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* pstore: Add mem_type property DT parsing supportMukesh Ojha2021-03-311-2/+16
| | | | | | | | | | | | | | | | | | There could be a scenario where we define some region in normal memory and use them store to logs which is later retrieved by bootloader during warm reset. In this scenario, we wanted to treat this memory as normal cacheable memory instead of default behaviour which is an overhead. Making it cacheable could improve performance. This commit gives control to change mem_type from Device tree, and also documents the value for normal memory. Signed-off-by: Mukesh Ojha <mojha@codeaurora.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/1616438537-13719-1-git-send-email-mojha@codeaurora.org
* pstore/ram: Rate-limit "uncorrectable error in header" messageDmitry Osipenko2021-03-021-1/+1
| | | | | | | | | | | | There is a quite huge "uncorrectable error in header" flood in KMSG on a clean system boot since there is no pstore buffer saved in RAM. Let's silence the redundant noisy messages by rate-limiting the printk message. Now there are maximum 10 messages printed repeatedly instead of 35+. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210302095850.30894-1-digetx@gmail.com
* pstore: switch to copy_from_user()Al Viro2020-04-231-3/+1
| | | | | | don't bother trying to do bulk access_ok() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* pstore/ram: Replace zero-length array with flexible-array memberGustavo A. R. Silva2020-03-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Link: https://lore.kernel.org/r/20200309202327.GA8813@embeddedor Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore/ram: Regularize prz label allocation lifetimeKees Cook2020-01-081-1/+1
| | | | | | | | | | | | | | | | | | | In my attempt to fix a memory leak, I introduced a double-free in the pstore error path. Instead of trying to manage the allocation lifetime between persistent_ram_new() and its callers, adjust the logic so persistent_ram_new() always takes a kstrdup() copy, and leaves the caller's allocation lifetime up to the caller. Therefore callers are _always_ responsible for freeing their label. Before, it only needed freeing when the prz itself failed to allocate, and not in any of the other prz failure cases, which callers would have no visibility into, which is the root design problem that lead to both the leak and now double-free bugs. Reported-by: Cengiz Can <cengiz@kernel.wtf> Link: https://lore.kernel.org/lkml/d4ec59002ede4aaf9928c7f7526da87c@kernel.wtf Fixes: 8df955a32a73 ("pstore/ram: Fix error-path memory leak in persistent_ram_new() callers") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282Thomas Gleixner2019-06-051-10/+1
| | | | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this software is licensed under the terms of the gnu general public license version 2 as published by the free software foundation and may be copied distributed and modified under those terms this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 285 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Remove 'type' argument from access_ok() functionLinus Torvalds2019-01-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pstore/ram: Do not treat empty buffers as validJoel Fernandes (Google)2018-12-031-0/+5
| | | | | | | | | | | | | | | | | | | | | | | The ramoops backend currently calls persistent_ram_save_old() even if a buffer is empty. While this appears to work, it is does not seem like the right thing to do and could lead to future bugs so lets avoid that. It also prevents misleading prints in the logs which claim the buffer is valid. I got something like: found existing buffer, size 0, start 0 When I was expecting: no valid data in buffer (sig = ...) This bails out early (and reports with pr_debug()), since it's an acceptable state. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore: Improve and update some comments and status outputKees Cook2018-12-031-1/+3
| | | | | | | | | | | | This improves and updates some comments: - dump handler comment out of sync from calling convention - fix kern-doc typo and improves status output: - reminder that only kernel crash dumps are compressed - do not be silent about ECC infrastructure failures Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore/ram: Add kern-doc for struct persistent_ram_zoneKees Cook2018-12-031-0/+10
| | | | | | | The struct persistent_ram_zone wasn't well documented. This adds kern-doc for it. Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore/ram: Report backend assignments with finer granularityKees Cook2018-12-031-0/+6
| | | | | | | | | | | In order to more easily perform automated regression testing, this adds pr_debug() calls to report each prz allocation which can then be verified against persistent storage. Specifically, seeing the dividing line between header, data, any ECC bytes. (And the general assignment output is updated to remove the bogus ECC blocksize which isn't actually recorded outside the prz instance.) Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore/ram: Standardize module name in ramoopsKees Cook2018-12-031-2/+3
| | | | | | | | | With both ram.c and ram_core.c built into ramoops.ko, it doesn't make sense to have differing pr_fmt prefixes. This fixes ram_core.c to use the module name (as ram.c already does). Additionally improves region reservation error to include the region name. Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore: Avoid duplicate call of persistent_ram_zap()Peng Wang2018-12-031-6/+9
| | | | | | | | | | | | | | | | | When initialing a prz, if invalid data is found (no PERSISTENT_RAM_SIG), the function call path looks like this: ramoops_init_prz -> persistent_ram_new -> persistent_ram_post_init -> persistent_ram_zap persistent_ram_zap As we can see, persistent_ram_zap() is called twice. We can avoid this by adding an option to persistent_ram_new(), and only call persistent_ram_zap() when it is needed. Signed-off-by: Peng Wang <wangpeng15@xiaomi.com> [kees: minor tweak to exit path and commit log] Signed-off-by: Kees Cook <keescook@chromium.org>
* Merge tag 'pstore-v4.20-rc1' of ↵Linus Torvalds2018-10-241-4/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull pstore updates from Kees Cook: "pstore improvements: - refactor init to happen as early as possible again (Joel Fernandes) - improve resource reservation names" * tag 'pstore-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: pstore/ram: Clarify resource reservation labels pstore: Refactor compression initialization pstore: Allocate compression during late_initcall() pstore: Centralize init/exit routines
| * pstore/ram: Clarify resource reservation labelsKees Cook2018-10-221-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When ramoops reserved a memory region in the kernel, it had an unhelpful label of "persistent_memory". When reading /proc/iomem, it would be repeated many times, did not hint that it was ramoops in particular, and didn't clarify very much about what each was used for: 400000000-407ffffff : Persistent Memory (legacy) 400000000-400000fff : persistent_memory 400001000-400001fff : persistent_memory ... 4000ff000-4000fffff : persistent_memory Instead, this adds meaningful labels for how the various regions are being used: 400000000-407ffffff : Persistent Memory (legacy) 400000000-400000fff : ramoops:dump(0/252) 400001000-400001fff : ramoops:dump(1/252) ... 4000fc000-4000fcfff : ramoops:dump(252/252) 4000fd000-4000fdfff : ramoops:console 4000fe000-4000fe3ff : ramoops:ftrace(0/3) 4000fe400-4000fe7ff : ramoops:ftrace(1/3) 4000fe800-4000febff : ramoops:ftrace(2/3) 4000fec00-4000fefff : ramoops:ftrace(3/3) 4000ff000-4000fffff : ramoops:pmsg Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Tested-by: Guenter Roeck <groeck@chromium.org>
* | pstore: Fix incorrect persistent ram buffer mappingBin Yang2018-09-131-3/+14
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | persistent_ram_vmap() returns the page start vaddr. persistent_ram_iomap() supports non-page-aligned mapping. persistent_ram_buffer_map() always adds offset-in-page to the vaddr returned from these two functions, which causes incorrect mapping of non-page-aligned persistent ram buffer. By default ftrace_size is 4096 and max_ftrace_cnt is nr_cpu_ids. Without this patch, the zone_sz in ramoops_init_przs() is 4096/nr_cpu_ids which might not be page aligned. If the offset-in-page > 2048, the vaddr will be in next page. If the next page is not mapped, it will cause kernel panic: [ 0.074231] BUG: unable to handle kernel paging request at ffffa19e0081b000 ... [ 0.075000] RIP: 0010:persistent_ram_new+0x1f8/0x39f ... [ 0.075000] Call Trace: [ 0.075000] ramoops_init_przs.part.10.constprop.15+0x105/0x260 [ 0.075000] ramoops_probe+0x232/0x3a0 [ 0.075000] platform_drv_probe+0x3e/0xa0 [ 0.075000] driver_probe_device+0x2cd/0x400 [ 0.075000] __driver_attach+0xe4/0x110 [ 0.075000] ? driver_probe_device+0x400/0x400 [ 0.075000] bus_for_each_dev+0x70/0xa0 [ 0.075000] driver_attach+0x1e/0x20 [ 0.075000] bus_add_driver+0x159/0x230 [ 0.075000] ? do_early_param+0x95/0x95 [ 0.075000] driver_register+0x70/0xc0 [ 0.075000] ? init_pstore_fs+0x4d/0x4d [ 0.075000] __platform_driver_register+0x36/0x40 [ 0.075000] ramoops_init+0x12f/0x131 [ 0.075000] do_one_initcall+0x4d/0x12c [ 0.075000] ? do_early_param+0x95/0x95 [ 0.075000] kernel_init_freeable+0x19b/0x222 [ 0.075000] ? rest_init+0xbb/0xbb [ 0.075000] kernel_init+0xe/0xfc [ 0.075000] ret_from_fork+0x3a/0x50 Signed-off-by: Bin Yang <bin.yang@intel.com> [kees: add comments describing the mapping differences, updated commit log] Fixes: 24c3d2f342ed ("staging: android: persistent_ram: Make it possible to use memory outside of bootmem") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore/ram: Do not use stack VLA for parity workspaceKees Cook2018-03-071-7/+22
| | | | | | | | | Instead of using a stack VLA for the parity workspace, preallocate a memory region. The preallocation is done to keep from needing to perform allocations during crash dump writing, etc. This also fixes a missed release of librs on free. Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore: Use dynamic spinlock initializerKees Cook2017-03-071-1/+1
| | | | | | | | | | | The per-prz spinlock should be using the dynamic initializer so that lockdep can correctly track it. Without this, under lockdep, we get a warning at boot that the lock is in non-static memory. Fixes: 109704492ef6 ("pstore: Make spinlock per zone instead of global") Fixes: 76d5692a5803 ("pstore: Correctly initialize spinlock and flags") Signed-off-by: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org
* pstore: Correctly initialize spinlock and flagsKees Cook2017-02-131-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ram backend wasn't always initializing its spinlock correctly. Since it was coming from kzalloc memory, though, it was harmless on architectures that initialize unlocked spinlocks to 0 (at least x86 and ARM). This also fixes a possibly ignored flag setting too. When running under CONFIG_DEBUG_SPINLOCK, the following Oops was visible: [ 0.760836] persistent_ram: found existing buffer, size 29988, start 29988 [ 0.765112] persistent_ram: found existing buffer, size 30105, start 30105 [ 0.769435] persistent_ram: found existing buffer, size 118542, start 118542 [ 0.785960] persistent_ram: found existing buffer, size 0, start 0 [ 0.786098] persistent_ram: found existing buffer, size 0, start 0 [ 0.786131] pstore: using zlib compression [ 0.790716] BUG: spinlock bad magic on CPU#0, swapper/0/1 [ 0.790729] lock: 0xffffffc0d1ca9bb0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0 [ 0.790742] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.10.0-rc2+ #913 [ 0.790747] Hardware name: Google Kevin (DT) [ 0.790750] Call trace: [ 0.790768] [<ffffff900808ae88>] dump_backtrace+0x0/0x2bc [ 0.790780] [<ffffff900808b164>] show_stack+0x20/0x28 [ 0.790794] [<ffffff9008460ee0>] dump_stack+0xa4/0xcc [ 0.790809] [<ffffff9008113cfc>] spin_dump+0xe0/0xf0 [ 0.790821] [<ffffff9008113d3c>] spin_bug+0x30/0x3c [ 0.790834] [<ffffff9008113e28>] do_raw_spin_lock+0x50/0x1b8 [ 0.790846] [<ffffff9008a2d2ec>] _raw_spin_lock_irqsave+0x54/0x6c [ 0.790862] [<ffffff90083ac3b4>] buffer_size_add+0x48/0xcc [ 0.790875] [<ffffff90083acb34>] persistent_ram_write+0x60/0x11c [ 0.790888] [<ffffff90083aab1c>] ramoops_pstore_write_buf+0xd4/0x2a4 [ 0.790900] [<ffffff90083a9d3c>] pstore_console_write+0xf0/0x134 [ 0.790912] [<ffffff900811c304>] console_unlock+0x48c/0x5e8 [ 0.790923] [<ffffff900811da18>] register_console+0x3b0/0x4d4 [ 0.790935] [<ffffff90083aa7d0>] pstore_register+0x1a8/0x234 [ 0.790947] [<ffffff90083ac250>] ramoops_probe+0x6b8/0x7d4 [ 0.790961] [<ffffff90085ca548>] platform_drv_probe+0x7c/0xd0 [ 0.790972] [<ffffff90085c76ac>] driver_probe_device+0x1b4/0x3bc [ 0.790982] [<ffffff90085c7ac8>] __device_attach_driver+0xc8/0xf4 [ 0.790996] [<ffffff90085c4bfc>] bus_for_each_drv+0xb4/0xe4 [ 0.791006] [<ffffff90085c7414>] __device_attach+0xd0/0x158 [ 0.791016] [<ffffff90085c7b18>] device_initial_probe+0x24/0x30 [ 0.791026] [<ffffff90085c648c>] bus_probe_device+0x50/0xe4 [ 0.791038] [<ffffff90085c35b8>] device_add+0x3a4/0x76c [ 0.791051] [<ffffff90087d0e84>] of_device_add+0x74/0x84 [ 0.791062] [<ffffff90087d19b8>] of_platform_device_create_pdata+0xc0/0x100 [ 0.791073] [<ffffff90087d1a2c>] of_platform_device_create+0x34/0x40 [ 0.791086] [<ffffff900903c910>] of_platform_default_populate_init+0x58/0x78 [ 0.791097] [<ffffff90080831fc>] do_one_initcall+0x88/0x160 [ 0.791109] [<ffffff90090010ac>] kernel_init_freeable+0x264/0x31c [ 0.791123] [<ffffff9008a25bd0>] kernel_init+0x18/0x11c [ 0.791133] [<ffffff9008082ec0>] ret_from_fork+0x10/0x50 [ 0.793717] console [pstore-1] enabled [ 0.797845] pstore: Registered ramoops as persistent store backend [ 0.804647] ramoops: attached 0x100000@0xf7edc000, ecc: 0/0 Fixes: 663deb47880f ("pstore: Allow prz to control need for locking") Fixes: 109704492ef6 ("pstore: Make spinlock per zone instead of global") Reported-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* pstore: Allow prz to control need for lockingJoel Fernandes2016-11-151-9/+15
| | | | | | | | | | 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>
* pstore: Make spinlock per zone instead of globalJoel Fernandes2016-11-111-6/+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>
* pstore/ram: Use memcpy_fromio() to save old bufferAndrew Bresticker2016-09-081-2/+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
* pstore/ram: Use memcpy_toio instead of memcpyFurquan Shaikh2016-09-081-1/+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
* pstore/pmsg: drop bounce bufferMark Salyzyn2016-09-081-2/+45
| | | | | | | | | | | | | | 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>
* pstore/core: drop cmpxchg based updatesSebastian Andrzej Siewior2016-09-081-41/+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
* pstore-ram: Allow optional mapping with pgprot_noncachedTony Lindgren2014-12-111-9/+22
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* pstore-ram: Fix hangs by using write-combine mappingsRob Herring2014-12-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* fs/pstore/ram_core.c: replace count*size kmalloc by kmalloc_arrayFabian Frederick2014-08-081-1/+1
| | | | | | | | | | 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>
* fs/pstore: logging clean-upFabian Frederick2014-06-061-19/+17
| | | | | | | | | | | | | | | | | | | - 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>
* pstore: Fix buffer overflow while write offset equal to buffer sizeLiu ShuoX2014-03-171-2/+2
| | | | | | | | | 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>
* pstore/ram: avoid atomic accesses for ioremapped regionsRob Herring2013-06-141-2/+52
| | | | | | | | | | | | 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>
* pstore/ram: Restore ecc information blockArve Hjønnevåg2013-04-031-0/+3
| | | | | | | | | 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>
* pstore/ram: Allow specifying ecc parameters in platform dataArve Hjønnevåg2013-04-031-30/+34
| | | | | | | | | | 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>
* pstore/ram: Include ecc_size when calculating ecc_blockArve Hjønnevåg2013-04-031-1/+2
| | | | | | | | | | 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>
* pstore: remove __dev* attributes.Greg Kroah-Hartman2013-01-031-5/+4
| | | | | | | | | | | | | | | | | 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>
* pstore/ram: Make tracing log versionedAnton Vorontsov2012-07-171-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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_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 Vorontsov2012-07-171-7/+8
| | | | | | | | | | | 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>
* 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: Probe as early as possibleAnton Vorontsov2012-06-201-4/+5
| | | | | | | | | | | | | | | | | | | | | | | 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_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_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 Vorontsov2012-06-131-7/+8
| | | | | | | | | | | | | | | 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>
* staging: android: persistent_ram: Move to fs/pstore/ram_core.cAnton Vorontsov2012-05-171-0/+532
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>
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