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* pstore/ram: Make tracing log versionedAnton Vorontsov2012-07-171-5/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* pstore/ram: Add ftrace messages handlingAnton Vorontsov2012-07-171-4/+33
| | | | | | | | | The ftrace log size is configurable via ramoops.ftrace_size module option, and the log itself is available via <pstore-mount>/ftrace-ramoops file. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pstore/ram: Convert to write_buf callbackAnton Vorontsov2012-07-171-8/+9
| | | | | | | | Don't use pstore.buf directly, instead convert the code to write_buf callback which passes a pointer to a buffer as an argument. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pstore/ram: Make ECC size configurableAnton Vorontsov2012-07-171-8/+14
| | | | | | | | | | | 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>
* pstore/ram: Fix error handling during przs allocationAnton Vorontsov2012-06-201-1/+1
| | | | | | | | | | persistent_ram_new() returns ERR_PTR() value on errors, so during freeing of the przs we should check for both NULL and IS_ERR() entries, otherwise bad things will happen. 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>
* pstore/ram: Probe as early as possibleAnton Vorontsov2012-06-201-31/+32
| | | | | | | | | | | | | | | | | | | | | | | 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>
* pstore/ram: Add console messages handlingAnton Vorontsov2012-06-131-14/+86
| | | | | | | | | | The console log size is configurable via ramoops.console_size module option, and the log itself is available via <pstore-mount>/console-ramoops file. 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>
* pstore/ram: Factor ramoops_get_next_prz() out of ramoops_pstore_read()Anton Vorontsov2012-06-131-9/+32
| | | | | | | | | | | | | This will help make code clearer when we'll add support for other message types. The patch also changes return value from -EINVAL to 0 in case of end-of-records. The exact value doesn't matter for pstore (it should be just <= 0), but 0 feels more correct. 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>
* pstore/ram: Factor dmesg przs initialization out of probe()Anton Vorontsov2012-06-131-37/+62
| | | | | | | | | | | | | | | | This will help make code clearer when we'll add support for other message types. This also makes probe() much shorter and understandable, plus makes mem/record size checking a bit easier. Implementation detail: we now use a paddr pointer, this will be used for allocating persistent ram zones for other message types. 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>
* pstore/ram: Give proper names to dump-related variablesAnton Vorontsov2012-06-131-17/+17
| | | | | | | | | We're about to add support for other message types, so let's rename some variables to not be confused later. 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>
* pstore/ram: Should zap persistent zone on unlinkAnton Vorontsov2012-06-131-0/+1
| | | | | | | | | Otherwise, unlinked file will reappear on the next boot. Reported-by: Kees Cook <keescook@chromium.org> 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>
* pstore/ram: Should update old dmesg buffer before readingAnton Vorontsov2012-06-131-0/+2
| | | | | | | | | | | | | | | 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>
* pstore/ram: Add ECC supportAnton Vorontsov2012-05-171-3/+12
| | | | | | | | | | This is now straightforward: just introduce a module parameter and pass the needed value to persistent_ram_new(). Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Marco Stornelli <marco.stornelli@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pstore/ram: Switch to persistent_ram routinesAnton Vorontsov2012-05-171-47/+59
| | | | | | | | | The patch switches pstore RAM backend to use persistent_ram routines, one step closer to the ECC support. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Marco Stornelli <marco.stornelli@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ramoops: Move to fs/pstore/ram.cAnton Vorontsov2012-05-161-0/+362
Since ramoops was converted to pstore, it has nothing to do with character devices nowadays. Instead, today it is just a RAM backend for pstore. The patch just moves things around. There are a few changes were needed because of the move: 1. Kconfig and Makefiles fixups, of course. 2. In pstore/ram.c we have to play a bit with MODULE_PARAM_PREFIX, this is needed to keep user experience the same as with ramoops driver (i.e. so that ramoops.foo kernel command line arguments would still work). Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Marco Stornelli <marco.stornelli@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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