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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
2016-11-16ramoops: 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>
2016-11-16pstore: 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>
2016-11-16pstore: 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>
2016-11-16pstore: 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>
2016-11-16pstore: 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>
2016-11-16pstore: 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>
2016-11-16pstore: 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>
2016-11-16pstore: 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>
2016-11-16ramoops: 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>
2016-11-16pstore: 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>
2016-11-16pstore: 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>
2016-11-09pstore: 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>
2016-10-11Merge 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
2016-09-28fs: 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>
2016-09-09ramoops: 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>
2016-09-09pstore/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
2016-09-09pstore/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
2016-09-09pstore/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>
2016-09-09pstore/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>
2016-09-09pstore: 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>
2016-09-09pstore/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
2016-09-09pstore/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-
2016-08-05ramoops: use persistent_ram_free() instead of kfree() for freeing przHiraku Toyooka1-3/+3
persistent_ram_zone(=prz) structures are allocated by persistent_ram_new(), which includes vmap() or ioremap(). But they are currently freed by kfree(). This uses persistent_ram_free() for correct this asymmetry usage. Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.kw@hitachi.com> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Seiji Aguchi <seiji.aguchi.tr@hitachi.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-08-05ramoops: use DT reserved-memory bindingsKees Cook1-16/+7
Instead of a ramoops-specific node, use a child node of /reserved-memory. This requires that of_platform_device_create() be explicitly called for the node, though, since "/reserved-memory" does not have its own "compatible" property. Suggested-by: Rob Herring <robh@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Rob Herring <robh@kernel.org>
2016-06-14pstore/ram: add Device Tree bindingsGreg Hackmann1-2/+93
ramoops is one of the remaining places where ARM vendors still rely on board-specific shims. Device Tree lets us replace those shims with generic code. These bindings mirror the ramoops module parameters, with two small differences: (1) dump_oops becomes an optional "no-dump-oops" property, since ramoops sets dump_oops=1 by default. (2) mem_type=1 becomes the more self-explanatory "unbuffered" property. Signed-off-by: Greg Hackmann <ghackmann@google.com> [fixed platform_get_drvdata() crash, thanks to Brian Norris] [switched from u64 to u32 to simplify code, various whitespace fixes] [use dev_of_node() to gain code-elimination for CONFIG_OF=n] Signed-off-by: Kees Cook <keescook@chromium.org>
2016-06-02pstore: drop file opened reference countGeliang Tang1-1/+0
In ee1d267423a1 ("pstore: add pstore unregister") I added: .owner = THIS_MODULE, in both pstore_fs_type and pstore_file_operations to increase a reference count when pstore filesystem is mounted and pstore file is opened. But, it's repetitive. There is no need to increase the opened reference count. We only need to increase the mounted reference count. When a file is opened, the filesystem can't be unmounted. Hence the pstore module can't be unloaded either. So I drop the opened reference count in this patch. Fixes: ee1d267423a1 ("pstore: add pstore unregister") Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-06-02pstore: add lzo/lz4 compression supportGeliang Tang3-14/+245
Like zlib compression in pstore, this patch added lzo and lz4 compression support so that users can have more options and better compression ratio. The original code treats the compressed data together with the uncompressed ECC correction notice by using zlib decompress. The ECC correction notice is missing in the decompression process. The treatment also makes lzo and lz4 not working. So I treat them separately by using pstore_decompress() to treat the compressed data, and memcpy() to treat the uncompressed ECC correction notice. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-05-31pstore: Cleanup pstore_dump()Namhyung Kim1-19/+13
The code is duplicate between compression is enabled or not. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-05-31pstore: Enable compression on normal path (again)Namhyung Kim1-6/+5
The commit f0e2efcfd2717 ("pstore: do not use message compression without lock") added a check to 'is_locked' to avoid breakage in concurrent accesses. But it has a side-effect of disabling compression on normal path since 'is_locked' variable is not set. As normal path always takes the lock, it should be initialized to 1. This also makes the unlock code a bit simpler. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2016-05-31ramoops: Only unregister when registeredKees Cook1-3/+5
While none of the "fragile" pstore backends unregister yet, if they ever did, the unregistering code for the non-dump targets might get confused. This adds a check for fragile backends on unregister. Signed-off-by: Kees Cook <keescook@chromium.org>
2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov1-2/+2
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-10pstore: Add support for 64 Bit address spaceWiebe, Wladislav (Nokia - DE/Ulm)1-2/+2
Some architectures have their reserved RAM in 64 Bit address space. Therefore convert mem_address module parameter to ullong. Signed-off-by: Wladislav Wiebe <wladislav.wiebe@nokia.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2016-01-23wrappers for ->i_mutex accessAl Viro1-3/+3
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-03pstore: fix code comment to match codeGeliang Tang1-2/+3
Fix code comment about kmsg_dump register so it matches the code. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-10-22pstore: Fix return type of pstore_is_mounted()Geliang Tang2-2/+2
This patch changes return type of pstore_is_mounted from int to bool. Signed-off-by: Geliang Tang <geliangtang@163.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-10-22pstore: add pstore unregisterGeliang Tang8-21/+86
pstore doesn't support unregistering yet. It was marked as TODO. This patch adds some code to fix it: 1) Add functions to unregister kmsg/console/ftrace/pmsg. 2) Add a function to free compression buffer. 3) Unmap the memory and free it. 4) Add a function to unregister pstore filesystem. Signed-off-by: Geliang Tang <geliangtang@163.com> Acked-by: Kees Cook <keescook@chromium.org> [Removed __exit annotation from ramoops_remove(). Reported by Arnd Bergmann] Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-10-21pstore: add a helper function pstore_register_kmsgGeliang Tang1-1/+6
Add a new wrapper function pstore_register_kmsg to keep the consistency with other similar pstore_register_* functions. Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-10-21pstore: add vmalloc error checkGeliang Tang1-0/+2
If vmalloc fails, make write_pmsg return -ENOMEM. Signed-off-by: Geliang Tang <geliangtang@163.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-07-04Merge branch 'for-linus' of ↵Linus Torvalds1-8/+4
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace updates from Eric Biederman: "Long ago and far away when user namespaces where young it was realized that allowing fresh mounts of proc and sysfs with only user namespace permissions could violate the basic rule that only root gets to decide if proc or sysfs should be mounted at all. Some hacks were put in place to reduce the worst of the damage could be done, and the common sense rule was adopted that fresh mounts of proc and sysfs should allow no more than bind mounts of proc and sysfs. Unfortunately that rule has not been fully enforced. There are two kinds of gaps in that enforcement. Only filesystems mounted on empty directories of proc and sysfs should be ignored but the test for empty directories was insufficient. So in my tree directories on proc, sysctl and sysfs that will always be empty are created specially. Every other technique is imperfect as an ordinary directory can have entries added even after a readdir returns and shows that the directory is empty. Special creation of directories for mount points makes the code in the kernel a smidge clearer about it's purpose. I asked container developers from the various container projects to help test this and no holes were found in the set of mount points on proc and sysfs that are created specially. This set of changes also starts enforcing the mount flags of fresh mounts of proc and sysfs are consistent with the existing mount of proc and sysfs. I expected this to be the boring part of the work but unfortunately unprivileged userspace winds up mounting fresh copies of proc and sysfs with noexec and nosuid clear when root set those flags on the previous mount of proc and sysfs. So for now only the atime, read-only and nodev attributes which userspace happens to keep consistent are enforced. Dealing with the noexec and nosuid attributes remains for another time. This set of changes also addresses an issue with how open file descriptors from /proc/<pid>/ns/* are displayed. Recently readlink of /proc/<pid>/fd has been triggering a WARN_ON that has not been meaningful since it was added (as all of the code in the kernel was converted) and is not now actively wrong. There is also a short list of issues that have not been fixed yet that I will mention briefly. It is possible to rename a directory from below to above a bind mount. At which point any directory pointers below the renamed directory can be walked up to the root directory of the filesystem. With user namespaces enabled a bind mount of the bind mount can be created allowing the user to pick a directory whose children they can rename to outside of the bind mount. This is challenging to fix and doubly so because all obvious solutions must touch code that is in the performance part of pathname resolution. As mentioned above there is also a question of how to ensure that developers by accident or with purpose do not introduce exectuable files on sysfs and proc and in doing so introduce security regressions in the current userspace that will not be immediately obvious and as such are likely to require breaking userspace in painful ways once they are recognized" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: vfs: Remove incorrect debugging WARN in prepend_path mnt: Update fs_fully_visible to test for permanently empty directories sysfs: Create mountpoints with sysfs_create_mount_point sysfs: Add support for permanently empty directories to serve as mount points. kernfs: Add support for always empty directories. proc: Allow creating permanently empty directories that serve as mount points sysctl: Allow creating permanently empty directories that serve as mountpoints. fs: Add helper functions for permanently empty directories. vfs: Ignore unlocked mounts in fs_fully_visible mnt: Modify fs_fully_visible to deal with locked ro nodev and atime mnt: Refactor the logic for mounting sysfs and proc in a user namespace
2015-07-01sysfs: Create mountpoints with sysfs_create_mount_pointEric W. Biederman1-8/+4
This allows for better documentation in the code and it allows for a simpler and fully correct version of fs_fully_visible to be written. The mount points converted and their filesystems are: /sys/hypervisor/s390/ s390_hypfs /sys/kernel/config/ configfs /sys/kernel/debug/ debugfs /sys/firmware/efi/efivars/ efivarfs /sys/fs/fuse/connections/ fusectl /sys/fs/pstore/ pstore /sys/kernel/tracing/ tracefs /sys/fs/cgroup/ cgroup /sys/kernel/security/ securityfs /sys/fs/selinux/ selinuxfs /sys/fs/smackfs/ smackfs Cc: stable@vger.kernel.org Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-05-21ramoops: make it possible to change mem_type param.Wang Long1-1/+1
If we set ramoops.mem_type=1 in command line, the current code can not change mem_type to 1, because it is assigned to 0 in function ramoops_register_dummy. This patch make it possible to change mem_type parameter in command line. Signed-off-by: Wang Long <long.wanglong@huawei.com> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-05-21pstore/ram: verify ramoops header before saving recordBen Zhang1-12/+28
On some devices the persistent memory contains junk after a cold boot, and /dev/pstore/dmesg-ramoops-* are created with random data which is not the result of a kernel crash. This patch adds a ramoops header check and skips any persistent_ram_zone that does not have a valid header. Signed-off-by: Ben Zhang <benzh@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-05-21fs/pstore: Optimization function ramoops_init_przslong.wanglong1-5/+3
The value of cxt->record_size does not change in the loop, so this patch optimize the assign statement by dropping sz entirely and using cxt->record_size in its place. Signed-off-by: Wang Long <long.wanglong@huawei.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-05-21fs/pstore: update the backend parameter in pstore moduleWang Long1-0/+6
This patch update the module parameter backend, so it is visible through /sys/module/pstore/parameters/backend. For example: if pstore backend is ramoops, with this patch: # cat /sys/module/pstore/parameters/backend ramoops and without this patch: # cat /sys/module/pstore/parameters/backend (null) Signed-off-by: Wang Long <long.wanglong@huawei.com> Acked-by: Mark Salyzyn <salyzyn@android.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2015-05-21pstore: do not use message compression without lockKonstantin Khlebnikov1-1/+1
pstore_compress() uses static stream buffer for zlib-deflate which easily crashes when several concurrent threads use one shared state. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Tony Luck <tony.luck@intel.com>