fbdev: imsttfb: fix a resource leak in probe

I've re-written the error handling but the bug is that if init_imstt()
fails we need to call iounmap(par->cmap_regs).

Fixes: c75f5a550610 ("fbdev: imsttfb: Fix use after free bug in imsttfb_probe")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Helge Deller <deller@gmx.de>

fbdev: imsttfb: fix double free in probe()

The init_imstt() function calls framebuffer_release() on error and then
the probe() function calls it again. It should only be done in probe.

Fixes: 518ecb6a209f ("fbdev: imsttfb: Fix error path of imsttfb_probe()")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Helge Deller <deller@gmx.de>

fbdev/imsttfb: Initialize fb_ops to fbdev I/O-memory helpers

Initialize the instance of struct fb_ops with fbdev initializer
macros for framebuffers in I/O address space. Set the read/write,
draw and mmap callbacks to the correct implementation and avoid
implicit defaults. Also select the necessary I/O helpers in Kconfig.

Fbdev drivers sometimes rely on the callbacks being NULL for a
default implementation to be invoked; hence requiring the I/O
helpers to be built in any case. Setting all callbacks in all
drivers explicitly will allow to make the I/O helpers optional.
This benefits systems that do not use these functions.

No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230927074722.6197-21-tzimmermann@suse.de

fbdev: Remove FBINFO_DEFAULT from framebuffer_alloc()'ed structs

The flag FBINFO_DEFAULT is 0 and has no effect, as struct fbinfo.flags
has been allocated to zero by framebuffer_alloc(). So do not set it.

Flags should signal differences from the default values. After cleaning
up all occurrences of FBINFO_DEFAULT, the token will be removed.

v4:
* clarify commit message (Geert, Dan)
v2:
* fix commit message (Miguel)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ferenc Bakonyi <fero@drama.obuda.kando.hu>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Maik Broemme <mbroemme@libmpq.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Kristoffer Ericson <kristoffer.ericson@gmail.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Steve Glendinning <steve.glendinning@shawell.net>
Cc: Bernie Thompson <bernie@plugable.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230715185343.7193-6-tzimmermann@suse.de

fbdev: imsttfb: Fix error path of imsttfb_probe()

Release ressources when init_imstt() returns failure.

Signed-off-by: Helge Deller <deller@gmx.de>

fbdev: imsttfb: Release framebuffer and dealloc cmap on error path

Add missing cleanups in error path.

Signed-off-by: Helge Deller <deller@gmx.de>

fbdev: imsttfb: Fix use after free bug in imsttfb_probe

A use-after-free bug may occur if init_imstt invokes framebuffer_release
and free the info ptr. The caller, imsttfb_probe didn't notice that and
still keep the ptr as private data in pdev.

If we remove the driver which will call imsttfb_remove to make cleanup,
UAF happens.

Fix it by return error code if bad case happens in init_imstt.

Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Helge Deller <deller@gmx.de>

fbdev: Add support for the nomodeset kernel parameter

Support the kernel's nomodeset parameter for all PCI-based fbdev
drivers that use aperture helpers to remove other, hardware-agnostic
graphics drivers.

The parameter is a simple way of using the firmware-provided scanout
buffer if the hardware's native driver is broken. The same effect
could be achieved with per-driver options, but the importance of the
graphics output for many users makes a single, unified approach
worthwhile.

With nomodeset specified, the fbdev driver module will not load. This
unifies behavior with similar DRM drivers. In DRM helpers, modules
first check the nomodeset parameter before registering the PCI
driver. As fbdev has no such module helpers, we have to modify each
driver individually.

The name 'nomodeset' is slightly misleading, but has been chosen for
historical reasons. Several drivers implemented it before it became a
general option for DRM. So keeping the existing name was preferred over
introducing a new one.

v2:
* print a warning if a driver does not init (Helge)
* wrap video_firmware_drivers_only() in helper

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221111133024.9897-3-tzimmermann@suse.de

fbdev: Remove conflicting devices on PCI bus

Remove firmware devices on the PCI bus, by calling
aperture_remove_conflicting_pci_devices() in the probe function of
each related fbdev driver. iSo far, most of these drivers did not
remove conflicting VESA or EFI devices, or outride failed for
resource conflicts (i.e., matroxfb.) This must have been broken
for quite some time.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220718072322.8927-7-tzimmermann@suse.de

fbdev: Remove trailing whitespaces

Fix coding style. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220718072322.8927-2-tzimmermann@suse.de

video: imsttfb: check for ioremap() failures

We should check if ioremap() were to somehow fail in imsttfb_probe() and
handle the unwinding of the resources allocated here properly.

Ideally if anyone cares about this driver (it's for a PowerMac era PCI
display card), they wouldn't even be using fbdev anymore. Or the devm_*
apis could be used, but that's just extra work for diminishing
returns...

Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-68-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "video: imsttfb: fix potential NULL pointer dereferences"

This reverts commit 1d84353d205a953e2381044953b7fa31c8c9702d.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted. It will be fixed up "correctly" in a
later kernel change.

The original commit here, while technically correct, did not fully
handle all of the reported issues that the commit stated it was fixing,
so revert it until it can be "fixed" fully.

Note, ioremap() probably will never fail for old hardware like this, and
if anyone actually used this hardware (a PowerMac era PCI display card),
they would not be using fbdev anymore.

Cc: Kangjie Lu <kjlu@umn.edu>
Cc: Aditya Pakki <pakki001@umn.edu>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Fixes: 1d84353d205a ("video: imsttfb: fix potential NULL pointer dereferences")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-67-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

video: constify fb ops across all drivers

Now that the fbops member of struct fb_info is const, we can start
making the ops const as well.

This does not cover all drivers; some actually modify the fbops struct,
for example to adjust for different configurations, and others do more
involved things that I'd rather not touch in practically obsolete
drivers. Mostly this is the low hanging fruit where we can add "const"
and be done with it.

v3:
- un-constify atyfb, mb862xx, nvidia and uvesabf (0day)

v2:
- fix typo (Christophe de Dinechin)
- use "static const" instead of "const static" in mx3fb.c
- also constify smscufx.c

Cc: linux-fbdev@vger.kernel.org
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ce67f14435f3af498f2e8bf35ce4be11f7504132.1575390740.git.jani.nikula@intel.com

video: fbdev: don't print error message on framebuffer_alloc() failure

framebuffer_alloc() can fail only on kzalloc() memory allocation
failure and since kzalloc() will print error message in such case
we can omit printing extra error message in drivers (which BTW is
what the majority of framebuffer_alloc() users is doing already).

Cc: "Bruno Prémont" <bonbons@linux-vserver.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

video: imsttfb: fix potential NULL pointer dereferences

In case ioremap fails, the fix releases resources and returns
-ENOMEM to avoid NULL pointer dereferences.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Cc: Aditya Pakki <pakki001@umn.edu>
Cc: Finn Thain <fthain@telegraphics.com.au>
Cc: Rob Herring <robh@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[b.zolnierkie: minor patch summary fixup]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

fbdev: Use of_node_name_eq for node name comparisons

Convert string compares of DT node names to use of_node_name_eq helper
instead. This removes direct access to the node name pointer.

For instances using of_node_cmp, this has the side effect of now using
case sensitive comparisons. This should not matter for any FDT based
system which omap is.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

powerpc, fbdev: Use NV_CMODE and NV_VMODE only when CONFIG_PPC32 && CONFIG_PPC_PMAC && CONFIG_NVRAM

This patch addresses inconsistencies in Mac framebuffer drivers and their
use of Kconfig symbols relating to NVRAM, so PPC64 can use CONFIG_NVRAM.

The defined(CONFIG_NVRAM) condition is replaced with the weaker
IS_REACHABLE(CONFIG_NVRAM) condition, like atari_scsi.

Macintosh framebuffer drivers use default settings for color mode and
video mode that are found in NVRAM. On PCI Macs, MacOS stores display
settings in the Name Registry (NR) partition in NVRAM*. On NuBus Macs,
there is no NR partition and MacOS stores display mode settings in PRAM**.

Early-model Macs are the ones most likely to benefit from these settings,
since they are more likely to have a fixed-frequency monitor connected to
the built-in framebuffer device. Moreover, a single NV_CMODE value and
a single NV_VMODE value provide for only one display.

The NV_CMODE and NV_VMODE constants are apparently offsets into the NR
partition for Old World machines. This also suggests that these defaults
are not useful on later models. The NR partition seems to be optional on
New World machines. CONFIG_NVRAM cannot be enabled on PPC64 at present.

It is safe to say that NVRAM support in PowerMac fbdev drivers is only
applicable to CONFIG_PPC32 so make this condition explicit. This means
matroxfb driver won't crash on PPC64 when CONFIG_NVRAM becomes available
there.

For imsttfb, add the missing CONFIG_NVRAM test to prevent a build failure,
since PPC64 does not implement nvram_read_byte(). Also add a missing
machine_is(powermac) check. Change the inconsistent dependency on
CONFIG_PPC and the matching #ifdef tests to CONFIG_PPC_PMAC.

For valkyriefb, to improve clarity and consistency with the other PowerMac
fbdev drivers, test for CONFIG_PPC_PMAC instead of !CONFIG_MAC. Remove a
bogus comment regarding PRAM.

* See GetPreferredConfiguration and SavePreferredConfiguration in
"Designing PCI Cards and Drivers for Power Macintosh Computers".

** See SetDefaultMode and GetDefaultMode in "Designing Cards and Drivers
for the Macintosh Family".

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fbdev: Convert to using %pOFn instead of device_node.name

In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

video: fbdev: imsttfb: constify pci_device_id.

pci_device_id are not supposed to change at runtime. All functions
working with pci_device_id provided by <linux/pci.h> work with
const pci_device_id. So mark the non-const structs as const.

File size before:
text data bss dec hex filename
6736 856 0 7592 1da8 drivers/video/fbdev/imsttfb.o

File size after adding 'const':
text data bss dec hex filename
6832 760 0 7592 1da8 drivers/video/fbdev/imsttfb.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Maik Broemme <mbroemme@libmpq.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

PCI: Remove includes of asm/pci-bridge.h

Drivers should include asm/pci-bridge.h only when they need the arch-
specific things provided there. Outside of the arch/ directories, the only
drivers that actually need things provided by asm/pci-bridge.h are the
powerpc RPA hotplug drivers in drivers/pci/hotplug/rpa*.

Remove the includes of asm/pci-bridge.h from the other drivers, adding an
include of linux/pci.h if necessary.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

fbdev: imsttfb: remove the dependency on PPC_OF

The OF functionality has moved to a common place and be used by many
archs. So we don't need to depend on PPC_OF option any more. This is
a preparation for killing PPC_OF.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

video: move fbdev to drivers/video/fbdev

The drivers/video directory is a mess. It contains generic video related
files, directories for backlight, console, linux logo, lots of fbdev
device drivers, fbdev framework files.

Make some order into the chaos by creating drivers/video/fbdev
directory, and move all fbdev related files there.

No functionality is changed, although I guess it is possible that some
subtle Makefile build order related issue could be created by this
patch.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>