This is my example conversion of a few existing mmap users. The mtdchar
case is actually disabled right now (and stays disabled), but I did it
because it showed up on my "git grep", and I was familiar with the code
due to fixing an overflow problem in the code in commit 9c603e53d3
("mtdchar: fix offset overflow detection").
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.
A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.
Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.
Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives. Allowing simple, safe,
well understood work-arounds to known problematic software.
This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work. While writing this patch I saw a handful of such
cases. The most significant being autofs that lives in the module
autofs4.
This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.
After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module. The common pattern in the kernel is to call request_module()
without regards to the users permissions. In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted. In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This code was broken because it assumed that all MTD devices were map-based.
Disable it for now, until it can be fixed properly for the next merge window.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
A long time ago, in v2.4, VM_RESERVED kept swapout process off VMA,
currently it lost original meaning but still has some effects:
| effect | alternative flags
-+------------------------+---------------------------------------------
1| account as reserved_vm | VM_IO
2| skip in core dump | VM_IO, VM_DONTDUMP
3| do not merge or expand | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP
4| do not mlock | VM_IO, VM_DONTEXPAND, VM_HUGETLB, VM_PFNMAP
This patch removes reserved_vm counter from mm_struct. Seems like nobody
cares about it, it does not exported into userspace directly, it only
reduces total_vm showed in proc.
Thus VM_RESERVED can be replaced with VM_IO or pair VM_DONTEXPAND | VM_DONTDUMP.
remap_pfn_range() and io_remap_pfn_range() set VM_IO|VM_DONTEXPAND|VM_DONTDUMP.
remap_vmalloc_range() set VM_DONTEXPAND | VM_DONTDUMP.
[akpm@linux-foundation.org: drivers/vfio/pci/vfio_pci.c fixup]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Venkatesh Pallipadi <venki@google.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sasha Levin has been running trinity in a KVM tools guest, and was able
to trigger the BUG_ON() at arch/x86/mm/pat.c:279 (verifying the range of
the memory type). The call trace showed that it was mtdchar_mmap() that
created an invalid remap_pfn_range().
The problem is that mtdchar_mmap() does various really odd and subtle
things with the vma page offset etc, and uses the wrong types (and the
wrong overflow) detection for it.
For example, the page offset may well be 32-bit on a 32-bit
architecture, but after shifting it up by PAGE_SHIFT, we need to use a
potentially 64-bit resource_size_t to correctly hold the full value.
Also, we need to check that the vma length plus offset doesn't overflow
before we check that it is smaller than the length of the mtdmap region.
This fixes things up and tries to make the code a bit easier to read.
Reported-and-tested-by: Sasha Levin <levinsasha928@gmail.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Artem Bityutskiy <dedekind1@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I'm seeing an oops in mtd_dataflash.c with Linux 3.3. What appears to
be happening is that otp_select_filemode calls mtd_read_fact_prot_reg
with -1 for offset and length and a NULL buffer to test if OTP
operations are supported. This finds its way down to otp_read in
mtd_dataflash.c and causes an oops when memcpying the returned data
into the NULL buf.
None of the checks in otp_read catches the negative length and offset.
Changing the length of the dummy read to 0 prevents the oops.
Cc: stable@kernel.org [3.3+]
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Pull second try at vfs part d#2 from Al Viro:
"Miklos' first series (with do_lookup() rewrite split into edible
chunks) + assorted bits and pieces.
The 'untangling of do_lookup()' series is is a splitup of what used to
be a monolithic patch from Miklos, so this series is basically "how do
I convince myself that his patch is correct (or find a hole in it)".
No holes found and I like the resulting cleanup, so in it went..."
Changes from try 1: Fix a boot problem with selinux, and commit messages
prettied up a bit.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (24 commits)
vfs: fix out-of-date dentry_unhash() comment
vfs: split __lookup_hash
untangling do_lookup() - take __lookup_hash()-calling case out of line.
untangling do_lookup() - switch to calling __lookup_hash()
untangling do_lookup() - merge d_alloc_and_lookup() callers
untangling do_lookup() - merge failure exits in !dentry case
untangling do_lookup() - massage !dentry case towards __lookup_hash()
untangling do_lookup() - get rid of need_reval in !dentry case
untangling do_lookup() - eliminate a loop.
untangling do_lookup() - expand the area under ->i_mutex
untangling do_lookup() - isolate !dentry stuff from the rest of it.
vfs: move MAY_EXEC check from __lookup_hash()
vfs: don't revalidate just looked up dentry
vfs: fix d_need_lookup/d_revalidate order in do_lookup
ext3: move headers to fs/ext3/
migrate ext2_fs.h guts to fs/ext2/ext2.h
new helper: ext2_image_size()
get rid of pointless includes of ext2_fs.h
ext2: No longer export ext2_fs.h to user space
mtdchar: kill persistently held vfsmount
...
... and mtdchar_notifier along with it; just have ->drop_inode() that
will unconditionally get evict them instead of dances on mtd device
removal and use simple_pin_fs() instead of kern_mount()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Artem's cleanup of the MTD API continues apace.
Fixes and improvements for ST FSMC and SuperH FLCTL NAND, amongst others.
More work on DiskOnChip G3, new driver for DiskOnChip G4.
Clean up debug/warning printks in JFFS2 to use pr_<level>.
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Merge tag 'for-linus-3.4' of git://git.infradead.org/mtd-2.6
Pull MTD changes from David Woodhouse:
- Artem's cleanup of the MTD API continues apace.
- Fixes and improvements for ST FSMC and SuperH FLCTL NAND, amongst
others.
- More work on DiskOnChip G3, new driver for DiskOnChip G4.
- Clean up debug/warning printks in JFFS2 to use pr_<level>.
Fix up various trivial conflicts, largely due to changes in calling
conventions for things like dmaengine_prep_slave_sg() (new inline
wrapper to hide new parameter, clashing with rewrite of previously last
parameter that used to be an 'append' flag, and is now a bitmap of
'unsigned long flags').
(Also some header file fallout - like so many merges this merge window -
and silly conflicts with sparse fixes)
* tag 'for-linus-3.4' of git://git.infradead.org/mtd-2.6: (120 commits)
mtd: docg3 add protection against concurrency
mtd: docg3 refactor cascade floors structure
mtd: docg3 increase write/erase timeout
mtd: docg3 fix inbound calculations
mtd: nand: gpmi: fix function annotations
mtd: phram: fix section mismatch for phram_setup
mtd: unify initialization of erase_info->fail_addr
mtd: support ONFI multi lun NAND
mtd: sm_ftl: fix typo in major number.
mtd: add device-tree support to spear_smi
mtd: spear_smi: Remove default partition information from driver
mtd: Add device-tree support to fsmc_nand
mtd: fix section mismatch for doc_probe_device
mtd: nand/fsmc: Remove sparse warnings and errors
mtd: nand/fsmc: Add DMA support
mtd: nand/fsmc: Access the NAND device word by word whenever possible
mtd: nand/fsmc: Use dev_err to report error scenario
mtd: nand/fsmc: Use devm routines
mtd: nand/fsmc: Modify fsmc driver to accept nand timing parameters via platform
mtd: fsmc_nand: add pm callbacks to support hibernation
...
This patch renames all MTD functions by adding a "_" prefix:
mtd->erase -> mtd->_erase
mtd->read_oob -> mtd->_read_oob
...
The reason is that we are re-working the MTD API and from now on it is
an error to use MTD function pointers directly - we have a corresponding
API call for every pointer. By adding a leading "_" we achieve the following:
1. Make sure we convert every direct pointer users
2. A leading "_" suggests that this interface is internal and it becomes
less likely that people will use them directly
3. Make sure all the out-of-tree modules stop compiling and the owners
spot the big API change and amend them.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
- Move open-coded filesystem magic numbers into magic.h
- Rearrange magic.h so that the filesystem-related constants are grouped
together.
Signed-off-by: Muthukumar R <muthur@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead, use the new 'mtd_can_have_bb()', or just rely on 'mtd_block_markbad()'
return code, which will be -EOPNOTSUPP if bad blocks are not supported.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch introduces new 'mtd_can_have_bb()' helper function which checks
whether the flash can have bad eraseblocks. Then it changes all the
direct 'mtd->block_isbad' use cases with 'mtd_can_have_bb()'.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Instead, call the corresponding MTD API function which will return
'-EOPNOTSUPP' if the operation is not supported.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch teaches 'mtd_sync()' to do nothing when the MTD driver does
not have the '->sync()' method, which allows us to remove all direct
'mtd->sync' accesses.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Instead, just call 'mtd_write_user_prot_reg()' and check the '-EOPNOTSUPP' return
code.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Instead, call 'mtd_read_*_prot_info()' and check for -EOPNOTSUPP.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Instead, call 'mtd_get_*_prot_info()' and check for '-EOPNOTSUPP'. While
on it, fix the return code from '-EOPNOTSUPP' to '-EINVAL' for the case
when the mode parameter is invalid.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Instead of checking whether 'mtd->read_oob' is defined, just call
'mtd_read_oob()' and handle the '-EOPNOTSUPP' error which will be returned
if the function is undefined.
Additionally, make 'mtd_write_oob()' return '-EOPNOTSUPP' if the function
is undefined.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Remove direct usage of mtd->get_unmapped_area. Instead, just call
'mtd_get_unmapped_area()' which will return -EOPNOTSUPP if the function
is not implemented and test for this error code.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
We are working in the direction of making sure that MTD clients to not
use 'mtd->func' pointers directly. In some places we want to know if
OOB operations are supported by an MTD device. Introduce 'mtd_has_oob()'
helper for these purposes.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
MTD functions always assign the 'retlen' argument to 0 at the very
beginning - the callers do not have to do this.
I used the following semantic patch to find these places:
@@
identifier retlen;
expression a, b, c, d, e;
constant C;
type T;
@@
(
- retlen = C;
|
T
-retlen = C
+ retlen
;
)
... when != retlen
when exists
(
mtd_read(a, b, c, &retlen, d)
|
mtd_write(a, b, c, &retlen, d)
|
mtd_panic_write(a, b, c, &retlen, d)
|
mtd_point(a, b, c, &retlen, d, e)
|
mtd_read_fact_prot_reg(a, b, c, &retlen, d)
|
mtd_write_user_prot_reg(a, b, c, &retlen, d)
|
mtd_read_user_prot_reg(a, b, c, &retlen, d)
|
mtd_writev(a, b, c, d, &retlen)
)
I ran it twice, because there were cases of double zero assigments
in mtd tests. Then I went through the patch to verify that spatch
did not find any false positives.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch is part of a patch-set which changes the MTD interface
from 'mtd->func()' form to 'mtd_func()' form. We need this because
we want to add common code to to all drivers in the mtd core level,
which is impossible with the current interface when MTD clients
call driver functions like 'read()' or 'write()' directly.
At this point we just introduce a new inline wrapper function, but
later some of them are expected to gain more code. E.g., the input
parameters check should be moved to the wrappers rather than be
duplicated at many drivers.
This particular patch introduced the 'mtd_erase()' interface. The
following patches add all the other interfaces one by one.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
We are going to re-work the MTD interface and change 'mtd->write()' to
'mtd_write()', 'mtd->read()' to 'mtd_read()' and so forth for all functions
in the 'struct mtd_info' structure.
However, mtdchar.c has its own 'mtd_read()', 'mtd_write()', etc functions
which collide with our changes. This patch renames these functions
to 'mtdchar_read()', 'mtdchar_write()', etc.
Additionally, to make the 'mtdchar.c' file look consistent, rename
similarly all the other functions starting with 'mtd_'.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* git://git.infradead.org/mtd-2.6: (226 commits)
mtd: tests: annotate as DANGEROUS in Kconfig
mtd: tests: don't use mtd0 as a default
mtd: clean up usage of MTD_DOCPROBE_ADDRESS
jffs2: add compr=lzo and compr=zlib options
jffs2: implement mount option parsing and compression overriding
mtd: nand: initialize ops.mode
mtd: provide an alias for the redboot module name
mtd: m25p80: don't probe device which has status of 'disabled'
mtd: nand_h1900 never worked
mtd: Add DiskOnChip G3 support
mtd: m25p80: add EON flash EN25Q32B into spi flash id table
mtd: mark block device queue as non-rotational
mtd: r852: make r852_pm_ops static
mtd: m25p80: add support for at25df321a spi data flash
mtd: mxc_nand: preset_v1_v2: unlock all NAND flash blocks
mtd: nand: switch `check_pattern()' to standard `memcmp()'
mtd: nand: invalidate cache on unaligned reads
mtd: nand: do not scan bad blocks with NAND_BBT_NO_OOB set
mtd: nand: wait to set BBT version
mtd: nand: scrub BBT on ECC errors
...
Fix up trivial conflicts:
- arch/arm/mach-at91/board-usb-a9260.c
Merged into board-usb-a926x.c
- drivers/mtd/maps/lantiq-flash.c
add_mtd_partitions -> mtd_device_register vs changed to use
mtd_device_parse_register.
Replace direct i_nlink updates with the respective updater function
(inc_nlink, drop_nlink, clear_nlink, inode_dec_link_count).
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
The ecctype and eccsize fields have been obsolete for a while. Since they
don't have any users, we can kill them and leave padding in their place
for now.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Implement a new ioctl for writing both page data and OOB to flash at the
same time. This ioctl is intended to be a generic interface that can
replace other ioctls (MEMWRITEOOB and MEMWRITEOOB64) and cover the
functionality of several other old ones, e.g., MEMWRITE can:
* write autoplaced OOB instead of using ECCGETLAYOUT (deprecated) and
working around the reserved areas
* write raw (no ECC) OOB instead of using MTDFILEMODE to set the
per-file-descriptor MTD_FILE_MODE_RAW
* write raw (no ECC) data instead of using MTDFILEMODE
(MTD_FILE_MODE_RAW) and using standard character device "write"
This ioctl is especially useful for MLC NAND, which cannot be written
twice (i.e., we cannot successfully write the page data and OOB in two
separate operations). Instead, MEMWRITE can write both in a single
operation.
Note that this ioctl is not affected by the MTD file mode (i.e.,
MTD_FILE_MODE_RAW vs. MTD_FILE_MODE_NORMAL), since it receives its write
mode as an input parameter.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
These modes hold their state only for the life of their file descriptor,
and they overlap functionality with the MTD_OPS_* modes. Particularly,
MTD_MODE_RAW and MTD_OPS_RAW cover the same function: to provide raw
(i.e., without ECC) access to the flash. In fact, although it may not be
clear, MTD_MODE_RAW implied that operations should enable the
MTD_OPS_RAW mode.
Thus, we should be specific on what each mode means. This is a start,
where MTD_FILE_MODE_* actually represents a "file mode," not necessarily
a true global MTD mode.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Linus Torvalds