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2011-03-18x86: Flush TLB if PGD entry is changed in i386 PAE modeShaohua Li2-10/+4
According to intel CPU manual, every time PGD entry is changed in i386 PAE mode, we need do a full TLB flush. Current code follows this and there is comment for this too in the code. But current code misses the multi-threaded case. A changed page table might be used by several CPUs, every such CPU should flush TLB. Usually this isn't a problem, because we prepopulate all PGD entries at process fork. But when the process does munmap and follows new mmap, this issue will be triggered. When it happens, some CPUs keep doing page faults: http://marc.info/?l=linux-kernel&m=129915020508238&w=2 Reported-by: Yasunori Goto<y-goto@jp.fujitsu.com> Tested-by: Yasunori Goto<y-goto@jp.fujitsu.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Shaohua Li<shaohua.li@intel.com> Cc: Mallick Asit K <asit.k.mallick@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm <linux-mm@kvack.org> Cc: stable <stable@kernel.org> LKML-Reference: <1300246649.2337.95.camel@sli10-conroe> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18x86, dumpstack: Correct stack dump info when frame pointer is availableNamhyung Kim9-30/+33
Current stack dump code scans entire stack and check each entry contains a pointer to kernel code. If CONFIG_FRAME_POINTER=y it could mark whether the pointer is valid or not based on value of the frame pointer. Invalid entries could be preceded by '?' sign. However this was not going to happen because scan start point was always higher than the frame pointer so that they could not meet. Commit 9c0729dc8062 ("x86: Eliminate bp argument from the stack tracing routines") delayed bp acquisition point, so the bp was read in lower frame, thus all of the entries were marked invalid. This patch fixes this by reverting above commit while retaining stack_frame() helper as suggested by Frederic Weisbecker. End result looks like below: before: [ 3.508329] Call Trace: [ 3.508551] [<ffffffff814f35c9>] ? panic+0x91/0x199 [ 3.508662] [<ffffffff814f3739>] ? printk+0x68/0x6a [ 3.508770] [<ffffffff81a981b2>] ? mount_block_root+0x257/0x26e [ 3.508876] [<ffffffff81a9821f>] ? mount_root+0x56/0x5a [ 3.508975] [<ffffffff81a98393>] ? prepare_namespace+0x170/0x1a9 [ 3.509216] [<ffffffff81a9772b>] ? kernel_init+0x1d2/0x1e2 [ 3.509335] [<ffffffff81003894>] ? kernel_thread_helper+0x4/0x10 [ 3.509442] [<ffffffff814f6880>] ? restore_args+0x0/0x30 [ 3.509542] [<ffffffff81a97559>] ? kernel_init+0x0/0x1e2 [ 3.509641] [<ffffffff81003890>] ? kernel_thread_helper+0x0/0x10 after: [ 3.522991] Call Trace: [ 3.523351] [<ffffffff814f35b9>] panic+0x91/0x199 [ 3.523468] [<ffffffff814f3729>] ? printk+0x68/0x6a [ 3.523576] [<ffffffff81a981b2>] mount_block_root+0x257/0x26e [ 3.523681] [<ffffffff81a9821f>] mount_root+0x56/0x5a [ 3.523780] [<ffffffff81a98393>] prepare_namespace+0x170/0x1a9 [ 3.523885] [<ffffffff81a9772b>] kernel_init+0x1d2/0x1e2 [ 3.523987] [<ffffffff81003894>] kernel_thread_helper+0x4/0x10 [ 3.524228] [<ffffffff814f6880>] ? restore_args+0x0/0x30 [ 3.524345] [<ffffffff81a97559>] ? kernel_init+0x0/0x1e2 [ 3.524445] [<ffffffff81003890>] ? kernel_thread_helper+0x0/0x10 -v5: * fix build breakage with oprofile -v4: * use 0 instead of regs->bp * separate out printk changes -v3: * apply comment from Frederic * add a couple of printk fixes Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Soren Sandmann <ssp@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Robert Richter <robert.richter@amd.com> LKML-Reference: <1300416006-3163-1-git-send-email-namhyung@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18x86: Clean up csum-copy_64.S a bitIngo Molnar1-120/+120
The many stray whitespaces and other uncleanlinesses made this code almost unreadable to me - so fix those. No changes to the code. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18x86: Fix common misspellingsLucas De Marchi50-67/+67
They were generated by 'codespell' and then manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi> Cc: trivial@kernel.org LKML-Reference: <1300389856-1099-3-git-send-email-lucas.demarchi@profusion.mobi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18x86: Fix misspelling and align paramsLucas De Marchi1-7/+7
Fix 'upto' misspelling and align parameters. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi> Cc: trivial@kernel.org LKML-Reference: <1300389856-1099-2-git-send-email-lucas.demarchi@profusion.mobi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-17x86: Use PentiumPro-optimized partial_csum() on VIA C7Jon Nettleton1-1/+1
Testing on the OLPC XO-1.5 (VIA C7-M 1000MHz CPU) shows a partial_csum() speed increase by a factor of 1.5 when we switch to the Pentium-optimized version. Signed-off-by: Daniel Drake <dsd@laptop.org> Cc: dilinger@queued.net Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-16Increase OSF partition limit from 8 to 18Linus Torvalds1-1/+1
It turns out that while a maximum of 8 partitions may be what people "should" have had, you can actually fit up to 18 entries(*) in a sector. And some people clearly were taking advantage of that, like Michael Cree, who had ten partitions on one of his OSF disks. (*) The OSF partition data starts at byte offset 64 in the first sector, and the array of 16-byte partition entries start at offset 148 in the on-disk partition structure. Reported-by: Michael Cree <mcree@orcon.net.nz> Cc: stable@kernel.org (v2.6.38) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-16prune back iprune_semChristoph Hellwig1-18/+14
iprune_sem is continously giving us lockdep warnings because we do take it in read mode in the reclaim path, but we're also doing non-NOFS allocations under it taken in write mode. Taking a bit deeper look at it I think it's fixable quite trivially: - for invalidate_inodes we do not need iprune_sem at all. We have an active reference on the superblock, so the filesystem is not going away until it has finished. - for evict_inodes we do need it, to make sure prune_icache has done it's work before we tear down the superblock. But there is no reason to hold it over the actual reclaim operation - it's enough to cycle through it after the actual reclaim to make sure we wait for any pending prune_icache to complete. We just have to remove the WARN_ON for otherwise busy inodes as they can actually happen now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-16vfs: add nonconflicting values for O_PATHStephen Rothwell3-0/+6
[AV: on architectures where default conflicts with existing flags, that is] Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-16x86, AMD: Set ARAT feature on AMD processorsBoris Ostrovsky1-0/+4
Support for Always Running APIC timer (ARAT) was introduced in commit db954b5898dd3ef3ef93f4144158ea8f97deb058. This feature allows us to avoid switching timers from LAPIC to something else (e.g. HPET) and go into timer broadcasts when entering deep C-states. AMD processors don't provide a CPUID bit for that feature but they also keep APIC timers running in deep C-states (except for cases when the processor is affected by erratum 400). Therefore we should set ARAT feature bit on AMD CPUs. Tested-by: Borislav Petkov <borislav.petkov@amd.com> Acked-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Mark Langsdorf <mark.langsdorf@amd.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com> LKML-Reference: <1300205624-4813-1-git-send-email-ostr@amd64.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-16x86, quirk: Fix SB600 revision checkAndreas Herrmann1-1/+6
Commit 7f74f8f28a2bd9db9404f7d364e2097a0c42cc12 (x86 quirk: Fix polarity for IRQ0 pin2 override on SB800 systems) introduced a regression. It removed some SB600 specific code to determine the revision ID without adapting a corresponding revision ID check for SB600. See this mail thread: http://marc.info/?l=linux-kernel&m=129980296006380&w=2 This patch adapts the corresponding check to cover all SB600 revisions. Tested-by: Wang Lei <f3d27b@gmail.com> Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@kernel.org # 38.x, 37.x, 32.x LKML-Reference: <20110315143137.GD29499@alberich.amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-16fix follow_link() breakageAl Viro1-4/+3
commit 574197e0de46a8a4db5c54ef7b65e43ffa8873a7 had a missing piece, breaking the loop detection ;-/ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15VFS: Fix the nfs sillyrename regression in kernel 2.6.38Trond Myklebust1-1/+6
The new vfs locking scheme introduced in 2.6.38 breaks NFS sillyrename because the latter relies on being able to determine the parent directory of the dentry in the ->iput() callback in order to send the appropriate unlink rpc call. Looking at the code that cares about races with dput(), there doesn't seem to be anything that specifically uses d_parent as a test for whether or not there is a race: - __d_lookup_rcu(), __d_lookup() all test for d_hashed() after d_parent - shrink_dcache_for_umount() is safe since nothing else can rearrange the dentries in that super block. - have_submount(), select_parent() and d_genocide() can test for a deletion if we set the DCACHE_DISCONNECTED flag when the dentry is removed from the parent's d_subdirs list. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org (2.6.38, needs commit c826cb7dfce8 "dcache.c: create helper function for duplicated functionality" ) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-15dcache.c: create helper function for duplicated functionalityLinus Torvalds1-51/+37
This creates a helper function for he "try to ascend into the parent directory" case, which was written out in triplicate before. With all the locking and subtle sequence number stuff, we really don't want to duplicate that kind of code. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-15tidy the trailing symlinks traversal upAl Viro1-45/+26
* pull the handling of current->total_link_count into __do_follow_link() * put the common "do ->put_link() if needed and path_put() the link" stuff into a helper (put_link(nd, link, cookie)) * rename __do_follow_link() to follow_link(), while we are at it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15Turn resolution of trailing symlinks iterative everywhereAl Viro1-54/+50
The last remaining place (resolution of nested symlink) converted to the loop of the same kind we have in path_lookupat() and path_openat(). Note that we still *do* have a recursion in pathname resolution; can't avoid it, really. However, it's strictly for nested symlinks now - i.e. ones in the middle of a pathname. link_path_walk() has lost the tail now - it always walks everything except the last component. do_follow_link() renamed to nested_symlink() and moved down. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15simplify link_path_walk() tailAl Viro1-7/+1
Now that link_path_walk() is called without LOOKUP_PARENT only from do_follow_link(), we can simplify the checks in last component handling. First of all, checking if we'd arrived to a directory is not needed - the caller will check it anyway. And LOOKUP_FOLLOW is guaranteed to be there, since we only get to that place with nd->depth > 0. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15Make trailing symlink resolution in path_lookupat() iterativeAl Viro1-10/+53
Now the only caller of link_path_walk() that does *not* pass LOOKUP_PARENT is do_follow_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15update nd->inode in __do_follow_link() instead of after do_follow_link()Al Viro1-3/+2
... and note that we only need to do it for LAST_BIND symlinks Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15pull handling of one pathname component into a helperAl Viro1-68/+55
new helper: walk_component(). Handles everything except symlinks; returns negative on error, 0 on success and 1 on symlinks we decided to follow. Drops out of RCU mode on such symlinks. link_path_walk() and do_last() switched to using that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15fs: allow AT_EMPTY_PATH in linkat(), limit that to CAP_DAC_READ_SEARCHAneesh Kumar K.V1-4/+16
We don't want to allow creation of private hardlinks by different application using the fd passed to them via SCM_RIGHTS. So limit the null relative name usage in linkat syscall to CAP_DAC_READ_SEARCH Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2011-03-15perf probe: Clean up probe_point_lazy_walker() return valueIngo Molnar1-1/+1
Newer compilers (gcc 4.6) complains about: return ret < 0 ?: 0; For the following reason: util/probe-finder.c: In function ‘probe_point_lazy_walker’: util/probe-finder.c:1331:18: error: the omitted middle operand in ?: will always be ‘true’, suggest explicit middle operand [-Werror=parentheses] And indeed the return value is a somewhat obscure (but correct) value of 'true', so return 'ret' instead - this is cleaner and unconfuses GCC as well. Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-15x86: stop_machine_text_poke() should issue sync_core()Mathieu Desnoyers1-1/+6
Intel Archiecture Software Developer's Manual section 7.1.3 specifies that a core serializing instruction such as "cpuid" should be executed on _each_ core before the new instruction is made visible. Failure to do so can lead to unspecified behavior (Intel XMC erratas include General Protection Fault in the list), so we should avoid this at all cost. This problem can affect modified code executed by interrupt handlers after interrupt are re-enabled at the end of stop_machine, because no core serializing instruction is executed between the code modification and the moment interrupts are reenabled. Because stop_machine_text_poke performs the text modification from the first CPU decrementing stop_machine_first, modified code executed in thread context is also affected by this problem. To explain why, we have to split the CPUs in two categories: the CPU that initiates the text modification (calls text_poke_smp) and all the others. The scheduler, executed on all other CPUs after stop_machine, issues an "iret" core serializing instruction, and therefore handles core serialization for all these CPUs. However, the text modification initiator can continue its execution on the same thread and access the modified text without any scheduler call. Given that the CPU that initiates the code modification is not guaranteed to be the one actually performing the code modification, it falls into the XMC errata. Q: Isn't this executed from an IPI handler, which will return with IRET (a serializing instruction) anyway? A: No, now stop_machine uses per-cpu workqueue, so that handler will be executed from worker threads. There is no iret anymore. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> LKML-Reference: <20110303160137.GB1590@Krystal> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: <stable@kernel.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-03-15x86, tlb, UV: Do small micro-optimization for native_flush_tlb_others()Xiao Guangrong1-2/+1
native_flush_tlb_others() is called from: flush_tlb_current_task() flush_tlb_mm() flush_tlb_page() All these functions disable preemption explicitly, so we can use smp_processor_id() instead of get_cpu() and put_cpu(). Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Cc: Cliff Wickman <cpw@sgi.com> LKML-Reference: <4D7EC791.4040003@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-15Allow passing O_PATH descriptors via SCM_RIGHTS datagramsAl Viro3-2/+4
Just need to make sure that AF_UNIX garbage collector won't confuse O_PATHed socket on filesystem for real AF_UNIX opened socket. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15readlinkat(), fchownat() and fstatat() with empty relative pathnamesAl Viro2-6/+11
For readlinkat() we simply allow empty pathname; it will fail unless we have dfd equal to O_PATH-opened symlink, so we are outside of POSIX scope here. For fchownat() and fstatat() we allow AT_EMPTY_PATH; let the caller explicitly ask for such behaviour. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15Allow O_PATH for symlinksAl Viro1-6/+19
At that point we can't do almost nothing with them. They can be opened with O_PATH, we can manipulate such descriptors with dup(), etc. and we can see them in /proc/*/{fd,fdinfo}/*. We can't (and won't be able to) follow /proc/*/fd/* symlinks for those; there's simply not enough information for pathname resolution to go on from such point - to resolve a symlink we need to know which directory does it live in. We will be able to do useful things with them after the next commit, though - readlinkat() and fchownat() will be possible to use with dfd being an O_PATH-opened symlink and empty relative pathname. Combined with open_by_handle() it'll give us a way to do realink-by-handle and lchown-by-handle without messing with more redundant syscalls. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15New kind of open files - "location only".Al Viro7-17/+119
New flag for open(2) - O_PATH. Semantics: * pathname is resolved, but the file itself is _NOT_ opened as far as filesystem is concerned. * almost all operations on the resulting descriptors shall fail with -EBADF. Exceptions are: 1) operations on descriptors themselves (i.e. close(), dup(), dup2(), dup3(), fcntl(fd, F_DUPFD), fcntl(fd, F_DUPFD_CLOEXEC, ...), fcntl(fd, F_GETFD), fcntl(fd, F_SETFD, ...)) 2) fcntl(fd, F_GETFL), for a common non-destructive way to check if descriptor is open 3) "dfd" arguments of ...at(2) syscalls, i.e. the starting points of pathname resolution * closing such descriptor does *NOT* affect dnotify or posix locks. * permissions are checked as usual along the way to file; no permission checks are applied to the file itself. Of course, giving such thing to syscall will result in permission checks (at the moment it means checking that starting point of ....at() is a directory and caller has exec permissions on it). fget() and fget_light() return NULL on such descriptors; use of fget_raw() and fget_raw_light() is needed to get them. That protects existing code from dealing with those things. There are two things still missing (they come in the next commits): one is handling of symlinks (right now we refuse to open them that way; see the next commit for semantics related to those) and another is descriptor passing via SCM_RIGHTS datagrams. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15ext4: Copy fs UUID to superblockAneesh Kumar K.V1-0/+2
File system UUID is made available to application via /proc/<pid>/mountinfo Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15ext3: Copy fs UUID to superblock.Aneesh Kumar K.V1-0/+1
File system UUID is made available to application via /proc/<pid>/mountinfo Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15vfs: Export file system uuid via /proc/<pid>/mountinfoAneesh Kumar K.V2-0/+17
We add a per superblock uuid field. File systems should update the uuid in the fill_super callback Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15unistd.h: Add new syscalls numbers to asm-genericAneesh Kumar K.V1-1/+5
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15x86: Add new syscalls for x86_64Aneesh Kumar K.V2-0/+6
This patch add new syscalls to x86_64 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15x86: Add new syscalls for x86_32Aneesh Kumar K.V2-1/+5
This patch adds new syscalls to x86_32 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15fs: Remove i_nlink check from file system link callbackAneesh Kumar K.V6-42/+0
Now that VFS check for inode->i_nlink == 0 and returns proper error, remove similar check from file system Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15fs: Don't allow to create hardlink for deleted fileAneesh Kumar K.V1-1/+5
Add inode->i_nlink == 0 check in VFS. Some of the file systems do this internally. A followup patch will remove those instance. This is needed to ensure that with link by handle we don't allow to create hardlink of an unlinked file. The check also prevent a race between unlink and link Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15vfs: Add open by file handle supportAneesh Kumar K.V6-0/+181
[AV: duplicate of open() guts removed; file_open_root() used instead] Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15vfs: Add name to file handle conversion supportAneesh Kumar K.V8-2/+139
The syscall also return mount id which can be used to lookup file system specific information such as uuid in /proc/<pid>/mountinfo Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-14Linux 2.6.38Linus Torvalds1-1/+1
2011-03-14New AT_... flag: AT_EMPTY_PATHAl Viro3-10/+21
For name_to_handle_at(2) we'll want both ...at()-style syscall that would be usable for non-directory descriptors (with empty relative pathname). Introduce new flag (AT_EMPTY_PATH) to deal with that and corresponding LOOKUP_EMPTY; teach user_path_at() and path_init() to deal with the latter. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-14Revert "oom: oom_kill_process: fix the child_points logic"Linus Torvalds1-8/+3
This reverts the parent commit. I hate doing that, but it's generating some discussion ("half of it is right"), and since I am planning on doing the 2.6.38 release later today we can punt it to stable if required. Let's not rock the boat right now. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-14oom: oom_kill_process: fix the child_points logicOleg Nesterov1-3/+8
oom_kill_process() starts with victim_points == 0. This means that (most likely) any child has more points and can be killed erroneously. Also, "children has a different mm" doesn't match the reality, we should check child->mm != t->mm. This check is not exactly correct if t->mm == NULL but this doesn't really matter, oom_kill_task() will kill them anyway. Note: "Kill all processes sharing p->mm" in oom_kill_task() is wrong too. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-14arm: Remove bogus comment in futex_atomic_cmpxchg_inatomic()Thomas Gleixner1-3/+0
commit 522d7dec(futex: Remove redundant pagefault_disable in futex_atomic_cmpxchg_inatomic()) added a bogus comment. /* Note that preemption is disabled by futex_atomic_cmpxchg_inatomic * call sites. */ Bogus in two aspects: 1) pagefault_disable != preempt_disable even if the mechanism we use is the same 2) we have a call site which deliberately does not disable pagefaults as it wants the possible fault to be handled - though that has been changed for consistency reasons now. Sigh. I really should have seen that when committing the above. :( Catched-by-and-rightfully-ranted-at-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <alpine.LFD.2.00.1103141126590.2787@localhost6.localdomain6> Cc: Michel Lespinasse <walken@google.com> Cc: Darren Hart <darren@dvhart.com>
2011-03-14futex: Deobfuscate handle_futex_death()Thomas Gleixner1-3/+14
handle_futex_death() uses futex_atomic_cmpxchg_inatomic() without disabling page faults. That's ok, but totally non obvious. We don't hold locks so we actually can and want to fault here, because the get_user() before futex_atomic_cmpxchg_inatomic() does not guarantee a R/W mapping. We could just add a big fat comment to explain this, but actually changing the code so that the functionality is entirely clear is better. Use the helper function which disables page faults around the futex_atomic_cmpxchg_inatomic() and handle a fault with a call to fault_in_user_writeable() as all other places in the futex code do as well. Pointed-out-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Darren Hart <darren@dvhart.com> Cc: Michel Lespinasse <walken@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> LKML-Reference: <alpine.LFD.2.00.1103141126590.2787@localhost6.localdomain6> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2011-03-14MIPS: Alchemy: Fix reset for MTX-1 and XXS1500Florian Fainelli2-4/+4
Since commit 32fd6901 (MIPS: Alchemy: get rid of common/reset.c) Alchemy-based boards use their own reset function. For MTX-1 and XXS1500, the reset function pokes at the BCSR.SYSTEM_RESET register, but this does not work. According to Bruno Randolf, this was not tested when written. Previously, the generic au1000_restart() routine called the board specific reset function, which for MTX-1 and XXS1500 did not work, but finally made a jump to the reset vector, which really triggers a system restart. Fix reboot for both targets by jumping to the reset vector. Signed-off-by: Florian Fainelli <florian@openwrt.org> To: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/2093/ Acked-by: Bruno Randolf <br1@einfach.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-03-14MIPS: MTX-1: Make au1000_eth probe all PHY addressesFlorian Fainelli1-0/+9
When au1000_eth probes the MII bus for PHY address, if we do not set au1000_eth platform data's phy_search_highest_address, the MII probing logic will exit early and will assume a valid PHY is found at address 0. For MTX-1, the PHY is at address 31, and without this patch, the link detection/speed/duplex would not work correctly. CC: stable@kernel.org Signed-off-by: Florian Fainelli <florian@openwrt.org> To: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/2111/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-03-14MIPS: Jz4740: Add HAVE_CLKMaurus Cuelenaere1-0/+1
Jz4740 supports the clock framework but doesn't have HAVE_CLK defined, so define it! Signed-off-by: Maurus Cuelenaere <mcuelenaere@gmail.com> To: linux-mips@linux-mips.org To: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/2112/ Acked-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-03-14MIPS: Move idle task creation to work queueMaksim Rayskiy1-2/+29
To avoid forking usermode thread when creating an idle task, move fork_idle to a work queue. If kernel starts with maxcpus= option which does not bring all available cpus online at boot time, idle tasks for offline cpus are not created. If later offline cpus are hotplugged through sysfs, __cpu_up is called in the context of the user task, and fork_idle copies its non-zero mm pointer. This causes BUG() in per_cpu_trap_init. This also avoids issues with resource limits of the CPU writing to sysfs, containers, maybe others. Signed-off-by: Maksim Rayskiy <mrayskiy@broadcom.com> To: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/2070/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-03-14MIPS, Perf-events: Use unsigned delta for right shift in event updateDeng-Cheng Zhu1-1/+1
Leverage the commit for ARM by Will Deacon: - 446a5a8b1eb91a6990e5c8fe29f14e7a95b69132 ARM: 6205/1: perf: ensure counter delta is treated as unsigned Hardware performance counters on ARM are 32-bits wide but atomic64_t variables are used to represent counter data in the hw_perf_event structure. The armpmu_event_update function right-shifts a signed 64-bit delta variable and adds the result to the event count. This can lead to shifting in sign-bits if the MSB of the 32-bit counter value is set. This results in perf output such as: Performance counter stats for 'sleep 20': 18446744073460670464 cycles <-- 0xFFFFFFFFF12A6000 7783773 instructions # 0.000 IPC 465 context-switches 161 page-faults 1172393 branches 20.154242147 seconds time elapsed This patch ensures that the delta value is treated as unsigned so that the right shift sets the upper bits to zero. Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com> To: a.p.zijlstra@chello.nl To: fweisbec@gmail.com To: will.deacon@arm.com Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: wuzhangjin@gmail.com Cc: paulus@samba.org Cc: mingo@elte.hu Cc: acme@redhat.com Cc: matt@console-pimps.org Cc: sshtylyov@mvista.com Patchwork: http://patchwork.linux-mips.org/patch/2015/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-03-14MIPS, Perf-events: Work with the new callchain interfaceDeng-Cheng Zhu1-57/+6
This is the MIPS part of the following commits by Frederic Weisbecker: - f72c1a931e311bb7780fee19e41a89ac42cab50e perf: Factorize callchain context handling Store the kernel and user contexts from the generic layer instead of archs, this gathers some repetitive code. - 56962b4449af34070bb1994621ef4f0265eed4d8 perf: Generalize some arch callchain code - Most archs use one callchain buffer per cpu, except x86 that needs to deal with NMIs. Provide a default perf_callchain_buffer() implementation that x86 overrides. - Centralize all the kernel/user regs handling and invoke new arch handlers from there: perf_callchain_user() / perf_callchain_kernel() That avoid all the user_mode(), current->mm checks and so... - Invert some parameters in perf_callchain_*() helpers: entry to the left, regs to the right, following the traditional (dst, src). - 70791ce9ba68a5921c9905ef05d23f62a90bc10c perf: Generalize callchain_store() callchain_store() is the same on every archs, inline it in perf_event.h and rename it to perf_callchain_store() to avoid any collision. This removes repetitive code. - c1a65932fd7216fdc9a0db8bbffe1d47842f862c perf: Drop unappropriate tests on arch callchains Drop the TASK_RUNNING test on user tasks for callchains as this check doesn't seem to make any sense. Also remove the tests for !current that is not supposed to happen and current->pid as this should be handled at the generic level, with exclude_idle attribute. Reported-by: Wu Zhangjin <wuzhangjin@gmail.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com> To: a.p.zijlstra@chello.nl To: will.deacon@arm.com Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: paulus@samba.org Cc: mingo@elte.hu Cc: acme@redhat.com Cc: dengcheng.zhu@gmail.com Cc: matt@console-pimps.org Cc: sshtylyov@mvista.com Patchwork: http://patchwork.linux-mips.org/patch/2014/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>