iommu/omap: Fix buffer overflow in debugfs

There are two issues here:

1) The "len" variable needs to be checked before the very first write.
Otherwise if omap2_iommu_dump_ctx() with "bytes" less than 32 it is a
buffer overflow.
2) The snprintf() function returns the number of bytes that *would* have
been copied if there were enough space. But we want to know the
number of bytes which were *actually* copied so use scnprintf()
instead.

Fixes: bd4396f09a4a ("iommu/omap: Consolidate OMAP IOMMU modules")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/YuvYh1JbE3v+abd5@kili
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Check for failure of a call to omap_iommu_dump_ctx

It is possible for the call to omap_iommu_dump_ctx to return
a negative error number, so check for the failure and return
the error number rather than pass the negative value to
simple_read_from_buffer.

Fixes: 14e0e6796a0d ("OMAP: iommu: add initial debugfs support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200714192211.744776-1-colin.king@canonical.com
Addresses-Coverity: ("Improper use of negative value")
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: No need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.

Cc: Joerg Roedel <joro@8bytes.org>
Cc: iommu@lists.linux-foundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iommu/omap: Remove DEBUG_SEQ_FOPS_RO()

Because we already have the DEFINE_SHOW_ATTRIBUTE,there is no need
to define such a macro.So remove DEBUG_SEQ_FOPS_RO.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Fix debugfs_create_*() usage

When exposing data access through debugfs, the correct
debugfs_create_*() functions must be used, depending on data type.

Remove all casts from data pointers passed to debugfs_create_*()
functions, as such casts prevent the compiler from flagging bugs.

omap_iommu.nr_tlb_entries is "int", hence casting to "u8 *" exposes only
a part of it. Fix this by using debugfs_create_u32() instead.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Align code with open parenthesis

This patch fixes one existing alignment checkpatch check
warning of the type "Alignment should match open parenthesis"
in the OMAP IOMMU debug source file.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void

The seq_<foo> function return values were frequently misused.

See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to
seq_has_overflowed() and make public")

All uses of these return values have been removed, so convert the
return types to void.

Miscellanea:

o Move seq_put_decimal_<type> and seq_escape prototypes closer the
other seq_vprintf prototypes
o Reorder seq_putc and seq_puts to return early on overflow
o Add argument names to seq_vprintf and seq_printf
o Update the seq_escape kernel-doc
o Convert a couple of leading spaces to tabs in seq_escape

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

iommu/omap: Fix debug_read_tlb() to use seq_printf()

The debug_read_tlb() uses the sprintf() functions directly on the buffer
allocated by buf = kmalloc(count), without taking into account the size
of the buffer, with the consequence corrupting the heap, depending on
the count requested by the user.

The patch fixes the issue replacing sprintf() by seq_printf().

Signed-off-by: Salva Peiró <speirofr@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Remove trailing semi-colon from a macro

Remove the trailing semi-colon in the DEBUG_FOPS_RO macro
definition. This fixes the checking warning,
"WARNING: macros should not use a trailing semicolon"

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Move debugfs functions to omap-iommu-debug.c

The main OMAP IOMMU driver file has some helper functions used
by the OMAP IOMMU debugfs functionality, and there is already a
dedicated source file omap-iommu-debug.c dealing with these debugfs
routines. Move all these functions to the omap-iommu-debug.c file,
so that all the debugfs related routines are in one place.

The move required exposing some new functions and moving some
definitions to the internal omap-iommu.h header file.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Switch pagetable debugfs entry to use seq_file

The debugfs entry 'pagetable' that shows the page table entry
(PTE) data currently outputs only data that can be fit into a
page. Switch the entry to use the seq_file interface so that
it can show all the valid page table entries.

The patch also corrected the output for L2 entries, and prints
the proper L2 PTE instead of the previous L1 page descriptor
pointer.

Signed-off-by: Suman Anna <s-anna@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Fix bus error on debugfs access of unattached IOMMU

Any debugfs access on an OMAP IOMMU that is not enabled (done during
attach) results in a bus error due to access of registers without
the clock or the reset enabled for the respective IOMMU. So, add a
check to make sure the IOMMU is enabled/attached by a client device.
This gracefully prints a "Operation not permitted" trace when the
corresponding IOMMU is not enabled.

Signed-off-by: Suman Anna <s-anna@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Integrate omap-iommu-debug into omap-iommu

The debugfs support for OMAP IOMMU is currently implemented
as a module, warranting certain OMAP-specific IOMMU API to
be exported. The OMAP IOMMU, when enabled, can only be built-in
into the kernel, so integrate the OMAP IOMMU debug module
into the OMAP IOMMU driver. This helps in eliminating the
need to export most of the current OMAP IOMMU API.

The following are the main changes:
- The debugfs directory and entry creation logic is reversed,
the calls are invoked by the OMAP IOMMU driver now.
- The current iffy circular logic of adding IOMMU archdata
to the IOMMU devices itself to get a pointer to the omap_iommu
object in the debugfs support code is replaced by directly
using the omap_iommu structure while creating the debugfs
entries.
- The debugfs root directory is renamed from the generic name
"iommu" to a specific name "omap_iommu".
- Unneeded headers have also been cleaned up while at this.
- There will no longer be a omap-iommu-debug.ko module after
this patch.
- The OMAP_IOMMU_DEBUG Kconfig option is converted to boolean
only, the OMAP IOMMU debugfs support is built alongside the
OMAP IOMMU driver only when this option is enabled.

Signed-off-by: Suman Anna <s-anna@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Make pagetable debugfs entry read-only

Remove the writeability on the 'pagetable' debugfs entry,
so that the mapping/unmapping into an OMAP IOMMU is only
limited to actual client devices/drivers at kernel-level.

Signed-off-by: Suman Anna <s-anna@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Fix the permissions on nr_tlb_entries

The permissions on the debugfs entry "nr_tlb_entries" should
have been octal, not decimal, so fix it.

Signed-off-by: Suman Anna <s-anna@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Remove ver debugfs entry

The debugfs entry 'ver' to read the OMAP IOMMU version is
not much useful for developers, so it has been removed. The
same can be deduced from the register dump, provided by the
debugfs entry 'regs', REVISION register. This also allows us
to remove the omap_iommu_arch_revision() which is currently
returning a fixed value.

Signed-off-by: Suman Anna <s-anna@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/omap: Remove virtual memory manager

The OMAP3 ISP driver was the only user of the OMAP IOVMM API. Now that
is has been ported to the DMA API, remove the unused virtual memory
manager.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/omap-iommu-debug.c: fix decimal permissions

These should have been octal.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ARM: OMAP2+: Move iommu/iovmm headers to platform_data

Move iommu/iovmm headers from plat/ to platform_data/ as part of the
single zImage work.

Partially based on an earlier version by Ido Yariv <ido@wizery.com>.

Cc: Ido Yariv <ido@wizery.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Omar Ramirez Luna <omar.luna@linaro.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

ARM: OMAP2+: Move iommu2 to drivers/iommu/omap-iommu2.c

This file should not be in arch/arm. Move it to drivers/iommu
to allow making most of the header local to drivers/iommu.

This is needed as we are removing plat and mach includes
from drivers for ARM common zImage support.

Cc: Ido Yariv <ido@wizery.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Omar Ramirez Luna <omar.luna@linaro.org>
Cc: linux-media@vger.kernel.org
Acked-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

ARM: OMAP2+: Move plat/iovmm.h to include/linux/omap-iommu.h

Looks like the iommu framework does not have generic functions
exported for all the needs yet. The hardware specific functions
are defined in files like intel-iommu.h and amd-iommu.h. Follow
the same standard for omap-iommu.h.

This is needed because we are removing plat and mach includes
for ARM common zImage support. Further work should continue
in the iommu framework context as only pure platform data will
be communicated from arch/arm/*omap*/* code to the iommu
framework.

Cc: Ido Yariv <ido@wizery.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Omar Ramirez Luna <omar.luna@linaro.org>
Cc: linux-media@vger.kernel.org
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

ARM: OMAP2+: Move iopgtable header to drivers/iommu/

The iopgtable header file is only used by the iommu & iovmm drivers, so
move it to drivers/iommu/, as part of the single zImage effort.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Omar Ramirez Luna <omar.luna@linaro.org>
Signed-off-by: Ido Yariv <ido@wizery.com>
Acked-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Joerg Roedel <joro@8bytes.org>
[tony@atomide.com: updated to be earlier in the series]
Signed-off-by: Tony Lindgren <tony@atomide.com>

simple_open: automatically convert to simple_open()

Many users of debugfs copy the implementation of default_open() when
they want to support a custom read/write function op. This leads to a
proliferation of the default_open() implementation across the entire
tree.

Now that the common implementation has been consolidated into libfs we
can replace all the users of this function with simple_open().

This replacement was done with the following semantic patch:

<smpl>
@ open @
identifier open_f != simple_open;
identifier i, f;
@@
-int open_f(struct inode *i, struct file *f)
-{
(
-if (i->i_private)
-f->private_data = i->i_private;
|
-f->private_data = i->i_private;
)
-return 0;
-}

@ has_open depends on open @
identifier fops;
identifier open.open_f;
@@
struct file_operations fops = {
...
-.open = open_f,
+.open = simple_open,
...
};
</smpl>

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

iommu/omap: fix NULL pointer dereference

Fix this:

root@omap4430-panda:~# cat /debug/iommu/ducati/mem
[ 62.725708] Unable to handle kernel NULL pointer dereference at virtual addre
ss 0000001c
[ 62.725708] pgd = e6240000
[ 62.737091] [0000001c] *pgd=a7168831, *pte=00000000, *ppte=00000000
[ 62.743682] Internal error: Oops: 17 [#1] SMP
[ 62.743682] Modules linked in: omap_iommu_debug omap_iovmm virtio_rpmsg_bus o
map_remoteproc remoteproc virtio_ring virtio mailbox_mach mailbox
[ 62.743682] CPU: 0 Not tainted (3.3.0-rc1-00265-g382f84e-dirty #682)
[ 62.743682] PC is at debug_read_mem+0x5c/0xac [omap_iommu_debug]
[ 62.743682] LR is at 0x1004
[ 62.777832] pc : [<bf033178>] lr : [<00001004>] psr: 60000013
[ 62.777832] sp : e72c7f40 ip : c0763c00 fp : 00000001
[ 62.777832] r10: 00000000 r9 : 00000000 r8 : e72c7f80
[ 62.777832] r7 : e6ffdc08 r6 : bed1ac78 r5 : 00001000 r4 : e7276000
[ 62.777832] r3 : e60f3460 r2 : 00000000 r1 : e60f38c0 r0 : 00000000
[ 62.777832] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
[ 62.816375] Control: 10c53c7d Table: a624004a DAC: 00000015
[ 62.816375] Process cat (pid: 1176, stack limit = 0xe72c62f8)
[ 62.828369] Stack: (0xe72c7f40 to 0xe72c8000)
...
[ 62.884185] [<bf033178>] (debug_read_mem+0x5c/0xac [omap_iommu_debug]) from [<c010e354>] (vfs_read+0xac/0x130)
[ 62.884185] [<c010e354>] (vfs_read+0xac/0x130) from [<c010e4a8>] (sys_read+0x40/0x70)
[ 62.884185] [<c010e4a8>] (sys_read+0x40/0x70) from [<c0014a00>] (ret_fast_syscall+0x0/0x3c)

Fix also its 'echo bla > /debug/iommu/ducati/mem' Oops sibling, too.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Hiroshi Doyu <hdoyu@nvidia.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Joerg Roedel <Joerg.Roedel@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

iommu/omap: fix erroneous omap-iommu-debug API calls

Adapt omap-iommu-debug to the latest omap-iommu API changes, which
were introduced by commit fabdbca "iommu/omap: eliminate the public
omap_find_iommu_device() method".

In a nutshell, iommu users are not expected to provide the omap_iommu
handle anymore - instead, iommus are attached using their user's device
handle.

omap-iommu-debug is a hybrid beast though: it invokes both public and
private omap iommu API, so fix it as necessary (otherwise a crash
is imminent).

Note: omap-iommu-debug is a bit disturbing, as it fiddles with internal
omap iommu data and requires exposing API which is otherwise not needed.
It should better be more tightly coupled with omap-iommu, to prevent
further bit rot and avoid exposing redundant API. Naturally that's out
of scope for the -rc cycle, so for now just fix the obvious.

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Hiroshi Doyu <hdoyu@nvidia.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Joerg Roedel <Joerg.Roedel@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

iommu: omap: Fix compile failure

Fix compile failure in drivers/iommu/omap-iommu-debug.c
because of missing module.h include.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

omap: iommu: omapify 'struct iommu' and exposed API

Prepend 'omap_' to OMAP's 'struct iommu' and exposed API, to prevent
namespace pollution and generally to improve readability of the code
that still uses the driver directly.

Update the users as needed as well.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

omap: iommu/iovmm: move to dedicated iommu folder

Move OMAP's iommu drivers to the dedicated iommu drivers folder.

While OMAP's iovmm (virtual memory manager) driver does not strictly
belong to the iommu drivers folder, move it there as well, because
it's by no means OMAP-specific (in concept. technically it is still
coupled with OMAP's iommu).

Eventually, iovmm will be completely replaced with the generic,
iommu-based, dma-mapping API.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>