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* pstore: remove __dev* attributes.Greg Kroah-Hartman2013-01-032-13/+10
| | | | | | | | | | | | | | | | | 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>
* lseek: the "whence" argument is called "whence"Andrew Morton2012-12-171-3/+3
| | | | | | | | | But the kernel decided to call it "origin" instead. Fix most of the sites. Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'for-v3.8' of git://git.infradead.org/users/cbou/linux-pstoreLinus Torvalds2012-12-152-12/+34
|\ | | | | | | | | | | | | | | | | | | | | | | Pull pstore update from Anton Vorontsov: "Here are just a few fixups for the pstore subsystem, nothing special this time" * tag 'for-v3.8' of git://git.infradead.org/users/cbou/linux-pstore: pstore/ftrace: Adjust for ftrace_ops->func prototype change pstore/ram: Fix bounds checks for mem_size, record_size, console_size and ftrace_size pstore/ram: Fix undefined usage of rounddown_pow_of_two(0) pstore/ram: Fixup section annotations
| * pstore/ftrace: Adjust for ftrace_ops->func prototype changeAnton Vorontsov2012-12-121-1/+3
| | | | | | | | | | | | | | | | | | | | | | This commit fixes the following warning: fs/pstore/ftrace.c:51:2: warning: initialization from incompatible pointer type [enabled by default] fs/pstore/ftrace.c:51:2: warning: (near initialization for ‘pstore_ftrace_ops.func’) [enabled by defaula Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
| * pstore/ram: Fix bounds checks for mem_size, record_size, console_size and ↵Arve Hjønnevåg2012-12-121-2/+16
| | | | | | | | | | | | | | | | | | | | | | ftrace_size The bounds check in ramoops_init_prz was incorrect and ramoops_init_przs had no check. Additionally, ramoops_init_przs allows record_size to be 0, but ramoops_pstore_write_buf would always crash in this case. Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
| * pstore/ram: Fix undefined usage of rounddown_pow_of_two(0)Maxime Bizon2012-11-171-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | record_size / console_size / ftrace_size can be 0 (this is how you disable the feature), but rounddown_pow_of_two(0) is undefined. As suggested by Kees Cook, use !is_power_of_2() as a condition to call rounddown_pow_of_two and avoid its undefined behavior on the value 0. This issue has been present since commit 1894a253 (ramoops: Move to fs/pstore/ram.c). Cc: stable@vger.kernel.org Signed-off-by: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Florian Fainelli <ffainelli@freebox.fr> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
| * pstore/ram: Fixup section annotationsHannes Reinecke2012-11-161-5/+7
| | | | | | | | | | | | | | | | | | | | | | The compiler complained about missing section annotations. Fix it. Signed-off-by: Hannes Reinecke <hare@suse.de> Cc: Colin Cross <ccross@android.com> Cc: Tony Luck <tony.luck@intel.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
* | efi_pstore: Add a sequence counter to a variable nameSeiji Aguchi2012-11-264-14/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [Issue] Currently, a variable name, which identifies each entry, consists of type, id and ctime. But if multiple events happens in a short time, a second/third event may fail to log because efi_pstore can't distinguish each event with current variable name. [Solution] A reasonable way to identify all events precisely is introducing a sequence counter to the variable name. The sequence counter has already supported in a pstore layer with "oopscount". So, this patch adds it to a variable name. Also, it is passed to read/erase callbacks of platform drivers in accordance with the modification of the variable name. <before applying this patch> a variable name of first event: dump-type0-1-12345678 a variable name of second event: dump-type0-1-12345678 type:0 id:1 ctime:12345678 If multiple events happen in a short time, efi_pstore can't distinguish them because variable names are same among them. <after applying this patch> it can be distinguishable by adding a sequence counter as follows. a variable name of first event: dump-type0-1-1-12345678 a variable name of Second event: dump-type0-1-2-12345678 type:0 id:1 sequence counter: 1(first event), 2(second event) ctime:12345678 In case of a write callback executed in pstore_console_write(), "0" is added to an argument of the write callback because it just logs all kernel messages and doesn't need to care about multiple events. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Mike Waychison <mikew@google.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* | efi_pstore: Add ctime to argument of erase callbackSeiji Aguchi2012-11-262-2/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [Issue] Currently, a variable name, which is used to identify each log entry, consists of type, id and ctime. But an erase callback does not use ctime. If efi_pstore supported just one log, type and id were enough. However, in case of supporting multiple logs, it doesn't work because it can't distinguish each entry without ctime at erasing time. <Example> As you can see below, efi_pstore can't differentiate first event from second one without ctime. a variable name of first event: dump-type0-1-12345678 a variable name of second event: dump-type0-1-23456789 type:0 id:1 ctime:12345678, 23456789 [Solution] This patch adds ctime to an argument of an erase callback. It works across reboots because ctime of pstore means the date that the record was originally stored. To do this, efi_pstore saves the ctime to variable name at writing time and passes it to pstore at reading time. Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com> Acked-by: Mike Waychison <mikew@google.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
* pstore: Fix NULL pointer dereference in console writesColin Ian King2012-11-141-1/+2
| | | | | | | | | | | | | | | Passing a NULL id causes a NULL pointer deference in writers such as erst_writer and efi_pstore_write because they expect to update this id. Pass a dummy id instead. This avoids a cascade of oopses caused when the initial pstore_console_write passes a null which in turn causes writes to the console causing further oopses in subsequent pstore_console_write calls. Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
* pstore: Avoid recursive spinlocks in the oops_in_progress caseChuansheng Liu2012-09-201-1/+7
| | | | | | | | | | Like 8250 driver, when pstore is registered as a console, to avoid recursive spinlocks when panic happening, change the spin_lock_irqsave to spin_trylock_irqsave when oops_in_progress is true. Signed-off-by: liu chuansheng <chuansheng.liu@intel.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
* pstore/ftrace: Convert to its own enable/disable debugfs knobAnton Vorontsov2012-09-064-1/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | With this patch we no longer reuse function tracer infrastructure, now we register our own tracer back-end via a debugfs knob. It's a bit more code, but that is the only downside. On the bright side we have: - Ability to make persistent_ram module removable (when needed, we can move ftrace_ops struct into a module). Note that persistent_ram is still not removable for other reasons, but with this patch it's just one thing less to worry about; - Pstore part is more isolated from the generic function tracer. We tried it already by registering our own tracer in available_tracers, but that way we're loosing ability to see the traces while we record them to pstore. This solution is somewhere in the middle: we only register "internal ftracer" back-end, but not the "front-end"; - When there is only pstore tracing enabled, the kernel will only write to the pstore buffer, omitting function tracer buffer (which, of course, still can be enabled via 'echo function > current_tracer'). Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
* pstore/ram: Add missing platform_device_unregisterJovi Zhang2012-08-311-0/+1
| | | | | | | | | We need to unregister platform device when module exit, this commit fixes the issue. Signed-off-by: Jovi Zhang <bookjovi@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
* pstore/ram: Mark ramoops_pstore_write_buf() as notraceAnton Vorontsov2012-08-041-6/+6
| | | | | | | | | | | | | write_buf() should be marked as notrace, otherwise it is prone to recursion. Though, yet the issue is never triggered in real life, because we run inside the function tracer, where ftrace does its own recurse protection. But it's still no good, plus soon we might switch to our own tracer ops, and then the issue will be fatal. So, let's fix it. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
* pstore/ram: Fix printk format warningRandy Dunlap2012-08-041-1/+1
| | | | | | | | | | Fix printk format warning (on i386) in pstore: fs/pstore/ram.c:409:3: warning: format '%lu' expects type 'long unsigned int', but argument 2 has type 'size_t' Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
* pstore/ram: Fix possible NULL dereferenceAnton Vorontsov2012-08-041-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | We can dereference 'cxt->cprz' if console and dump logging are disabled (which is unlikely, but still possible to do). This patch fixes the issue by changing the code so that we don't dereference przs at all, we can just calculate bufsize from console_size and record_size values. Plus, while at it, the patch improves the buffer size calculation. After Kay's printk rework, we know the optimal buffer size for console logging -- it is LOG_LINE_MAX (defined privately in printk.c). Previously, if only console logging was enabled, we would allocate unnecessary large buffer in pstore, while we only need LOG_LINE_MAX. (Pstore console logging is still capable of handling buffers > LOG_LINE_MAX, it will just do multiple calls to psinfo->write). Note that I don't export the constant, since we will do even a better thing soon: we will switch console logging to a new write_buf API, which will eliminate the need for the additional buffer; and so we won't need the constant. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Kees Cook <keescook@chromium.org>
* pstore/ram: Make tracing log versionedAnton Vorontsov2012-07-172-10/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Headers should include all stuff they useAnton Vorontsov2012-07-171-0/+2
| | | | | | | | | | | | | | | | | | | | | Headers should really include all the needed prototypes, types, defines etc. to be self-contained. This is a long-standing issue, but apparently the new tracing code unearthed it (SMP=n is also a prerequisite): In file included from fs/pstore/internal.h:4:0, from fs/pstore/ftrace.c:21: include/linux/pstore.h:43:15: error: field ‘read_mutex’ has incomplete type While at it, I also added the following: linux/types.h -> size_t, phys_addr_t, uXX and friends linux/spinlock.h -> spinlock_t linux/errno.h -> Exxxx linux/time.h -> struct timespec (struct passed by value) struct module and rs_control forward declaration (passed via pointers). 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: Add persistent function tracingAnton Vorontsov2012-07-176-5/+199
| | | | | | | | | | | | | | | | | | With this support kernel can save function call chain log into a persistent ram buffer that can be decoded and dumped after reboot through pstore filesystem. It can be used to determine what function was last called before a reset or panic. We store the log in a binary format and then decode it at read time. p.s. Mostly the code comes from trace_persistent.c driver found in the Android git tree, written by Colin Cross <ccross@android.com> (according to sign-off history). I reworked the driver a little bit, and ported it to pstore. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pstore: Introduce write_buf backend callbackAnton Vorontsov2012-07-171-0/+10
| | | | | | | | | | | | For function tracing we need to stop using pstore.buf directly, since in a tracing callback we can't use spinlocks, and thus we can't safely use the global buffer. With write_buf callback, backends no longer need to access pstore.buf directly, and thus we can pass any buffers (e.g. allocated on stack). Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pstore/ram_core: Get rid of prz->ecc enable/disable flagAnton Vorontsov2012-07-171-6/+4
| | | | | | | | | 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>
* pstore/ram: Make ECC size configurableAnton Vorontsov2012-07-172-15/+22
| | | | | | | | | | | 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_core: Get rid of prz->ecc_symsize and prz->ecc_polyAnton Vorontsov2012-07-171-4/+3
| | | | | | | | | | | | | | 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>
* Merge 3.5-rc4 into staging-nextGreg Kroah-Hartman2012-06-251-22/+12
|\ | | | | | | | | | | | | This picks up the staging changes made in 3.5-rc4 so that everyone can sync up properly. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * Merge tag 'staging-3.5-rc4' of ↵Linus Torvalds2012-06-203-11/+21
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging Pull staging tree fixes from Greg Kroah-Hartman: "Here are a number of small fixes for the drivers/staging tree, as well as iio and pstore drivers (which came from the staging tree in the 3.5-rc1 merge). All of these are tiny, but resolve issues that people have been reporting. There's also a documentation update to reflect what the iio drivers really are doing, which is good to get straightened out. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" * tag 'staging-3.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: staging: r8712u: Add new USB IDs staging: gdm72xx: Release netlink socket properly iio: drop wrong reference from Kconfig pstore/inode: Make pstore_fill_super() static pstore/ram: Should zap persistent zone on unlink pstore/ram_core: Factor persistent_ram_zap() out of post_init() pstore/ram_core: Do not reset restored zone's position and size pstore/ram: Should update old dmesg buffer before reading staging:iio:ad7298: Fix linker error due to missing IIO kfifo buffer Revert "staging: usbip: bugfix for stack corruption on 64-bit architectures" staging: usbip: bugfix for stack corruption on 64-bit architectures staging/comedi: fix build for USB not enabled staging: omapdrm: fix crash when freeing bad fb staging:iio:ad7606: Re-add missing scale attribute iio: Fix potential use after free staging:iio: remove num_interrupt_lines from documentation iio: documentation: Add out_altvoltage and friends
| * | kmsg - kmsg_dump() use iterator to receive log buffer contentKay Sievers2012-06-151-22/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide an iterator to receive the log buffer content, and convert all kmsg_dump() users to it. The structured data in the kmsg buffer now contains binary data, which should no longer be copied verbatim to the kmsg_dump() users. The iterator should provide reliable access to the buffer data, and also supports proper log line-aware chunking of data while iterating. Signed-off-by: Kay Sievers <kay@vrfy.org> Tested-by: Tony Luck <tony.luck@intel.com> Reported-by: Anton Vorontsov <anton.vorontsov@linaro.org> Tested-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | pstore/ram_core: Better ECC size checkingAnton Vorontsov2012-06-201-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - 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>
* | | pstore/ram_core: Proper checking for post_init errors (e.g. improper ECC size)Anton Vorontsov2012-06-201-7/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | 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 Vorontsov2012-06-202-35/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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/platform: Disable automatic updates by defaultAnton Vorontsov2012-06-131-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Having automatic updates seems pointless for production system, and even dangerous and thus counter-productive: 1. If we can mount pstore, or read files, we can as well read /proc/kmsg. So, there's little point in duplicating the functionality and present the same information but via another userland ABI; 2. Expecting the kernel to behave sanely after oops/panic is naive. It might work, but you'd rather not try it. Screwed up kernel can do rather bad things, like recursive faults[1]; and pstore rather provoking bad things to happen. It uses: 1. Timers (assumes sane interrupts state); 2. Workqueues and mutexes (assumes scheduler in a sane state); 3. kzalloc (a working slab allocator); That's too much for a dead kernel, so the debugging facility itself might just make debugging harder, which is not what we want. Maybe for non-oops message types it would make sense to re-enable automatic updates, but so far I don't see any use case for this. Even for tracing, it has its own run-time/normal ABI, so we're only interested in pstore upon next boot, to retrieve what has gone wrong with HW or SW. So, let's disable the updates by default. [1] BUG: unable to handle kernel paging request at fffffffffffffff8 IP: [<ffffffff8104801b>] kthread_data+0xb/0x20 [...] Process kworker/0:1 (pid: 14, threadinfo ffff8800072c0000, task ffff88000725b100) [... Call Trace: [<ffffffff81043710>] wq_worker_sleeping+0x10/0xa0 [<ffffffff813687a8>] __schedule+0x568/0x7d0 [<ffffffff8106c24d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff81087e22>] ? call_rcu_sched+0x12/0x20 [<ffffffff8102b596>] ? release_task+0x156/0x2d0 [<ffffffff8102b45e>] ? release_task+0x1e/0x2d0 [<ffffffff8106c24d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff81368ac4>] schedule+0x24/0x70 [<ffffffff8102cba8>] do_exit+0x1f8/0x370 [<ffffffff810051e7>] oops_end+0x77/0xb0 [<ffffffff8135c301>] no_context+0x1a6/0x1b5 [<ffffffff8135c4de>] __bad_area_nosemaphore+0x1ce/0x1ed [<ffffffff81053156>] ? ttwu_queue+0xc6/0xe0 [<ffffffff8135c50b>] bad_area_nosemaphore+0xe/0x10 [<ffffffff8101fa47>] do_page_fault+0x2c7/0x450 [<ffffffff8106e34b>] ? __lock_release+0x6b/0xe0 [<ffffffff8106bf21>] ? mark_held_locks+0x61/0x140 [<ffffffff810502fe>] ? __wake_up+0x4e/0x70 [<ffffffff81185f7d>] ? trace_hardirqs_off_thunk+0x3a/0x3c [<ffffffff81158970>] ? pstore_register+0x120/0x120 [<ffffffff8136a37f>] page_fault+0x1f/0x30 [<ffffffff81158970>] ? pstore_register+0x120/0x120 [<ffffffff81185ab8>] ? memcpy+0x68/0x110 [<ffffffff8115875a>] ? pstore_get_records+0x3a/0x130 [<ffffffff811590f4>] ? persistent_ram_copy_old+0x64/0x90 [<ffffffff81158bf4>] ramoops_pstore_read+0x84/0x130 [<ffffffff81158799>] pstore_get_records+0x79/0x130 [<ffffffff81042536>] ? process_one_work+0x116/0x450 [<ffffffff81158970>] ? pstore_register+0x120/0x120 [<ffffffff8115897e>] pstore_dowork+0xe/0x10 [<ffffffff81042594>] process_one_work+0x174/0x450 [<ffffffff81042536>] ? process_one_work+0x116/0x450 [<ffffffff81042e13>] worker_thread+0x123/0x2d0 [<ffffffff81042cf0>] ? manage_workers.isra.28+0x120/0x120 [<ffffffff81047d8e>] kthread+0x8e/0xa0 [<ffffffff8136ba74>] kernel_thread_helper+0x4/0x10 [<ffffffff8136a199>] ? retint_restore_args+0xe/0xe [<ffffffff81047d00>] ? __init_kthread_worker+0x70/0x70 [<ffffffff8136ba70>] ? gs_change+0xb/0xb Code: be e2 00 00 00 48 c7 c7 d1 2a 4e 81 e8 bf fb fd ff 48 8b 5d f0 4c 8b 65 f8 c9 c3 0f 1f 44 00 00 48 8b 87 08 02 00 00 55 48 89 e5 <48> 8b 40 f8 5d c3 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 RIP [<ffffffff8104801b>] kthread_data+0xb/0x20 RSP <ffff8800072c1888> CR2: fffffffffffffff8 ---[ end trace 996a332dc399111d ]--- Fixing recursive fault but reboot is needed! Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | pstore/platform: Make automatic updates interval configurableAnton Vorontsov2012-06-131-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | There is no behavioural change, the default value is still 60 seconds. 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_core: Remove now unused codeAnton Vorontsov2012-06-131-77/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | pstore/ram_core: Silence some printksAnton Vorontsov2012-06-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | 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: Add console log messages supportAnton Vorontsov2012-06-133-0/+47
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | Pstore doesn't support logging kernel messages in run-time, it only dumps dmesg when kernel oopses/panics. This makes pstore useless for debugging hangs caused by HW issues or improper use of HW (e.g. weird device inserted -> driver tried to write a reserved bits -> SoC hanged. In that case we don't get any messages in the pstore. Therefore, let's add a runtime logging support: PSTORE_TYPE_CONSOLE. 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>
* | pstore/inode: Make pstore_fill_super() staticAnton Vorontsov2012-06-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | There's no reason to extern it. The patch fixes the annoying sparse warning: CHECK fs/pstore/inode.c fs/pstore/inode.c:264:5: warning: symbol 'pstore_fill_super' was not declared. Should it be static? 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_core: Factor persistent_ram_zap() out of post_init()Anton Vorontsov2012-06-131-3/+8
| | | | | | | | | | | | | | | | | | 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>
* | pstore/ram_core: Do not reset restored zone's position and sizeAnton Vorontsov2012-06-131-0/+1
| | | | | | | | | | | | | | | | 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>
* | pstore/ram: Should update old dmesg buffer before readingAnton Vorontsov2012-06-132-7/+10
|/ | | | | | | | | | | | | | | 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>
* Merge tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linuxLinus Torvalds2012-05-281-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull writeback tree from Wu Fengguang: "Mainly from Jan Kara to avoid iput() in the flusher threads." * tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: Avoid iput() from flusher thread vfs: Rename end_writeback() to clear_inode() vfs: Move waiting for inode writeback from end_writeback() to evict_inode() writeback: Refactor writeback_single_inode() writeback: Remove wb->list_lock from writeback_single_inode() writeback: Separate inode requeueing after writeback writeback: Move I_DIRTY_PAGES handling writeback: Move requeueing when I_SYNC set to writeback_sb_inodes() writeback: Move clearing of I_SYNC into inode_sync_complete() writeback: initialize global_dirty_limit fs: remove 8 bytes of padding from struct writeback_control on 64 bit builds mm: page-writeback.c: local functions should not be exposed globally
| * vfs: Rename end_writeback() to clear_inode()Jan Kara2012-05-061-1/+1
| | | | | | | | | | | | | | | | | | After we moved inode_sync_wait() from end_writeback() it doesn't make sense to call the function end_writeback() anymore. Rename it to clear_inode() which well says what the function really does - set I_CLEAR flag. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
* | 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>
generated by cgit v1.1 at 2024-12-26 22:28:41 +0000