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* docs: Fix some broken referencesMauro Carvalho Chehab2018-06-151-1/+1
| | | | | | | | | | | | | | | | | | As we move stuff around, some doc references are broken. Fix some of them via this script: ./scripts/documentation-file-ref-check --fix Manually checked if the produced result is valid, removing a few false-positives. Acked-by: Takashi Iwai <tiwai@suse.de> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Jonathan Corbet <corbet@lwn.net>
* treewide: Use array_size() in vmalloc()Kees Cook2018-06-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The vmalloc() function has no 2-factor argument form, so multiplication factors need to be wrapped in array_size(). This patch replaces cases of: vmalloc(a * b) with: vmalloc(array_size(a, b)) as well as handling cases of: vmalloc(a * b * c) with: vmalloc(array3_size(a, b, c)) This does, however, attempt to ignore constant size factors like: vmalloc(4 * 1024) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( vmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | vmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( vmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(u8) * COUNT + COUNT , ...) | vmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | vmalloc( - sizeof(char) * COUNT + COUNT , ...) | vmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( vmalloc( - sizeof(TYPE) * (COUNT_ID) + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT_ID + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT_CONST + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vmalloc( - sizeof(THING) * (COUNT_ID) + array_size(COUNT_ID, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT_ID + array_size(COUNT_ID, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT_CONST + array_size(COUNT_CONST, sizeof(THING)) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ vmalloc( - SIZE * COUNT + array_size(COUNT, SIZE) , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( vmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( vmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( vmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( vmalloc(C1 * C2 * C3, ...) | vmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants. @@ expression E1, E2; constant C1, C2; @@ ( vmalloc(C1 * C2, ...) | vmalloc( - E1 * E2 + array_size(E1, E2) , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
* treewide: kmalloc() -> kmalloc_array()Kees Cook2018-06-122-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
* Merge tag 'overflow-v4.18-rc1' of ↵Linus Torvalds2018-06-061-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull overflow updates from Kees Cook: "This adds the new overflow checking helpers and adds them to the 2-factor argument allocators. And this adds the saturating size helpers and does a treewide replacement for the struct_size() usage. Additionally this adds the overflow testing modules to make sure everything works. I'm still working on the treewide replacements for allocators with "simple" multiplied arguments: *alloc(a * b, ...) -> *alloc_array(a, b, ...) and *zalloc(a * b, ...) -> *calloc(a, b, ...) as well as the more complex cases, but that's separable from this portion of the series. I expect to have the rest sent before -rc1 closes; there are a lot of messy cases to clean up. Summary: - Introduce arithmetic overflow test helper functions (Rasmus) - Use overflow helpers in 2-factor allocators (Kees, Rasmus) - Introduce overflow test module (Rasmus, Kees) - Introduce saturating size helper functions (Matthew, Kees) - Treewide use of struct_size() for allocators (Kees)" * tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: treewide: Use struct_size() for devm_kmalloc() and friends treewide: Use struct_size() for vmalloc()-family treewide: Use struct_size() for kmalloc()-family device: Use overflow helpers for devm_kmalloc() mm: Use overflow helpers in kvmalloc() mm: Use overflow helpers in kmalloc_array*() test_overflow: Add memory allocation overflow tests overflow.h: Add allocation size calculation helpers test_overflow: Report test failures test_overflow: macrofy some more, do more tests for free lib: add runtime test of check_*_overflow functions compiler.h: enable builtin overflow checkers and add fallback code
| * treewide: Use struct_size() for kmalloc()-familyKees Cook2018-06-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct foo { int stuff; void *entry[]; }; instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL); This patch makes the changes for kmalloc()-family (and kvmalloc()-family) uses. It was done via automatic conversion with manual review for the "CHECKME" non-standard cases noted below, using the following Coccinelle script: // pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len * // sizeof *pkey_cache->table, GFP_KERNEL); @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP) + alloc(struct_size(VAR, ELEMENT, COUNT), GFP) // mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL); @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; identifier VAR, ELEMENT; expression COUNT; @@ - alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP) + alloc(struct_size(VAR, ELEMENT, COUNT), GFP) // Same pattern, but can't trivially locate the trailing element name, // or variable name. @@ identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc"; expression GFP; expression SOMETHING, COUNT, ELEMENT; @@ - alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP) + alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP) Signed-off-by: Kees Cook <keescook@chromium.org>
* | Merge branch 'for-4.18' of ↵Linus Torvalds2018-06-056-395/+512
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - For cpustat, cgroup has a percpu hierarchical stat mechanism which propagates up the hierarchy lazily. This contains commits to factor out and generalize the mechanism so that it can be used for other cgroup stats too. The original intention was to update memcg stats to use it but memcg went for a different approach, so still the only user is cpustat. The factoring out and generalization still make sense and it's likely that this can be used for other purposes in the future. - cgroup uses kernfs_notify() (which uses fsnotify()) to inform user space of certain events. A rate limiting mechanism is added. - Other misc changes. * 'for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: css_set_lock should nest inside tasklist_lock rdmacg: Convert to use match_string() helper cgroup: Make cgroup_rstat_updated() ready for root cgroup usage cgroup: Add memory barriers to plug cgroup_rstat_updated() race window cgroup: Add cgroup_subsys->css_rstat_flush() cgroup: Replace cgroup_rstat_mutex with a spinlock cgroup: Factor out and expose cgroup_rstat_*() interface functions cgroup: Reorganize kernel/cgroup/rstat.c cgroup: Distinguish base resource stat implementation from rstat cgroup: Rename stat to rstat cgroup: Rename kernel/cgroup/stat.c to kernel/cgroup/rstat.c cgroup: Limit event generation frequency cgroup: Explicitly remove core interface files
| * | cgroup: css_set_lock should nest inside tasklist_lockTejun Heo2018-05-231-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup_enable_task_cg_lists() incorrectly nests non-irq-safe tasklist_lock inside irq-safe css_set_lock triggering the following lockdep warning. WARNING: possible irq lock inversion dependency detected 4.17.0-rc1-00027-gb37d049 #6 Not tainted -------------------------------------------------------- systemd/1 just changed the state of lock: 00000000fe57773b (css_set_lock){..-.}, at: cgroup_free+0xf2/0x12a but this lock took another, SOFTIRQ-unsafe lock in the past: (tasklist_lock){.+.+} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tasklist_lock); local_irq_disable(); lock(css_set_lock); lock(tasklist_lock); <Interrupt> lock(css_set_lock); *** DEADLOCK *** The condition is highly unlikely to actually happen especially given that the path is executed only once per boot. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Boqun Feng <boqun.feng@gmail.com>
| * | rdmacg: Convert to use match_string() helperAndy Shevchenko2018-05-071-19/+16
| | | | | | | | | | | | | | | | | | | | | | | | The new helper returns index of the matching string in an array. We are going to use it here. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: Make cgroup_rstat_updated() ready for root cgroup usageTejun Heo2018-04-261-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup_rstat_updated() ensures that the cgroup's rstat is linked to the parent. If there's no parent, it never gets linked and the function ends up grabbing and releasing the cgroup_rstat_lock each time for no reason which can be expensive. This hasn't been a problem till now because nobody was calling the function for the root cgroup but rstat is gonna be exposed to controllers and use cases, so let's get ready. Make cgroup_rstat_updated() an no-op for the root cgroup. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: Add memory barriers to plug cgroup_rstat_updated() race windowTejun Heo2018-04-261-3/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup_rstat_updated() has a small race window where an updated signaling can race with flush and could be lost till the next update. This wasn't a problem for the existing usages, but we plan to use rstat to track counters which need to be accurate. This patch plugs the race window by synchronizing cgroup_rstat_updated() and flush path with memory barriers around cgroup_rstat_cpu->updated_next pointer. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: Add cgroup_subsys->css_rstat_flush()Tejun Heo2018-04-262-1/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds cgroup_subsys->css_rstat_flush(). If a subsystem has this callback, its csses are linked on cgrp->css_rstat_list and rstat will call the function whenever the associated cgroup is flushed. Flush is also performed when such csses are released so that residual counts aren't lost. Combined with the rstat API previous patches factored out, this allows controllers to plug into rstat to manage their statistics in a scalable way. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: Replace cgroup_rstat_mutex with a spinlockTejun Heo2018-04-261-13/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, rstat flush path is protected with a mutex which is fine as all the existing users are from interface file show path. However, rstat is being generalized for use by controllers and flushing from atomic contexts will be necessary. This patch replaces cgroup_rstat_mutex with a spinlock and adds a irq-safe flush function - cgroup_rstat_flush_irqsafe(). Explicit yield handling is added to the flush path so that other flush functions can yield to other threads and flushers. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: Factor out and expose cgroup_rstat_*() interface functionsTejun Heo2018-04-262-13/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup_rstat is being generalized so that controllers can use it too. This patch factors out and exposes the following interface functions. * cgroup_rstat_updated(): Renamed from cgroup_rstat_cpu_updated() for consistency. * cgroup_rstat_flush_hold/release(): Factored out from base stat implementation. * cgroup_rstat_flush(): Verbatim expose. While at it, drop assert on cgroup_rstat_mutex in cgroup_base_stat_flush() as it crosses layers and make a minor comment update. v2: Added EXPORT_SYMBOL_GPL(cgroup_rstat_updated) to fix a build bug. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: Reorganize kernel/cgroup/rstat.cTejun Heo2018-04-262-89/+95
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, rstat.c has rstat and base stat implementations intermixed. Collect base stat implementation at the end of the file. Also, reorder the prototypes. This patch doesn't make any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: Distinguish base resource stat implementation from rstatTejun Heo2018-04-263-37/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Base resource stat accounts universial (not specific to any controller) resource consumptions on top of rstat. Currently, its implementation is intermixed with rstat implementation making the code confusing to follow. This patch clarifies the distintion by doing the followings. * Encapsulate base resource stat counters, currently only cputime, in struct cgroup_base_stat. * Move prev_cputime into struct cgroup and initialize it with cgroup. * Rename the related functions so that they start with cgroup_base_stat. * Prefix the related variables and field names with b. This patch doesn't make any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: Rename stat to rstatTejun Heo2018-04-263-101/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | stat is too generic a name and ends up causing subtle confusions. It'll be made generic so that controllers can plug into it, which will make the problem worse. Let's rename it to something more specific - cgroup_rstat for cgroup recursive stat. This patch does the following renames. No other changes. * cpu_stat -> rstat_cpu * stat -> rstat * ?cstat -> ?rstatc Note that the renames are selective. The unrenamed are the ones which implement basic resource statistics on top of rstat. This will be further cleaned up in the following patches. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: Rename kernel/cgroup/stat.c to kernel/cgroup/rstat.cTejun Heo2018-04-262-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | stat is too generic a name and ends up causing subtle confusions. It'll be made generic so that controllers can plug into it, which will make the problem worse. Let's rename it to something more specific - cgroup_rstat for cgroup recursive stat. First, rename kernel/cgroup/stat.c to kernel/cgroup/rstat.c. No content changes. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: Limit event generation frequencyTejun Heo2018-04-261-2/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ".events" files generate file modified event to notify userland of possible new events. Some of the events can be quite bursty (e.g. memory high event) and generating notification each time is costly and pointless. This patch implements a event rate limit mechanism. If a new notification is requested before 10ms has passed since the previous notification, the new notification is delayed till then. As this only delays from the second notification on in a given close cluster of notifications, userland reactions to notifications shouldn't be delayed at all in most cases while avoiding notification storms. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: Explicitly remove core interface filesTejun Heo2018-04-261-13/+22
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "cgroup." core interface files bypass the usual interface removal path and get removed recursively along with the cgroup itself. While this works now, the subtle discrepancy gets in the way of implementing common mechanisms. This patch updates cgroup core interface file handling so that it's consistent with controller interface files. When added, the css is marked CSS_VISIBLE and they're explicitly removed before the cgroup is destroyed. This doesn't cause user-visible behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org>
* | proc: introduce proc_create_single{,_data}Christoph Hellwig2018-05-163-15/+3
|/ | | | | | | | | Variants of proc_create{,_data} that directly take a seq_file show callback and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig <hch@lst.de>
* Merge branch 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds2018-04-031-14/+7
|\ | | | | | | | | | | | | | | | | | | | | | | Pull workqueue updates from Tejun Heo: "rcu_work addition and a couple trivial changes" * 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: remove the comment about the old manager_arb mutex workqueue: fix the comments of nr_idle fs/aio: Use rcu_work instead of explicit rcu and work item cgroup: Use rcu_work instead of explicit rcu and work item RCU, workqueue: Implement rcu_work
| * cgroup: Use rcu_work instead of explicit rcu and work itemTejun Heo2018-03-191-14/+7
| | | | | | | | | | | | | | Workqueue now has rcu_work. Use it instead of open-coding rcu -> work item bouncing. Signed-off-by: Tejun Heo <tj@kernel.org>
* | cgroup: fix rule checking for threaded mode switchingTejun Heo2018-02-211-0/+10
|/ | | | | | | | | | | | | | | | | | | | | A domain cgroup isn't allowed to be turned threaded if its subtree is populated or domain controllers are enabled. cgroup_enable_threaded() depended on cgroup_can_be_thread_root() test to enforce this rule. A parent which has populated domain descendants or have domain controllers enabled can't become a thread root, so the above rules are enforced automatically. However, for the root cgroup which can host mixed domain and threaded children, cgroup_can_be_thread_root() doesn't check any of those conditions and thus first level cgroups ends up escaping those rules. This patch fixes the bug by adding explicit checks for those rules in cgroup_enable_threaded(). Reported-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: 8cfd8147df67 ("cgroup: implement cgroup v2 thread support") Cc: stable@vger.kernel.org # v4.14+
* kernel/cpuset: current_cpuset_is_being_rebound can be booleanYaowei Bai2018-02-061-2/+2
| | | | | | | | | | | | Make current_cpuset_is_being_rebound return bool due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1513266622-15860-4-git-send-email-baiyaowei@cmss.chinamobile.com Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* string: drop __must_check from strscpy() and restore strscpy() usages in cgroupTejun Heo2018-01-191-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | e7fd37ba1217 ("cgroup: avoid copying strings longer than the buffers") converted possibly unsafe strncpy() usages in cgroup to strscpy(). However, although the callsites are completely fine with truncated copied, because strscpy() is marked __must_check, it led to the following warnings. kernel/cgroup/cgroup.c: In function ‘cgroup_file_name’: kernel/cgroup/cgroup.c:1400:10: warning: ignoring return value of ‘strscpy’, declared with attribute warn_unused_result [-Wunused-result] strscpy(buf, cft->name, CGROUP_FILE_NAME_MAX); ^ To avoid the warnings, 50034ed49645 ("cgroup: use strlcpy() instead of strscpy() to avoid spurious warning") switched them to strlcpy(). strlcpy() is worse than strlcpy() because it unconditionally runs strlen() on the source string, and the only reason we switched to strlcpy() here was because it was lacking __must_check, which doesn't reflect any material differences between the two function. It's just that someone added __must_check to strscpy() and not to strlcpy(). These basic string copy operations are used in variety of ways, and one of not-so-uncommon use cases is safely handling truncated copies, where the caller naturally doesn't care about the return value. The __must_check doesn't match the actual use cases and forces users to opt for inferior variants which lack __must_check by happenstance or spread ugly (void) casts. Remove __must_check from strscpy() and restore strscpy() usages in cgroup. Signed-off-by: Tejun Heo <tj@kernel.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Chris Metcalf <cmetcalf@ezchip.com>
* cgroup: make cgroup.threads delegatableRoman Gushchin2018-01-101-0/+1
| | | | | | | | | | Make cgroup.threads file delegatable. The behavior of cgroup.threads should follow the behavior of cgroup.procs. Signed-off-by: Roman Gushchin <guro@fb.com> Discovered-by: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup: fix css_task_iter crash on CSS_TASK_ITER_PROCTejun Heo2017-12-201-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While teaching css_task_iter to handle skipping over tasks which aren't group leaders, bc2fb7ed089f ("cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS") introduced a silly bug. CSS_TASK_ITER_PROCS is implemented by repeating css_task_iter_advance() while the advanced cursor is pointing to a non-leader thread. However, the cursor variable, @l, wasn't updated when the iteration has to advance to the next css_set and the following repetition would operate on the terminal @l from the previous iteration which isn't pointing to a valid task leading to oopses like the following or infinite looping. BUG: unable to handle kernel NULL pointer dereference at 0000000000000254 IP: __task_pid_nr_ns+0xc7/0xf0 PGD 0 P4D 0 Oops: 0000 [#1] SMP ... CPU: 2 PID: 1 Comm: systemd Not tainted 4.14.4-200.fc26.x86_64 #1 Hardware name: System manufacturer System Product Name/PRIME B350M-A, BIOS 3203 11/09/2017 task: ffff88c4baee8000 task.stack: ffff96d5c3158000 RIP: 0010:__task_pid_nr_ns+0xc7/0xf0 RSP: 0018:ffff96d5c315bd50 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff88c4b68c6000 RCX: 0000000000000250 RDX: ffffffffa5e47960 RSI: 0000000000000000 RDI: ffff88c490f6ab00 RBP: ffff96d5c315bd50 R08: 0000000000001000 R09: 0000000000000005 R10: ffff88c4be006b80 R11: ffff88c42f1b8004 R12: ffff96d5c315bf18 R13: ffff88c42d7dd200 R14: ffff88c490f6a510 R15: ffff88c4b68c6000 FS: 00007f9446f8ea00(0000) GS:ffff88c4be680000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000254 CR3: 00000007f956f000 CR4: 00000000003406e0 Call Trace: cgroup_procs_show+0x19/0x30 cgroup_seqfile_show+0x4c/0xb0 kernfs_seq_show+0x21/0x30 seq_read+0x2ec/0x3f0 kernfs_fop_read+0x134/0x180 __vfs_read+0x37/0x160 ? security_file_permission+0x9b/0xc0 vfs_read+0x8e/0x130 SyS_read+0x55/0xc0 entry_SYSCALL_64_fastpath+0x1a/0xa5 RIP: 0033:0x7f94455f942d RSP: 002b:00007ffe81ba2d00 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00005574e2233f00 RCX: 00007f94455f942d RDX: 0000000000001000 RSI: 00005574e2321a90 RDI: 000000000000002b RBP: 0000000000000000 R08: 00005574e2321a90 R09: 00005574e231de60 R10: 00007f94458c8b38 R11: 0000000000000293 R12: 00007f94458c8ae0 R13: 00007ffe81ba3800 R14: 0000000000000000 R15: 00005574e2116560 Code: 04 74 0e 89 f6 48 8d 04 76 48 8d 04 c5 f0 05 00 00 48 8b bf b8 05 00 00 48 01 c7 31 c0 48 8b 0f 48 85 c9 74 18 8b b2 30 08 00 00 <3b> 71 04 77 0d 48 c1 e6 05 48 01 f1 48 3b 51 38 74 09 5d c3 8b RIP: __task_pid_nr_ns+0xc7/0xf0 RSP: ffff96d5c315bd50 Fix it by moving the initialization of the cursor below the repeat label. While at it, rename it to @next for readability. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: bc2fb7ed089f ("cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS") Cc: stable@vger.kernel.org # v4.14+ Reported-by: Laura Abbott <labbott@redhat.com> Reported-by: Bronek Kozicki <brok@incorrekt.com> Reported-by: George Amanakis <gamanakis@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup: Fix deadlock in cpu hotplug pathPrateek Sood2017-12-191-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Deadlock during cgroup migration from cpu hotplug path when a task T is being moved from source to destination cgroup. kworker/0:0 cpuset_hotplug_workfn() cpuset_hotplug_update_tasks() hotplug_update_tasks_legacy() remove_tasks_in_empty_cpuset() cgroup_transfer_tasks() // stuck in iterator loop cgroup_migrate() cgroup_migrate_add_task() In cgroup_migrate_add_task() it checks for PF_EXITING flag of task T. Task T will not migrate to destination cgroup. css_task_iter_start() will keep pointing to task T in loop waiting for task T cg_list node to be removed. Task T do_exit() exit_signals() // sets PF_EXITING exit_task_namespaces() switch_task_namespaces() free_nsproxy() put_mnt_ns() drop_collected_mounts() namespace_unlock() synchronize_rcu() _synchronize_rcu_expedited() schedule_work() // on cpu0 low priority worker pool wait_event() // waiting for work item to execute Task T inserted a work item in the worklist of cpu0 low priority worker pool. It is waiting for expedited grace period work item to execute. This work item will only be executed once kworker/0:0 complete execution of cpuset_hotplug_workfn(). kworker/0:0 ==> Task T ==>kworker/0:0 In case of PF_EXITING task being migrated from source to destination cgroup, migrate next available task in source cgroup. Signed-off-by: Prateek Sood <prsood@codeaurora.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup: use strlcpy() instead of strscpy() to avoid spurious warningArnd Bergmann2017-12-151-3/+3
| | | | | | | | | As long as cft->name is guaranteed to be NUL-terminated, using strlcpy() would work just as well and avoid that warning, so the change below could be folded into that commit. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup: avoid copying strings longer than the buffersMa Shimiao2017-12-121-3/+3
| | | | | | | | | | cgroup root name and file name have max length limit, we should avoid copying longer name than that to the name. tj: minor update to $SUBJ. Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* Revert "cgroup/cpuset: remove circular dependency deadlock"Tejun Heo2017-12-041-30/+23
| | | | | | | | | | | | | This reverts commit aa24163b2ee5c92120e32e99b5a93143a0f4258e. This and the following commit led to another circular locking scenario and the scenario which is fixed by this commit no longer exists after e8b3f8db7aad ("workqueue/hotplug: simplify workqueue_offline_cpu()") which removes work item flushing from hotplug path. Revert it for now. Signed-off-by: Tejun Heo <tj@kernel.org>
* Revert "cpuset: Make cpuset hotplug synchronous"Tejun Heo2017-12-041-20/+21
| | | | | | | | | | | | | This reverts commit 1599a185f0e6113be185b9fb809c621c73865829. This and the previous commit led to another circular locking scenario and the scenario which is fixed by this commit no longer exists after e8b3f8db7aad ("workqueue/hotplug: simplify workqueue_offline_cpu()") which removes work item flushing from hotplug path. Revert it for now. Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup: properly init u64_statsLucas Stach2017-11-281-2/+6
| | | | | | | | | | Lockdep complains that the stats update is trying to register a non-static key. This is because u64_stats are using a seqlock on 32bit arches, which needs to be initialized before usage. Fixes: 041cd640b2f3 (cgroup: Implement cgroup2 basic CPU usage accounting) Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Signed-off-by: Tejun Heo <tj@kernel.org>
* debug cgroup: use task_css_set instead of rcu_dereferenceWang Long2017-11-271-2/+2
| | | | | | | | This macro `task_css_set` verifies that the caller is inside proper critical section if the kernel set CONFIG_PROVE_RCU=y. Signed-off-by: Wang Long <wanglong19@meituan.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* cpuset: Make cpuset hotplug synchronousPrateek Sood2017-11-271-21/+20
| | | | | | | | | | | | Convert cpuset_hotplug_workfn() into synchronous call for cpu hotplug path. For memory hotplug path it still gets queued as a work item. Since cpuset_hotplug_workfn() can be made synchronous for cpu hotplug path, it is not required to wait for cpuset hotplug while thawing processes. Signed-off-by: Prateek Sood <prsood@codeaurora.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup/cpuset: remove circular dependency deadlockPrateek Sood2017-11-271-23/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove circular dependency deadlock in a scenario where hotplug of CPU is being done while there is updation in cgroup and cpuset triggered from userspace. Process A => kthreadd => Process B => Process C => Process A Process A cpu_subsys_offline(); cpu_down(); _cpu_down(); percpu_down_write(&cpu_hotplug_lock); //held cpuhp_invoke_callback(); workqueue_offline_cpu(); queue_work_on(); // unbind_work on system_highpri_wq __queue_work(); insert_work(); wake_up_worker(); flush_work(); wait_for_completion(); worker_thread(); manage_workers(); create_worker(); kthread_create_on_node(); wake_up_process(kthreadd_task); kthreadd kthreadd(); kernel_thread(); do_fork(); copy_process(); percpu_down_read(&cgroup_threadgroup_rwsem); __rwsem_down_read_failed_common(); //waiting Process B kernfs_fop_write(); cgroup_file_write(); cgroup_procs_write(); percpu_down_write(&cgroup_threadgroup_rwsem); //held cgroup_attach_task(); cgroup_migrate(); cgroup_migrate_execute(); cpuset_can_attach(); mutex_lock(&cpuset_mutex); //waiting Process C kernfs_fop_write(); cgroup_file_write(); cpuset_write_resmask(); mutex_lock(&cpuset_mutex); //held update_cpumask(); update_cpumasks_hier(); rebuild_sched_domains_locked(); get_online_cpus(); percpu_down_read(&cpu_hotplug_lock); //waiting Eliminating deadlock by reversing the locking order for cpuset_mutex and cpu_hotplug_lock. Signed-off-by: Prateek Sood <prsood@codeaurora.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* Merge branch 'for-4.15' of ↵Linus Torvalds2017-11-154-3/+499
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Cgroup2 cpu controller support is finally merged. - Basic cpu statistics support to allow monitoring by default without the CPU controller enabled. - cgroup2 cpu controller support. - /sys/kernel/cgroup files to help dealing with new / optional features" * 'for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: export list of cgroups v2 features using sysfs cgroup: export list of delegatable control files using sysfs cgroup: mark @cgrp __maybe_unused in cpu_stat_show() MAINTAINERS: relocate cpuset.c cgroup, sched: Move basic cpu stats from cgroup.stat to cpu.stat sched: Implement interface for cgroup unified hierarchy sched: Misc preps for cgroup unified hierarchy interface sched/cputime: Add dummy cputime_adjust() implementation for CONFIG_VIRT_CPU_ACCOUNTING_NATIVE cgroup: statically initialize init_css_set->dfl_cgrp cgroup: Implement cgroup2 basic CPU usage accounting cpuacct: Introduce cgroup_account_cputime[_field]() sched/cputime: Expose cputime_adjust()
| * cgroup: export list of cgroups v2 features using sysfsRoman Gushchin2017-11-061-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The active development of cgroups v2 sometimes leads to a creation of interfaces, which are not turned on by default (to provide backward compatibility). It's handy to know from userspace, which cgroup v2 features are supported without calculating it based on the kernel version. So, let's export the list of such features using /sys/kernel/cgroup/features pseudo-file. The list is hardcoded and has to be extended when new functionality is added. Each feature is printed on a new line. Example: $ cat /sys/kernel/cgroup/features nsdelegate Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: kernel-team@fb.com Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: export list of delegatable control files using sysfsRoman Gushchin2017-11-061-0/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Delegatable cgroup v2 control files may require special handling (e.g. chowning), and the exact list of such files varies between kernel versions (and likely to be extended in the future). To guarantee correctness of this list and simplify the life of userspace (systemd, first of all), let's export the list via /sys/kernel/cgroup/delegate pseudo-file. Format is siple: each control file name is printed on a new line. Example: $ cat /sys/kernel/cgroup/delegate cgroup.procs cgroup.subtree_control Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: kernel-team@fb.com Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: mark @cgrp __maybe_unused in cpu_stat_show()Tejun Heo2017-10-301-1/+1
| | | | | | | | | | | | | | | | The local variable @cgrp isn't used if !CONFIG_CGROUP_SCHED. Mark the variable with __maybe_unused to avoid a compile warning. Reported-by: "kbuild-all@01.org" <kbuild-all@01.org> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup, sched: Move basic cpu stats from cgroup.stat to cpu.statTejun Heo2017-10-263-7/+64
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The basic cpu stat is currently shown with "cpu." prefix in cgroup.stat, and the same information is duplicated in cpu.stat when cpu controller is enabled. This is ugly and not very scalable as we want to expand the coverage of stat information which is always available. This patch makes cgroup core always create "cpu.stat" file and show the basic cpu stat there and calls the cpu controller to show the extra stats when enabled. This ensures that the same information isn't presented in multiple places and makes future expansion of basic stats easier. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
| * cgroup: statically initialize init_css_set->dfl_cgrpTejun Heo2017-09-251-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Like other csets, init_css_set's dfl_cgrp is initialized when the cset gets linked. init_css_set gets linked in cgroup_init(). This has been fine till now but the recently added basic CPU usage accounting may end up accessing dfl_cgrp of init before cgroup_init() leading to the following oops. SELinux: Initializing. BUG: unable to handle kernel NULL pointer dereference at 00000000000000b0 IP: account_system_index_time+0x60/0x90 PGD 0 P4D 0 Oops: 0000 [#1] SMP Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-rc2-00003-g041cd64 #10 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS +1.9.3-20161025_171302-gandalf 04/01/2014 task: ffffffff81e10480 task.stack: ffffffff81e00000 RIP: 0010:account_system_index_time+0x60/0x90 RSP: 0000:ffff880011e03cb8 EFLAGS: 00010002 RAX: ffffffff81ef8800 RBX: ffffffff81e10480 RCX: 0000000000000003 RDX: 0000000000000000 RSI: 00000000000f4240 RDI: 0000000000000000 RBP: ffff880011e03cc0 R08: 0000000000010000 R09: 0000000000000000 R10: 0000000000000020 R11: 0000003b9aca0000 R12: 000000000001c100 R13: 0000000000000000 R14: ffffffff81e10480 R15: ffffffff81e03cd8 FS: 0000000000000000(0000) GS:ffff880011e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000b0 CR3: 0000000001e09000 CR4: 00000000000006b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> account_system_time+0x45/0x60 account_process_tick+0x5a/0x140 update_process_times+0x22/0x60 tick_periodic+0x2b/0x90 tick_handle_periodic+0x25/0x70 timer_interrupt+0x15/0x20 __handle_irq_event_percpu+0x7e/0x1b0 handle_irq_event_percpu+0x23/0x60 handle_irq_event+0x42/0x70 handle_level_irq+0x83/0x100 handle_irq+0x6f/0x110 do_IRQ+0x46/0xd0 common_interrupt+0x9d/0x9d Fix it by statically initializing init_css_set.dfl_cgrp so that init's default cgroup is accessible from the get-go. Fixes: 041cd640b2f3 ("cgroup: Implement cgroup2 basic CPU usage accounting") Reported-by: “kbuild-all@01.org” <kbuild-all@01.org> Signed-off-by: Tejun Heo <tj@kernel.org>
| * cgroup: Implement cgroup2 basic CPU usage accountingTejun Heo2017-09-254-3/+365
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In cgroup1, while cpuacct isn't actually controlling any resources, it is a separate controller due to combination of two factors - 1. enabling cpu controller has significant side effects, and 2. we have to pick one of the hierarchies to account CPU usages on. cpuacct controller is effectively used to designate a hierarchy to track CPU usages on. cgroup2's unified hierarchy removes the second reason and we can account basic CPU usages by default. While we can use cpuacct for this purpose, both its interface and implementation leave a lot to be desired - it collects and exposes two sources of truth which don't agree with each other and some of the exposed statistics don't make much sense. Also, it propagates all the way up the hierarchy on each accounting event which is unnecessary. This patch adds basic resource accounting mechanism to cgroup2's unified hierarchy and accounts CPU usages using it. * All accountings are done per-cpu and don't propagate immediately. It just bumps the per-cgroup per-cpu counters and links to the parent's updated list if not already on it. * On a read, the per-cpu counters are collected into the global ones and then propagated upwards. Only the per-cpu counters which have changed since the last read are propagated. * CPU usage stats are collected and shown in "cgroup.stat" with "cpu." prefix. Total usage is collected from scheduling events. User/sys breakdown is sourced from tick sampling and adjusted to the usage using cputime_adjust(). This keeps the accounting side hot path O(1) and per-cpu and the read side O(nr_updated_since_last_read). v2: Minor changes and documentation updates as suggested by Waiman and Roman. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Waiman Long <longman@redhat.com> Cc: Roman Gushchin <guro@fb.com>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2017-11-151-7/+31
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from David Miller: "Highlights: 1) Maintain the TCP retransmit queue using an rbtree, with 1GB windows at 100Gb this really has become necessary. From Eric Dumazet. 2) Multi-program support for cgroup+bpf, from Alexei Starovoitov. 3) Perform broadcast flooding in hardware in mv88e6xxx, from Andrew Lunn. 4) Add meter action support to openvswitch, from Andy Zhou. 5) Add a data meta pointer for BPF accessible packets, from Daniel Borkmann. 6) Namespace-ify almost all TCP sysctl knobs, from Eric Dumazet. 7) Turn on Broadcom Tags in b53 driver, from Florian Fainelli. 8) More work to move the RTNL mutex down, from Florian Westphal. 9) Add 'bpftool' utility, to help with bpf program introspection. From Jakub Kicinski. 10) Add new 'cpumap' type for XDP_REDIRECT action, from Jesper Dangaard Brouer. 11) Support 'blocks' of transformations in the packet scheduler which can span multiple network devices, from Jiri Pirko. 12) TC flower offload support in cxgb4, from Kumar Sanghvi. 13) Priority based stream scheduler for SCTP, from Marcelo Ricardo Leitner. 14) Thunderbolt networking driver, from Amir Levy and Mika Westerberg. 15) Add RED qdisc offloadability, and use it in mlxsw driver. From Nogah Frankel. 16) eBPF based device controller for cgroup v2, from Roman Gushchin. 17) Add some fundamental tracepoints for TCP, from Song Liu. 18) Remove garbage collection from ipv6 route layer, this is a significant accomplishment. From Wei Wang. 19) Add multicast route offload support to mlxsw, from Yotam Gigi" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2177 commits) tcp: highest_sack fix geneve: fix fill_info when link down bpf: fix lockdep splat net: cdc_ncm: GetNtbFormat endian fix openvswitch: meter: fix NULL pointer dereference in ovs_meter_cmd_reply_start netem: remove unnecessary 64 bit modulus netem: use 64 bit divide by rate tcp: Namespace-ify sysctl_tcp_default_congestion_control net: Protect iterations over net::fib_notifier_ops in fib_seq_sum() ipv6: set all.accept_dad to 0 by default uapi: fix linux/tls.h userspace compilation error usbnet: ipheth: prevent TX queue timeouts when device not ready vhost_net: conditionally enable tx polling uapi: fix linux/rxrpc.h userspace compilation errors net: stmmac: fix LPI transitioning for dwmac4 atm: horizon: Fix irq release error net-sysfs: trigger netlink notification on ifalias change via sysfs openvswitch: Using kfree_rcu() to simplify the code openvswitch: Make local function ovs_nsh_key_attr_size() static openvswitch: Fix return value check in ovs_meter_cmd_features() ...
| * \ Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2017-11-044-0/+4
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | Files removed in 'net-next' had their license header updated in 'net'. We take the remove from 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
| * \ \ Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2017-10-051-0/+8
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | Just simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | bpf: introduce BPF_PROG_QUERY commandAlexei Starovoitov2017-10-041-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | introduce BPF_PROG_QUERY command to retrieve a set of either attached programs to given cgroup or a set of effective programs that will execute for events within a cgroup Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> for cgroup bits Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | | bpf: multi program support for cgroup+bpfAlexei Starovoitov2017-10-041-7/+21
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | introduce BPF_F_ALLOW_MULTI flag that can be used to attach multiple bpf programs to a cgroup. The difference between three possible flags for BPF_PROG_ATTACH command: - NONE(default): No further bpf programs allowed in the subtree. - BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program, the program in this cgroup yields to sub-cgroup program. - BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program, that cgroup program gets run in addition to the program in this cgroup. NONE and BPF_F_ALLOW_OVERRIDE existed before. This patch doesn't change their behavior. It only clarifies the semantics in relation to new flag. Only one program is allowed to be attached to a cgroup with NONE or BPF_F_ALLOW_OVERRIDE flag. Multiple programs are allowed to be attached to a cgroup with BPF_F_ALLOW_MULTI flag. They are executed in FIFO order (those that were attached first, run first) The programs of sub-cgroup are executed first, then programs of this cgroup and then programs of parent cgroup. All eligible programs are executed regardless of return code from earlier programs. To allow efficient execution of multiple programs attached to a cgroup and to avoid penalizing cgroups without any programs attached introduce 'struct bpf_prog_array' which is RCU protected array of pointers to bpf programs. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> for cgroup bits Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* | | | Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar2017-11-084-0/+4
|\ \ \ \ | | |_|/ | |/| | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-024-0/+4
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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