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* Merge branch 'for-linus' of ↵Linus Torvalds2014-08-11
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "Stuff in here: - acct.c fixes and general rework of mnt_pin mechanism. That allows to go for delayed-mntput stuff, which will permit mntput() on deep stack without worrying about stack overflows - fs shutdown will happen on shallow stack. IOW, we can do Eric's umount-on-rmdir series without introducing tons of stack overflows on new mntput() call chains it introduces. - Bruce's d_splice_alias() patches - more Miklos' rename() stuff. - a couple of regression fixes (stable fodder, in the end of branch) and a fix for API idiocy in iov_iter.c. There definitely will be another pile, maybe even two. I'd like to get Eric's series in this time, but even if we miss it, it'll go right in the beginning of for-next in the next cycle - the tricky part of prereqs is in this pile" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits) fix copy_tree() regression __generic_file_write_iter(): fix handling of sync error after DIO switch iov_iter_get_pages() to passing maximal number of pages fs: mark __d_obtain_alias static dcache: d_splice_alias should detect loops exportfs: update Exporting documentation dcache: d_find_alias needn't recheck IS_ROOT && DCACHE_DISCONNECTED dcache: remove unused d_find_alias parameter dcache: d_obtain_alias callers don't all want DISCONNECTED dcache: d_splice_alias should ignore DCACHE_DISCONNECTED dcache: d_splice_alias mustn't create directory aliases dcache: close d_move race in d_splice_alias dcache: move d_splice_alias namei: trivial fix to vfs_rename_dir comment VFS: allow ->d_manage() to declare -EISDIR in rcu_walk mode. cifs: support RENAME_NOREPLACE hostfs: support rename flags shmem: support RENAME_EXCHANGE shmem: support RENAME_NOREPLACE btrfs: add RENAME_NOREPLACE ...
| * kernel/acct.c: fix coding style warnings and errorsIonut Alexa2014-08-07
| | | | | | | | | | | | Signed-off-by: Ionut Alexa <ionut.m.alexa@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * death to mnt_pinnedAl Viro2014-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than playing silly buggers with vfsmount refcounts, just have acct_on() ask fs/namespace.c for internal clone of file->f_path.mnt and replace it with said clone. Then attach the pin to original vfsmount. Voila - the clone will be alive until the file gets closed, making sure that underlying superblock remains active, etc., and we can drop the original vfsmount, so that it's not kept busy. If the file lives until the final mntput of the original vfsmount, we'll notice that there's an fs_pin (one in bsd_acct_struct that holds that file) and mnt_pin_kill() will take it out. Since ->kill() is synchronous, we won't proceed past that point until these files are closed (and private clones of our vfsmount are gone), so we get the same ordering warranties we used to get. mnt_pin()/mnt_unpin()/->mnt_pinned is gone now, and good riddance - it never became usable outside of kernel/acct.c (and racy wrt umount even there). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * take fs_pin stuff to fs/*Al Viro2014-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new field to fs_pin - kill(pin). That's what umount and r/o remount will be calling for all pins attached to vfsmount and superblock resp. Called after bumping the refcount, so it won't go away under us. Dropping the refcount is responsibility of the instance. All generic stuff moved to fs/fs_pin.c; the next step will rip all the knowledge of kernel/acct.c from fs/super.c and fs/namespace.c. After that - death to mnt_pin(); it was intended to be usable as generic mechanism for code that wants to attach objects to vfsmount, so that they would not make the sucker busy and would get killed on umount. Never got it right; it remained acct.c-specific all along. Now it's very close to being killable. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * start carving bsd_acct_struct upAl Viro2014-08-07
| | | | | | | | | | | | | | | | pull generic parts into struct fs_pin. Eventually we want those to replace mnt_pin()/mnt_unpin() mess; that stuff will move to fs/*. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * acct: move mnt_pin() upwards.Al Viro2014-08-07
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * make acct_kill() wait for file closing.Al Viro2014-08-07
| | | | | | | | | | | | | | Do actual closing of file via schedule_work(). And use __fput_sync() there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * acct: get rid of acct_lock for acct->countAl Viro2014-08-07
| | | | | | | | | | | | | | | | | | * make acct->count atomic and acct freeing - rcu-delayed. * instead of grabbing acct_lock around the places where we take a reference, do that under rcu_read_lock() with atomic_long_inc_not_zero(). * have the new acct locked before making ns->bacct point to it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * acct: get rid of acct_listAl Viro2014-08-07
| | | | | | | | | | | | | | | | Put these suckers on per-vfsmount and per-superblock lists instead. Note: right now it's still acct_lock for everything, but that's going to change. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * acct: simplify check_free_space()Al Viro2014-08-07
| | | | | | | | | | | | | | | | | | a) file can't be NULL b) file can't be changed under us c) all writes are serialized by acct->lock; no need to mess with spinlock there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * acct: new lifetime rulesAl Viro2014-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do not reuse bsd_acct_struct after closing the damn thing. Structure lifetime is controlled by refcount now. We also have a mutex in there, held over closing and writing (the file is O_APPEND, so we are not losing any concurrency). As the result, we do not need to bother with get_file()/fput() on log write anymore. Moreover, do_acct_process() only needs acct itself; file and pidns are picked from it. Killed instances are distinguished by having NULL ->ns. Refcount is protected by acct_lock; anybody taking the mutex needs to grab a reference first. The things will get a lot simpler in the next commits - this is just the minimal chunk switching to the new lifetime rules. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * acct: serialize acct_on()Al Viro2014-08-07
| | | | | | | | | | | | brute-force - on a global mutex that isn't nested into anything. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * acct() should honour the limits from the very beginningAl Viro2014-08-07
| | | | | | | | | | | | We need to check free space on the first write to freshly opened log. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * split the slow path in acct_process() offAl Viro2014-08-07
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * separate namespace-independent parts of filling acct_tAl Viro2014-08-07
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * acct: switch to __kernel_write()Al Viro2014-08-07
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * acct: encode_comp_t(0) is 0, fortunately...Al Viro2014-08-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There was an amusing bogosity in ac_rw calculation - it tried to do encode_comp_t(encode_comp_t(0) / 1024). Seeing that comp_t is a 3-bit exponent + 13-bit mantissa... it's a good thing that 0 is represented by all-bits-clear. The history of that one is interesting - it was introduced in 2.1.68pre1, when acct.c had been reworked and moved to separate file. Two months later (2.1.86) somebody has noticed that the sucker won't compile - there was no task_struct::io_usage. At which point the ac_io calculation had changed from encode_comp_t(current->io_usage) to encode_comp_t(0) and the bug in the next line (absolutely real back then, had it ever managed to compile) become a harmless bogosity. Looks like nobody has ever noticed until now. Anyway, let's bury that idiocy now that it got noticed. 17 years is long enough... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * Merge commit 'ccbf62d8a284cf181ac28c8e8407dd077d90dd4b' into for-nextAl Viro2014-08-07
| |\ | | | | | | | | | backmerge to avoid kernel/acct.c conflict
* | \ Merge tag 'modules-next-for-linus' of ↵Linus Torvalds2014-08-11
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "This finally applies the stricter sysfs perms checking we pulled out before last merge window. A few stragglers are fixed (thanks linux-next!)" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: arch/powerpc/platforms/powernv/opal-dump.c: fix world-writable sysfs files arch/powerpc/platforms/powernv/opal-elog.c: fix world-writable sysfs files drivers/video/fbdev/s3c2410fb.c: don't make debug world-writable. ARM: avoid ARM binutils leaking ELF local symbols scripts: modpost: Remove numeric suffix pattern matching scripts: modpost: fix compilation warning sysfs: disallow world-writable files. module: return bool from within_module*() module: add within_module() function modules: Fix build error in moduleloader.h
| * | | ARM: avoid ARM binutils leaking ELF local symbolsRussell King2014-07-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Symbols starting with .L are ELF local symbols and should not appear in ELF symbol tables. However, unfortunately ARM binutils leaks the .LANCHOR symbols into the symbol table, which leads kallsyms to report these symbols rather than the real name. It is not very useful when %pf reports symbols against these leaked .LANCHOR symbols. Arrange for kallsyms to ignore these symbols using the same mechanism that is used for the ARM mapping symbols. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | | module: add within_module() functionPetr Mladek2014-07-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is just a small optimization that allows to replace few occurrences of within_module_init() || within_module_core() with a single call. Signed-off-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | | | Merge tag 'trace-fixes-3.16' of ↵Linus Torvalds2014-08-09
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull trace file read iterator fixes from Steven Rostedt: "This contains a fix for two long standing bugs. Both of which are rarely ever hit, and requires the user to do something that users rarely do. It took a few special test cases to even trigger this bug, and one of them was just one test in the process of finishing up as another one started. Both bugs have to do with the ring buffer iterator rb_iter_peek(), but one is more indirect than the other. The fist bug fix is simply an increase in the safety net loop counter. The counter makes sure that the rb_iter_peek() only iterates the number of times we expect it can, and no more. Well, there was one way it could iterate one more than we expected, and that caused the ring buffer to shutdown with a nasty warning. The fix was simply to up that counter by one. The other bug has to be with rb_iter_reset() (called by rb_iter_peek()). This happens when a user reads both the trace_pipe and trace files. The trace_pipe is a consuming read and does not use the ring buffer iterator, but the trace file is not a consuming read and does use the ring buffer iterator. When the trace file is being read, if it detects that a consuming read occurred, it resets the iterator and starts over. But the reset code that does this (rb_iter_reset()), checks if the reader_page is linked to the ring buffer or not, and will look into the ring buffer itself if it is not. This is wrong, as it should always try to read the reader page first. Not to mention, the code that looked into the ring buffer did it wrong, and used the header_page "read" offset to start reading on that page. That offset is bogus for pages in the writable ring buffer, and was corrupting the iterator, and it would start returning bogus events" * tag 'trace-fixes-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Always reset iterator to reader page ring-buffer: Up rb_iter_peek() loop count to 3
| * | | | ring-buffer: Always reset iterator to reader pageSteven Rostedt (Red Hat)2014-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When performing a consuming read, the ring buffer swaps out a page from the ring buffer with a empty page and this page that was swapped out becomes the new reader page. The reader page is owned by the reader and since it was swapped out of the ring buffer, writers do not have access to it (there's an exception to that rule, but it's out of scope for this commit). When reading the "trace" file, it is a non consuming read, which means that the data in the ring buffer will not be modified. When the trace file is opened, a ring buffer iterator is allocated and writes to the ring buffer are disabled, such that the iterator will not have issues iterating over the data. Although the ring buffer disabled writes, it does not disable other reads, or even consuming reads. If a consuming read happens, then the iterator is reset and starts reading from the beginning again. My tests would sometimes trigger this bug on my i386 box: WARNING: CPU: 0 PID: 5175 at kernel/trace/trace.c:1527 __trace_find_cmdline+0x66/0xaa() Modules linked in: CPU: 0 PID: 5175 Comm: grep Not tainted 3.16.0-rc3-test+ #8 Hardware name: /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006 00000000 00000000 f09c9e1c c18796b3 c1b5d74c f09c9e4c c103a0e3 c1b5154b f09c9e78 00001437 c1b5d74c 000005f7 c10bd85a c10bd85a c1cac57c f09c9eb0 ed0e0000 f09c9e64 c103a185 00000009 f09c9e5c c1b5154b f09c9e78 f09c9e80^M Call Trace: [<c18796b3>] dump_stack+0x4b/0x75 [<c103a0e3>] warn_slowpath_common+0x7e/0x95 [<c10bd85a>] ? __trace_find_cmdline+0x66/0xaa [<c10bd85a>] ? __trace_find_cmdline+0x66/0xaa [<c103a185>] warn_slowpath_fmt+0x33/0x35 [<c10bd85a>] __trace_find_cmdline+0x66/0xaa^M [<c10bed04>] trace_find_cmdline+0x40/0x64 [<c10c3c16>] trace_print_context+0x27/0xec [<c10c4360>] ? trace_seq_printf+0x37/0x5b [<c10c0b15>] print_trace_line+0x319/0x39b [<c10ba3fb>] ? ring_buffer_read+0x47/0x50 [<c10c13b1>] s_show+0x192/0x1ab [<c10bfd9a>] ? s_next+0x5a/0x7c [<c112e76e>] seq_read+0x267/0x34c [<c1115a25>] vfs_read+0x8c/0xef [<c112e507>] ? seq_lseek+0x154/0x154 [<c1115ba2>] SyS_read+0x54/0x7f [<c188488e>] syscall_call+0x7/0xb ---[ end trace 3f507febd6b4cc83 ]--- >>>> ##### CPU 1 buffer started #### Which was the __trace_find_cmdline() function complaining about the pid in the event record being negative. After adding more test cases, this would trigger more often. Strangely enough, it would never trigger on a single test, but instead would trigger only when running all the tests. I believe that was the case because it required one of the tests to be shutting down via delayed instances while a new test started up. After spending several days debugging this, I found that it was caused by the iterator becoming corrupted. Debugging further, I found out why the iterator became corrupted. It happened with the rb_iter_reset(). As consuming reads may not read the full reader page, and only part of it, there's a "read" field to know where the last read took place. The iterator, must also start at the read position. In the rb_iter_reset() code, if the reader page was disconnected from the ring buffer, the iterator would start at the head page within the ring buffer (where writes still happen). But the mistake there was that it still used the "read" field to start the iterator on the head page, where it should always start at zero because readers never read from within the ring buffer where writes occur. I originally wrote a patch to have it set the iter->head to 0 instead of iter->head_page->read, but then I questioned why it wasn't always setting the iter to point to the reader page, as the reader page is still valid. The list_empty(reader_page->list) just means that it was successful in swapping out. But the reader_page may still have data. There was a bug report a long time ago that was not reproducible that had something about trace_pipe (consuming read) not matching trace (iterator read). This may explain why that happened. Anyway, the correct answer to this bug is to always use the reader page an not reset the iterator to inside the writable ring buffer. Cc: stable@vger.kernel.org # 2.6.28+ Fixes: d769041f8653 "ring_buffer: implement new locking" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | | | ring-buffer: Up rb_iter_peek() loop count to 3Steven Rostedt (Red Hat)2014-08-06
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After writting a test to try to trigger the bug that caused the ring buffer iterator to become corrupted, I hit another bug: WARNING: CPU: 1 PID: 5281 at kernel/trace/ring_buffer.c:3766 rb_iter_peek+0x113/0x238() Modules linked in: ipt_MASQUERADE sunrpc [...] CPU: 1 PID: 5281 Comm: grep Tainted: G W 3.16.0-rc3-test+ #143 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007 0000000000000000 ffffffff81809a80 ffffffff81503fb0 0000000000000000 ffffffff81040ca1 ffff8800796d6010 ffffffff810c138d ffff8800796d6010 ffff880077438c80 ffff8800796d6010 ffff88007abbe600 0000000000000003 Call Trace: [<ffffffff81503fb0>] ? dump_stack+0x4a/0x75 [<ffffffff81040ca1>] ? warn_slowpath_common+0x7e/0x97 [<ffffffff810c138d>] ? rb_iter_peek+0x113/0x238 [<ffffffff810c138d>] ? rb_iter_peek+0x113/0x238 [<ffffffff810c14df>] ? ring_buffer_iter_peek+0x2d/0x5c [<ffffffff810c6f73>] ? tracing_iter_reset+0x6e/0x96 [<ffffffff810c74a3>] ? s_start+0xd7/0x17b [<ffffffff8112b13e>] ? kmem_cache_alloc_trace+0xda/0xea [<ffffffff8114cf94>] ? seq_read+0x148/0x361 [<ffffffff81132d98>] ? vfs_read+0x93/0xf1 [<ffffffff81132f1b>] ? SyS_read+0x60/0x8e [<ffffffff8150bf9f>] ? tracesys+0xdd/0xe2 Debugging this bug, which triggers when the rb_iter_peek() loops too many times (more than 2 times), I discovered there's a case that can cause that function to legitimately loop 3 times! rb_iter_peek() is different than rb_buffer_peek() as the rb_buffer_peek() only deals with the reader page (it's for consuming reads). The rb_iter_peek() is for traversing the buffer without consuming it, and as such, it can loop for one more reason. That is, if we hit the end of the reader page or any page, it will go to the next page and try again. That is, we have this: 1. iter->head > iter->head_page->page->commit (rb_inc_iter() which moves the iter to the next page) try again 2. event = rb_iter_head_event() event->type_len == RINGBUF_TYPE_TIME_EXTEND rb_advance_iter() try again 3. read the event. But we never get to 3, because the count is greater than 2 and we cause the WARNING and return NULL. Up the counter to 3. Cc: stable@vger.kernel.org # 2.6.37+ Fixes: 69d1b839f7ee "ring-buffer: Bind time extend and data events together" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | | Merge branch 'for-linus' of ↵Linus Torvalds2014-08-09
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "This is a bunch of small changes built against 3.16-rc6. The most significant change for users is the first patch which makes setns drmatically faster by removing unneded rcu handling. The next chunk of changes are so that "mount -o remount,.." will not allow the user namespace root to drop flags on a mount set by the system wide root. Aks this forces read-only mounts to stay read-only, no-dev mounts to stay no-dev, no-suid mounts to stay no-suid, no-exec mounts to stay no exec and it prevents unprivileged users from messing with a mounts atime settings. I have included my test case as the last patch in this series so people performing backports can verify this change works correctly. The next change fixes a bug in NFS that was discovered while auditing nsproxy users for the first optimization. Today you can oops the kernel by reading /proc/fs/nfsfs/{servers,volumes} if you are clever with pid namespaces. I rebased and fixed the build of the !CONFIG_NFS_FS case yesterday when a build bot caught my typo. Given that no one to my knowledge bases anything on my tree fixing the typo in place seems more responsible that requiring a typo-fix to be backported as well. The last change is a small semantic cleanup introducing /proc/thread-self and pointing /proc/mounts and /proc/net at it. This prevents several kinds of problemantic corner cases. It is a user-visible change so it has a minute chance of causing regressions so the change to /proc/mounts and /proc/net are individual one line commits that can be trivially reverted. Unfortunately I lost and could not find the email of the original reporter so he is not credited. From at least one perspective this change to /proc/net is a refgression fix to allow pthread /proc/net uses that were broken by the introduction of the network namespace" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Point /proc/mounts at /proc/thread-self/mounts instead of /proc/self/mounts proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net proc: Implement /proc/thread-self to point at the directory of the current thread proc: Have net show up under /proc/<tgid>/task/<tid> NFS: Fix /proc/fs/nfsfs/servers and /proc/fs/nfsfs/volumes mnt: Add tests for unprivileged remount cases that have found to be faulty mnt: Change the default remount atime from relatime to the existing value mnt: Correct permission checks in do_remount mnt: Move the test for MNT_LOCK_READONLY from change_mount_flags into do_remount mnt: Only change user settable mount flags in remount namespaces: Use task_lock and not rcu to protect nsproxy
| * | | | namespaces: Use task_lock and not rcu to protect nsproxyEric W. Biederman2014-07-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The synchronous syncrhonize_rcu in switch_task_namespaces makes setns a sufficiently expensive system call that people have complained. Upon inspect nsproxy no longer needs rcu protection for remote reads. remote reads are rare. So optimize for same process reads and write by switching using rask_lock instead. This yields a simpler to understand lock, and a faster setns system call. In particular this fixes a performance regression observed by Rafael David Tinoco <rafael.tinoco@canonical.com>. This is effectively a revert of Pavel Emelyanov's commit cf7b708c8d1d7a27736771bcf4c457b332b0f818 Make access to task's nsproxy lighter from 2007. The race this originialy fixed no longer exists as do_notify_parent uses task_active_pid_ns(parent) instead of parent->nsproxy. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | | | | Merge branch 'signal-cleanup' of ↵Linus Torvalds2014-08-09
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc Pull arch signal handling cleanup from Richard Weinberger: "This patch series moves all remaining archs to the get_signal(), signal_setup_done() and sigsp() functions. Currently these archs use open coded variants of the said functions. Further, unused parameters get removed from get_signal_to_deliver(), tracehook_signal_handler() and signal_delivered(). At the end of the day we save around 500 lines of code." * 'signal-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/misc: (43 commits) powerpc: Use sigsp() openrisc: Use sigsp() mn10300: Use sigsp() mips: Use sigsp() microblaze: Use sigsp() metag: Use sigsp() m68k: Use sigsp() m32r: Use sigsp() hexagon: Use sigsp() frv: Use sigsp() cris: Use sigsp() c6x: Use sigsp() blackfin: Use sigsp() avr32: Use sigsp() arm64: Use sigsp() arc: Use sigsp() sas_ss_flags: Remove nested ternary if Rip out get_signal_to_deliver() Clean up signal_delivered() tracehook_signal_handler: Remove sig, info, ka and regs ...
| * | | | | Rip out get_signal_to_deliver()Richard Weinberger2014-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now we can turn get_signal() to the main function. Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | | | Clean up signal_delivered()Richard Weinberger2014-08-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Pass a ksignal struct to it - Remove unused regs parameter - Make it private as it's nowhere outside of kernel/signal.c is used Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | | | tracehook_signal_handler: Remove sig, info, ka and regsRichard Weinberger2014-08-06
| | |/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | These parameters are nowhere used, so we can remove them. Signed-off-by: Richard Weinberger <richard@nod.at>
* | | | | kexec: verify the signature of signed PE bzImageVivek Goyal2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the final piece of the puzzle of verifying kernel image signature during kexec_file_load() syscall. This patch calls into PE file routines to verify signature of bzImage. If signature are valid, kexec_file_load() succeeds otherwise it fails. Two new config options have been introduced. First one is CONFIG_KEXEC_VERIFY_SIG. This option enforces that kernel has to be validly signed otherwise kernel load will fail. If this option is not set, no signature verification will be done. Only exception will be when secureboot is enabled. In that case signature verification should be automatically enforced when secureboot is enabled. But that will happen when secureboot patches are merged. Second config option is CONFIG_KEXEC_BZIMAGE_VERIFY_SIG. This option enables signature verification support on bzImage. If this option is not set and previous one is set, kernel image loading will fail because kernel does not have support to verify signature of bzImage. I tested these patches with both "pesign" and "sbsign" signed bzImages. I used signing_key.priv key and signing_key.x509 cert for signing as generated during kernel build process (if module signing is enabled). Used following method to sign bzImage. pesign ====== - Convert DER format cert to PEM format cert openssl x509 -in signing_key.x509 -inform DER -out signing_key.x509.PEM -outform PEM - Generate a .p12 file from existing cert and private key file openssl pkcs12 -export -out kernel-key.p12 -inkey signing_key.priv -in signing_key.x509.PEM - Import .p12 file into pesign db pk12util -i /tmp/kernel-key.p12 -d /etc/pki/pesign - Sign bzImage pesign -i /boot/vmlinuz-3.16.0-rc3+ -o /boot/vmlinuz-3.16.0-rc3+.signed.pesign -c "Glacier signing key - Magrathea" -s sbsign ====== sbsign --key signing_key.priv --cert signing_key.x509.PEM --output /boot/vmlinuz-3.16.0-rc3+.signed.sbsign /boot/vmlinuz-3.16.0-rc3+ Patch details: Well all the hard work is done in previous patches. Now bzImage loader has just call into that code and verify whether bzImage signature are valid or not. Also create two config options. First one is CONFIG_KEXEC_VERIFY_SIG. This option enforces that kernel has to be validly signed otherwise kernel load will fail. If this option is not set, no signature verification will be done. Only exception will be when secureboot is enabled. In that case signature verification should be automatically enforced when secureboot is enabled. But that will happen when secureboot patches are merged. Second config option is CONFIG_KEXEC_BZIMAGE_VERIFY_SIG. This option enables signature verification support on bzImage. If this option is not set and previous one is set, kernel image loading will fail because kernel does not have support to verify signature of bzImage. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Matt Fleming <matt@console-pimps.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | kexec: support for kexec on panic using new system callVivek Goyal2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support for loading a kexec on panic (kdump) kernel usning new system call. It prepares ELF headers for memory areas to be dumped and for saved cpu registers. Also prepares the memory map for second kernel and limits its boot to reserved areas only. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | kexec-bzImage64: support for loading bzImage using 64bit entryVivek Goyal2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is loader specific code which can load bzImage and set it up for 64bit entry. This does not take care of 32bit entry or real mode entry. 32bit mode entry can be implemented if somebody needs it. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | kexec: load and relocate purgatory at kernel load timeVivek Goyal2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Load purgatory code in RAM and relocate it based on the location. Relocation code has been inspired by module relocation code and purgatory relocation code in kexec-tools. Also compute the checksums of loaded kexec segments and store them in purgatory. Arch independent code provides this functionality so that arch dependent bootloaders can make use of it. Helper functions are provided to get/set symbol values in purgatory which are used by bootloaders later to set things like stack and entry point of second kernel etc. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | kexec: implementation of new syscall kexec_file_loadVivek Goyal2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previous patch provided the interface definition and this patch prvides implementation of new syscall. Previously segment list was prepared in user space. Now user space just passes kernel fd, initrd fd and command line and kernel will create a segment list internally. This patch contains generic part of the code. Actual segment preparation and loading is done by arch and image specific loader. Which comes in next patch. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | kexec: new syscall kexec_file_load() declarationVivek Goyal2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the new syscall kexec_file_load() declaration/interface. I have reserved the syscall number only for x86_64 so far. Other architectures (including i386) can reserve syscall number when they enable the support for this new syscall. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Borislav Petkov <bp@suse.de> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | resource: provide new functions to walk through resourcesVivek Goyal2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I have added two more functions to walk through resources. Currently walk_system_ram_range() deals with pfn and /proc/iomem can contain partial pages. By dealing in pfn, callback function loses the info that last page of a memory range is a partial page and not the full page. So I implemented walk_system_ram_res() which returns u64 values to callback functions and now it properly return start and end address. walk_system_ram_range() uses find_next_system_ram() to find the next ram resource. This in turn only travels through siblings of top level child and does not travers through all the nodes of the resoruce tree. I also need another function where I can walk through all the resources, for example figure out where "GART" aperture is. Figure out where ACPI memory is. So I wrote another function walk_iomem_res() which walks through all /proc/iomem resources and returns matches as asked by caller. Caller can specify "name" of resource, start and end and flags. Got rid of find_next_system_ram_res() and instead implemented more generic find_next_iomem_res() which can be used to traverse top level children only based on an argument. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | kexec: use common function for kimage_normal_alloc() and kimage_crash_alloc()Vivek Goyal2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kimage_normal_alloc() and kimage_crash_alloc() are doing lot of similar things and differ only little. So instead of having two separate functions create a common function kimage_alloc_init() and pass it the "flags" argument which tells whether it is normal kexec or kexec_on_panic. And this function should be able to deal with both the cases. This consolidation also helps later where we can use a common function kimage_file_alloc_init() to handle normal and crash cases for new file based kexec syscall. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | kexec: move segment verification code in a separate functionVivek Goyal2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously do_kimage_alloc() will allocate a kimage structure, copy segment list from user space and then do the segment list sanity verification. Break down this function in 3 parts. do_kimage_alloc_init() to do actual allocation and basic initialization of kimage structure. copy_user_segment_list() to copy segment list from user space and sanity_check_segment_list() to verify the sanity of segment list as passed by user space. In later patches, I need to only allocate kimage and not copy segment list from user space. So breaking down in smaller functions enables re-use of code at other places. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | kexec: rename unusebale_pages to unusable_pagesVivek Goyal2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let's use the more common "unusable". This patch was originally written and posted by Boris. I am including it in this patch series. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | bin2c: move bin2c in scripts/basicVivek Goyal2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch series does not do kernel signature verification yet. I plan to post another patch series for that. Now distributions are already signing PE/COFF bzImage with PKCS7 signature I plan to parse and verify those signatures. Primary goal of this patchset is to prepare groundwork so that kernel image can be signed and signatures be verified during kexec load. This should help with two things. - It should allow kexec/kdump on secureboot enabled machines. - In general it can help even without secureboot. By being able to verify kernel image signature in kexec, it should help with avoiding module signing restrictions. Matthew Garret showed how to boot into a custom kernel, modify first kernel's memory and then jump back to old kernel and bypass any policy one wants to. This patch (of 15): Kexec wants to use bin2c and it wants to use it really early in the build process. See arch/x86/purgatory/ code in later patches. So move bin2c in scripts/basic so that it can be built very early and be usable by arch/x86/purgatory/ Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | shm: add memfd_create() syscallDavid Herrmann2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | memfd_create() is similar to mmap(MAP_ANON), but returns a file-descriptor that you can pass to mmap(). It can support sealing and avoids any connection to user-visible mount-points. Thus, it's not subject to quotas on mounted file-systems, but can be used like malloc()'ed memory, but with a file-descriptor to it. memfd_create() returns the raw shmem file, so calls like ftruncate() can be used to modify the underlying inode. Also calls like fstat() will return proper information and mark the file as regular file. If you want sealing, you can specify MFD_ALLOW_SEALING. Otherwise, sealing is not supported (like on all other regular files). Compared to O_TMPFILE, it does not require a tmpfs mount-point and is not subject to a filesystem size limit. It is still properly accounted to memcg limits, though, and to the same overcommit or no-overcommit accounting as all user memory. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ryan Lortie <desrt@desrt.ca> Cc: Lennart Poettering <lennart@poettering.net> Cc: Daniel Mack <zonque@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | mm: allow drivers to prevent new writable mappingsDavid Herrmann2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (of 6): The i_mmap_writable field counts existing writable mappings of an address_space. To allow drivers to prevent new writable mappings, make this counter signed and prevent new writable mappings if it is negative. This is modelled after i_writecount and DENYWRITE. This will be required by the shmem-sealing infrastructure to prevent any new writable mappings after the WRITE seal has been set. In case there exists a writable mapping, this operation will fail with EBUSY. Note that we rely on the fact that iff you already own a writable mapping, you can increase the counter without using the helpers. This is the same that we do for i_writecount. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ryan Lortie <desrt@desrt.ca> Cc: Lennart Poettering <lennart@poettering.net> Cc: Daniel Mack <zonque@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | kernel/acct.c: fix coding style warnings and errorsIonut Alexa2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ionut Alexa <ionut.m.alexa@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | shm: make exit_shm work proportional to task activityJack Miller2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is small set of patches our team has had kicking around for a few versions internally that fixes tasks getting hung on shm_exit when there are many threads hammering it at once. Anton wrote a simple test to cause the issue: http://ozlabs.org/~anton/junkcode/bust_shm_exit.c Before applying this patchset, this test code will cause either hanging tracebacks or pthread out of memory errors. After this patchset, it will still produce output like: root@somehost:~# ./bust_shm_exit 1024 160 ... INFO: rcu_sched detected stalls on CPUs/tasks: {} (detected by 116, t=2111 jiffies, g=241, c=240, q=7113) INFO: Stall ended before state dump start ... But the task will continue to run along happily, so we consider this an improvement over hanging, even if it's a bit noisy. This patch (of 3): exit_shm obtains the ipc_ns shm rwsem for write and holds it while it walks every shared memory segment in the namespace. Thus the amount of work is related to the number of shm segments in the namespace not the number of segments that might need to be cleaned. In addition, this occurs after the task has been notified the thread has exited, so the number of tasks waiting for the ns shm rwsem can grow without bound until memory is exausted. Add a list to the task struct of all shmids allocated by this task. Init the list head in copy_process. Use the ns->rwsem for locking. Add segments after id is added, remove before removing from id. On unshare of NEW_IPCNS orphan any ids as if the task had exited, similar to handling of semaphore undo. I chose a define for the init sequence since its a simple list init, otherwise it would require a function call to avoid include loops between the semaphore code and the task struct. Converting the list_del to list_del_init for the unshare cases would remove the exit followed by init, but I left it blow up if not inited. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Jack Miller <millerjo@us.ibm.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | panic: add TAINT_SOFTLOCKUPJosh Hunt2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This taint flag will be set if the system has ever entered a softlockup state. Similar to TAINT_WARN it is useful to know whether or not the system has been in a softlockup state when debugging. [akpm@linux-foundation.org: apply the taint before calling panic()] Signed-off-by: Josh Hunt <johunt@akamai.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | kernel/gcov/fs.c: remove unnecessary null test before debugfs_removeFabian Frederick2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes checkpatch warning: WARNING: debugfs_remove(NULL) is safe this check is probably not required Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | kernel/fork.c: make mm_init_owner staticVladimir Davydov2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's only used in fork.c:mm_init(). Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | fork: copy mm's vm usage counters under mmap_semVladimir Davydov2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a forking process has a thread calling (un)mmap (silly but still), the child process may have some of its mm's vm usage counters (total_vm and friends) screwed up, because currently they are copied from oldmm w/o holding any locks (memcpy in dup_mm). This patch moves the counters initialization to dup_mmap() to be called under oldmm->mmap_sem, which eliminates any possibility of race. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | fork: reset mm->pinned_vmVladimir Davydov2014-08-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mm->pinned_vm counts pages of mm's address space that were permanently pinned in memory by increasing their reference counter. The counter was introduced by commit bc3e53f682d9 ("mm: distinguish between mlocked and pinned pages"), while before it locked_vm had been used for such pages. Obviously, we should reset the counter on fork if !CLONE_VM, just like we do with locked_vm, but currently we don't. Let's fix it. This patch will fix the contents of /proc/pid/status:VmPin. ib_umem_get[infiniband] and perf_mmap still check pinned_vm against RLIMIT_MEMLOCK. It's left from the times when pinned pages were accounted under locked_vm, but today it looks wrong. It isn't clear how we should deal with it. We still have some drivers accounting pinned pages under mm->locked_vm - this is what commit bc3e53f682d9 was fighting against. It's infiniband/usnic and vfio. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Roland Dreier <roland@kernel.org> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Hal Rosenstock <hal.rosenstock@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>