linux/drivers/gpu/drm
Kees Cook 3c8ba0d61d kernel.h: Retain constant expression output for max()/min()
In the effort to remove all VLAs from the kernel[1], it is desirable to
build with -Wvla.  However, this warning is overly pessimistic, in that
it is only happy with stack array sizes that are declared as constant
expressions, and not constant values.  One case of this is the
evaluation of the max() macro which, due to its construction, ends up
converting constant expression arguments into a constant value result.

All attempts to rewrite this macro with __builtin_constant_p() failed
with older compilers (e.g.  gcc 4.4)[2].  However, Martin Uecker,
constructed[3] a mind-shattering solution that works everywhere.
Cthulhu fhtagn!

This patch updates the min()/max() macros to evaluate to a constant
expression when called on constant expression arguments.  This removes
several false-positive stack VLA warnings from an x86 allmodconfig build
when -Wvla is added:

  $ diff -u before.txt after.txt | grep ^-
  -drivers/input/touchscreen/cyttsp4_core.c:871:2: warning: ISO C90 forbids variable length array ‘ids’ [-Wvla]
  -fs/btrfs/tree-checker.c:344:4: warning: ISO C90 forbids variable length array ‘namebuf’ [-Wvla]
  -lib/vsprintf.c:747:2: warning: ISO C90 forbids variable length array ‘sym’ [-Wvla]
  -net/ipv4/proc.c:403:2: warning: ISO C90 forbids variable length array ‘buff’ [-Wvla]
  -net/ipv6/proc.c:198:2: warning: ISO C90 forbids variable length array ‘buff’ [-Wvla]
  -net/ipv6/proc.c:218:2: warning: ISO C90 forbids variable length array ‘buff64’ [-Wvla]

This also updates two cases where different enums were being compared
and explicitly casts them to int (which matches the old side-effect of
the single-evaluation code): one in tpm/tpm_tis_core.h, and one in
drm/drm_color_mgmt.c.

 [1] https://lkml.org/lkml/2018/3/7/621
 [2] https://lkml.org/lkml/2018/3/10/170
 [3] https://lkml.org/lkml/2018/3/20/845

Co-Developed-by: Linus Torvalds <torvalds@linux-foundation.org>
Co-Developed-by: Martin Uecker <Martin.Uecker@med.uni-goettingen.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-05 14:17:16 -07:00
..
amd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2018-04-05 11:56:35 -07:00
arc drm/arcpgu: remove drm_encoder_slave 2018-01-30 18:05:25 +01:00
arm drm: mali-dp: Add YUV->RGB conversion support for video layers 2018-03-14 11:41:01 +00:00
armada drm: Don't pass clip to drm_atomic_helper_check_plane_state() 2018-03-05 20:48:25 +02:00
ast Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
atmel-hlcdc drm/atmel-hlcdc: Use the alpha format field in drm_format_info 2018-01-29 12:08:37 +01:00
bochs drm/ttm: add bo as parameter to the ttm_tt_create callback 2018-03-14 14:38:27 -05:00
bridge Char/Misc patches for 4.17-rc1 2018-04-04 20:07:20 -07:00
cirrus Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
etnaviv drm/etnaviv: bump HW job limit to 4 2018-03-22 11:08:48 +01:00
exynos Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
fsl-dcu drm/fsl-dcu: Use drm_mode_config_helper_suspend/resume() 2017-12-05 13:46:41 +01:00
gma500 pci-v4.16-changes 2018-02-06 09:59:40 -08:00
hisilicon drm/ttm: add bo as parameter to the ttm_tt_create callback 2018-03-14 14:38:27 -05:00
i2c drm/i2c: tda998x: Remove duplicate NULL check 2018-01-18 16:24:38 +02:00
i810
i915 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2018-04-05 11:56:35 -07:00
imx Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
lib License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mediatek drm: Don't pass clip to drm_atomic_helper_check_plane_state() 2018-03-05 20:48:25 +02:00
meson Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
mga
mgag200 drm/ttm: add bo as parameter to the ttm_tt_create callback 2018-03-14 14:38:27 -05:00
msm Merge tag 'drm-msm-next-2018-03-20' of git://people.freedesktop.org/~robclark/linux into drm-next 2018-03-21 14:06:00 +10:00
mxsfb drm/mxsfb: Do not use deprecated drm_driver.{enable|disable)_vblank 2018-02-22 17:58:59 +01:00
nouveau Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
omapdrm drm/omap: fix compile error when DPI is disabled 2018-03-14 10:39:50 +02:00
panel drm/panel: rm68200: Add backlight dependency 2018-03-14 11:51:24 +01:00
pl111 drm/pl111: Use max memory bandwidth for resolution 2018-03-07 23:14:24 +01:00
qxl Merge airlied/drm-next into drm-misc-next 2018-03-21 09:40:55 -04:00
r128 r128: don't open-code memdup_user() 2017-12-27 19:00:09 -05:00
radeon Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
rcar-du drm-misc-next for 4.17: 2018-03-14 10:59:16 +10:00
rockchip drm/rockchip: cdn-dp: remove the DP phy switch 2018-03-16 11:51:11 +01:00
savage
scheduler treewide/trivial: Remove ';;$' typo noise 2018-02-22 10:59:33 +01:00
selftests Merge tag 'drm-misc-next-2017-11-30' of git://anongit.freedesktop.org/drm/drm-misc into drm-next 2017-12-04 05:42:49 +10:00
shmobile main drm pull request for v4.15 2017-11-15 20:42:10 -08:00
sis
sti drm/sti: Use drm_fb_cma_fbdev_init/fini() 2017-12-08 14:47:41 +01:00
stm drm/stm: check pitch and size calculations even if !CONFIG_MMU 2018-02-23 09:37:12 +01:00
sun4i Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
tdfx
tegra main drm pull request for v4.17 2018-04-02 07:59:23 -07:00
tilcdc drm/tilcdc: tilcdc_panel: Rename device from "panel" to "tilcdc-panel" 2018-02-28 11:48:25 +02:00
tinydrm tinydrm: add backlight dependency 2018-02-28 15:08:56 -05:00
ttm drm/ttm: Export the ttm_k[un]map_atomic_prot API. 2018-03-22 11:10:06 +01:00
tve200 drm/tve200: Do not use deprecated drm_driver.{enable|disable)_vblank 2018-02-22 17:58:59 +01:00
udl drm: udl: Properly check framebuffer mmap offsets 2018-03-22 07:59:01 +01:00
vc4 sound updates for 4.17-rc1 2018-04-05 10:42:07 -07:00
vgem treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
via Merge tag 'drm-misc-next-2017-11-30' of git://anongit.freedesktop.org/drm/drm-misc into drm-next 2017-12-04 05:42:49 +10:00
virtio Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
vmwgfx Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
zte drm: Don't pass clip to drm_atomic_helper_check_plane_state() 2018-03-05 20:48:25 +02:00
ati_pcigart.c
drm_agpsupport.c
drm_atomic_helper.c drm: Remove now pointelss blob->data casts 2018-03-16 15:44:01 +02:00
drm_atomic.c drm: Verify gamma/degamma LUT size 2018-03-16 15:44:01 +02:00
drm_auth.c drm: Check for lessee in DROP_MASTER ioctl 2018-01-31 09:27:51 +01:00
drm_blend.c drm/docs: Align layout of optional plane blending properties 2018-02-20 12:10:46 +01:00
drm_bridge.c
drm_bufs.c drm: dma_bufs: Fixed checkpatch issues 2018-03-19 09:31:20 -04:00
drm_cache.c
drm_color_mgmt.c kernel.h: Retain constant expression output for max()/min() 2018-04-05 14:17:16 -07:00
drm_connector.c drm/docs: Document "scaling mode" property better 2018-02-20 12:10:46 +01:00
drm_context.c
drm_crtc_helper_internal.h
drm_crtc_helper.c
drm_crtc_internal.h drm/atomic: Include color encoding/range in plane state dump 2018-03-02 14:41:21 +02:00
drm_crtc.c drm: Check that the plane supports the request format+modifier combo 2018-02-26 16:29:47 +02:00
drm_debugfs_crc.c drm/crc: Add support for polling on the data fd. 2018-02-05 13:22:44 +01:00
drm_debugfs.c drm/debugfs: Fix framebuffer debugfs file init 2017-11-14 11:08:17 +02:00
drm_dma.c
drm_dp_aux_dev.c sched/wait, drivers/drm: Convert wait_on_atomic_t() usage to the new wait_var_event() API 2018-03-20 08:23:18 +01:00
drm_dp_dual_mode_helper.c
drm_dp_helper.c drm/dp: Add HBR3 support in existing DRM DP helpers 2018-01-26 13:36:53 +02:00
drm_dp_mst_topology.c drm: NULL pointer dereference [null-pointer-deref] (CWE 476) problem 2018-02-19 12:58:20 +01:00
drm_drv.c drm: NULL pointer dereference [null-pointer-deref] (CWE 476) problem 2018-03-06 08:14:16 +01:00
drm_dumb_buffers.c
drm_edid_load.c
drm_edid.c Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
drm_encoder_slave.c
drm_encoder.c drm: Warn if plane/crtc/encoder/connector index exceeds our 32bit bitmasks 2018-01-29 18:46:53 +02:00
drm_fb_cma_helper.c drm/cma-helper: Add drm_fb_cma_fbdev_init/fini() 2017-12-08 14:27:47 +01:00
drm_fb_helper.c drm: Remove now pointelss blob->data casts 2018-03-16 15:44:01 +02:00
drm_file.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
drm_flip_work.c
drm_fourcc.c drm/fourcc: Add a alpha field to drm_format_info 2018-01-29 12:07:47 +01:00
drm_framebuffer.c Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
drm_gem_cma_helper.c drm: gem_cma_helper.c: Allow importing of contiguous scatterlists with nents > 1 2017-11-15 18:14:46 +01:00
drm_gem_framebuffer_helper.c drm/gem-fb-helper: drm_gem_fbdev_fb_create() make funcs optional 2017-12-08 14:26:00 +01:00
drm_gem.c drm: Use idr_init_base(1) when using id==0 for invalid 2018-02-19 12:21:24 +00:00
drm_global.c
drm_hashtab.c
drm_info.c
drm_internal.h Merge airlied/drm-next into drm-misc-next 2017-11-21 14:17:56 +01:00
drm_ioc32.c
drm_ioctl.c drm: Print the pid when debug logging an ioctl error. 2018-02-10 22:23:10 +00:00
drm_irq.c
drm_kms_helper_common.c
drm_lease.c drm: Fix kerneldoc warnings for drm_lease 2018-02-19 10:49:59 +01:00
drm_legacy.h
drm_lock.c
drm_memory.c drm: fix drm_get_max_iomem type mismatch 2018-02-22 11:18:58 -05:00
drm_mipi_dsi.c drm/dsi: Fix improper use of mipi_dsi_device_transfer() return value 2018-01-16 17:10:14 -05:00
drm_mm.c Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
drm_mode_config.c Linux 4.15-rc4 2017-12-19 21:37:24 +10:00
drm_mode_object.c drm/mode_object: fix documentation for object lookups. 2017-11-10 13:50:47 +10:00
drm_modes.c drm: Fix uabi regression by allowing garbage mode->type from userspace 2018-03-23 13:51:12 +02:00
drm_modeset_helper.c drm/modeset-helper: Add simple modeset suspend/resume helpers 2017-11-30 18:18:08 +01:00
drm_modeset_lock.c drm/atomic: Call ww_acquire_done after drm_modeset_lock_all 2018-03-05 10:35:32 +01:00
drm_of.c drm: of: simplify component probe code 2018-03-06 14:05:00 +05:30
drm_panel_orientation_quirks.c drm: Include the header with the prototype for drm_get_panel_orientation_quirk() 2018-02-26 17:39:59 +02:00
drm_panel.c
drm_pci.c
drm_plane_helper.c drm: Don't pass clip to drm_atomic_helper_check_plane_state() 2018-03-05 20:48:25 +02:00
drm_plane.c Merge airlied/drm-next into drm-misc-next 2018-03-21 09:40:55 -04:00
drm_prime.c drm/prime: make the pages array optional for drm_prime_sg_to_page_addr_arrays 2018-03-06 12:24:52 -05:00
drm_print.c drm: Reduce object size of DRM_DEV_<LEVEL> uses 2018-03-19 15:15:42 +01:00
drm_probe_helper.c Linux 4.16-rc7 2018-03-28 14:30:41 +10:00
drm_property.c Revert "drm: Use a flexible array member for blob property data" 2018-03-16 15:44:01 +02:00
drm_rect.c
drm_scatter.c
drm_scdc_helper.c
drm_simple_kms_helper.c drm: Don't pass clip to drm_atomic_helper_check_plane_state() 2018-03-05 20:48:25 +02:00
drm_syncobj.c drm: Use idr_init_base(1) when using id==0 for invalid 2018-02-19 12:21:24 +00:00
drm_sysfs.c
drm_trace_points.c
drm_trace.h main drm pull request for v4.15 2017-11-15 20:42:10 -08:00
drm_vblank.c Merge tag 'drm-intel-next-2018-03-08' of git://anongit.freedesktop.org/drm/drm-intel into drm-next 2018-03-14 14:53:01 +10:00
drm_vm.c
drm_vma_manager.c drm/drm_vma_manager.c: Remove useless goto statement 2017-11-02 10:44:08 +01:00
Kconfig Fixes for 4.16: 2018-01-25 11:42:25 +10:00
Makefile drm: fix gpu scheduler link order 2018-01-24 15:49:04 -05:00