@ -2709,8 +2715,9 @@ static enum bp_result get_bracket_layout_record(

genericTableOffset = bp->object_info_tbl_offset +
bp->object_info_tbl.v1_3->usMiscObjectTableOffset;
- object_table = (ATOM_OBJECT_TABLE *)
- GET_IMAGE(ATOM_OBJECT_TABLE, genericTableOffset);
+ object_table = ((ATOM_OBJECT_TABLE *) bios_get_image(&bp->base,
+ genericTableOffset,
+ struct_size(object_table, asObjects, 1)));
if (!object_table)
return BP_RESULT_FAILURE;

diff --git a/drivers/gpu/drm/amd/include/atombios.h b/drivers/gpu/drm/amd/include/atombios.h
index b5b1d073f8e2..55ae93c1e365 100644
--- a/drivers/gpu/drm/amd/include/atombios.h
+++ b/drivers/gpu/drm/amd/include/atombios.h
@@ -4386,7 +4386,7 @@ typedef struct _ATOM_GPIO_PIN_ASSIGNMENT
typedef struct _ATOM_GPIO_PIN_LUT
{
ATOM_COMMON_TABLE_HEADER sHeader;
- ATOM_GPIO_PIN_ASSIGNMENT asGPIO_Pin[1];
+ ATOM_GPIO_PIN_ASSIGNMENT asGPIO_Pin[];
}ATOM_GPIO_PIN_LUT;

/****************************************************************************/
@@ -4513,7 +4513,7 @@ typedef struct _ATOM_DISPLAY_OBJECT_PATH
USHORT usSize; //the size of ATOM_DISPLAY_OBJECT_PATH
USHORT usConnObjectId; //Connector Object ID
USHORT usGPUObjectId; //GPU ID
- USHORT usGraphicObjIds[1]; //1st Encoder Obj source from GPU to last Graphic Obj destinate to connector.
+ USHORT usGraphicObjIds[]; //1st Encoder Obj source from GPU to last Graphic Obj destinate to connector.
}ATOM_DISPLAY_OBJECT_PATH;

typedef struct _ATOM_DISPLAY_EXTERNAL_OBJECT_PATH
@@ -4530,7 +4530,7 @@ typedef struct _ATOM_DISPLAY_OBJECT_PATH_TABLE
UCHAR ucNumOfDispPath;
UCHAR ucVersion;
UCHAR ucPadding[2];
- ATOM_DISPLAY_OBJECT_PATH asDispPath[1];
+ ATOM_DISPLAY_OBJECT_PATH asDispPath[];
}ATOM_DISPLAY_OBJECT_PATH_TABLE;

typedef struct _ATOM_OBJECT //each object has this structure
@@ -4545,7 +4545,7 @@ typedef struct _ATOM_OBJECT_TABLE //Above 4 object table
{
UCHAR ucNumberOfObjects;
UCHAR ucPadding[3];
- ATOM_OBJECT asObjects[1];
+ ATOM_OBJECT asObjects[];
}ATOM_OBJECT_TABLE;

typedef struct _ATOM_SRC_DST_TABLE_FOR_ONE_OBJECT //usSrcDstTableOffset pointing to this structure
--
2.37.3
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