Linus Torvalds 61bbbde9b6 drm: fix EDID struct for old ARM OABI format ... [ Upstream commit 47f15561b6 ] When building the kernel for arm with the "-mabi=apcs-gnu" option, gcc will force alignment of all structures and unions to a word boundary (see also STRUCTURE_SIZE_BOUNDARY and the "-mstructure-size-boundary=XX" option if you're a gcc person), even when the members of said structures do not want or need said alignment. This completely messes up the structure alignment of 'struct edid' on those targets, because even though all the embedded structures are marked with "__attribute__((packed))", the unions that contain them are not. This was exposed by commit f1e4c916f9 ("drm/edid: add EDID block count and size helpers"), but the bug is pre-existing. That commit just made the structure layout problem cause a build failure due to the addition of the BUILD_BUG_ON(sizeof(*edid) != EDID_LENGTH); sanity check in drivers/gpu/drm/drm_edid.c:edid_block_data(). This legacy union alignment should probably not be used in the first place, but we can fix the layout by adding the packed attribute to the union entries even when each member is already packed and it shouldn't matter in a sane build environment. You can see this issue with a trivial test program: union { struct { char c[5]; }; struct { char d; unsigned e; } __attribute__((packed)); } a = { "1234" }; where building this with a normal "gcc -S" will result in the expected 5-byte size of said union: .type a, @object .size a, 5 but with an ARM compiler and the old ABI: arm-linux-gnu-gcc -mabi=apcs-gnu -mfloat-abi=soft -S t.c you get .type a, %object .size a, 8 instead, because even though each member of the union is packed, the union itself still gets aligned. This was reported by Sudip for the spear3xx_defconfig target. Link: https://lore.kernel.org/lkml/YpCUzStDnSgQLNFN@debian/ Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		2022-06-09 10:20:59 +02:00
..
acpi	ACPICA: actypes.h: Expand the ACPI_ACCESS_ definitions	2022-01-27 10:54:18 +01:00
asm-generic	tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry	2022-04-20 09:23:22 +02:00
clocksource	clocksource/drivers/timer-ti-dm: Save and restore timer TIOCP_CFG	2021-07-14 16:56:12 +02:00
crypto	crypto: drbg - make reseeding from get_random_bytes() synchronous	2022-06-06 08:42:42 +02:00
drm	drm: fix EDID struct for old ARM OABI format	2022-06-09 10:20:59 +02:00
dt-bindings	clk: imx8mq: remove SYS PLL 1/2 clock gates	2021-07-14 16:56:20 +02:00
keys	certs: Add EFI_CERT_X509_GUID support for dbx entries	2021-06-30 08:47:30 -04:00
kunit	kunit: fix display of failed expectations for strings	2020-11-10 13:45:15 -07:00
kvm	ARM:	2020-10-23 11:17:56 -07:00
linux	ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP	2022-06-09 10:20:49 +02:00
math-emu
media	media: subdev: disallow ioctl for saa6588/davinci	2021-07-19 09:45:02 +02:00
memory	memory: renesas-rpc-if: Fix HF/OSPI data transfer in Manual Mode	2022-05-09 09:05:02 +02:00
misc
net	ipv6: fix locking issues with loops over idev->addr_list	2022-06-09 10:20:50 +02:00
pcmcia
ras	mm,hwpoison: introduce MF_MSG_UNSPLIT_THP	2020-10-16 11:11:17 -07:00
rdma	RDMA/netlink: Add __maybe_unused to static inline in C file	2021-11-26 10:39:21 +01:00
scsi	scsi: iscsi: Fix conn cleanup and stop race during iscsid restart	2022-04-20 09:23:17 +02:00
soc	firmware: raspberrypi: Keep count of all consumers	2021-09-15 09:50:41 +02:00
sound	ALSA: jack: Access input_dev under mutex	2022-06-09 10:20:51 +02:00
target	scsi: target: Fix ordered tag handling	2021-11-26 10:39:11 +01:00
trace	tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate	2022-06-09 10:20:58 +02:00
uapi	include/uapi/linux/xfrm.h: Fix XFRM_MSG_MAPPING ABI breakage	2022-05-25 09:18:02 +02:00
vdso
video	gpu: ipu-v3: remove unused functions	2020-10-26 10:42:38 +01:00
xen	xen/gnttab: fix gnttab_end_foreign_access() without page specified	2022-03-11 12:11:54 +01:00