- 17 12月, 2015 2 次提交
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由 Daniel Mentz 提交于
dma-debug uses struct dma_debug_entry to keep track of dma coherent memory allocation requests. The virtual address is converted into a pfn and an offset. Previously, the offset was calculated using an incorrect bit mask. As a result, we saw incorrect error messages from dma-debug like the following: "DMA-API: exceeded 7 overlapping mappings of cacheline 0x03e00000" Cacheline 0x03e00000 does not exist on our platform. Cc: <stable@vger.kernel.org> Fixes: 0abdd7a8 ("dma-debug: introduce debug_dma_assert_idle()") Signed-off-by: NDaniel Mentz <danielmentz@google.com> Signed-off-by: NDan Williams <dan.j.williams@intel.com>
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由 Herbert Xu 提交于
The commit ba7c95ea ("rhashtable: Fix sleeping inside RCU critical section in walk_stop") introduced a new spinlock for the walker list. However, it did not convert all existing users of the list over to the new spin lock. Some continued to use the old mutext for this purpose. This obviously led to corruption of the list. The fix is to use the spin lock everywhere where we touch the list. This also allows us to do rcu_rad_lock before we take the lock in rhashtable_walk_start. With the old mutex this would've deadlocked but it's safe with the new spin lock. Fixes: ba7c95ea ("rhashtable: Fix sleeping inside RCU...") Reported-by: NColin Ian King <colin.king@canonical.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 16 12月, 2015 1 次提交
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由 Herbert Xu 提交于
William Hua <william.hua@canonical.com> wrote: > > I wasn't aware there was an enforced minimum size. I simply set the > nelem_hint in the rhastable_params struct to 1, expecting it to grow as > needed. This caused a segfault afterwards when trying to insert an > element. OK we're doing the size computation before we enforce the limit on min_size. ---8<--- We need to do the initial hash table size computation after we have obtained the correct min_size/max_size parameters. Otherwise we may end up with a hash table whose size is outside the allowed envelope. Fixes: a998f712 ("rhashtable: Round up/down min/max_size to...") Reported-by: NWilliam Hua <william.hua@canonical.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 12 12月, 2015 5 次提交
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
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由 Christoph Hellwig 提交于
There is no good reason to keep them apart, and this makes using the API a bit simpler. Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
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由 Christoph Hellwig 提交于
There is no good reason to start out disabled - drivers can control if the poll instance can be scheduled by simply not scheduling it yet. Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
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由 Christoph Hellwig 提交于
The new name is irq_poll as iopoll is already taken. Better suggestions welcome. Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NBart Van Assche <bart.vanassche@sandisk.com>
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- 06 12月, 2015 1 次提交
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由 David S. Miller 提交于
This reverts commit d3716f18. vmalloc cannot be used in BH disabled contexts, even with GFP_ATOMIC. And we certainly want to support rhashtable users inserting entries with software interrupts disabled. Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 05 12月, 2015 2 次提交
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由 Herbert Xu 提交于
When an rhashtable user pounds rhashtable hard with back-to-back insertions we may end up growing the table in GFP_ATOMIC context. Unfortunately when the table reaches a certain size this often fails because we don't have enough physically contiguous pages to hold the new table. Eric Dumazet suggested (and in fact wrote this patch) using __vmalloc instead which can be used in GFP_ATOMIC context. Reported-by: NPhil Sutter <phil@nwl.cc> Suggested-by: NEric Dumazet <eric.dumazet@gmail.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Herbert Xu 提交于
Thomas and Phil observed that under stress rhashtable insertion sometimes failed with EBUSY, even though this error should only ever been seen when we're under attack and our hash chain length has grown to an unacceptable level, even after a rehash. It turns out that the logic for detecting whether there is an existing rehash is faulty. In particular, when two threads both try to grow the same table at the same time, one of them may see the newly grown table and thus erroneously conclude that it had been rehashed. This is what leads to the EBUSY error. This patch fixes this by remembering the current last table we used during insertion so that rhashtable_insert_rehash can detect when another thread has also done a resize/rehash. When this is detected we will give up our resize/rehash and simply retry the insertion with the new table. Reported-by: NThomas Graf <tgraf@suug.ch> Reported-by: NPhil Sutter <phil@nwl.cc> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au> Tested-by: NPhil Sutter <phil@nwl.cc> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 23 11月, 2015 1 次提交
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由 Peter Zijlstra 提交于
There were still a number of references to my old Red Hat email address in the kernel source. Remove these while keeping the Red Hat copyright notices intact. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 11 11月, 2015 1 次提交
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由 Andy Shevchenko 提交于
8-byte constant is too big for long and compiler complains about this. lib/string.c:907:20: warning: constant 0x0101010101010101 is so big it is long Append ULL suffix to explicitly show its type. Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 10 11月, 2015 1 次提交
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由 Andrew Morton 提交于
Switch everything to the new and more capable implementation of abs(). Mainly to give the new abs() a bit of a workout. Cc: Michal Nazarewicz <mina86@mina86.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 07 11月, 2015 17 次提交
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由 Robin Murphy 提交于
Like dma_unmap_sg, dma_sync_sg* should be called with the original number of entries passed to dma_map_sg, so do the same check in the sync path as we do in the unmap path. Signed-off-by: NRobin Murphy <robin.murphy@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Sakari Ailus <sakari.ailus@iki.fi> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andy Shevchenko 提交于
There is a classical off-by-one error in case when we try to place, for example, 1+1 bytes as hex in the buffer of size 6. The expected result is to get an output truncated, but in the reality we get 6 bytes filed followed by terminating NUL. Change the logic how we fill the output in case of byte dumping into limited space. This will follow the snprintf() behaviour by truncating output even on half bytes. Fixes: 114fc1af (hexdump: make it return number of bytes placed in buffer) Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com> Reported-by: NAaro Koskinen <aaro.koskinen@nokia.com> Tested-by: NAaro Koskinen <aaro.koskinen@nokia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Oleg Nesterov 提交于
Change current_is_single_threaded() to use for_each_thread() rather than deprecated while_each_thread(). Signed-off-by: NOleg Nesterov <oleg@redhat.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
Sometimes kobject_set_name_vargs is called with a format string conaining no %, or a format string of precisely "%s", where the single vararg happens to point to .rodata. kvasprintf_const detects these cases for us and returns a copy of that pointer instead of duplicating the string, thus saving some run-time memory. Otherwise, it falls back to kvasprintf. We just need to always deallocate ->name using kfree_const. Unfortunately, the dance we need to do to perform the '/' -> '!' sanitization makes the resulting code rather ugly. I instrumented kstrdup_const to provide some statistics on the memory saved, and for me this gave an additional ~14KB after boot (306KB was already saved; this patch bumped that to 320KB). I have KMALLOC_SHIFT_LOW==3, and since 80% of the kvasprintf_const hits were satisfied by an 8-byte allocation, the 14K would roughly be quadrupled when KMALLOC_SHIFT_LOW==5. Whether these numbers are sufficient to justify the ugliness I'll leave to others to decide. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Greg KH <greg@kroah.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
This adds kvasprintf_const which tries to use kstrdup_const if possible: If the format string contains no % characters, or if the format string is exactly "%s", we delegate to kstrdup_const. Otherwise, we fall back to kvasprintf. Just as for kstrdup_const, the main motivation is to save memory by reusing .rodata when possible. The return value should be freed by kfree_const, just like for kstrdup_const. There is deliberately no kasprintf_const: In the vast majority of cases, the format string argument is a literal, so one can determine statically whether one could instead use kstrdup_const directly (which would also require one to change all corresponding kfree calls to kfree_const). Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Greg KH <greg@kroah.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Dmitry Vyukov 提交于
llist_del_first reads entry->next, but it did not acquire visibility over the entry node. As the result it can get a stale value of entry->next (e.g. NULL or whatever garbage was there before the appending thread wrote correct value). And then commit that value as llist head with cmpxchg. That will corrupt llist. Note there is a control-dependency between read of head->first and read of entry->next, but it does not make the code correct. Kernel memory model unambiguously says: "A load-load control dependency requires a full read memory barrier". Use smp_load_acquire to acquire visibility over the entry node. The data race was found with KernelThreadSanitizer (KTSAN). Here is an example of KTSAN report: ThreadSanitizer: data-race in llist_del_first Read of size 1 by thread T389 (K2630, CPU0): [<ffffffff8156b8a9>] llist_del_first+0x39/0x70 lib/llist.c:74 [< inlined >] tty_buffer_alloc drivers/tty/tty_buffer.c:181 [<ffffffff81664af4>] __tty_buffer_request_room+0xb4/0x250 drivers/tty/tty_buffer.c:292 [<ffffffff81664e6c>] tty_insert_flip_string_fixed_flag+0x6c/0x150 drivers/tty/tty_buffer.c:337 [< inlined >] tty_insert_flip_string include/linux/tty_flip.h:35 [<ffffffff81667422>] pty_write+0x72/0xc0 drivers/tty/pty.c:110 [< inlined >] process_output_block drivers/tty/n_tty.c:611 [<ffffffff8165c016>] n_tty_write+0x346/0x7f0 drivers/tty/n_tty.c:2401 [< inlined >] do_tty_write drivers/tty/tty_io.c:1159 [<ffffffff816568df>] tty_write+0x21f/0x3f0 drivers/tty/tty_io.c:1245 [<ffffffff8125f00f>] __vfs_write+0x5f/0x1f0 fs/read_write.c:489 [<ffffffff8125ff8f>] vfs_write+0xef/0x280 fs/read_write.c:538 [< inlined >] SYSC_write fs/read_write.c:585 [<ffffffff81261390>] SyS_write+0x70/0xe0 fs/read_write.c:577 [<ffffffff81ee862e>] entry_SYSCALL_64_fastpath+0x12/0x71 arch/x86/entry/entry_64.S:186 Previous write of size 8 by thread T226 (K761, CPU0): [<ffffffff8156b832>] llist_add_batch+0x32/0x70 lib/llist.c:44 (discriminator 16) [< inlined >] llist_add include/linux/llist.h:180 [<ffffffff816649fc>] tty_buffer_free+0x6c/0xb0 drivers/tty/tty_buffer.c:221 [<ffffffff816651e7>] flush_to_ldisc+0x107/0x300 drivers/tty/tty_buffer.c:514 [<ffffffff810b20ee>] process_one_work+0x47e/0x930 kernel/workqueue.c:2036 [<ffffffff810b2650>] worker_thread+0xb0/0x900 kernel/workqueue.c:2170 [<ffffffff810bbe20>] kthread+0x150/0x170 kernel/kthread.c:209 [<ffffffff81ee8a1f>] ret_from_fork+0x3f/0x70 arch/x86/entry/entry_64.S:526 Signed-off-by: NDmitry Vyukov <dvyukov@google.com> Reviewed-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Huang Ying <ying.huang@intel.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Vitaly Kuznetsov 提交于
Add a couple of simple tests for string_get_size(). The last one will hang the kernel without the 'lib/string_helpers.c: fix infinite loop in string_get_size()' fix. Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com> Cc: James Bottomley <JBottomley@Odin.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Alexander Kuleshov 提交于
<linux/bitops.h> provides rol32() inline function, let's use already predefined function instead of direct expression. Signed-off-by: NAlexander Kuleshov <kuleshovmail@gmail.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
%n is no longer just ignored; it results in early return from vsnprintf. Also add a request to add test cases for future %p extensions. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: NMartin Kletzander <mkletzan@redhat.com> Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
This adds a simple module for testing the kernel's printf facilities. Previously, some %p extensions have caused a wrong return value in case the entire output didn't fit and/or been unusable in kasprintf(). This should help catch such issues. Also, it should help ensure that changes to the formatting algorithms don't break anything. I'm not sure if we have a struct dentry or struct file lying around at boot time or if we can fake one, but most %p extensions should be testable, as should the ordinary number and string formatting. The nature of vararg functions means we can't use a more conventional table-driven approach. For now, this is mostly a skeleton; contributions are very welcome. Some tests are/will be slightly annoying to write, since the expected output depends on stuff like CONFIG_*, sizeof(long), runtime values etc. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: NKees Cook <keescook@chromium.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Martin Kletzander <mkletzan@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
As a quick git grep -E '%[ +0#-]*#[ +0#-]*(\*|[0-9]+)?(\.(\*|[0-9]+)?)?p' shows, nobody uses the # flag with %p. Should one try to do so, one will be met with warning: `#' flag used with `%p' gnu_printf format [-Wformat] (POSIX and C99 both say "... For other conversion specifiers, the behavior is undefined.". Obviously, the kernel can choose to define the behaviour however it wants, but as long as gcc issues that warning, users are unlikely to show up.) Since default_width is effectively always 2*sizeof(void*), we can simplify the prologue of pointer() and save a few instructions. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: NKees Cook <keescook@chromium.org> Cc: Martin Kletzander <mkletzan@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
Quoting from 2aa2f9e2 ("lib/vsprintf.c: improve sanity check in vsnprintf()"): On 64 bit, size may very well be huge even if bit 31 happens to be 0. Somehow it doesn't feel right that one can pass a 5 GiB buffer but not a 3 GiB one. So cap at INT_MAX as was probably the intention all along. This is also the made-up value passed by sprintf and vsprintf. I should have seen this copy-pasted instance back then, but let's just do it now. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: NKees Cook <keescook@chromium.org> Cc: Martin Kletzander <mkletzan@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
If we meet any invalid or unsupported format specifier, 'handling' it by just printing it as a literal string is not safe: Presumably the format string and the arguments passed gcc's type checking, but that means something like sprintf(buf, "%n %pd", &intvar, dentry) would end up interpreting &intvar as a struct dentry*. When the offending specifier was %n it used to be at the end of the format string, but we can't rely on that always being the case. Also, gcc doesn't complain about some more or less exotic qualifiers (or 'length modifiers' in posix-speak) such as 'j' or 'q', but being unrecognized by the kernel's printf implementation, they'd be interpreted as unknown specifiers, and the rest of arguments would be interpreted wrongly. So let's complain about anything we don't understand, not just %n, and stop pretending that we'd be able to make sense of the rest of the format/arguments. If the offending specifier is in a printk() call we unfortunately only get a "BUG: recent printk recursion!", but at least direct users of the sprintf family will be caught. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: NKees Cook <keescook@chromium.org> Cc: Martin Kletzander <mkletzan@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Martin Kletzander 提交于
Move all pointer-formatting documentation to one place in the code and one place in the documentation instead of keeping it in three places with different level of completeness. Documentation/printk-formats.txt has detailed information about each modifier, docstring above pointer() has short descriptions of them (as that is the function dealing with %p) and docstring above vsprintf() is removed as redundant. Both docstrings in the code that were modified are updated with a reminder of updating the documentation upon any further change. [akpm@linux-foundation.org: fix comment] Signed-off-by: NMartin Kletzander <mkletzan@redhat.com> Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
Using kstrdup_const, thus reusing .rodata when possible, saves around 2 kB of runtime memory on my laptop/.config combination. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Jason Baron <jbaron@akamai.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
__GFP_WAIT was used to signal that the caller was in atomic context and could not sleep. Now it is possible to distinguish between true atomic context and callers that are not willing to sleep. The latter should clear __GFP_DIRECT_RECLAIM so kswapd will still wake. As clearing __GFP_WAIT behaves differently, there is a risk that people will clear the wrong flags. This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly indicate what it does -- setting it allows all reclaim activity, clearing them prevents it. [akpm@linux-foundation.org: fix build] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NMel Gorman <mgorman@techsingularity.net> Acked-by: NMichal Hocko <mhocko@suse.com> Acked-by: NVlastimil Babka <vbabka@suse.cz> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Acked-by: NDavid Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd __GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: NMel Gorman <mgorman@techsingularity.net> Acked-by: NVlastimil Babka <vbabka@suse.cz> Acked-by: NMichal Hocko <mhocko@suse.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 06 11月, 2015 2 次提交
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由 Andrey Ryabinin 提交于
It's recommended to have slub's user tracking enabled with CONFIG_KASAN, because: a) User tracking disables slab merging which improves detecting out-of-bounds accesses. b) User tracking metadata acts as redzone which also improves detecting out-of-bounds accesses. c) User tracking provides additional information about object. This information helps to understand bugs. Currently it is not enabled by default. Besides recompiling the kernel with KASAN and reinstalling it, user also have to change the boot cmdline, which is not very handy. Enable slub user tracking by default with KASAN=y, since there is no good reason to not do this. [akpm@linux-foundation.org: little fixes, per David] Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Wang Long 提交于
Add some out of bounds testcases to test_kasan module. Signed-off-by: NWang Long <long.wanglong@huawei.com> Acked-by: NAndrey Ryabinin <aryabinin@virtuozzo.com> Cc: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 05 11月, 2015 2 次提交
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由 Yang Shi 提交于
When running "mod X" operation, if X is 0 the filter has to be halt. Add new test cases to cover A = A mod X if X is 0, and A = A mod 1. CC: Xi Wang <xi.wang@gmail.com> CC: Zi Shen Lim <zlim.lnx@gmail.com> Signed-off-by: NYang Shi <yang.shi@linaro.org> Acked-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NZi Shen Lim <zlim.lnx@gmail.com> Acked-by: NXi Wang <xi.wang@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David S. Miller 提交于
The value returned from iommu_tbl_range_alloc() (and the one passed in as a fourth argument to iommu_tbl_range_free) is not a DMA address, it is rather an index into the IOMMU page table. Therefore using DMA_ERROR_CODE is not appropriate. Use a more type matching error code define, IOMMU_ERROR_CODE, and update all users of this interface. Reported-by: NAndre Przywara <andre.przywara@arm.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 23 10月, 2015 2 次提交
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由 Florian Westphal 提交于
interval displays the probability and vice versa. Fixes: 6adc4a22 ("fault-inject: add ratelimit option") Acked-by: NAkinobu Mita <akinobu.mita@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrey Ryabinin 提交于
When the kernel compiled with KASAN=y, GCC adds redzones for each variable on stack. This enlarges function's stack frame and causes: 'warning: the frame size of X bytes is larger than Y bytes' The worst case I've seen for now is following: ../net/wireless/nl80211.c: In function `nl80211_send_wiphy': ../net/wireless/nl80211.c:1731:1: warning: the frame size of 5448 bytes is larger than 2048 bytes [-Wframe-larger-than=] That kind of warning becomes useless with KASAN=y. It doesn't necessarily indicate that there is some problem in the code, thus we should turn it off. (The KASAN=y stack size in increased from 16k to 32k for this reason) Signed-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com> Reported-by: NFengguang Wu <fengguang.wu@intel.com> Acked-by: NAbylay Ospan <aospan@netup.ru> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Mauro Carvalho Chehab <m.chehab@samsung.com> Cc: Kozlov Sergey <serjk@netup.ru> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 21 10月, 2015 1 次提交
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由 David Howells 提交于
Merge the type-specific data with the payload data into one four-word chunk as it seems pointless to keep them separate. Use user_key_payload() for accessing the payloads of overloaded user-defined keys. Signed-off-by: NDavid Howells <dhowells@redhat.com> cc: linux-cifs@vger.kernel.org cc: ecryptfs@vger.kernel.org cc: linux-ext4@vger.kernel.org cc: linux-f2fs-devel@lists.sourceforge.net cc: linux-nfs@vger.kernel.org cc: ceph-devel@vger.kernel.org cc: linux-ima-devel@lists.sourceforge.net
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- 20 10月, 2015 1 次提交
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由 Stephan Mueller 提交于
The patch fixes the analysis of the input data which contains an off by one. The issue is visible when the SGL contains one byte per SG entry. The code for checking for zero bytes does not operate on the data byte. Signed-off-by: NStephan Mueller <smueller@chronox.de> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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- 17 10月, 2015 1 次提交
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由 Andrew Morton 提交于
lib/built-in.o: In function `__bitrev32': deftree.c:(.text+0x1e799): undefined reference to `byte_rev_table' deftree.c:(.text+0x1e7a0): undefined reference to `byte_rev_table' deftree.c:(.text+0x1e7b4): undefined reference to `byte_rev_table' deftree.c:(.text+0x1e7c1): undefined reference to `byte_rev_table' Anything which uses bitrevX() has to select BITREVERSE, to grab lib/bitrev.o. Reported-by: NJim Davis <jim.epost@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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