summaryrefslogtreecommitdiffstats
Commit message (Collapse)AuthorAgeFilesLines
* sysctl: protect poll() in entries that may go awayLucas De Marchi2012-03-221-1/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Protect code accessing ctl_table by grabbing the header with grab_header() and after releasing with sysctl_head_finish(). This is needed if poll() is called in entries created by modules: currently only hostname and domainname support poll(), but this bug may be triggered when/if modules use it and if user called poll() in a file that doesn't support it. Dave Jones reported the following when using a syscall fuzzer while hibernating/resuming: RIP: 0010:[<ffffffff81233e3e>] [<ffffffff81233e3e>] proc_sys_poll+0x4e/0x90 RAX: 0000000000000145 RBX: ffff88020cab6940 RCX: 0000000000000000 RDX: ffffffff81233df0 RSI: 6b6b6b6b6b6b6b6b RDI: ffff88020cab6940 [ ... ] Code: 00 48 89 fb 48 89 f1 48 8b 40 30 4c 8b 60 e8 b8 45 01 00 00 49 83 7c 24 28 00 74 2e 49 8b 74 24 30 48 85 f6 74 24 48 85 c9 75 32 <8b> 16 b8 45 01 00 00 48 63 d2 49 39 d5 74 10 8b 06 48 98 48 89 If an entry goes away while we are polling() it, ctl_table may not exist anymore. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Don't call sysctl_follow_link unless we are a link.Eric W. Biederman2012-02-011-12/+12
| | | | | | | | | There are no functional changes. Just code motion to make it clear that we don't follow a link between sysctl roots unless the directory entry actually is a link. Suggested-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Comments to make the code clearer.Eric W. Biederman2012-02-011-0/+16
| | | | | | | Document get_subdir and that find_subdir alwasy takes a reference. Suggested-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Correct error return from get_subdirEric W. Biederman2012-02-011-1/+4
| | | | | | | | | When insert_header fails ensure we return the proper error value from get_subdir. In practice nothing cares, but there is no need to be sloppy. Reported-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: An easier to read version of find_subdirEric W. Biederman2012-02-011-3/+3
| | | | | Suggested-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: fix memset parameters in setup_sysctl_set()Dan Carpenter2012-01-301-1/+1
| | | | | | | The current code is a nop. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: remove an unused variableDan Carpenter2012-01-301-2/+0
| | | | | | | "links" is never used, so we can remove it. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Add register_sysctl for normal sysctl usersEric W. Biederman2012-01-242-0/+18
| | | | | | | | | | The plan is to convert all callers of register_sysctl_table and register_sysctl_paths to register_sysctl. The interface to register_sysctl is enough nicer this should make the callers a bit more readable. Additionally after the conversion the 230 lines of backwards compatibility can be removed. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Index sysctl directories with rbtrees.Eric W. Biederman2012-01-242-92/+142
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One of the most important jobs of sysctl is to export network stack tunables. Several of those tunables are per network device. In several instances people are running with 1000+ network devices in there network stacks, which makes the simple per directory linked list in sysctl a scaling bottleneck. Replace O(N^2) sysctl insertion and lookup times with O(NlogN) by using an rbtree to index the sysctl directories. Benchmark before: make-dummies 0 999 -> 0.32s rmmod dummy -> 0.12s make-dummies 0 9999 -> 1m17s rmmod dummy -> 17s Benchmark after: make-dummies 0 999 -> 0.074s rmmod dummy -> 0.070s make-dummies 0 9999 -> 3.4s rmmod dummy -> 0.44s Benchmark after (without dev_snmp6): make-dummies 0 9999 -> 0.75s rmmod dummy -> 0.44s make-dummies 0 99999 -> 11s rmmod dummy -> 4.3s At 10,000 dummy devices the bottleneck becomes the time to add and remove the files under /proc/sys/net/dev_snmp6. I have commented out the code that adds and removes files under /proc/sys/net/dev_snmp6 and taken measurments of creating and destroying 100,000 dummies to verify the sysctl continues to scale. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Make the header lists per directory.Eric W. Biederman2012-01-242-18/+12
| | | | | | | | | | | | | | | | | | | Slightly enhance efficiency and clarity of the code by making the header list per directory instead of per set. Benchmark before: make-dummies 0 999 -> 0.63s rmmod dummy -> 0.12s make-dummies 0 9999 -> 2m35s rmmod dummy -> 18s Benchmark after: make-dummies 0 999 -> 0.32s rmmod dummy -> 0.12s make-dummies 0 9999 -> 1m17s rmmod dummy -> 17s Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Move sysctl_check_dups into insert_headerEric W. Biederman2012-01-241-9/+11
| | | | | | | | | | | | | | | Simplify the callers of insert_header by removing explicit calls to check for duplicates and instead have insert_header do the work. This makes the code slightly more maintainable by enabling changes to data structures where the insertion of new entries without duplicate suppression is not possible. There is not always a convenient path string where insert_header is called so modify sysctl_check_dups to use sysctl_print_dir when printing the full path when a duplicate is discovered. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Modify __register_sysctl_paths to take a set instead of a root and ↵Eric W. Biederman2012-01-243-27/+17
| | | | | | | | | | an nsproxy An nsproxy argument here has always been awkard and now the nsproxy argument is completely unnecessary so remove it, replacing it with the set we want the registered tables to show up in. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Replace root_list with links between sysctl_table_sets.Eric W. Biederman2012-01-242-104/+296
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Piecing together directories by looking first in one directory tree, than in another directory tree and finally in a third directory tree makes it hard to verify that some directory entries are not multiply defined and makes it hard to create efficient implementations the sysctl filesystem. Replace the sysctl wide list of roots with autogenerated links from the core sysctl directory tree to the other sysctl directory trees. This simplifies sysctl directory reading and lookups as now only entries in a single sysctl directory tree need to be considered. Benchmark before: make-dummies 0 999 -> 0.44s rmmod dummy -> 0.065s make-dummies 0 9999 -> 1m36s rmmod dummy -> 0.4s Benchmark after: make-dummies 0 999 -> 0.63s rmmod dummy -> 0.12s make-dummies 0 9999 -> 2m35s rmmod dummy -> 18s The slowdown is caused by the lookups used in insert_headers and put_links to see if we need to add links or remove links. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Add sysctl_print_dir and use it in get_subdirEric W. Biederman2012-01-241-1/+10
| | | | | | | | When there are errors it is very nice to know the full sysctl path. Add a simple function that computes the sysctl path and prints it out. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Stop requiring explicit management of sysctl directoriesEric W. Biederman2012-01-242-202/+150
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simplify the code and the sysctl semantics by autogenerating sysctl directories when a sysctl table is registered that needs the directories and autodeleting the directories when there are no more sysctl tables registered that need them. Autogenerating directories keeps sysctl tables from depending on each other, removing all of the arcane register/unregister ordering constraints and makes it impossible to get the order wrong when reigsering and unregistering sysctl tables. Autogenerating directories yields one unique entity that dentries can point to, retaining the current effective use of the dcache. Add struct ctl_dir as the type of these new autogenerated directories. The attached_by and attached_to fields in ctl_table_header are removed as they are no longer needed. The child field in ctl_table is no longer needed by the core of the sysctl code. ctl_table.child can be removed once all of the existing users have been updated. Benchmark before: make-dummies 0 999 -> 0.7s rmmod dummy -> 0.07s make-dummies 0 9999 -> 1m10s rmmod dummy -> 0.4s Benchmark after: make-dummies 0 999 -> 0.44s rmmod dummy -> 0.065s make-dummies 0 9999 -> 1m36s rmmod dummy -> 0.4s Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Add a root pointer to ctl_table_setEric W. Biederman2012-01-243-3/+8
| | | | | | | Add a ctl_table_root pointer to ctl_table set so it is easy to go from a ctl_table_set to a ctl_table_root. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Rewrite proc_sys_readdir in terms of first_entry and next_entryEric W. Biederman2012-01-241-36/+62
| | | | | | | | | | | | | Replace sysctl_head_next with first_entry and next_entry. These new iterators operate at the level of sysctl table entries and filter out any sysctl tables that should not be shown. Utilizing two specialized functions instead of a single function removes conditionals for handling awkward special cases that only come up at the beginning of iteration, making the iterators easier to read and understand. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Rewrite proc_sys_lookup introducing find_entry and lookup_entry.Eric W. Biederman2012-01-241-26/+76
| | | | | | | | | | | | | | | | | Replace the helpers that proc_sys_lookup uses with helpers that work in terms of an entire sysctl directory. This is worse for sysctl_lock hold times but it is much better for code clarity and the code cleanups to come. find_in_table is no longer needed so it is removed. find_entry a general helper to find entries in a directory is added. lookup_entry is a simple wrapper around find_entry that takes the sysctl_lock increases the use count if an entry is found and drops the sysctl_lock. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Normalize the root_table data structure.Eric W. Biederman2012-01-241-4/+11
| | | | | | | Every other directory has a .child member and we look at the .child for our entries. Do the same for the root_table. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Factor out insert_header and erase_headerEric W. Biederman2012-01-241-3/+13
| | | | Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Factor out init_header from __register_sysctl_pathsEric W. Biederman2012-01-241-8/+17
| | | | | | Factor out a routing to initialize the sysctl_table_header. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Initial support for auto-unregistering sysctl tables.Eric W. Biederman2012-01-242-9/+20
| | | | | | | | | | Add nreg to ctl_table_header. When nreg drops to 0 the ctl_table_header will be unregistered. Factor out drop_sysctl_table from unregister_sysctl_table, and add the logic for decrementing nreg. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: A more obvious version of grab_header.Eric W. Biederman2012-01-241-4/+4
| | | | | | | | Instead of relying on sysct_head_next(NULL) to magically return the right header for the root directory instead explicitly transform NULL into the root directories header. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Remove the now unused ctl_table parent field.Eric W. Biederman2012-01-242-12/+1
| | | | | | | | | While useful at one time for selinux and the sysctl sanity checks those users no longer use the parent field and we can safely remove it. Inspired-by: Lucian Adrian Grijincu <lucian.grijincu@gmil.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Improve the sysctl sanity checksEric W. Biederman2012-01-242-144/+86
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Stop validating subdirectories now that we only register leaf tables - Cleanup and improve the duplicate filename check. * Run the duplicate filename check under the sysctl_lock to guarantee we never add duplicate names. * Reduce the duplicate filename check to nearly O(M*N) where M is the number of entries in tthe table we are registering and N is the number of entries in the directory before we got there. - Move the duplicate filename check into it's own function and call it directtly from __register_sysctl_table - Kill the config option as the sanity checks are now cheap enough the config option is unnecessary. The original reason for the config option was because we had a huge table used to verify the proc filename to binary sysctl mapping. That table has now evolved into the binary_sysctl translation layer and is no longer part of the sysctl_check code. - Tighten up the permission checks. Guarnateeing that files only have read or write permissions. - Removed redudant check for parents having a procname as now everything has a procname. - Generalize the backtrace logic so that we print a backtrace from any failure of __register_sysctl_table that was not caused by a memmory allocation failure. The backtrace allows us to track down who erroneously registered a sysctl table. Bechmark before (CONFIG_SYSCTL_CHECK=y): make-dummies 0 999 -> 12s rmmod dummy -> 0.08s Bechmark before (CONFIG_SYSCTL_CHECK=n): make-dummies 0 999 -> 0.7s rmmod dummy -> 0.06s make-dummies 0 99999 -> 1m13s rmmod dummy -> 0.38s Benchmark after: make-dummies 0 999 -> 0.65s rmmod dummy -> 0.055s make-dummies 0 9999 -> 1m10s rmmod dummy -> 0.39s The sysctl sanity checks now impose no measurable cost. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: register only tables of sysctl filesEric W. Biederman2012-01-242-19/+148
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Split the registration of a complex ctl_table array which may have arbitrary numbers of directories (->child != NULL) and tables of files into a series of simpler registrations that only register tables of files. Graphically: register('dir', { + file-a + file-b + subdir1 + file-c + subdir2 + file-d + file-e }) is transformed into: wrapper->subheaders[0] = register('dir', {file1-a, file1-b}) wrapper->subheaders[1] = register('dir/subdir1', {file-c}) wrapper->subheaders[2] = register('dir/subdir2', {file-d, file-e}) return wrapper This guarantees that __register_sysctl_table will only see a simple ctl_table array with all entries having (->child == NULL). Care was taken to pass the original simple ctl_table arrays to __register_sysctl_table whenever possible. This change is derived from a similar patch written by Lucrian Grijincu. Inspired-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Add ctl_table chains into cstring pathsEric W. Biederman2012-01-241-0/+9
| | | | | | | | | | | | For any component of table passed to __register_sysctl_paths that actually serves as a path, add that to the cstring path that is passed to __register_sysctl_table. The result is that for most calls to __register_sysctl_paths we only pass a table to __register_sysctl_table that contains no child directories. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Add support for register sysctl tables with a normal cstring path.Eric W. Biederman2012-01-242-10/+87
| | | | | | | | | | | | | | | | | | | | Make __register_sysctl_table the core sysctl registration operation and make it take a char * string as path. Now that binary paths have been banished into the real of backwards compatibility in kernel/binary_sysctl.c where they can be safely ignored there is no longer a need to use struct ctl_path to represent path names when registering ctl_tables. Start the transition to using normal char * strings to represent pathnames when registering sysctl tables. Normal strings are easier to deal with both in the internal sysctl implementation and for programmers registering sysctl tables. __register_sysctl_paths is turned into a backwards compatibility wrapper that converts a ctl_path array into a normal char * string. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Create local copies of directory names used in pathsEric W. Biederman2012-01-241-3/+8
| | | | | | | | | | | | | | Creating local copies of directory names is a good idea for two reasons. - The dynamic names used by callers must be copied into new strings by the callers today to ensure the strings do not change between register and unregister of the sysctl table. - Sysctl directories have a potentially different lifetime than the time between register and unregister of any particular sysctl table. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Remove the unnecessary sysctl_set parent concept.Eric W. Biederman2012-01-243-9/+10
| | | | | | | | | | | | In sysctl_net register the two networking roots in the proper order. In register_sysctl walk the sysctl sets in the reverse order of the sysctl roots. Remove parent from ctl_table_set and setup_sysctl_set as it is no longer needed. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Implement retire_sysctl_setEric W. Biederman2012-01-243-1/+6
| | | | | | | This adds a small helper retire_sysctl_set to remove the intimate knowledge about the how a sysctl_set is implemented from net/sysct_net.c Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Make the directories have nlink == 1Eric W. Biederman2012-01-241-1/+0
| | | | | | | | | | I goofed when I made sysctl directories have nlink == 0. nlink == 0 means the directory has been deleted. nlink == 1 meands a directory does not count subdirectories. Use the default nlink == 1 for sysctl directories. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Move the implementation into fs/proc/proc_sysctl.cEric W. Biederman2012-01-246-641/+625
| | | | | | | | | | | | | | | | Move the core sysctl code from kernel/sysctl.c and kernel/sysctl_check.c into fs/proc/proc_sysctl.c. Currently sysctl maintenance is hampered by the sysctl implementation being split across 3 files with artificial layering between them. Consolidate the entire sysctl implementation into 1 file so that it is easier to see what is going on and hopefully allowing for simpler maintenance. For functions that are now only used in fs/proc/proc_sysctl.c remove their declarations from sysctl.h and make them static in fs/proc/proc_sysctl.c Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Register the base sysctl table like any other sysctl table.Eric W. Biederman2012-01-244-12/+9
| | | | | | | | | | | | | | Simplify the code by treating the base sysctl table like any other sysctl table and register it with register_sysctl_table. To ensure this table is registered early enough to avoid problems call sysctl_init from proc_sys_init. Rename sysctl_net.c:sysctl_init() to net_sysctl_init() to avoid name conflicts now that kernel/sysctl.c:sysctl_init() is no longer static. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: Consolidate !CONFIG_SYSCTL handlingEric W. Biederman2012-01-242-59/+62
| | | | | | | | | | - In sysctl.h move functions only available if CONFIG_SYSCL is defined inside of #ifdef CONFIG_SYSCTL - Move the stub function definitions for !CONFIG_SYSCTL into sysctl.h and make them static inlines. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* sysctl: remove impossible condition checkLucas De Marchi2012-01-241-12/+2
| | | | | | | | | | | | | Remove checks for conditions that will never happen. If procname is NULL the loop would already had bailed out, so there's no need to check it again. At the same time this also compacts the function find_in_table() by refactoring it to be easier to read. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi> Reviewed-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* Linux 3.3-rc1v3.3-rc1Linus Torvalds2012-01-191-2/+2
|
*---. Merge branches 'sched-urgent-for-linus', 'perf-urgent-for-linus' and ↵Linus Torvalds2012-01-199-104/+444
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/accounting, proc: Fix /proc/stat interrupts sum * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tracepoints/module: Fix disabling tracepoints with taint CRAP or OOT x86/kprobes: Add arch/x86/tools/insn_sanity to .gitignore x86/kprobes: Fix typo transferred from Intel manual * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, syscall: Need __ARCH_WANT_SYS_IPC for 32 bits x86, tsc: Fix SMI induced variation in quick_pit_calibrate() x86, opcode: ANDN and Group 17 in x86-opcode-map.txt x86/kconfig: Move the ZONE_DMA entry under a menu x86/UV2: Add accounting for BAU strong nacks x86/UV2: Ack BAU interrupt earlier x86/UV2: Remove stale no-resources test for UV2 BAU x86/UV2: Work around BAU bug x86/UV2: Fix BAU destination timeout initialization x86/UV2: Fix new UV2 hardware by using native UV2 broadcast mode x86: Get rid of dubious one-bit signed bitfield
| | | * x86, syscall: Need __ARCH_WANT_SYS_IPC for 32 bitsH. Peter Anvin2012-01-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In checkin 303395ac3bf3 x86: Generate system call tables and unistd_*.h from tables the feature macros in <asm/unistd.h> were unified between 32 and 64 bits. Unfortunately 32 bits requires __ARCH_WANT_SYS_IPC and this was inadvertently dropped. Reported-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Link: http://lkml.kernel.org/r/CALLzPKbeXN5gdngo8uYYU8mAow=XhrwBFBhKfG811f37BubQOg@mail.gmail.com
| | | * Merge remote-tracking branch 'linus/master' into x86/urgentH. Peter Anvin2012-01-199677-298341/+502894
| | | |\
| | | * | x86, tsc: Fix SMI induced variation in quick_pit_calibrate()Linus Torvalds2012-01-171-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pit_expect_msb() returns success wrongly in the below SMI scenario: a. pit_verify_msb() has not yet seen the MSB transition. b. we are close to the MSB transition though and got a SMI immediately after returning from pit_verify_msb() which didn't see the MSB transition. PIT MSB transition has happened somewhere during SMI execution. c. returned from SMI and we noted down the 'tsc', saw the pit MSB change now and exited the loop to calculate 'deltatsc'. Instead of noting the TSC at the MSB transition, we are way off because of the SMI. And as the SMI happened between the pit_verify_msb() and before the 'tsc' is recorded in the for loop, 'delattsc' (d1/d2 in quick_pit_calibrate()) will be small and quick_pit_calibrate() will not notice this error. Depending on whether SMI disturbance happens while computing d1 or d2, we will see the TSC calibrated value smaller or bigger than the expected value. As a result, in a cluster we were seeing a variation of approximately +/- 20MHz in the calibrated values, resulting in NTP failures. [ As far as the SMI source is concerned, this is a periodic SMI that gets disabled after ACPI is enabled by the OS. But the TSC calibration happens before the ACPI is enabled. ] To address this, change pit_expect_msb() so that - the 'tsc' is the TSC in between the two reads that read the MSB change from the PIT (same as before) - the 'delta' is the difference in TSC from *before* the MSB changed to *after* the MSB changed. Now the delta is twice as big as before (it covers four PIT accesses, roughly 4us) and quick_pit_calibrate() will loop a bit longer to get the calibrated value with in the 500ppm precision. As the delta (d1/d2) covers four PIT accesses, actual calibrated result might be closer to 250ppm precision. As the loop now takes longer to stabilize, double MAX_QUICK_PIT_MS to 50. SMI disturbance will showup as much larger delta's and the loop will take longer than usual for the result to be with in the accepted precision. Or will fallback to slow PIT calibration if it takes more than 50msec. Also while we are at this, remove the calibration correction that aims to get the result to the middle of the error bars. We really don't know which direction to correct into, so remove it. Reported-and-tested-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1326843337.5291.4.camel@sbsiddha-mobl2 Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| | | * | x86, opcode: ANDN and Group 17 in x86-opcode-map.txtUlrich Drepper2012-01-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Intel documentation at http://software.intel.com/file/36945 shows the ANDN opcode and Group 17 with encoding f2 and f3 encoding respectively. The current version of x86-opcode-map.txt shows them with f3 and f4. Unless someone can point to documentation which shows the currently used encoding the following patch be applied. Signed-off-by: Ulrich Drepper <drepper@gmail.com> Link: http://lkml.kernel.org/r/CAOPLpQdq5SuVo9=023CYhbFLAX9rONyjmYq7jJkqc5xwctW5eA@mail.gmail.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| | | * | x86/kconfig: Move the ZONE_DMA entry under a menuRandy Dunlap2012-01-171-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the ZONE_DMA kconfig symbol under a menu item instead of having it listed before everything else in "make {xconfig | gconfig | nconfig | menuconfig}". This drops the first line of the top-level kernel config menu (in 3.2) below and moves it under "Processor type and features". [*] DMA memory allocation support General setup ---> [*] Enable loadable module support ---> [*] Enable the block layer ---> Processor type and features ---> Power management and ACPI options ---> Bus options (PCI etc.) ---> Executable file formats / Emulations ---> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: David Rientjes <rientjes@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-mm@kvack.org <linux-mm@kvack.org> Link: http://lkml.kernel.org/r/4F14811E.6090107@xenotime.net Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: David Rientjes <rientjes@google.com>
| | | * | x86/UV2: Add accounting for BAU strong nacksCliff Wickman2012-01-172-5/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds separate accounting of UV2 message "strong nack's" in the BAU statistics. Signed-off-by: Cliff Wickman <cpw@sgi.com> Link: http://lkml.kernel.org/r/20120116212238.GF5767@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | x86/UV2: Ack BAU interrupt earlierCliff Wickman2012-01-171-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch moves the ack of the BAU interrupt to the beginning of the interrupt handler so that there is less possibility of a lost interrupt and slower response to a shootdown message. Signed-off-by: Cliff Wickman <cpw@sgi.com> Link: http://lkml.kernel.org/r/20120116212146.GE5767@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | x86/UV2: Remove stale no-resources test for UV2 BAUCliff Wickman2012-01-171-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes an unnecessary test for a no-destination-resources-available condition that looks like a destination timeout in UV1, but is separately distinguishable in UV2. Signed-off-by: Cliff Wickman <cpw@sgi.com> Link: http://lkml.kernel.org/r/20120116212050.GD5767@sgi.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | x86/UV2: Work around BAU bugCliff Wickman2012-01-172-33/+254
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements a workaround for a UV2 hardware bug. The bug is a non-atomic update of a memory-mapped register. When hardware message delivery and software message acknowledge occur simultaneously the pending message acknowledge for the arriving message may be lost. This causes the sender's message status to stay busy. Part of the workaround is to not acknowledge a completed message until it is verified that no other message is actually using the resource that is mistakenly recorded in the completed message. Part of the workaround is to test for long elapsed time in such a busy condition, then handle it by using a spare sending descriptor. The stay-busy condition is eventually timed out by hardware, and then the original sending descriptor can be re-used. Most of that logic change is in keeping track of the current descriptor and the state of the spares. The occurrences of the workaround are added to the BAU statistics. Signed-off-by: Cliff Wickman <cpw@sgi.com> Link: http://lkml.kernel.org/r/20120116211947.GC5767@sgi.com Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | x86/UV2: Fix BAU destination timeout initializationCliff Wickman2012-01-171-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the call to enable_timeouts() forward so that BAU_MISC_CONTROL is initialized before using it in calculate_destination_timeout(). Fix the calculation of a BAU destination timeout for UV2 (in calculate_destination_timeout()). Signed-off-by: Cliff Wickman <cpw@sgi.com> Link: http://lkml.kernel.org/r/20120116211848.GB5767@sgi.com Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | x86/UV2: Fix new UV2 hardware by using native UV2 broadcast modeCliff Wickman2012-01-172-30/+151
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update the use of the Broadcast Assist Unit on SGI Altix UV2 to the use of native UV2 mode on new hardware (not the legacy mode). UV2 native mode has a different format for a broadcast message. We also need quick differentiaton between UV1 and UV2. Signed-off-by: Cliff Wickman <cpw@sgi.com> Link: http://lkml.kernel.org/r/20120116211750.GA5767@sgi.com Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | x86: Get rid of dubious one-bit signed bitfieldAnton Vorontsov2012-01-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This very noisy sparse warning appears on almost every file in the kernel: CHECK init/main.c arch/x86/include/asm/thread_info.h:43:55: error: dubious one-bit signed bitfield arch/x86/include/asm/thread_info.h:44:46: error: dubious one-bit signed bitfield Sparse is right and this patch changes sig_on_uaccess_error and uaccess_err flags to unsigned type and thus fixes the warning. Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com> Acked-by: Andy Lutomirski <luto@mit.edu> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Dan Carpenter <error27@gmail.com> Link: http://lkml.kernel.org/r/20120111011146.GA30428@oksana.dev.rtsoft.ru Signed-off-by: Ingo Molnar <mingo@elte.hu>
OpenPOWER on IntegriCloud