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2017-03-22pstore: Drop needless inode lock during populationKees Cook1-8/+2
Lockdep complains about a possible deadlock between mount and unlink, but it seems that the inode lock in pstore_mkfile() isn't needed for d_alloc_name() and d_add() calls. Additionally, pstore's own read_mutex should be protecting this anyway (since it is held for both get_records() and unlink()). As such, drop the explicit inode locking. -> #1 (&sb->s_type->i_mutex_key#14){++++++}: lock_acquire+0xc9/0x220 down_write+0x3f/0x70 pstore_mkfile+0x1f4/0x460 pstore_get_records+0x17a/0x320 pstore_fill_super+0xa4/0xc0 mount_single+0x89/0xb0 pstore_mount+0x13/0x20 mount_fs+0xf/0x90 vfs_kern_mount+0x66/0x170 do_mount+0x190/0xd50 SyS_mount+0x90/0xd0 entry_SYSCALL_64_fastpath+0x1c/0xb1 -> #0 (&psinfo->read_mutex){+.+.+.}: __lock_acquire+0x1ac0/0x1bb0 lock_acquire+0xc9/0x220 __mutex_lock+0x6e/0x990 mutex_lock_nested+0x16/0x20 pstore_unlink+0x3f/0xa0 vfs_unlink+0xb5/0x190 do_unlinkat+0x24c/0x2a0 SyS_unlinkat+0x16/0x30 entry_SYSCALL_64_fastpath+0x1c/0xb1 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#14); lock(&psinfo->read_mutex); lock(&sb->s_type->i_mutex_key#14); lock(&psinfo->read_mutex); Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: simplify write_user_compat()Kees Cook1-26/+20
Nothing actually uses write_user_compat() currently, but there is no reason to reuse the dmesg buffer. Instead, just allocate a new record buffer, copy in from userspace, and pass it to write() as normal. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Remove write_buf() callbackKees Cook4-24/+29
Now that write() and write_buf() are functionally identical, this removes write_buf(), and renames write_buf_user() to write_user(). Additionally adds sanity-checks for pstore_info's declared functions and flags at registration time. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Replace arguments for write_buf_user() APIKees Cook3-35/+23
Removes argument list in favor of pstore record, though the user buffer remains passed separately since it must carry the __user annotation. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Replace arguments for write_buf() APIKees Cook3-33/+50
As with the other API updates, this removes the long argument list in favor of passing a single pstore recaord. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Replace arguments for erase() APIKees Cook2-15/+12
This removes the argument list for the erase() callback and replaces it with a pointer to the backend record details to be removed. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Do not duplicate record metadataKees Cook2-33/+30
This switches the inode-private data from carrying duplicate metadata to keeping the record passed in during pstore_mkfile(). Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Allocate records on heap instead of stackKees Cook1-8/+22
In preparation for handling records off to pstore_mkfile(), allocate the record instead of reusing stack. This still always frees the record, though, since pstore_mkfile() isn't yet keeping it. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Pass record contents instead of copyingKees Cook2-11/+27
pstore_mkfile() shouldn't have to memcpy the record contents. It can use the existing copy instead. This adjusts the allocation lifetime management and renames the contents variable from "data" to "buf" to assist moving to struct pstore_record in the future. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Always allocate buffer for decompressionKees Cook1-14/+24
Currently, pstore_mkfile() performs a memcpy() of the record contents, so it can live anywhere. However, this is needlessly wasteful. In preparation of pstore_mkfile() keeping the record contents, always allocate a buffer for the contents. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Replace arguments for write() APIKees Cook1-27/+35
Similar to the pstore_info read() callback, there were too many arguments. This switches to the new struct pstore_record pointer instead. This adds "reason" and "part" to the record structure as well. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Replace arguments for read() APIKees Cook2-30/+30
The argument list for the pstore_read() interface is unwieldy. This changes passes the new struct pstore_record instead. The erst backend was already doing something similar internally. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Switch pstore_mkfile to pass recordKees Cook3-34/+34
Instead of the long list of arguments, just pass the new record struct. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Move record decompression to functionKees Cook1-30/+37
This moves the record decompression logic out to a separate function to avoid the deep indentation. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Extract common arguments into structureKees Cook1-25/+30
The read/mkfile pair pass the same arguments and should be cleared between calls. Move to a structure and wipe it after every loop. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Improve register_pstore() error reportingKees Cook1-1/+5
Uncommon errors are better to get reported to dmesg so developers can more easily figure out why pstore is unhappy with a backend attempting to register. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Avoid race in module unloadingKees Cook1-2/+2
Technically, it might be possible for struct pstore_info to go out of scope after the module_put(), so report the backend name first. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-03-07pstore: Shut down worker when unregisteringKees Cook1-1/+9
When built as a module and running with update_ms >= 0, pstore will Oops during module unload since the work timer is still running. This makes sure the worker is stopped before unloading. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org
2017-03-07pstore: Use dynamic spinlock initializerKees Cook1-1/+1
The per-prz spinlock should be using the dynamic initializer so that lockdep can correctly track it. Without this, under lockdep, we get a warning at boot that the lock is in non-static memory. Fixes: 109704492ef6 ("pstore: Make spinlock per zone instead of global") Fixes: 76d5692a5803 ("pstore: Correctly initialize spinlock and flags") Signed-off-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org
2017-03-07pstore: constify pstore_zbackend structuresBhumika Goyal1-4/+4
The references of pstore_zbackend structures are stored into the pointer zbackend of type struct pstore_zbackend. The pointer zbackend can be made const as it is only dereferenced. After making this change the pstore_zbackend structures whose references are stored into the pointer zbackend can be made const too. File size before: text data bss dec hex filename 4817 541 172 5530 159a fs/pstore/platform.o File size after: text data bss dec hex filename 4865 477 172 5514 158a fs/pstore/platform.o Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-02-24fs/pstore: fs/squashfs: change usage of LZ4 to work with new LZ4 versionSven Schmidt1-9/+13
Update fs/pstore and fs/squashfs to use the updated functions from the new LZ4 module. Link: http://lkml.kernel.org/r/1486321748-19085-5-git-send-email-4sschmid@informatik.uni-hamburg.de Signed-off-by: Sven Schmidt <4sschmid@informatik.uni-hamburg.de> Cc: Bongkyu Kim <bongkyu.kim@lge.com> Cc: Rui Salvaterra <rsalvaterra@gmail.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: David S. Miller <davem@davemloft.net> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-13pstore: Check for prz allocation in walkerKees Cook1-2/+3
Instead of needing additional checks in callers for unallocated przs, perform the check in the walker, which gives us a more universal way to handle the situation. Signed-off-by: Kees Cook <keescook@chromium.org>
2017-02-13pstore: Correctly initialize spinlock and flagsKees Cook1-5/+7
The ram backend wasn't always initializing its spinlock correctly. Since it was coming from kzalloc memory, though, it was harmless on architectures that initialize unlocked spinlocks to 0 (at least x86 and ARM). This also fixes a possibly ignored flag setting too. When running under CONFIG_DEBUG_SPINLOCK, the following Oops was visible: [ 0.760836] persistent_ram: found existing buffer, size 29988, start 29988 [ 0.765112] persistent_ram: found existing buffer, size 30105, start 30105 [ 0.769435] persistent_ram: found existing buffer, size 118542, start 118542 [ 0.785960] persistent_ram: found existing buffer, size 0, start 0 [ 0.786098] persistent_ram: found existing buffer, size 0, start 0 [ 0.786131] pstore: using zlib compression [ 0.790716] BUG: spinlock bad magic on CPU#0, swapper/0/1 [ 0.790729] lock: 0xffffffc0d1ca9bb0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 [ 0.790742] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.10.0-rc2+ #913 [ 0.790747] Hardware name: Google Kevin (DT) [ 0.790750] Call trace: [ 0.790768] [<ffffff900808ae88>] dump_backtrace+0x0/0x2bc [ 0.790780] [<ffffff900808b164>] show_stack+0x20/0x28 [ 0.790794] [<ffffff9008460ee0>] dump_stack+0xa4/0xcc [ 0.790809] [<ffffff9008113cfc>] spin_dump+0xe0/0xf0 [ 0.790821] [<ffffff9008113d3c>] spin_bug+0x30/0x3c [ 0.790834] [<ffffff9008113e28>] do_raw_spin_lock+0x50/0x1b8 [ 0.790846] [<ffffff9008a2d2ec>] _raw_spin_lock_irqsave+0x54/0x6c [ 0.790862] [<ffffff90083ac3b4>] buffer_size_add+0x48/0xcc [ 0.790875] [<ffffff90083acb34>] persistent_ram_write+0x60/0x11c [ 0.790888] [<ffffff90083aab1c>] ramoops_pstore_write_buf+0xd4/0x2a4 [ 0.790900] [<ffffff90083a9d3c>] pstore_console_write+0xf0/0x134 [ 0.790912] [<ffffff900811c304>] console_unlock+0x48c/0x5e8 [ 0.790923] [<ffffff900811da18>] register_console+0x3b0/0x4d4 [ 0.790935] [<ffffff90083aa7d0>] pstore_register+0x1a8/0x234 [ 0.790947] [<ffffff90083ac250>] ramoops_probe+0x6b8/0x7d4 [ 0.790961] [<ffffff90085ca548>] platform_drv_probe+0x7c/0xd0 [ 0.790972] [<ffffff90085c76ac>] driver_probe_device+0x1b4/0x3bc [ 0.790982] [<ffffff90085c7ac8>] __device_attach_driver+0xc8/0xf4 [ 0.790996] [<ffffff90085c4bfc>] bus_for_each_drv+0xb4/0xe4 [ 0.791006] [<ffffff90085c7414>] __device_attach+0xd0/0x158 [ 0.791016] [<ffffff90085c7b18>] device_initial_probe+0x24/0x30 [ 0.791026] [<ffffff90085c648c>] bus_probe_device+0x50/0xe4 [ 0.791038] [<ffffff90085c35b8>] device_add+0x3a4/0x76c [ 0.791051] [<ffffff90087d0e84>] of_device_add+0x74/0x84 [ 0.791062] [<ffffff90087d19b8>] of_platform_device_create_pdata+0xc0/0x100 [ 0.791073] [<ffffff90087d1a2c>] of_platform_device_create+0x34/0x40 [ 0.791086] [<ffffff900903c910>] of_platform_default_populate_init+0x58/0x78 [ 0.791097] [<ffffff90080831fc>] do_one_initcall+0x88/0x160 [ 0.791109] [<ffffff90090010ac>] kernel_init_freeable+0x264/0x31c [ 0.791123] [<ffffff9008a25bd0>] kernel_init+0x18/0x11c [ 0.791133] [<ffffff9008082ec0>] ret_from_fork+0x10/0x50 [ 0.793717] console [pstore-1] enabled [ 0.797845] pstore: Registered ramoops as persistent store backend [ 0.804647] ramoops: attached 0x100000@0xf7edc000, ecc: 0/0 Fixes: 663deb47880f ("pstore: Allow prz to control need for locking") Fixes: 109704492ef6 ("pstore: Make spinlock per zone instead of global") Reported-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2017-02-09pstore: don't OOPS when there are no ftrace zonesBrian Norris1-1/+1
We'll OOPS in ramoops_get_next_prz() if the platform didn't ask for any ftrace zones (i.e., cxt->fprzs will be NULL). Let's just skip this entire FTRACE section if there's no 'fprzs'. Regression seen on a coreboot/depthcharge-based Chromebook. Fixes: 2fbea82bbb89 ("pstore: Merge per-CPU ftrace records into one") Cc: Joel Fernandes <joelaf@google.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-12-13Merge tag 'pstore-v4.10-rc1' of ↵Linus Torvalds6-126/+293
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull pstore updates from Kees Cook: "Improvements and fixes to pstore subsystem: - add additional checks for bad platform data - remove bounce buffer in console writer - protect read/unlink race with a mutex - correctly give up during dump locking failures - increase ftrace bandwidth by splitting ftrace buffers per CPU" * tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: ramoops: add pdata NULL check to ramoops_probe pstore: Convert console write to use ->write_buf pstore: Protect unlink with read_mutex pstore: Use global ftrace filters for function trace filtering ftrace: Provide API to use global filtering for ftrace ops pstore: Clarify context field przs as dprzs pstore: improve error report for failed setup pstore: Merge per-CPU ftrace records into one pstore: Add ftrace timestamp counter ramoops: Split ftrace buffer space into per-CPU zones pstore: Make ramoops_init_przs generic for other prz arrays pstore: Allow prz to control need for locking pstore: Warn on PSTORE_TYPE_PMSG using deprecated function pstore: Make spinlock per zone instead of global pstore: Actually give up during locking failure
2016-11-15ramoops: add pdata NULL check to ramoops_probeKees Cook1-2/+11
This adds a check for a NULL platform data, which should only be possible if a driver incorrectly sets up a probe request without also having defined the platform_data structure. This is based on a patch from Geliang Tang. Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15pstore: Convert console write to use ->write_bufNamhyung Kim1-2/+2
Maybe I'm missing something, but I don't know why it needs to copy the input buffer to psinfo->buf and then write. Instead we can write the input buffer directly. The only implementation that supports console message (i.e. ramoops) already does it for ftrace messages. For the upcoming virtio backend driver, it needs to protect psinfo->buf overwritten from console messages. If it could use ->write_buf method instead of ->write, the problem will be solved easily. Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15pstore: Protect unlink with read_mutexNamhyung Kim1-2/+5
When update_ms is set, pstore_get_records() will be called when there's a new entry. But unlink can be called at the same time and might contend with the open-read-close loop. Depending on the implementation of platform driver, it may be safe or not. But I think it'd be better to protect those race in the first place. Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15pstore: Use global ftrace filters for function trace filteringJoel Fernandes1-2/+5
Currently, pstore doesn't have any filters setup for function tracing. This has the associated overhead and may not be useful for users looking for tracing specific set of functions. ftrace's regular function trace filtering is done writing to tracing/set_ftrace_filter however this is not available if not requested. In order to be able to use this feature, the support to request global filtering introduced earlier in the series should be requested before registering the ftrace ops. Here we do the same. Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15pstore: Clarify context field przs as dprzsKees Cook1-12/+12
Since "przs" (persistent ram zones) is a general name in the code now, so rename the Oops-dump zones to dprzs from przs. Based on a patch from Nobuhiro Iwamatsu. Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15pstore: improve error report for failed setupKees Cook1-19/+34
When setting ramoops record sizes, sometimes it's not clear which parameters contributed to the allocation failure. This adds a per-zone name and expands the failure reports. Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15pstore: Merge per-CPU ftrace records into oneJoel Fernandes1-13/+109
Up until this patch, each of the per CPU ftrace buffers appear as a separate ftrace-ramoops-N file. In this patch we merge all the zones into one and populate a single ftrace-ramoops-0 file. Signed-off-by: Joel Fernandes <joelaf@google.com> [kees: clarified variables names, added -ENOMEM handling] Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15pstore: Add ftrace timestamp counterJoel Fernandes3-37/+9
In preparation for merging the per CPU buffers into one buffer when we retrieve the pstore ftrace data, we store the timestamp as a counter in the ftrace pstore record. We store the CPU number as well if !PSTORE_CPU_IN_IP, in this case we shift the counter and may lose ordering there but we preserve the same record size. The timestamp counter is also racy, and not doing any locking or synchronization here results in the benefit of lower overhead. Since we don't care much here for exact ordering of function traces across CPUs, we don't synchronize and may lose some counter updates but I'm ok with that. Using trace_clock() results in much lower performance so avoid using it since we don't want accuracy in timestamp and need a rough ordering to perform merge. Signed-off-by: Joel Fernandes <joelaf@google.com> [kees: updated commit message, added comments] Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15ramoops: Split ftrace buffer space into per-CPU zonesJoel Fernandes1-17/+55
If the RAMOOPS_FLAG_FTRACE_PER_CPU flag is passed to ramoops pdata, split the ftrace space into multiple zones depending on the number of CPUs. This speeds up the performance of function tracing by about 280% in my tests as we avoid the locking. The trade off being lesser space available per CPU. Let the ramoops user decide which option they want based on pdata flag. Signed-off-by: Joel Fernandes <joelaf@google.com> [kees: added max_ftrace_cnt to track size, added DT logic and docs] Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15pstore: Make ramoops_init_przs generic for other prz arraysKees Cook1-28/+54
Currently ramoops_init_przs() is hard wired only for panic dump zone array. In preparation for the ftrace zone array (one zone per-cpu) and pmsg zone array, make the function more generic to be able to handle this case. Heavily based on similar work from Joel Fernandes. Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-15pstore: Allow prz to control need for lockingJoel Fernandes2-11/+18
In preparation of not locking at all for certain buffers depending on if there's contention, make locking optional depending on the initialization of the prz. Signed-off-by: Joel Fernandes <joelaf@google.com> [kees: moved locking flag into prz instead of via caller arguments] Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-11pstore: Warn on PSTORE_TYPE_PMSG using deprecated functionJoel Fernandes1-4/+2
PMSG now uses ramoops_pstore_write_buf_user() instead of ...write_buf(). Print a ratelimited warning if gets accidentally called. Signed-off-by: Joel Fernandes <joelaf@google.com> [kees: adjusted commit log and added -EINVAL return] Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-11pstore: Make spinlock per zone instead of globalJoel Fernandes1-6/+5
Currently pstore has a global spinlock for all zones. Since the zones are independent and modify different areas of memory, there's no need to have a global lock, so we should use a per-zone lock as introduced here. Also, when ramoops's ftrace use-case has a FTRACE_PER_CPU flag introduced later, which splits the ftrace memory area into a single zone per CPU, it will eliminate the need for locking. In preparation for this, make the locking optional. Signed-off-by: Joel Fernandes <joelaf@google.com> [kees: updated commit message] Signed-off-by: Kees Cook <keescook@chromium.org>
2016-11-08pstore: Actually give up during locking failureLi Pengcheng1-0/+1
Without a return after the pr_err(), dumps will collide when two threads call pstore_dump() at the same time. Signed-off-by: Liu Hailong <liuhailong5@huawei.com> Signed-off-by: Li Pengcheng <lipengcheng8@huawei.com> Signed-off-by: Li Zhong <lizhong11@hisilicon.com> [kees: improved commit message] Signed-off-by: Kees Cook <keescook@chromium.org>
2016-10-24docs: fix locations of several documents that got movedMauro Carvalho Chehab1-1/+1
The previous patch renamed several files that are cross-referenced along the Kernel documentation. Adjust the links to point to the right places. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-10-10Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
2016-09-27fs: Replace CURRENT_TIME with current_time() for inode timestampsDeepa Dinamani1-1/+1
CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_time() instead. CURRENT_TIME is also not y2038 safe. This is also in preparation for the patch that transitions vfs timestamps to use 64 bit time and hence make them y2038 safe. As part of the effort current_time() will be extended to do range checks. Hence, it is necessary for all file system timestamps to use current_time(). Also, current_time() will be transitioned along with vfs to be y2038 safe. Note that whenever a single call to current_time() is used to change timestamps in different inodes, it is because they share the same time granularity. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Felipe Balbi <balbi@kernel.org> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-08ramoops: move spin_lock_init after kmalloc error checkingGeliang Tang1-1/+1
If cxt->pstore.buf allocated failed, no need to initialize cxt->pstore.buf_lock. So this patch moves spin_lock_init() after the error checking. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-09-08pstore/ram: Use memcpy_fromio() to save old bufferAndrew Bresticker1-2/+2
The ramoops buffer may be mapped as either I/O memory or uncached memory. On ARM64, this results in a device-type (strongly-ordered) mapping. Since unnaligned accesses to device-type memory will generate an alignment fault (regardless of whether or not strict alignment checking is enabled), it is not safe to use memcpy(). memcpy_fromio() is guaranteed to only use aligned accesses, so use that instead. Signed-off-by: Andrew Bresticker <abrestic@chromium.org> Signed-off-by: Enric Balletbo Serra <enric.balletbo@collabora.com> Reviewed-by: Puneet Kumar <puneetster@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org
2016-09-08pstore/ram: Use memcpy_toio instead of memcpyFurquan Shaikh1-1/+1
persistent_ram_update uses vmap / iomap based on whether the buffer is in memory region or reserved region. However, both map it as non-cacheable memory. For armv8 specifically, non-cacheable mapping requests use a memory type that has to be accessed aligned to the request size. memcpy() doesn't guarantee that. Signed-off-by: Furquan Shaikh <furquan@google.com> Signed-off-by: Enric Balletbo Serra <enric.balletbo@collabora.com> Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-by: Olof Johansson <olofj@chromium.org> Tested-by: Furquan Shaikh <furquan@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org
2016-09-08pstore/pmsg: drop bounce bufferMark Salyzyn4-31/+106
Removing a bounce buffer copy operation in the pmsg driver path is always better. We also gain in overall performance by not requesting a vmalloc on every write as this can cause precious RT tasks, such as user facing media operation, to stall while memory is being reclaimed. Added a write_buf_user to the pstore functions, a backup platform write_buf_user that uses the small buffer that is part of the instance, and implemented a ramoops write_buf_user that only supports PSTORE_TYPE_PMSG. Signed-off-by: Mark Salyzyn <salyzyn@android.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-09-08pstore/ram: Set pstore flags dynamicallyNamhyung Kim1-1/+7
The ramoops can be configured to enable each pstore type by setting their size. In that case, it'd be better not to register disabled types in the first place. Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-09-08pstore: Split pstore fragile flagsNamhyung Kim2-7/+12
This patch adds new PSTORE_FLAGS for each pstore type so that they can be enabled separately. This is a preparation for ongoing virtio-pstore work to support those types flexibly. The PSTORE_FLAGS_FRAGILE is changed to PSTORE_FLAGS_DMESG to preserve the original behavior. Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: linux-acpi@vger.kernel.org Cc: linux-efi@vger.kernel.org Signed-off-by: Namhyung Kim <namhyung@kernel.org> [kees: retained "FRAGILE" for now to make merges easier] Signed-off-by: Kees Cook <keescook@chromium.org>
2016-09-08pstore/core: drop cmpxchg based updatesSebastian Andrzej Siewior1-41/+2
I have here a FPGA behind PCIe which exports SRAM which I use for pstore. Now it seems that the FPGA no longer supports cmpxchg based updates and writes back 0xff…ff and returns the same. This leads to crash during crash rendering pstore useless. Since I doubt that there is much benefit from using cmpxchg() here, I am dropping this atomic access and use the spinlock based version. Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Rabin Vincent <rabinv@axis.com> Tested-by: Rabin Vincent <rabinv@axis.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> [kees: remove "_locked" suffix since it's the only option now] Signed-off-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org
2016-09-08pstore/ramoops: fixup driver removalSebastian Andrzej Siewior1-5/+12
A basic rmmod ramoops segfaults. Let's see why. Since commit 34f0ec82e0a9 ("pstore: Correct the max_dump_cnt clearing of ramoops") sets ->max_dump_cnt to zero before looping over ->przs but we didn't use it before that either. And since commit ee1d267423a1 ("pstore: add pstore unregister") we free that memory on rmmod. But even then, we looped until a NULL pointer or ERR. I don't see where it is ensured that the last member is NULL. Let's try this instead: simply error recovery and free. Clean up in error case where resources were allocated. And then, in the free path, rely on ->max_dump_cnt in the free path. Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org # 4.4.x-
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