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path: root/drivers/md/dm-ioctl.c
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2022-12-01dm ioctl: fix a couple ioctl codesMikulas Patocka1-2/+2
Change the ioctl codes from DM_DEV_ARM_POLL to DM_DEV_ARM_POLL_CMD and from DM_GET_TARGET_VERSION to DM_GET_TARGET_VERSION_CMD. Note that the "cmd" field of "struct _ioctls" is never used, thus this commit doesn't fix any bug, it just makes the code consistent. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-12-01dm ioctl: a small code cleanup in list_version_get_infoMikulas Patocka1-1/+1
No need to modify info->vers if we overwrite it immediately. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-11-18dm ioctl: fix misbehavior if list_versions races with module loadingMikulas Patocka1-2/+2
__list_versions will first estimate the required space using the "dm_target_iterate(list_version_get_needed, &needed)" call and then will fill the space using the "dm_target_iterate(list_version_get_info, &iter_info)" call. Each of these calls locks the targets using the "down_read(&_lock)" and "up_read(&_lock)" calls, however between the first and second "dm_target_iterate" there is no lock held and the target modules can be loaded at this point, so the second "dm_target_iterate" call may need more space than what was the first "dm_target_iterate" returned. The code tries to handle this overflow (see the beginning of list_version_get_info), however this handling is incorrect. The code sets "param->data_size = param->data_start + needed" and "iter_info.end = (char *)vers+len" - "needed" is the size returned by the first dm_target_iterate call; "len" is the size of the buffer allocated by userspace. "len" may be greater than "needed"; in this case, the code will write up to "len" bytes into the buffer, however param->data_size is set to "needed", so it may write data past the param->data_size value. The ioctl interface copies only up to param->data_size into userspace, thus part of the result will be truncated. Fix this bug by setting "iter_info.end = (char *)vers + needed;" - this guarantees that the second "dm_target_iterate" call will write only up to the "needed" buffer and it will exit with "DM_BUFFER_FULL_FLAG" if it overflows the "needed" space - in this case, userspace will allocate a larger buffer and retry. Note that there is also a bug in list_version_get_needed - we need to add "strlen(tt->name) + 1" to the needed size, not "strlen(tt->name)". Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-10-19dm: change from DMWARN to DMERR or DMCRIT for fatal errorsMikulas Patocka1-39/+39
Change DMWARN to DMERR in cases when there is an unrecoverable error. Change DMWARN to DMCRIT when handling of a case is unimplemented. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-07-07dm table: remove dm_table_get_num_targets() wrapperMike Snitzer1-3/+3
More efficient and readable to just access table->num_targets directly. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-04-01dm ioctl: log an error if the ioctl structure is corruptedMikulas Patocka1-3/+12
This will help triage bugs when userspace is passing invalid ioctl structure to the kernel. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> [snitzer: log errors using DMERR instead of DMWARN] Signed-off-by: Mike Snitzer <snitzer@kernel.org>
2022-02-22dm ioctl: prevent potential spectre v1 gadgetJordy Zomer1-0/+2
It appears like cmd could be a Spectre v1 gadget as it's supplied by a user and used as an array index. Prevent the contents of kernel memory from being leaked to userspace via speculative execution by using array_index_nospec. Signed-off-by: Jordy Zomer <jordy@pwning.systems> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-08-10dm ima: measure data on device renameTushar Sugandhi1-0/+3
A given block device is identified by it's name and UUID. However, both these parameters can be renamed. For an external attestation service to correctly attest a given device, it needs to keep track of these rename events. Update the device data with the new values for IMA measurements. Measure both old and new device name/UUID parameters in the same IMA measurement event, so that the old and the new values can be connected later. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-08-10dm ima: measure data on table clearTushar Sugandhi1-0/+3
For a given block device, an inactive table slot contains the parameters to configure the device with. The inactive table can be cleared multiple times, accidentally or maliciously, which may impact the functionality of the device, and compromise the system. Therefore it is important to measure and log the event when a table is cleared. Measure device parameters, and table hashes when the inactive table slot is cleared. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-08-10dm ima: measure data on device removeTushar Sugandhi1-0/+3
Presence of an active block-device, configured with expected parameters, is important for an external attestation service to determine if a system meets the attestation requirements. Therefore it is important for DM to measure the device remove events. Measure device parameters and table hashes when the device is removed, using either remove or remove_all. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-08-10dm ima: measure data on device resumeTushar Sugandhi1-2/+6
A given block device can load a table multiple times, with different input parameters, before eventually resuming it. Further, a device may be suspended and then resumed. The device may never resume after a table-load. Because of the above valid scenarios for a given device, it is important to measure and log the device resume event using IMA. Also, if the table is large, measuring it in clear-text each time the device changes state, will unnecessarily increase the size of IMA log. Since the table clear-text is already measured during table-load event, measuring the hash during resume should be sufficient to validate the table contents. Measure the device parameters, and hash of the active table, when the device is resumed. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-08-10dm ima: measure data on table loadTushar Sugandhi1-1/+6
DM configures a block device with various target specific attributes passed to it as a table. DM loads the table, and calls each target’s respective constructors with the attributes as input parameters. Some of these attributes are critical to ensure the device meets certain security bar. Thus, IMA should measure these attributes, to ensure they are not tampered with, during the lifetime of the device. So that the external services can have high confidence in the configuration of the block-devices on a given system. Some devices may have large tables. And a given device may change its state (table-load, suspend, resume, rename, remove, table-clear etc.) many times. Measuring these attributes each time when the device changes its state will significantly increase the size of the IMA logs. Further, once configured, these attributes are not expected to change unless a new table is loaded, or a device is removed and recreated. Therefore the clear-text of the attributes should only be measured during table load, and the hash of the active/inactive table should be measured for the remaining device state changes. Export IMA function ima_measure_critical_data() to allow measurement of DM device parameters, as well as target specific attributes, during table load. Compute the hash of the inactive table and store it for measurements during future state change. If a load is called multiple times, update the inactive table hash with the hash of the latest populated table. So that the correct inactive table hash is measured when the device transitions to different states like resume, remove, rename, etc. Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> # leak fix Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-08-09dm: move setting md->type into dm_setup_md_queueChristoph Hellwig1-4/+0
Move setting md->type from both callers into dm_setup_md_queue. This ensures that md->type is only set to a valid value after the queue has been fully setup, something we'll rely on future changes. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20210804094147.459763-7-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-26dm ioctl: filter the returned values according to name or uuid prefixMikulas Patocka1-0/+28
If we set non-empty param->name or param->uuid on the DM_LIST_DEVICES_CMD ioctl, the set values are considered filter prefixes. The ioctl will only return entries with matching name or uuid prefix. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-03-26dm ioctl: return UUID in DM_LIST_DEVICES_CMD resultMikulas Patocka1-3/+17
When LVM needs to find a device with a particular UUID it needs to ask for UUID for each device. This patch returns UUID directly in the list of devices, so that LVM doesn't have to query all the devices with an ioctl. The UUID is returned if the flag DM_UUID_FLAG is set in the parameters. Returning UUID is done in backward-compatible way. There's one unused 32-bit word value after the event number. This patch sets the bit DM_NAME_LIST_FLAG_HAS_UUID if UUID is present and DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID if it isn't (if none of these bits is set, then we have an old kernel that doesn't support returning UUIDs). The UUID is stored after this word. The 'next' value is updated to point after the UUID, so that old version of libdevmapper will skip the UUID without attempting to interpret it. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-03-26dm ioctl: replace device hash with red-black treeMikulas Patocka1-112/+142
For high numbers of DM devices the 64-entry hash table has non-trivial overhead. Fix this by replacing the hash table with a red-black tree. Reported-by: Zdenek Kabelac <zkabelac@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2021-03-26dm ioctl: fix out of bounds array access when no devicesMikulas Patocka1-1/+1
If there are not any dm devices, we need to zero the "dev" argument in the first structure dm_name_list. However, this can cause out of bounds write, because the "needed" variable is zero and len may be less than eight. Fix this bug by reporting DM_BUFFER_FULL_FLAG if the result buffer is too small to hold the "nl->dev" value. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-12-05dm ioctl: fix error return code in target_messageQinglang Miao1-0/+1
Fix to return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Fixes: 2ca4c92f58f9 ("dm ioctl: prevent empty message") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-10-01dm: export dm_copy_name_and_uuidMike Snitzer1-1/+1
Allow DM targets to access the configured name and uuid. Also, bump DM ioctl version. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-08-07Merge tag 'for-5.9/dm-changes' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device mapper updates from Mike Snitzer: - DM multipath locking fixes around m->flags tests and improvements to bio-based code so that it follows patterns established by request-based code. - Request-based DM core improvement to eliminate unnecessary call to blk_mq_queue_stopped(). - Add "panic_on_corruption" error handling mode to DM verity target. - DM bufio fix to to perform buffer cleanup from a workqueue rather than wait for IO in reclaim context from shrinker. - DM crypt improvement to optionally avoid async processing via workqueues for reads and/or writes -- via "no_read_workqueue" and "no_write_workqueue" features. This more direct IO processing improves latency and throughput with faster storage. Avoiding workqueue IO submission for writes (DM_CRYPT_NO_WRITE_WORKQUEUE) is a requirement for adding zoned block device support to DM crypt. - Add zoned block device support to DM crypt. Makes use of DM_CRYPT_NO_WRITE_WORKQUEUE and a new optional feature (DM_CRYPT_WRITE_INLINE) that allows write completion to wait for encryption to complete. This allows write ordering to be preserved, which is needed for zoned block devices. - Fix DM ebs target's check for REQ_OP_FLUSH. - Fix DM core's report zones support to not report more zones than were requested. - A few small compiler warning fixes. - DM dust improvements to return output directly to the user rather than require they scrape the system log for output. * tag 'for-5.9/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm: don't call report zones for more than the user requested dm ebs: Fix incorrect checking for REQ_OP_FLUSH dm init: Set file local variable static dm ioctl: Fix compilation warning dm raid: Remove empty if statement dm verity: Fix compilation warning dm crypt: Enable zoned block device support dm crypt: add flags to optionally bypass kcryptd workqueues dm bufio: do buffer cleanup from a workqueue dm rq: don't call blk_mq_queue_stopped() in dm_stop_queue() dm dust: add interface to list all badblocks dm dust: report some message results directly back to user dm verity: add "panic_on_corruption" error handling mode dm mpath: use double checked locking in fast path dm mpath: rename current_pgpath to pgpath in multipath_prepare_ioctl dm mpath: rework __map_bio() dm mpath: factor out multipath_queue_bio dm mpath: push locking down to must_push_back_rq() dm mpath: take m->lock spinlock when testing QUEUE_IF_NO_PATH dm mpath: changes from initial m->flags locking audit
2020-08-04dm ioctl: Fix compilation warningDamien Le Moal1-1/+1
In retrieve_status(), when copying the target type name in the target_type string field of struct dm_target_spec, copy at most DM_MAX_TYPE_NAME - 1 character to avoid the compilation warning: warning: ‘__builtin_strncpy’ specified bound 16 equals destination size [-Wstringop-truncation] when compiling with W-1. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2020-07-16treewide: Remove uninitialized_var() usageKees Cook1-1/+1
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org>
2020-06-17dm ioctl: use struct_size() helper in retrieve_deps()Gustavo A. R. Silva1-1/+1
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct dm_target_deps { ... __u64 dev[0]; /* out */ }; Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-09-16dm: introduce DM_GET_TARGET_VERSIONMikulas Patocka1-3/+29
This commit introduces a new ioctl DM_GET_TARGET_VERSION. It will load a target that is specified in the "name" entry in the parameter structure and return its version. This functionality is intended to be used by cryptsetup, so that it can query kernel capabilities before activating the device. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-23dm: make dm_table_find_target return NULLMikulas Patocka1-1/+1
Currently, if we pass too high sector number to dm_table_find_target, it returns zeroed dm_target structure and callers test if the structure is zeroed with the macro dm_target_is_valid. However, returning NULL is common practice to indicate errors. This patch refactors the dm code, so that dm_table_find_target returns NULL and its callers test the returned value for NULL. The macro dm_target_is_valid is deleted. In alloc_targets, we no longer allocate an extra zeroed target. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-05-16dm ioctl: fix hang in early create error conditionHelen Koike1-1/+5
The dm_early_create() function (which deals with "dm-mod.create=" kernel command line option) calls dm_hash_insert() who gets an extra reference to the md object. In case of failure, this reference wasn't being released, causing dm_destroy() to hang, thus hanging the whole boot process. Fix this by calling __hash_remove() in the error path. Fixes: 6bbc923dfcf57d ("dm: add support to directly boot to a mapped device") Cc: stable@vger.kernel.org Signed-off-by: Helen Koike <helen.koike@collabora.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-03-05dm: add support to directly boot to a mapped deviceHelen Koike1-0/+103
Add a "create" module parameter, which allows device-mapper targets to be configured at boot time. This enables early use of DM targets in the boot process (as the root device or otherwise) without the need of an initramfs. The syntax used in the boot param is based on the concise format from the dmsetup tool to follow the rule of least surprise: dmsetup table --concise /dev/mapper/lroot Which is: dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+] Where, <name> ::= The device name. <uuid> ::= xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx | "" <minor> ::= The device minor number | "" <flags> ::= "ro" | "rw" <table> ::= <start_sector> <num_sectors> <target_type> <target_args> <target_type> ::= "verity" | "linear" | ... For example, the following could be added in the boot parameters: dm-mod.create="lroot,,,rw, 0 4096 linear 98:16 0, 4096 4096 linear 98:32 0" root=/dev/dm-0 Only the targets that were tested are allowed and the ones that don't change any block device when the device is create as read-only. For example, mirror and cache targets are not allowed. The rationale behind this is that if the user makes a mistake, choosing the wrong device to be the mirror or the cache can corrupt data. The only targets initially allowed are: * crypt * delay * linear * snapshot-origin * striped * verity Co-developed-by: Will Drewry <wad@chromium.org> Co-developed-by: Kees Cook <keescook@chromium.org> Co-developed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Helen Koike <helen.koike@collabora.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-10-18dm ioctl: harden copy_params()'s copy_from_user() from malicious usersWenwen Wang1-12/+6
In copy_params(), the struct 'dm_ioctl' is first copied from the user space buffer 'user' to 'param_kernel' and the field 'data_size' is checked against 'minimum_data_size' (size of 'struct dm_ioctl' payload up to its 'data' member). If the check fails, an error code EINVAL will be returned. Otherwise, param_kernel->data_size is used to do a second copy, which copies from the same user-space buffer to 'dmi'. After the second copy, only 'dmi->data_size' is checked against 'param_kernel->data_size'. Given that the buffer 'user' resides in the user space, a malicious user-space process can race to change the content in the buffer between the two copies. This way, the attacker can inject inconsistent data into 'dmi' (versus previously validated 'param_kernel'). Fix redundant copying of 'minimum_data_size' from user-space buffer by using the first copy stored in 'param_kernel'. Also remove the 'data_size' check after the second copy because it is now unnecessary. Cc: stable@vger.kernel.org Signed-off-by: Wenwen Wang <wang6495@umn.edu> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-06-08dm: report which conflicting type caused error during table_load()Mike Snitzer1-1/+2
Eases troubleshooting to know the before vs after types. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2018-04-03dm: allow targets to return output from messages they are sentMike Snitzer1-1/+1
Could be useful for a target to return stats or other information. If a target does DMEMIT() anything to @result from its .message method then it must return 1 to the caller. Signed-off-By: Mike Snitzer <snitzer@redhat.com>
2018-02-12vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds1-1/+1
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-28the rest of drivers/*: annotate ->poll() instancesAl Viro1-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-25dm ioctl: fix alignment of event number in the device listMikulas Patocka1-13/+24
The size of struct dm_name_list is different on 32-bit and 64-bit kernels (so "(nl + 1)" differs between 32-bit and 64-bit kernels). This mismatch caused some harmless difference in padding when using 32-bit or 64-bit kernel. Commit 23d70c5e52dd ("dm ioctl: report event number in DM_LIST_DEVICES") added reporting event number in the output of DM_LIST_DEVICES_CMD. This difference in padding makes it impossible for userspace to determine the location of the event number (the location would be different when running on 32-bit and 64-bit kernels). Fix the padding by using offsetof(struct dm_name_list, name) instead of sizeof(struct dm_name_list) to determine the location of entries. Also, the ioctl version number is incremented to 37 so that userspace can use the version number to determine that the event number is present and correctly located. In addition, a global event is now raised when a DM device is created, removed, renamed or when table is swapped, so that the user can monitor for device changes. Reported-by: Eugene Syromiatnikov <esyr@redhat.com> Fixes: 23d70c5e52dd ("dm ioctl: report event number in DM_LIST_DEVICES") Cc: stable@vger.kernel.org # 4.13 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-08-28dm ioctl: constify ioctl lookup tableEric Biggers1-1/+1
Constify the lookup table for device-mapper ioctls so that it is placed in .rodata. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-06-19dm ioctl: report event number in DM_LIST_DEVICESMikulas Patocka1-1/+5
Report the event numbers for all the devices, so that the user doesn't have to ask them one by one. The event number is reported after the name field in the dm_name_list structure. The location of the next record is specified in the dm_name_list->next field, that means that we can put the new data after the end of name and it is backward compatible with the old code. The old code just skips the event number without interpreting it. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Andy Grover <agrover@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-06-19dm ioctl: add a new DM_DEV_ARM_POLL ioctlMikulas Patocka1-21/+35
This ioctl will record the current global event number in the structure dm_file, so that next select or poll call will wait until new events arrived since this ioctl. The DM_DEV_ARM_POLL ioctl has the same effect as closing and reopening the handle. Using the DM_DEV_ARM_POLL ioctl is optional - if the userspace is OK with closing and reopening the /dev/mapper/control handle after select or poll, there is no need to re-arm via ioctl. Usage: 1. open the /dev/mapper/control device 2. send the DM_DEV_ARM_POLL ioctl 3. scan the event numbers of all devices we are interested in and process them 4. call select, poll or epoll on the handle (it waits until some new event happens since the DM_DEV_ARM_POLL ioctl) 5. go to step 2 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Andy Grover <agrover@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-06-19dm: add basic support for using the select or poll functionMikulas Patocka1-1/+48
Add the ability to poll on the /dev/mapper/control device. The select or poll function waits until any event happens on any dm device since opening the /dev/mapper/control device. When select or poll returns the device as readable, we must close and reopen the device to wait for new dm events. Usage: 1. open the /dev/mapper/control device 2. scan the event numbers of all devices we are interested in and process them 3. call select, poll or epoll on the handle (it waits until some new event happens since opening the device) 4. close the /dev/mapper/control handle 5. go to step 1 The next commit allows to re-arm the polling without closing and reopening the device. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Andy Grover <agrover@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-05-23dm ioctl: restore __GFP_HIGH in copy_params()Junaid Shahid1-2/+3
Commit d224e9381897 ("drivers/md/dm-ioctl.c: use kvmalloc rather than opencoded variant") left out the __GFP_HIGH flag when converting from __vmalloc to kvmalloc. This can cause the DM ioctl to fail in some low memory situations where it wouldn't have failed earlier. Add __GFP_HIGH back to avoid any potential regression. Fixes: d224e9381897 ("drivers/md/dm-ioctl.c: use kvmalloc rather than opencoded variant") Signed-off-by: Junaid Shahid <junaids@google.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-05-09drivers/md/dm-ioctl.c: use kvmalloc rather than opencoded variantMichal Hocko1-9/+4
copy_params uses kmalloc with vmalloc fallback. We already have a helper for that - kvmalloc. This caller requires GFP_NOIO semantic so it hasn't been converted with many others by previous patches. All we need to achieve this semantic is to use the scope memalloc_noio_{save,restore} around kvmalloc. Link: http://lkml.kernel.org/r/20170306103327.2766-4-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-28dm: introduce enum dm_queue_mode to cleanup related codeBart Van Assche1-1/+1
Introduce an enumeration type for the queue mode. This patch does not change any functionality but makes the DM code easier to read. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-04-27dm ioctl: prevent stack leak in dm ioctl callAdrian Salido1-1/+1
When calling a dm ioctl that doesn't process any data (IOCTL_FLAGS_NO_PARAMS), the contents of the data field in struct dm_ioctl are left initialized. Current code is incorrectly extending the size of data copied back to user, causing the contents of kernel stack to be leaked to user. Fix by only copying contents before data and allow the functions processing the ioctl to override. Cc: stable@vger.kernel.org Signed-off-by: Adrian Salido <salidoa@google.com> Reviewed-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-04-24dm ioctl: remove double parenthesesMatthias Kaehlcke1-2/+2
The extra pair of parantheses is not needed and causes clang to generate warnings about the DM_DEV_CREATE_CMD comparison in validate_params(). Also remove another double parentheses that doesn't cause a warning. Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-04-24dm: remove dummy dm_table definitionMikulas Patocka1-8/+0
This dummy structure definition was required for RCU macros, but it isn't required anymore, so delete it. The dummy definition confuses the crash tool, see: https://www.redhat.com/archives/dm-devel/2017-April/msg00197.html Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2017-03-02sched/headers: Prepare to move the memalloc_noio_*() APIs to <linux/sched/mm.h>Ingo Molnar1-0/+1
Update the .c files that depend on these APIs. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-24Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds1-1/+1
This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-08dm ioctl: use offsetof() instead of open-coding itBart Van Assche1-1/+1
Subtracting sizes is a fragile approach because the result is only correct if the compiler has not added any padding at the end of the structure. Hence use offsetof() instead of size subtraction. An additional advantage of offsetof() is that it makes the intent more clear. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-21dm: allow bio-based table to be upgraded to bio-based with DAX supportToshi Kani1-1/+10
Allow table type DM_TYPE_BIO_BASED to extend with DM_TYPE_DAX_BIO_BASED since DM_TYPE_DAX_BIO_BASED supports bio-based requests. This is needed to allow a snapshot of an LV with DAX support to be removed. One of the intermediate table reloads that lvm2 does switches from DM_TYPE_BIO_BASED to DM_TYPE_DAX_BIO_BASED. No known reason to disallow this so... Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-07-01dm ioctl: Simplify parameter buffer management codeBart Van Assche1-12/+6
Merge the two DM_PARAMS_[KV]MALLOC flags into a single flag. Doing so avoids the crashes seen with previous attempts to consolidate buffer management to use kvfree() without first flagging that memory had actually been allocated. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2016-06-10dm: move request-based code out to dm-rq.[hc]Mike Snitzer1-1/+1
Add some seperation between bio-based and request-based DM core code. 'struct mapped_device' and other DM core only structures and functions have been moved to dm-core.h and all relevant DM core .c files have been updated to include dm-core.h rather than dm.h DM targets should _never_ include dm-core.h! [block core merge conflict resolution from Stephen Rothwell] Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
2016-05-05dm ioctl: drop use of __GFP_REPEAT in copy_params()'s __vmalloc() callMichal Hocko1-1/+1
copy_params()'s use of __GFP_REPEAT for the __vmalloc() call doesn't make much sense because vmalloc doesn't rely on costly high order allocations. Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>