- 19 May, 2017 1 commit
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Petr Mladek authored
The commit 42a0bb3f ("printk/nmi: generic solution for safe printk in NMI") caused that printk stores messages into a temporary buffer in NMI context. The buffer is per-CPU and therefore the size is rather limited. It works quite well for NMI backtraces. But there are longer logs that might get printed in NMI context, for example, lockdep warnings, ftrace_dump_on_oops. The temporary buffer is used to avoid deadlocks caused by logbuf_lock. Also it is needed to avoid races with the other temporary buffer that is used when PRINTK_SAFE_CONTEXT is entered. But the main buffer can be used in NMI if the lock is available and we did not interrupt PRINTK_SAFE_CONTEXT. The lock is checked using raw_spin_is_locked(). It might cause false negatives when the lock is taken on another CPU and this CPU is in the safe context from other reasons. Note that the safe context is used also to get console semaphore or when calling console drivers. For this reason, we do the check in printk_nmi_enter(). It makes the handling consistent for the entire NMI handler and avoids reshuffling of the messages. The patch also defines special printk context that allows to use printk_deferred() in NMI. Note that we could not flush the messages to the consoles because console drivers might use many other internal locks. The newly created vprintk_deferred() disables the preemption only around the irq work handling. It is needed there to keep the consistency between the two per-CPU variables. But there is no reason to disable preemption around vprintk_emit(). Finally, the patch puts back explicit serialization of the NMI backtraces from different CPUs. It was removed by the commit a9edc880 ("x86/nmi: Perform a safe NMI stack trace on all CPUs"). It was not needed because the flushing of the temporary per-CPU buffers was serialized. Link: http://lkml.kernel.org/r/1493912763-24873-1-git-send-email-pmladek@suse.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <rack+kernel@arm.linux.org.uk> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: x86@kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Suggested-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by:
Petr Mladek <pmladek@suse.com>
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- 04 May, 2017 2 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printkLinus Torvalds authored
Pull printk updates from Petr Mladek: - There is a situation when early console is not deregistered because the preferred one matches a wrong entry. It caused messages to appear twice. This is the 2nd attempt to fix it. The first one was wrong, see the commit c6c7d83b ('Revert "console: don't prefer first registered if DT specifies stdout-path"'). The fix is coupled with some small code clean up. Well, the console registration code would deserve a big one. We need to think about it. - Do not lose information about the preemtive context when the console semaphore is re-taken. - Do not block CPU hotplug when someone else is already pushing messages to the console. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: printk: fix double printing with earlycon printk: rename selected_console -> preferred_console printk: fix name/type/scope of preferred_console var printk: Correctly handle preemption in console_unlock() printk: use console_trylock() in console_cpu_notify()
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Linus Torvalds authored
Merge misc updates from Andrew Morton: - a few misc things - most of MM - KASAN updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (102 commits) kasan: separate report parts by empty lines kasan: improve double-free report format kasan: print page description after stacks kasan: improve slab object description kasan: change report header kasan: simplify address description logic kasan: change allocation and freeing stack traces headers kasan: unify report headers kasan: introduce helper functions for determining bug type mm: hwpoison: call shake_page() after try_to_unmap() for mlocked page mm: hwpoison: call shake_page() unconditionally mm/swapfile.c: fix swap space leak in error path of swap_free_entries() mm/gup.c: fix access_ok() argument type mm/truncate: avoid pointless cleancache_invalidate_inode() calls. mm/truncate: bail out early from invalidate_inode_pages2_range() if mapping is empty fs/block_dev: always invalidate cleancache in invalidate_bdev() fs: fix data invalidation in the cleancache during direct IO zram: reduce load operation in page_same_filled zram: use zram_free_page instead of open-coded zram: introduce zram data accessor ...
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- 03 May, 2017 37 commits
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Andrey Konovalov authored
Makes the report easier to read. Link: http://lkml.kernel.org/r/20170302134851.101218-10-andreyknvl@google.comSigned-off-by:
Andrey Konovalov <andreyknvl@google.com> Acked-by:
Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Andrey Konovalov authored
Changes double-free report header from BUG: Double free or freeing an invalid pointer Unexpected shadow byte: 0xFB to BUG: KASAN: double-free or invalid-free in kmalloc_oob_left+0xe5/0xef This makes a bug uniquely identifiable by the first report line. To account for removing of the unexpected shadow value, print shadow bytes at the end of the report as in reports for other kinds of bugs. Link: http://lkml.kernel.org/r/20170302134851.101218-9-andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
Moves page description after the stacks since it's less important. Link: http://lkml.kernel.org/r/20170302134851.101218-8-andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
Changes slab object description from: Object at ffff880068388540, in cache kmalloc-128 size: 128 to: The buggy address belongs to the object at ffff880068388540 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 123 bytes inside of 128-byte region [ffff880068388540, ffff8800683885c0) Makes it more explanatory and adds information about relative offset of the accessed address to the start of the object. Link: http://lkml.kernel.org/r/20170302134851.101218-7-andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
Change report header format from: BUG: KASAN: use-after-free in unwind_get_return_address+0x28a/0x2c0 at addr ffff880069437950 Read of size 8 by task insmod/3925 to: BUG: KASAN: use-after-free in unwind_get_return_address+0x28a/0x2c0 Read of size 8 at addr ffff880069437950 by task insmod/3925 The exact access address is not usually important, so move it to the second line. This also makes the header look visually balanced. Link: http://lkml.kernel.org/r/20170302134851.101218-6-andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
Simplify logic for describing a memory address. Add addr_to_page() helper function. Makes the code easier to follow. Link: http://lkml.kernel.org/r/20170302134851.101218-5-andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
Change stack traces headers from: Allocated: PID = 42 to: Allocated by task 42: Makes the report one line shorter and look better. Link: http://lkml.kernel.org/r/20170302134851.101218-4-andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
Unify KASAN report header format for different kinds of bad memory accesses. Makes the code simpler. Link: http://lkml.kernel.org/r/20170302134851.101218-3-andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
Patch series "kasan: improve error reports", v2. This patchset improves KASAN reports by making them easier to read and a little more detailed. Also improves mm/kasan/report.c readability. Effectively changes a use-after-free report to: ================================================================== BUG: KASAN: use-after-free in kmalloc_uaf+0xaa/0xb6 [test_kasan] Write of size 1 at addr ffff88006aa59da8 by task insmod/3951 CPU: 1 PID: 3951 Comm: insmod Tainted: G B 4.10.0+ #84 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x292/0x398 print_address_description+0x73/0x280 kasan_report.part.2+0x207/0x2f0 __asan_report_store1_noabort+0x2c/0x30 kmalloc_uaf+0xaa/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x7f22cfd0b9da RSP: 002b:00007ffe69118a78 EFLAGS: 00000206 ORIG_RAX: 00000000000000af RAX: ffffffffffffffda RBX: 0000555671242090 RCX: 00007f22cfd0b9da RDX: 00007f22cffcaf88 RSI: 000000000004df7e RDI: 00007f22d0399000 RBP: 00007f22cffcaf88 R08: 0000000000000003 R09: 0000000000000000 R10: 00007f22cfd07d0a R11: 0000000000000206 R12: 0000555671243190 R13: 000000000001fe81 R14: 0000000000000000 R15: 0000000000000004 Allocated by task 3951: save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_kmalloc+0xad/0xe0 kmem_cache_alloc_trace+0x82/0x270 kmalloc_uaf+0x56/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 Freed by task 3951: save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_slab_free+0x72/0xc0 kfree+0xe8/0x2b0 kmalloc_uaf+0x85/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc The buggy address belongs to the object at ffff88006aa59da0 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 8 bytes inside of 16-byte region [ffff88006aa59da0, ffff88006aa59db0) The buggy address belongs to the page: page:ffffea0001aa9640 count:1 mapcount:0 mapping: (null) index:0x0 flags: 0x100000000000100(slab) raw: 0100000000000100 0000000000000000 0000000000000000 0000000180800080 raw: ffffea0001abe380 0000000700000007 ffff88006c401b40 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88006aa59c80: 00 00 fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc ffff88006aa59d00: 00 00 fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc >ffff88006aa59d80: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ^ ffff88006aa59e00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ffff88006aa59e80: fb fb fc fc 00 00 fc fc 00 00 fc fc 00 00 fc fc ================================================================== from: ================================================================== BUG: KASAN: use-after-free in kmalloc_uaf+0xaa/0xb6 [test_kasan] at addr ffff88006c4dcb28 Write of size 1 by task insmod/3984 CPU: 1 PID: 3984 Comm: insmod Tainted: G B 4.10.0+ #83 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x292/0x398 kasan_object_err+0x1c/0x70 kasan_report.part.1+0x20e/0x4e0 __asan_report_store1_noabort+0x2c/0x30 kmalloc_uaf+0xaa/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 RIP: 0033:0x7feca0f779da RSP: 002b:00007ffdfeae5218 EFLAGS: 00000206 ORIG_RAX: 00000000000000af RAX: ffffffffffffffda RBX: 000055a064c13090 RCX: 00007feca0f779da RDX: 00007feca1236f88 RSI: 000000000004df7e RDI: 00007feca1605000 RBP: 00007feca1236f88 R08: 0000000000000003 R09: 0000000000000000 R10: 00007feca0f73d0a R11: 0000000000000206 R12: 000055a064c14190 R13: 000000000001fe81 R14: 0000000000000000 R15: 0000000000000004 Object at ffff88006c4dcb20, in cache kmalloc-16 size: 16 Allocated: PID = 3984 save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_kmalloc+0xad/0xe0 kmem_cache_alloc_trace+0x82/0x270 kmalloc_uaf+0x56/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 Freed: PID = 3984 save_stack_trace+0x16/0x20 save_stack+0x43/0xd0 kasan_slab_free+0x73/0xc0 kfree+0xe8/0x2b0 kmalloc_uaf+0x85/0xb6 [test_kasan] kmalloc_tests_init+0x4f/0xa48 [test_kasan] do_one_initcall+0xf3/0x390 do_init_module+0x215/0x5d0 load_module+0x54de/0x82b0 SYSC_init_module+0x3be/0x430 SyS_init_module+0x9/0x10 entry_SYSCALL_64_fastpath+0x1f/0xc2 Memory state around the buggy address: ffff88006c4dca00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ffff88006c4dca80: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc >ffff88006c4dcb00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ^ ffff88006c4dcb80: fb fb fc fc 00 00 fc fc fb fb fc fc fb fb fc fc ffff88006c4dcc00: fb fb fc fc fb fb fc fc fb fb fc fc fb fb fc fc ================================================================== This patch (of 9): Introduce get_shadow_bug_type() function, which determines bug type based on the shadow value for a particular kernel address. Introduce get_wild_bug_type() function, which determines bug type for addresses which don't have a corresponding shadow value. Link: http://lkml.kernel.org/r/20170302134851.101218-2-andreyknvl@google.comSigned-off-by: -
Naoya Horiguchi authored
Memory error handler calls try_to_unmap() for error pages in various states. If the error page is a mlocked page, error handling could fail with "still referenced by 1 users" message. This is because the page is linked to and stays in lru cache after the following call chain. try_to_unmap_one page_remove_rmap clear_page_mlock putback_lru_page lru_cache_add memory_failure() calls shake_page() to hanlde the similar issue, but current code doesn't cover because shake_page() is called only before try_to_unmap(). So this patches adds shake_page(). Fixes: 23a003bf ("mm/madvise: pass return code of memory_failure() to userspace") Link: http://lkml.kernel.org/r/20170417055948.GM31394@yexl-desktop Link: http://lkml.kernel.org/r/1493197841-23986-3-git-send-email-n-horiguchi@ah.jp.nec.comSigned-off-by:Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by:
kernel test robot <lkp@intel.com> Cc: Xiaolong Ye <xiaolong.ye@intel.com> Cc: Chen Gong <gong.chen@linux.intel.com> Signed-off-by:
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Naoya Horiguchi authored
shake_page() is called before going into core error handling code in order to ensure that the error page is flushed from lru_cache lists where pages stay during transferring among LRU lists. But currently it's not fully functional because when the page is linked to lru_cache by calling activate_page(), its PageLRU flag is set and shake_page() is skipped. The result is to fail error handling with "still referenced by 1 users" message. When the page is linked to lru_cache by isolate_lru_page(), its PageLRU is clear, so that's fine. This patch makes shake_page() unconditionally called to avoild the failure. Fixes: 23a003bf ("mm/madvise: pass return code of memory_failure() to userspace") Link: http://lkml.kernel.org/r/20170417055948.GM31394@yexl-desktop Link: http://lkml.kernel.org/r/1493197841-23986-2-git-send-email-n-horiguchi@ah.jp.nec.comSigned-off-by:
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Huang Ying authored
In swapcache_free_entries(), if swap_info_get_cont() returns NULL, something wrong occurs for the swap entry. But we should still continue to free the following swap entries in the array instead of skip them to avoid swap space leak. This is just problem in error path, where system may be in an inconsistent state, but it is still good to fix it. Link: http://lkml.kernel.org/r/20170421124739.24534-1-ying.huang@intel.comSigned-off-by:
"Huang, Ying" <ying.huang@intel.com> Acked-by:
Tim Chen <tim.c.chen@linux.intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by:
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Arnd Bergmann authored
MIPS just got changed to only accept a pointer argument for access_ok(), causing one warning in drivers/scsi/pmcraid.c. I tried changing x86 the same way and found the same warning in __get_user_pages_fast() and nowhere else in the kernel during randconfig testing: mm/gup.c: In function '__get_user_pages_fast': mm/gup.c:1578:6: error: passing argument 1 of '__chk_range_not_ok' makes pointer from integer without a cast [-Werror=int-conversion] It would probably be a good idea to enforce type-safety in general, so let's change this file to not cause a warning if we do that. I don't know why the warning did not appear on MIPS. Fixes: 2667f50e ("mm: introduce a general RCU get_user_pages_fast()") Link: http://lkml.kernel.org/r/20170421162659.3314521-1-arnd@arndb.deSigned-off-by:
Arnd Bergmann <arnd@arndb.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Acked-by:
Ingo Molnar <mingo@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Signed-off-by:
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Andrey Ryabinin authored
cleancache_invalidate_inode() called truncate_inode_pages_range() and invalidate_inode_pages2_range() twice - on entry and on exit. It's stupid and waste of time. It's enough to call it once at exit. Link: http://lkml.kernel.org/r/20170424164135.22350-5-aryabinin@virtuozzo.comSigned-off-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by:
Jan Kara <jack@suse.cz> Acked-by:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexey Kuznetsov <kuznet@virtuozzo.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Nikolay Borisov <n.borisov.lkml@gmail.com> Signed-off-by:
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Andrey Ryabinin authored
If mapping is empty (both ->nrpages and ->nrexceptional is zero) we can avoid pointless lookups in empty radix tree and bail out immediately after cleancache invalidation. Link: http://lkml.kernel.org/r/20170424164135.22350-4-aryabinin@virtuozzo.comSigned-off-by:
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Andrey Ryabinin authored
invalidate_bdev() calls cleancache_invalidate_inode() iff ->nrpages != 0 which doen't make any sense. Make sure that invalidate_bdev() always calls cleancache_invalidate_inode() regardless of mapping->nrpages value. Fixes: c515e1fd ("mm/fs: add hooks to support cleancache") Link: http://lkml.kernel.org/r/20170424164135.22350-3-aryabinin@virtuozzo.comSigned-off-by:
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Andrey Ryabinin authored
Patch series "Properly invalidate data in the cleancache", v2. We've noticed that after direct IO write, buffered read sometimes gets stale data which is coming from the cleancache. The reason for this is that some direct write hooks call call invalidate_inode_pages2[_range]() conditionally iff mapping->nrpages is not zero, so we may not invalidate data in the cleancache. Another odd thing is that we check only for ->nrpages and don't check for ->nrexceptional, but invalidate_inode_pages2[_range] also invalidates exceptional entries as well. So we invalidate exceptional entries only if ->nrpages != 0? This doesn't feel right. - Patch 1 fixes direct IO writes by removing ->nrpages check. - Patch 2 fixes similar case in invalidate_bdev(). Note: I only fixed conditional cleancache_invalidate_inode() here. Do we also need to add ->nrexceptional check in into invalidate_bdev()? - Patches 3-4: some optimizations. This patch (of 4): Some direct IO write fs hooks call invalidate_inode_pages2[_range]() conditionally iff mapping->nrpages is not zero. This can't be right, because invalidate_inode_pages2[_range]() also invalidate data in the cleancache via cleancache_invalidate_inode() call. So if page cache is empty but there is some data in the cleancache, buffered read after direct IO write would get stale data from the cleancache. Also it doesn't feel right to check only for ->nrpages because invalidate_inode_pages2[_range] invalidates exceptional entries as well. Fix this by calling invalidate_inode_pages2[_range]() regardless of nrpages state. Note: nfs,cifs,9p doesn't need similar fix because the never call cleancache_get_page() (nor directly, nor via mpage_readpage[s]()), so they are not affected by this bug. Fixes: c515e1fd ("mm/fs: add hooks to support cleancache") Link: http://lkml.kernel.org/r/20170424164135.22350-2-aryabinin@virtuozzo.comSigned-off-by: -
Sangwoo Park authored
In page_same_filled function, all elements in the page is compared with next index value. The current comparison routine compares the (i)th and (i+1)th values of the page. In this case, two load operaions occur for each comparison. But if we store first value of the page stores at 'val' variable and using it to compare with others, the load opearation is reduced. It reduce load operation per page by up to 64times. Link: http://lkml.kernel.org/r/1488428104-7257-1-git-send-email-sangwoo2.park@lge.comSigned-off-by:
Sangwoo Park <sangwoo2.park@lge.com> Reviewed-by:
Minchan Kim <minchan@kernel.org> Signed-off-by:
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Minchan Kim authored
The zram_free_page already handles NULL handle case and same page so use it to reduce error probability. (Acutaully, I made a mistake when I handled same page feature) Link: http://lkml.kernel.org/r/1492052365-16169-7-git-send-email-minchan@kernel.orgSigned-off-by:
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Minchan Kim authored
With element, sometime I got confused handle and element access. It might be my bad but I think it's time to introduce accessor to prevent future idiot like me. This patch is just clean-up patch so it shouldn't change any behavior. Link: http://lkml.kernel.org/r/1492052365-16169-6-git-send-email-minchan@kernel.orgSigned-off-by:
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Minchan Kim authored
It's redundant now. Instead, remove it and use zram structure directly. Link: http://lkml.kernel.org/r/1492052365-16169-5-git-send-email-minchan@kernel.orgSigned-off-by:
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Minchan Kim authored
With this clean-up phase, I want to use zram's wrapper function to lock table access which is more consistent with other zram's functions. Link: http://lkml.kernel.org/r/1492052365-16169-4-git-send-email-minchan@kernel.orgSigned-off-by:
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Minchan Kim authored
For architecture(PAGE_SIZE > 4K), zram have supported partial IO. However, the mixed code for handling normal/partial IO is too mess, error-prone to modify IO handler functions with upcoming feature so this patch aims for cleaning up zram's IO handling functions. Link: http://lkml.kernel.org/r/1492052365-16169-3-git-send-email-minchan@kernel.orgSigned-off-by:
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Minchan Kim authored
Patch series "zram clean up", v2. This patchset aims to clean up zram . [1] clean up multiple pages's bvec handling. [2] clean up partial IO handling [3-6] clean up zram via using accessor and removing pointless structure. With [2-6] applied, we can get a few hundred bytes as well as huge readibility enhance. x86: 708 byte save add/remove: 1/1 grow/shrink: 0/11 up/down: 478/-1186 (-708) function old new delta zram_special_page_read - 478 +478 zram_reset_device 317 314 -3 mem_used_max_store 131 128 -3 compact_store 96 93 -3 mm_stat_show 203 197 -6 zram_add 719 712 -7 zram_slot_free_notify 229 214 -15 zram_make_request 819 803 -16 zram_meta_free 128 111 -17 zram_free_page 180 151 -29 disksize_store 432 361 -71 zram_decompress_page.isra 504 - -504 zram_bvec_rw 2592 2080 -512 Total: Before=25350773, After=25350065, chg -0.00% ppc64: 231 byte save add/remove: 2/0 grow/shrink: 1/9 up/down: 681/-912 (-231) function old new delta zram_special_page_read - 480 +480 zram_slot_lock - 200 +200 vermagic 39 40 +1 mm_stat_show 256 248 -8 zram_meta_free 200 184 -16 zram_add 944 912 -32 zram_free_page 348 308 -40 disksize_store 572 492 -80 zram_decompress_page 664 564 -100 zram_slot_free_notify 292 160 -132 zram_make_request 1132 1000 -132 zram_bvec_rw 2768 2396 -372 Total: Before=17565825, After=17565594, chg -0.00% This patch (of 6): Johannes Thumshirn reported system goes the panic when using NVMe over Fabrics loopback target with zram. The reason is zram expects each bvec in bio contains a single page but nvme can attach a huge bulk of pages attached to the bio's bvec so that zram's index arithmetic could be wrong so that out-of-bound access makes system panic. [1] in mainline solved solved the problem by limiting max_sectors with SECTORS_PER_PAGE but it makes zram slow because bio should split with each pages so this patch makes zram aware of multiple pages in a bvec so it could solve without any regression(ie, bio split). [1] 0bc31538, zram: set physical queue limits to avoid array out of bounds accesses Link: http://lkml.kernel.org/r/20170413134057.GA27499@bboxSigned-off-by:Johannes Thumshirn <jthumshirn@suse.de> Tested-by:
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Tetsuo Handa authored
Commit c0a32fc5 ("mm: more intensive memory corruption debugging") changed to check debug_guardpage_minorder() > 0 when reporting allocation failures. The reasoning was When we use guard page to debug memory corruption, it shrinks available pages to 1/2, 1/4, 1/8 and so on, depending on parameter value. In such case memory allocation failures can be common and printing errors can flood dmesg. If somebody debug corruption, allocation failures are not the things he/she is interested about. but this is misguided. Allocation requests with __GFP_NOWARN flag by definition do not cause flooding of allocation failure messages. Allocation requests with __GFP_NORETRY flag likely also have __GFP_NOWARN flag. Costly allocation requests likely also have __GFP_NOWARN flag. Allocation requests without __GFP_DIRECT_RECLAIM flag likely also have __GFP_NOWARN flag or __GFP_HIGH flag. Non-costly allocation requests with __GFP_DIRECT_RECLAIM flag basically retry forever due to the "too small to fail" memory-allocation rule. Therefore, as a whole, shrinking available pages by debug_guardpage_minorder= kernel boot parameter might cause flooding of OOM killer messages but unlikely causes flooding of allocation failure messages. Let's remove debug_guardpage_minorder() > 0 check which would likely be pointless. Link: http://lkml.kernel.org/r/1491910035-4231-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jpSigned-off-by:
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by:
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Anshuman Khandual authored
It helps to provide page flag description along with the raw value in error paths during soft offline process. From sample experiments Before the patch: soft offline: 0x6100: migration failed 1, type 3ffff800008018 soft offline: 0x7400: migration failed 1, type 3ffff800008018 After the patch: soft offline: 0x5900: migration failed 1, type 3ffff800008018 (uptodate|dirty|head) soft offline: 0x6c00: migration failed 1, type 3ffff800008018 (uptodate|dirty|head) Link: http://lkml.kernel.org/r/20170409023829.10788-1-khandual@linux.vnet.ibm.comSigned-off-by:
Anshuman Khandual <khandual@linux.vnet.ibm.com> Acked-by:
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Anshuman Khandual authored
madvise_behavior_valid() should be called before acting upon the behavior parameter. Hence move up the function. This also includes MADV_SOFT_OFFLINE and MADV_HWPOISON options as valid behavior parameter for the system call madvise(). Link: http://lkml.kernel.org/r/20170418052844.24891-1-khandual@linux.vnet.ibm.comSigned-off-by:
David Rientjes <rientjes@google.com> Acked-by:
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Anshuman Khandual authored
This cleans up handling MADV_SOFT_OFFLINE and MADV_HWPOISON called through madvise() system call. * madvise_memory_failure() was misleading to accommodate handling of both memory_failure() as well as soft_offline_page() functions. Basically it handles memory error injection from user space which can go either way as memory failure or soft offline. Renamed as madvise_inject_error() instead. * Renamed struct page pointer 'p' to 'page'. * pr_info() was essentially printing PFN value but it said 'page' which was misleading. Made the process virtual address explicit. Before the patch: Soft offlining page 0x15e3e at 0x3fff8c230000 Soft offlining page 0x1f3 at 0x3fffa0da0000 Soft offlining page 0x744 at 0x3fff7d200000 Soft offlining page 0x1634d at 0x3fff95e20000 Soft offlining page 0x16349 at 0x3fff95e30000 Soft offlining page 0x1d6 at 0x3fff9e8b0000 Soft offlining page 0x5f3 at 0x3fff91bd0000 Injecting memory failure for page 0x15c8b at 0x3fff83280000 Injecting memory failure for page 0x16190 at 0x3fff83290000 Injecting memory failure for page 0x740 at 0x3fff9a2e0000 Injecting memory failure for page 0x741 at 0x3fff9a2f0000 After the patch: Soft offlining pfn 0x1484e at process virtual address 0x3fff883c0000 Soft offlining pfn 0x1484f at process virtual address 0x3fff883d0000 Soft offlining pfn 0x14850 at process virtual address 0x3fff883e0000 Soft offlining pfn 0x14851 at process virtual address 0x3fff883f0000 Soft offlining pfn 0x14852 at process virtual address 0x3fff88400000 Soft offlining pfn 0x14853 at process virtual address 0x3fff88410000 Soft offlining pfn 0x14854 at process virtual address 0x3fff88420000 Soft offlining pfn 0x1521c at process virtual address 0x3fff6bc70000 Injecting memory failure for pfn 0x10fcf at process virtual address 0x3fff86310000 Injecting memory failure for pfn 0x10fd0 at process virtual address 0x3fff86320000 Injecting memory failure for pfn 0x10fd1 at process virtual address 0x3fff86330000 Injecting memory failure for pfn 0x10fd2 at process virtual address 0x3fff86340000 Injecting memory failure for pfn 0x10fd3 at process virtual address 0x3fff86350000 Injecting memory failure for pfn 0x10fd4 at process virtual address 0x3fff86360000 Injecting memory failure for pfn 0x10fd5 at process virtual address 0x3fff86370000 Link: http://lkml.kernel.org/r/20170410084701.11248-1-khandual@linux.vnet.ibm.comSigned-off-by:
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Mike Kravetz authored
Adding a brief overview of hugetlbfs reservation design and implementation as an aid to those making code modifications in this area. Link: http://lkml.kernel.org/r/1491586995-13085-1-git-send-email-mike.kravetz@oracle.comSigned-off-by:
Mike Kravetz <mike.kravetz@oracle.com> Acked-by:
Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
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Huang Ying authored
This is a code cleanup patch, no functionality changes. There are 2 unused function prototype in swap.h, they are removed. Link: http://lkml.kernel.org/r/20170405071017.23677-1-ying.huang@intel.comSigned-off-by:
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Johannes Weiner authored
The memory controllers stat function names are awkwardly long and arbitrarily different from the zone and node stat functions. The current interface is named: mem_cgroup_read_stat() mem_cgroup_update_stat() mem_cgroup_inc_stat() mem_cgroup_dec_stat() mem_cgroup_update_page_stat() mem_cgroup_inc_page_stat() mem_cgroup_dec_page_stat() This patch renames it to match the corresponding node stat functions: memcg_page_state() [node_page_state()] mod_memcg_state() [mod_node_state()] inc_memcg_state() [inc_node_state()] dec_memcg_state() [dec_node_state()] mod_memcg_page_state() [mod_node_page_state()] inc_memcg_page_state() [inc_node_page_state()] dec_memcg_page_state() [dec_node_page_state()] Link: http://lkml.kernel.org/r/20170404220148.28338-4-hannes@cmpxchg.orgSigned-off-by:
Johannes Weiner <hannes@cmpxchg.org> Acked-by:
Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by:
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Johannes Weiner authored
The current duplication is a high-maintenance mess, and it's painful to add new items or query memcg state from the rest of the VM. This increases the size of the stat array marginally, but we should aim to track all these stats on a per-cgroup level anyway. Link: http://lkml.kernel.org/r/20170404220148.28338-3-hannes@cmpxchg.orgSigned-off-by:
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Johannes Weiner authored
The current duplication is a high-maintenance mess, and it's painful to add new items. This increases the size of the event array, but we'll eventually want most of the VM events tracked on a per-cgroup basis anyway. Link: http://lkml.kernel.org/r/20170404220148.28338-2-hannes@cmpxchg.orgSigned-off-by:
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Johannes Weiner authored
We only ever count single events, drop the @nr parameter. Rename the function accordingly. Remove low-information kerneldoc. Link: http://lkml.kernel.org/r/20170404220148.28338-1-hannes@cmpxchg.orgSigned-off-by:
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Johannes Weiner authored
Since commit 59dc76b0 ("mm: vmscan: reduce size of inactive file list") we noticed bigger IO spikes during changes in cache access patterns. The patch in question shrunk the inactive list size to leave more room for the current workingset in the presence of streaming IO. However, workingset transitions that previously happened on the inactive list are now pushed out of memory and incur more refaults to complete. This patch disables active list protection when refaults are being observed. This accelerates workingset transitions, and allows more of the new set to establish itself from memory, without eating into the ability to protect the established workingset during stable periods. The workloads that were measurably affected for us were hit pretty bad by it, with refault/majfault rates doubling and tripling during cache transitions, and the machines sustaining half-hour periods of 100% IO utilization, where they'd previously have sub-minute peaks at 60-90%. Stateful services that handle user data tend to be more conservative with kernel upgrades. As a result we hit most page cache issues with some delay, as was the case here. The severity seemed to warrant a stable tag. Fixes: 59dc76b0 ("mm: vmscan: reduce size of inactive file list") Link: http://lkml.kernel.org/r/20170404220052.27593-1-hannes@cmpxchg.orgSigned-off-by:
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Anshuman Khandual authored
Commit 091d0d55 ("shm: fix null pointer deref when userspace specifies invalid hugepage size") had replaced MAP_HUGE_MASK with SHM_HUGE_MASK. Though both of them contain the same numeric value of 0x3f, MAP_HUGE_MASK flag sounds more appropriate than the other one in the context. Hence change it back. Link: http://lkml.kernel.org/r/20170404045635.616-1-khandual@linux.vnet.ibm.comSigned-off-by:
Matthew Wilcox <mawilcox@microsoft.com> Acked-by:
Balbir Singh <bsingharora@gmail.com> Acked-by:
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Michal Hocko authored
Tetsuo has reported that sysrq triggered OOM killer will print a misleading information when no tasks are selected: sysrq: SysRq : Manual OOM execution Out of memory: Kill process 4468 ((agetty)) score 0 or sacrifice child Killed process 4468 ((agetty)) total-vm:43704kB, anon-rss:1760kB, file-rss:0kB, shmem-rss:0kB sysrq: SysRq : Manual OOM execution Out of memory: Kill process 4469 (systemd-cgroups) score 0 or sacrifice child Killed process 4469 (systemd-cgroups) total-vm:10704kB, anon-rss:120kB, file-rss:0kB, shmem-rss:0kB sysrq: SysRq : Manual OOM execution sysrq: OOM request ignored because killer is disabled sysrq: SysRq : Manual OOM execution sysrq: OOM request ignored because killer is disabled sysrq: SysRq : Manual OOM execution sysrq: OOM request ignored because killer is disabled The real reason is that there are no eligible tasks for the OOM killer to select but since commit 7c5f64f8 ("mm: oom: deduplicate victim selection code for memcg and global oom") the semantic of out_of_memory has changed without updating moom_callback. This patch updates moom_callback to tell that no task was eligible which is the case for both oom killer disabled and no eligible tasks. In order to help distinguish first case from the second add printk to both oom_killer_{enable,disable}. This information is useful on its own because it might help debugging potential memory allocation failures. Fixes: 7c5f64f8 ("mm: oom: deduplicate victim selection code for memcg and global oom") Link: http://lkml.kernel.org/r/20170404134705.6361-1-mhocko@kernel.orgSigned-off-by:
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