linux/drivers
Chris Wilson 5684514ba9 drm/i915: Deconstruct struct sgt_dma initialiser
gcc-4.4 complains about:

	struct sgt_dma iter = {
		.sg = vma->pages->sgl,
		.dma = sg_dma_address(iter.sg),
		.max = iter.dma + iter.sg->length,
	};

drivers/gpu/drm/i915/i915_gem_gtt.c: In function ‘gen8_ppgtt_insert_4lvl’:
drivers/gpu/drm/i915/i915_gem_gtt.c:938: error: ‘iter.sg’ is used uninitialized in this function
drivers/gpu/drm/i915/i915_gem_gtt.c:939: error: ‘iter.dma’ is used uninitialized in this function

and worse generates invalid code that triggers a GPF:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915]
PGD 0
Oops: 0000 [#1] SMP
Modules linked in: snd_aloop nf_conntrack_ipv6 nf_defrag_ipv6 nf_log_ipv6 ip6table_filter ip6_tables ctr ccm xt_state nf_log_ipv4
nf_log_common xt_LOG xt_limit xt_recent xt_owner xt_addrtype iptable_filter ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat
nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c ip_tables dm_mod vhost_net macvtap macvlan vhost tun kvm_intel kvm
irqbypass uas usb_storage hid_multitouch btusb btrtl uvcvideo videobuf2_v4l2 videobuf2_core videodev media videobuf2_vmalloc videobuf2_memops
sg ppdev dell_wmi sparse_keymap mei_wdt sd_mod iTCO_wdt iTCO_vendor_support rtsx_pci_ms memstick rtsx_pci_sdmmc mmc_core dell_smm_hwmon hwmon
dell_laptop dell_smbios dcdbas joydev input_leds hci_uart btintel btqca btbcm bluetooth parport_pc parport i2c_hid
  intel_lpss_acpi intel_lpss pcspkr wmi int3400_thermal acpi_thermal_rel dell_rbtn mei_me mei snd_hda_codec_hdmi snd_hda_codec_realtek
snd_hda_codec_generic ahci libahci acpi_pad xhci_pci xhci_hcd snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_seq snd_seq_device
snd_pcm snd_timer snd soundcore int3403_thermal arc4 e1000e ptp pps_core i2c_i801 iwlmvm mac80211 rtsx_pci iwlwifi cfg80211 rfkill
intel_pch_thermal processor_thermal_device int340x_thermal_zone intel_soc_dts_iosf i915 video fjes
CPU: 2 PID: 2408 Comm: X Not tainted 4.10.0-rc5+ #1
Hardware name: Dell Inc. Latitude E7470/0T6HHJ, BIOS 1.11.3 11/09/2016
task: ffff880219fe4740 task.stack: ffffc90005f98000
RIP: 0010:gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915]
RSP: 0018:ffffc90005f9b8c8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8802167d8000 RCX: 0000000000000001
RDX: 00000000ffff7000 RSI: ffff880219f94140 RDI: ffff880228444000
RBP: ffffc90005f9b948 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000080
R13: 0000000000000001 R14: ffffc90005f9bcd7 R15: ffff88020c9a83c0
FS:  00007fb53e1ee920(0000) GS:ffff88024dd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000022ef95000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  ppgtt_bind_vma+0x40/0x50 [i915]
  i915_vma_bind+0xcb/0x1c0 [i915]
  __i915_vma_do_pin+0x6e/0xd0 [i915]
  i915_gem_execbuffer_reserve_vma+0x162/0x1d0 [i915]
  i915_gem_execbuffer_reserve+0x4fc/0x510 [i915]
  ? __kmalloc+0x134/0x250
  ? i915_gem_wait_for_error+0x25/0x100 [i915]
  ? i915_gem_wait_for_error+0x25/0x100 [i915]
  i915_gem_do_execbuffer+0x2df/0xa00 [i915]
  ? drm_malloc_gfp.clone.0+0x42/0x80 [i915]
  ? path_put+0x22/0x30
  ? __check_object_size+0x62/0x1f0
  ? terminate_walk+0x44/0x90
  i915_gem_execbuffer2+0x95/0x1e0 [i915]
  drm_ioctl+0x243/0x490
  ? handle_pte_fault+0x1d7/0x220
  ? i915_gem_do_execbuffer+0xa00/0xa00 [i915]
  ? handle_mm_fault+0x10d/0x2a0
  vfs_ioctl+0x18/0x30
  do_vfs_ioctl+0x14b/0x3f0
  SyS_ioctl+0x92/0xa0
  entry_SYSCALL_64_fastpath+0x1a/0xa9
RIP: 0033:0x7fb53b4fcb77
RSP: 002b:00007ffe0c572898 EFLAGS: 00003246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fb53e17c038 RCX: 00007fb53b4fcb77
RDX: 00007ffe0c572900 RSI: 0000000040406469 RDI: 000000000000000b
RBP: 00007fb5376d67e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000028 R11: 0000000000003246 R12: 0000000000000000
R13: 0000000000000000 R14: 000055eecb314d00 R15: 000055eecb315460
Code: 0f 84 5d ff ff ff eb a2 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 58 0f 1f 44 00 00 31 c0 89 4d b0 <4c>
8b 60 10 44 8b 70 0c 48 89 d0 4c 8b 2e 48 c1 e8 27 25 ff 01
RIP: gen8_ppgtt_insert_4lvl+0x1b/0x1e0 [i915] RSP: ffffc90005f9b8c8
CR2: 0000000000000010

Recent gccs, such as 4.9, 6.3 or 7.2, do not generate the warning nor do
they explode on use. If we manually create the struct using locals from
the stack, this should eliminate this issue, and does not alter code
generation with gcc-7.2.

Fixes: 894ccebee2 ("drm/i915: Micro-optimise gen8_ppgtt_insert_entries()")
Reported-by: Kelly French <kfrench@federalhill.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kelly French <kfrench@federalhill.net>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171106211128.12538-1-chris@chris-wilson.co.uk
Tested-by: Kelly French <kfrench@federalhill.net>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
2017-11-07 11:09:35 +00:00
..
accessibility
acpi Merge branch 'acpi-apei' 2017-09-28 22:18:15 +02:00
amba
android ANDROID: binder: don't queue async transactions to thread. 2017-09-01 09:22:50 +02:00
ata Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata 2017-09-06 22:41:21 -07:00
atm
auxdisplay
base PM / OPP: Call notifier without holding opp_table->lock 2017-09-26 00:44:32 +02:00
bcma
block loop: remove union of use_aio and ref in struct loop_cmd 2017-09-25 08:56:05 -06:00
bluetooth Bluetooth: hci_bcm: Handle empty packet after firmware loading 2017-08-17 22:51:50 +03:00
bus ARM: SoC driver updates for v4.14 2017-09-10 20:40:00 -07:00
cdrom
char Merge branch 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2017-09-24 11:34:28 -07:00
clk The diff is dominated by the Allwinner A10/A20 SoCs getting converted to 2017-09-13 11:04:14 -07:00
clocksource x86/numachip: Add const and __initconst to numachip2_clockevent 2017-09-25 09:36:15 +02:00
connector
cpufreq cpufreq: dt: Fix sysfs duplicate filename creation for platform-device 2017-09-26 01:10:08 +02:00
cpuidle ARM: cpuidle: Avoid memleak if init fail 2017-09-19 23:10:51 +02:00
crypto crypto: caam - fix LS1021A support on ARMv7 multiplatform kernel 2017-09-20 17:42:42 +08:00
dax - Some request-based DM core and DM multipath fixes and cleanups 2017-09-14 13:43:16 -07:00
dca
devfreq PM / devfreq: Fix memory leak when fail to register device 2017-08-28 10:31:08 +09:00
dio
dma dmaengine updates for 4.14-rc1 2017-09-07 14:03:05 -07:00
dma-buf dma-buf: make reservation_object_copy_fences rcu save 2017-10-09 11:07:56 -04:00
edac EDAC, mce_amd: Get rid of local var in amd_filter_mce() 2017-08-21 17:59:38 +02:00
eisa
extcon extcon: max77693: Allow MHL attach notifier 2017-08-25 09:32:27 +09:00
firewire
firmware dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
fmc drivers/fmc: carrier can program FPGA on registration 2017-08-28 16:24:22 +02:00
fpga
fsi drivers/fsi/scom: Remove reset before every putscom 2017-08-28 17:15:16 +02:00
gpio - New Drivers 2017-09-07 13:51:13 -07:00
gpu drm/i915: Deconstruct struct sgt_dma initialiser 2017-11-07 11:09:35 +00:00
hid media updates for v4.14-rc1 2017-09-07 12:53:14 -07:00
hsi
hv Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-07 09:25:15 -07:00
hwmon dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
hwspinlock
hwtracing stm class / intel_th: Updates for 4.14 2017-08-28 16:58:19 +02:00
i2c i2c: i2c-stm32f7: add driver 2017-09-14 17:34:43 +02:00
ide Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-block 2017-09-07 11:59:42 -07:00
idle Power management updates for v4.14-rc1 2017-09-05 12:19:08 -07:00
iio - New Drivers 2017-09-07 13:51:13 -07:00
infiniband IB/hfi1: Unsuccessful PCIe caps tuning should not fail driver load 2017-09-27 11:10:36 -04:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2017-09-22 17:23:41 -10:00
iommu iommu/amd: pr_err() strings should end with newlines 2017-09-27 17:01:35 +02:00
ipack
irqchip irqchip/mips-gic: Use effective affinity to unmask 2017-09-25 21:23:44 +02:00
isdn isdn/i4l: fetch the ppp_write buffer in one shot 2017-09-20 16:01:36 -07:00
leds as3645a: Unregister indicator LED on device unbind 2017-09-23 21:17:43 +02:00
lightnvm
macintosh powerpc/macintosh: constify wf_sensor_ops structures 2017-09-01 16:42:54 +10:00
mailbox Just behavorial changes to a controller driver: 2017-09-07 13:23:37 -07:00
mcb Char/Misc drivers for 4.14-rc1 2017-09-05 11:08:17 -07:00
md md/raid5: cap worker count 2017-09-27 20:08:44 -07:00
media Merge drm-upstream/drm-next into drm-intel-next-queued 2017-09-28 15:56:49 +03:00
memory ARM: SoC driver updates for v4.14 2017-09-10 20:40:00 -07:00
memstick
message scsi: scsi_transport_sas: switch to bsg-lib for SMP passthrough 2017-08-29 21:51:45 -04:00
mfd dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
misc mm: treewide: remove GFP_TEMPORARY allocation flag 2017-09-13 18:53:16 -07:00
mmc MMC host: 2017-09-26 16:54:22 -07:00
mtd mtd: nand: atmel: fix buffer overflow in atmel_pmecc_user 2017-09-27 17:33:28 +02:00
mux mux: make device_type const 2017-08-29 13:46:35 +02:00
net net: phy: Fix truncation of large IRQ numbers in phy_attached_print() 2017-09-21 20:35:17 -07:00
nfc
ntb
nubus
nvdimm libnvdimm, namespace: fix btt claim class crash 2017-09-18 17:29:01 -07:00
nvme nvme-fcloop: fix port deletes and callbacks 2017-09-25 12:42:11 -06:00
nvmem nvmem: core: remove unneeded NULL check 2017-08-28 17:33:23 +02:00
of dma-mapping updates for 4.14: 2017-09-12 13:30:06 -07:00
oprofile
parisc parisc: Fix up devices below a PCI-PCI MegaRAID controller bridge 2017-08-24 18:46:44 +02:00
parport Char/Misc drivers for 4.14-rc1 2017-09-05 11:08:17 -07:00
pci PCI: Fix race condition with driver_override 2017-09-25 18:34:54 -05:00
pcmcia MIPS: Alchemy: Threaded carddetect irqs for devboards 2017-08-29 15:21:53 +02:00
perf drivers/perf: arm_pmu_acpi: Release memory obtained by kasprintf 2017-09-22 15:11:46 +01:00
phy Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
pinctrl pinctrl/amd: save pin registers over suspend/resume 2017-09-12 15:58:45 +02:00
platform platform/x86: fujitsu-laptop: Don't oops when FUJ02E3 is not presnt 2017-09-27 00:04:43 -07:00
pnp dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
power power supply and reset changes for the v4.14 series 2017-09-09 14:44:39 -07:00
powercap
pps drivers/pps: use surrounding "if PPS" to remove numerous dependency checks 2017-09-08 18:26:51 -07:00
ps3
ptp ptp: make ptp_clock_info const 2017-08-22 11:04:51 -07:00
pwm pwm: Changes for v4.14-rc1 2017-09-11 13:04:32 -07:00
rapidio lib/scatterlist: Fix offset type in sg_alloc_table_from_pages 2017-09-07 10:48:27 +01:00
ras
regulator - New Drivers 2017-09-07 13:51:13 -07:00
remoteproc rpmsg updates for v4.14 2017-09-09 14:34:38 -07:00
reset Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
rpmsg rpmsg: glink: initialize ret to zero to ensure error status check is correct 2017-09-04 10:52:30 -07:00
rtc RTC for 4.14 2017-09-13 10:56:00 -07:00
s390 s390/cio: recover from bad paths 2017-09-19 08:36:19 +02:00
sbus
scsi SCSI fixes on 20170930 2017-09-30 12:50:56 -07:00
sfi
sh
sn
soc Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
spi ACPI updates for v4.14-rc1 2017-09-05 12:45:03 -07:00
spmi spmi: pmic-arb: Move the ownership check to irq_chip callback 2017-08-28 13:52:22 +02:00
ssb
staging drm: Pass struct drm_file * to __drm_mode_object_find [v2] 2017-10-12 10:03:04 +10:00
target Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 18:13:32 -07:00
tc
tee
thermal Merge branches 'thermal-core', 'thermal-soc', 'thermal-intel' and 'const-thermal-zone-structure' into next 2017-09-08 11:20:04 +08:00
thunderbolt ACPI updates for v4.14-rc1 2017-09-05 12:45:03 -07:00
tty dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
uio
usb Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 18:13:32 -07:00
uwb
vfio vfio: platform: constify amba_id 2017-08-30 14:03:42 -06:00
vhost lib/interval_tree: fast overlap detection 2017-09-08 18:26:49 -07:00
video fbdev changes for v4.14: 2017-09-14 13:33:33 -07:00
virt virt: Convert to using %pOF instead of full_name 2017-08-29 08:52:51 -05:00
virtio SCSI misc on 20170907 2017-09-07 21:11:05 -07:00
vlynq
vme
w1 power supply and reset changes for the v4.14 series 2017-09-09 14:44:39 -07:00
watchdog Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
xen xen: fixes for 4.14-rc3 2017-09-29 12:24:28 -07:00
zorro
Kconfig
Makefile x86/lguest: Remove lguest support 2017-08-24 09:57:28 +02:00