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path: root/fs/pstore/ram_core.c
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2016-11-15pstore: Allow prz to control need for lockingJoel Fernandes
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: Make spinlock per zone instead of globalJoel Fernandes
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>
2016-09-08pstore/ram: Use memcpy_fromio() to save old bufferAndrew Bresticker
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 Shaikh
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 Salyzyn
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/core: drop cmpxchg based updatesSebastian Andrzej Siewior
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
2014-12-11pstore-ram: Allow optional mapping with pgprot_noncachedTony Lindgren
On some ARMs the memory can be mapped pgprot_noncached() and still be working for atomic operations. As pointed out by Colin Cross <ccross@android.com>, in some cases you do want to use pgprot_noncached() if the SoC supports it to see a debug printk just before a write hanging the system. On ARMs, the atomic operations on strongly ordered memory are implementation defined. So let's provide an optional kernel parameter for configuring pgprot_noncached(), and use pgprot_writecombine() by default. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robherring2@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Olof Johansson <olof@lixom.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: stable@vger.kernel.org Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2014-12-11pstore-ram: Fix hangs by using write-combine mappingsRob Herring
Currently trying to use pstore on at least ARMs can hang as we're mapping the peristent RAM with pgprot_noncached(). On ARMs, pgprot_noncached() will actually make the memory strongly ordered, and as the atomic operations pstore uses are implementation defined for strongly ordered memory, they may not work. So basically atomic operations have undefined behavior on ARM for device or strongly ordered memory types. Let's fix the issue by using write-combine variants for mappings. This corresponds to normal, non-cacheable memory on ARM. For many other architectures, this change does not change the mapping type as by default we have: #define pgprot_writecombine pgprot_noncached The reason why pgprot_noncached() was originaly used for pstore is because Colin Cross <ccross@android.com> had observed lost debug prints right before a device hanging write operation on some systems. For the platforms supporting pgprot_noncached(), we can add a an optional configuration option to support that. But let's get pstore working first before adding new features. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Anton Vorontsov <cbouatmailru@gmail.com> Cc: Colin Cross <ccross@android.com> Cc: Olof Johansson <olof@lixom.net> Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Rob Herring <rob.herring@calxeda.com> [tony@atomide.com: updated description] Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2014-08-08fs/pstore/ram_core.c: replace count*size kmalloc by kmalloc_arrayFabian Frederick
kmalloc_array manages count*sizeof overflow. Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06fs/pstore: logging clean-upFabian Frederick
- Define pr_fmt in plateform.c and ram_core.c for global prefix. - Coalesce format fragments. - Separate format/arguments on lines > 80 characters. Note: Some pr_foo() were initially declared without prefix and therefore this could break existing log analyzer. [akpm@linux-foundation.org: missed a couple of prefix removals] Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Joe Perches <joe@perches.com> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-17pstore: Fix buffer overflow while write offset equal to buffer sizeLiu ShuoX
In case new offset is equal to prz->buffer_size, it won't wrap at this time and will return old(overflow) value next time. Signed-off-by: Liu ShuoX <shuox.liu@intel.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2013-06-14pstore/ram: avoid atomic accesses for ioremapped regionsRob Herring
For persistent RAM outside of main memory, the memory may have limitations on supported accesses. For internal RAM on highbank platform exclusive accesses are not supported and will hang the system. So atomic_cmpxchg cannot be used. This commit uses spinlock protection for buffer size and start updates on ioremapped regions instead. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Acked-by: Anton Vorontsov <anton@enomsg.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2013-04-03pstore/ram: Restore ecc information blockArve Hjønnevåg
This was lost when proc/last_kmsg moved to pstore/console-ramoops. Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Anton Vorontsov <anton@enomsg.org>
2013-04-03pstore/ram: Allow specifying ecc parameters in platform dataArve Hjønnevåg
Allow specifying ecc parameters in platform data Signed-off-by: Arve Hjønnevåg <arve@android.com> [jstultz: Tweaked commit subject & add commit message] Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Anton Vorontsov <anton@enomsg.org>
2013-04-03pstore/ram: Include ecc_size when calculating ecc_blockArve Hjønnevåg
Wastes less memory and allows using more memory for ecc than data. Signed-off-by: Arve Hjønnevåg <arve@android.com> [jstultz: Tweaked commit subject] Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Anton Vorontsov <anton@enomsg.org>
2013-01-03pstore: remove __dev* attributes.Greg Kroah-Hartman
CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit from the pstore filesystem. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: Anton Vorontsov <cbouatmailru@gmail.com> Cc: Colin Cross <ccross@android.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17pstore/ram: Make tracing log versionedAnton Vorontsov
Decoding the binary trace w/ a different kernel might be troublesome since we convert addresses to symbols. For kernels with minimal changes, the mappings would probably match, but it's not guaranteed at all. (But still we could convert the addresses by hand, since we do print raw addresses.) If we use modules, the symbols could be loaded at different addresses from the previously booted kernel, and so this would also fail, but there's nothing we can do about it. Also, the binary data format that pstore/ram is using in its ringbuffer may change between the kernels, so here we too must ensure that we're running the same kernel. So, there are two questions really: 1. How to compute the unique kernel tag; 2. Where to store it. In this patch we're using LINUX_VERSION_CODE, just as hibernation (suspend-to-disk) does. This way we are protecting from the kernel version mismatch, making sure that we're running the same kernel version and patch level. We could use CRC of a symbol table (as suggested by Tony Luck), but for now let's not be that strict. And as for storing, we are using a small trick here. Instead of allocating a dedicated buffer for the tag (i.e. another prz), or hacking ram_core routines to "reserve" some control data in the buffer, we are just encoding the tag into the buffer signature (and XOR'ing it with the actual signature value, so that buffers not needing a tag can just pass zero, which will result into the plain old PRZ signature). Suggested-by: Steven Rostedt <rostedt@goodmis.org> Suggested-by: Tony Luck <tony.luck@intel.com> Suggested-by: Colin Cross <ccross@android.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17pstore/ram_core: Get rid of prz->ecc enable/disable flagAnton Vorontsov
Nowadays we can use prz->ecc_size as a flag, no need for the special member in the prz struct. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17pstore/ram: Make ECC size configurableAnton Vorontsov
This is now pretty straightforward: instead of using bool, just pass an integer. For backwards compatibility ramoops.ecc=1 means 16 bytes ECC (using 1 byte for ECC isn't much of use anyway). Suggested-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-17pstore/ram_core: Get rid of prz->ecc_symsize and prz->ecc_polyAnton Vorontsov
The struct members were never used anywhere outside of persistent_ram_init_ecc(), so there's actually no need for them to be in the struct. If we ever want to make polynomial or symbol size configurable, it would make more sense to just pass initialized rs_decoder to the persistent_ram init functions. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-20pstore/ram_core: Better ECC size checkingAnton Vorontsov
- Instead of exploiting unsigned overflows (which doesn't work for all sizes), use straightforward checking for ECC total size not exceeding initial buffer size; - Printing overflowed buffer_size is not informative. Instead, print ecc_size and buffer_size; - No need for buffer_size argument in persistent_ram_init_ecc(), we can address prz->buffer_size directly. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-20pstore/ram_core: Proper checking for post_init errors (e.g. improper ECC size)Anton Vorontsov
We will implement variable-sized ECC buffers soon, so post_init routine might fail much more likely, so we'd better check for its errors. To make error handling simple, modify persistent_ram_free() to it be safe at all times. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-20pstore/ram: Probe as early as possibleAnton Vorontsov
Registering the platform driver before module_init allows us to log oopses that happen during device probing. This requires changing module_init to postcore_initcall, and switching from platform_driver_probe to platform_driver_register because the platform device is not registered when the platform driver is registered; and because we use driver_register, now can't use create_bundle() (since it will try to register the same driver once again), so we have to switch to platform_device_register_data(). Also, some __init -> __devinit changes were needed. Overall, the registration logic is now much clearer, since we have only one driver registration point, and just an optional dummy device, which is created from the module parameters. Suggested-by: Colin Cross <ccross@android.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13pstore/ram_core: Remove now unused codeAnton Vorontsov
The code tried to maintain the global list of persistent ram zones, which isn't a great idea overall, plus since Android's ram_console is no longer there, we can remove some unused functions. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Colin Cross <ccross@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13pstore/ram_core: Silence some printksAnton Vorontsov
Since we use multiple regions, the messages are somewhat annoying. We do print total mapped memory already, so no need to print the information for each region in the library routines. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Colin Cross <ccross@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13pstore/ram_core: Factor persistent_ram_zap() out of post_init()Anton Vorontsov
A handy function that we will use outside of ram_core soon. But so far just factor it out and start using it in post_init(). Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13pstore/ram_core: Do not reset restored zone's position and sizeAnton Vorontsov
Otherwise, the files will survive just one reboot, and on a subsequent boot they will disappear. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13pstore/ram: Should update old dmesg buffer before readingAnton Vorontsov
Without the update, we'll only see the new dmesg buffer after the reboot, but previously we could see it right away. Making an oops visible in pstore filesystem before reboot is a somewhat dubious feature, but removing it wasn't an intentional change, so let's restore it. For this we have to make persistent_ram_save_old() safe for calling multiple times, and also extern it. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-17staging: android: persistent_ram: Move to fs/pstore/ram_core.cAnton Vorontsov
This is a first step for adding ECC support for pstore RAM backend: we will use the persistent_ram routines, kindly provided by Google. Basically, persistent_ram is a set of helper routines to deal with the [optionally] ECC-protected persistent ram regions. A bit of Makefile, Kconfig and header files adjustments were needed because of the move. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>