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* | fs: proc: use PDE() to get proc_dir_entryAlexander Kuleshov2015-02-122-2/+2
| | | | | | | | | | | | | | | | | | Use the PDE() helper to get proc_dir_entry instead of coding it directly. Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | fs/proc/task_mmu.c: add user-space support for resetting mm->hiwater_rss ↵Petr Cermak2015-02-121-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (peak RSS) Peak resident size of a process can be reset back to the process's current rss value by writing "5" to /proc/pid/clear_refs. The driving use-case for this would be getting the peak RSS value, which can be retrieved from the VmHWM field in /proc/pid/status, per benchmark iteration or test scenario. [akpm@linux-foundation.org: clarify behaviour in documentation] Signed-off-by: Petr Cermak <petrcermak@chromium.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Primiano Tucci <primiano@chromium.org> Cc: Petr Cermak <petrcermak@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: /proc/pid/clear_refs: avoid split_huge_page()Kirill A. Shutemov2015-02-111-3/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently pagewalker splits all THP pages on any clear_refs request. It's not necessary. We can handle this on PMD level. One side effect is that soft dirty will potentially see more dirty memory, since we will mark whole THP page dirty at once. Sanity checked with CRIU test suite. More testing is required. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)Naoya Horiguchi2015-02-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | walk_page_range() silently skips vma having VM_PFNMAP set, which leads to undesirable behaviour at client end (who called walk_page_range). For example for pagemap_read(), when no callbacks are called against VM_PFNMAP vma, pagemap_read() may prepare pagemap data for next virtual address range at wrong index. That could confuse and/or break userspace applications. This patch avoid this misbehavior caused by vma(VM_PFNMAP) like follows: - for pagemap_read() which has its own ->pte_hole(), call the ->pte_hole() over vma(VM_PFNMAP), - for clear_refs and queue_pages which have their own ->tests_walk, just return 1 and skip vma(VM_PFNMAP). This is no problem because these are not interested in hole regions, - for other callers, just skip the vma(VM_PFNMAP) as a default behavior. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Shiraz Hashim <shashim@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | numa_maps: remove numa_maps->vmaNaoya Horiguchi2015-02-111-16/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pagewalk.c can handle vma in itself, so we don't have to pass vma via walk->private. And show_numa_map() walks pages on vma basis, so using walk_page_vma() is preferable. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | numa_maps: fix typo in gather_hugetbl_statsNaoya Horiguchi2015-02-111-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just doing s/gather_hugetbl_stats/gather_hugetlb_stats/g, this makes code grep-friendly. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | pagemap: use walk->vma instead of calling find_vma()Naoya Horiguchi2015-02-111-54/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Page table walker has the information of the current vma in mm_walk, so we don't have to call find_vma() in each pagemap_(pte|hugetlb)_range() call any longer. Currently pagemap_pte_range() does vma loop itself, so this patch reduces many lines of code. NULL-vma check is omitted because we assume that we never run these callbacks on any address outside vma. And even if it were broken, NULL pointer dereference would be detected, so we can get enough information for debugging. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | clear_refs: remove clear_refs_private->vma and introduce clear_refs_test_walk()Naoya Horiguchi2015-02-111-24/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clear_refs_write() has some prechecks to determine if we really walk over a given vma. Now we have a test_walk() callback to filter vmas, so let's utilize it. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | smaps: remove mem_size_stats->vma and use walk_page_vma()Naoya Horiguchi2015-02-111-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pagewalk.c can handle vma in itself, so we don't have to pass vma via walk->private. And show_smap() walks pages on vma basis, so using walk_page_vma() is preferable. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc/pagemap: walk page tables under pte lockKonstantin Khlebnikov2015-02-111-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lockless access to pte in pagemap_pte_range() might race with page migration and trigger BUG_ON(!PageLocked()) in migration_entry_to_page(): CPU A (pagemap) CPU B (migration) lock_page() try_to_unmap(page, TTU_MIGRATION...) make_migration_entry() set_pte_at() <read *pte> pte_to_pagemap_entry() remove_migration_ptes() unlock_page() if(is_migration_entry()) migration_entry_to_page() BUG_ON(!PageLocked(page)) Also lockless read might be non-atomic if pte is larger than wordsize. Other pte walkers (smaps, numa_maps, clear_refs) already lock ptes. Fixes: 052fb0d635df ("proc: report file/anon bit in /proc/pid/pagemap") Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> [3.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: account pmd page tables to the processKirill A. Shutemov2015-02-111-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dave noticed that unprivileged process can allocate significant amount of memory -- >500 MiB on x86_64 -- and stay unnoticed by oom-killer and memory cgroup. The trick is to allocate a lot of PMD page tables. Linux kernel doesn't account PMD tables to the process, only PTE. The use-cases below use few tricks to allocate a lot of PMD page tables while keeping VmRSS and VmPTE low. oom_score for the process will be 0. #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/mman.h> #include <sys/prctl.h> #define PUD_SIZE (1UL << 30) #define PMD_SIZE (1UL << 21) #define NR_PUD 130000 int main(void) { char *addr = NULL; unsigned long i; prctl(PR_SET_THP_DISABLE); for (i = 0; i < NR_PUD ; i++) { addr = mmap(addr + PUD_SIZE, PUD_SIZE, PROT_WRITE|PROT_READ, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); if (addr == MAP_FAILED) { perror("mmap"); break; } *addr = 'x'; munmap(addr, PMD_SIZE); mmap(addr, PMD_SIZE, PROT_WRITE|PROT_READ, MAP_ANONYMOUS|MAP_PRIVATE|MAP_FIXED, -1, 0); if (addr == MAP_FAILED) perror("re-mmap"), exit(1); } printf("PID %d consumed %lu KiB in PMD page tables\n", getpid(), i * 4096 >> 10); return pause(); } The patch addresses the issue by account PMD tables to the process the same way we account PTE. The main place where PMD tables is accounted is __pmd_alloc() and free_pmd_range(). But there're few corner cases: - HugeTLB can share PMD page tables. The patch handles by accounting the table to all processes who share it. - x86 PAE pre-allocates few PMD tables on fork. - Architectures with FIRST_USER_ADDRESS > 0. We need to adjust sanity check on exit(2). Accounting only happens on configuration where PMD page table's level is present (PMD is not folded). As with nr_ptes we use per-mm counter. The counter value is used to calculate baseline for badness score by oom-killer. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: David Rientjes <rientjes@google.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm:add KPF_ZERO_PAGE flag for /proc/kpageflagsWang, Yalin2015-02-111-3/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | Add KPF_ZERO_PAGE flag for zero_page, so that userspace processes can detect zero_page in /proc/kpageflags, and then do memory analysis more accurately. Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com> Acked-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc: drop handling non-linear mappingsKirill A. Shutemov2015-02-101-16/+0
|/ | | | | | | | | We have to handle non-linear mappings for /proc/PID/{smaps,clear_refs} which is unused now. Let's drop it. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds2014-12-191-1/+1
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq core fix from Thomas Gleixner: "A single fix plugging a long standing race between proc/stat and proc/interrupts access and freeing of interrupt descriptors" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Prevent proc race against freeing of irq descriptors
| * genirq: Prevent proc race against freeing of irq descriptorsThomas Gleixner2014-12-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the rework of the sparse interrupt code to actually free the unused interrupt descriptors there exists a race between the /proc interfaces to the irq subsystem and the code which frees the interrupt descriptor. CPU0 CPU1 show_interrupts() desc = irq_to_desc(X); free_desc(desc) remove_from_radix_tree(); kfree(desc); raw_spinlock_irq(&desc->lock); /proc/interrupts is the only interface which can actively corrupt kernel memory via the lock access. /proc/stat can only read from freed memory. Extremly hard to trigger, but possible. The interfaces in /proc/irq/N/ are not affected by this because the removal of the proc file is serialized in procfs against concurrent readers/writers. The removal happens before the descriptor is freed. For architectures which have CONFIG_SPARSE_IRQ=n this is a non issue as the descriptor is never freed. It's merely cleared out with the irq descriptor lock held. So any concurrent proc access will either see the old correct value or the cleared out ones. Protect the lookup and access to the irq descriptor in show_interrupts() with the sparse_irq_lock. Provide kstat_irqs_usr() which is protecting the lookup and access with sparse_irq_lock and switch /proc/stat to use it. Document the existing kstat_irqs interfaces so it's clear that the caller needs to take care about protection. The users of these interfaces are either not affected due to SPARSE_IRQ=n or already protected against removal. Fixes: 1f5a5b87f78f "genirq: Implement a sane sparse_irq allocator" Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
* | fs/proc/meminfo.c: include cma info in proc/meminfoPintu Kumar2014-12-181-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch include CMA info (CMATotal, CMAFree) in /proc/meminfo. Currently, in a CMA enabled system, if somebody wants to know the total CMA size declared, there is no way to tell, other than the dmesg or /var/log/messages logs. With this patch we are showing the CMA info as part of meminfo, so that it can be determined at any point of time. This will be populated only when CMA is enabled. Below is the sample output from a ARM based device with RAM:512MB and CMA:16MB. MemTotal: 471172 kB MemFree: 111712 kB MemAvailable: 271172 kB . . . CmaTotal: 16384 kB CmaFree: 6144 kB This patch also fix below checkpatch errors that were found during these changes. ERROR: space required after that ',' (ctx:ExV) 199: FILE: fs/proc/meminfo.c:199: + ,atomic_long_read(&num_poisoned_pages) << (PAGE_SHIFT - 10) ^ ERROR: space required after that ',' (ctx:ExV) 202: FILE: fs/proc/meminfo.c:202: + ,K(global_page_state(NR_ANON_TRANSPARENT_HUGEPAGES) * ^ ERROR: space required after that ',' (ctx:ExV) 206: FILE: fs/proc/meminfo.c:206: + ,K(totalcma_pages) ^ total: 3 errors, 0 warnings, 2 checks, 236 lines checked Signed-off-by: Pintu Kumar <pintu.k@samsung.com> Signed-off-by: Vishnu Pratap Singh <vishnu.ps@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-linus' of ↵Linus Torvalds2014-12-171-0/+53
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace related fixes from Eric Biederman: "As these are bug fixes almost all of thes changes are marked for backporting to stable. The first change (implicitly adding MNT_NODEV on remount) addresses a regression that was created when security issues with unprivileged remount were closed. I go on to update the remount test to make it easy to detect if this issue reoccurs. Then there are a handful of mount and umount related fixes. Then half of the changes deal with the a recently discovered design bug in the permission checks of gid_map. Unix since the beginning has allowed setting group permissions on files to less than the user and other permissions (aka ---rwx---rwx). As the unix permission checks stop as soon as a group matches, and setgroups allows setting groups that can not later be dropped, results in a situtation where it is possible to legitimately use a group to assign fewer privileges to a process. Which means dropping a group can increase a processes privileges. The fix I have adopted is that gid_map is now no longer writable without privilege unless the new file /proc/self/setgroups has been set to permanently disable setgroups. The bulk of user namespace using applications even the applications using applications using user namespaces without privilege remain unaffected by this change. Unfortunately this ix breaks a couple user space applications, that were relying on the problematic behavior (one of which was tools/selftests/mount/unprivileged-remount-test.c). To hopefully prevent needing a regression fix on top of my security fix I rounded folks who work with the container implementations mostly like to be affected and encouraged them to test the changes. > So far nothing broke on my libvirt-lxc test bed. :-) > Tested with openSUSE 13.2 and libvirt 1.2.9. > Tested-by: Richard Weinberger <richard@nod.at> > Tested on Fedora20 with libvirt 1.2.11, works fine. > Tested-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com> > Ok, thanks - yes, unprivileged lxc is working fine with your kernels. > Just to be sure I was testing the right thing I also tested using > my unprivileged nsexec testcases, and they failed on setgroup/setgid > as now expected, and succeeded there without your patches. > Tested-by: Serge Hallyn <serge.hallyn@ubuntu.com> > I tested this with Sandstorm. It breaks as is and it works if I add > the setgroups thing. > Tested-by: Andy Lutomirski <luto@amacapital.net> # breaks things as designed :(" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: userns: Unbreak the unprivileged remount tests userns; Correct the comment in map_write userns: Allow setting gid_maps without privilege when setgroups is disabled userns: Add a knob to disable setgroups on a per user namespace basis userns: Rename id_map_mutex to userns_state_mutex userns: Only allow the creator of the userns unprivileged mappings userns: Check euid no fsuid when establishing an unprivileged uid mapping userns: Don't allow unprivileged creation of gid mappings userns: Don't allow setgroups until a gid mapping has been setablished userns: Document what the invariant required for safe unprivileged mappings. groups: Consolidate the setgroups permission checks mnt: Clear mnt_expire during pivot_root mnt: Carefully set CL_UNPRIVILEGED in clone_mnt mnt: Move the clear of MNT_LOCKED from copy_tree to it's callers. umount: Do not allow unmounting rootfs. umount: Disallow unprivileged mount force mnt: Update unprivileged remount test mnt: Implicitly add MNT_NODEV on remount when it was implicitly added by mount
| * | userns: Add a knob to disable setgroups on a per user namespace basisEric W. Biederman2014-12-111-0/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Expose the knob to user space through a proc file /proc/<pid>/setgroups A value of "deny" means the setgroups system call is disabled in the current processes user namespace and can not be enabled in the future in this user namespace. A value of "allow" means the segtoups system call is enabled. - Descendant user namespaces inherit the value of setgroups from their parents. - A proc file is used (instead of a sysctl) as sysctls currently do not allow checking the permissions at open time. - Writing to the proc file is restricted to before the gid_map for the user namespace is set. This ensures that disabling setgroups at a user namespace level will never remove the ability to call setgroups from a process that already has that ability. A process may opt in to the setgroups disable for itself by creating, entering and configuring a user namespace or by calling setns on an existing user namespace with setgroups disabled. Processes without privileges already can not call setgroups so this is a noop. Prodcess with privilege become processes without privilege when entering a user namespace and as with any other path to dropping privilege they would not have the ability to call setgroups. So this remains within the bounds of what is possible without a knob to disable setgroups permanently in a user namespace. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2014-12-163-149/+16
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile #2 from Al Viro: "Next pile (and there'll be one or two more). The large piece in this one is getting rid of /proc/*/ns/* weirdness; among other things, it allows to (finally) make nameidata completely opaque outside of fs/namei.c, making for easier further cleanups in there" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: coda_venus_readdir(): use file_inode() fs/namei.c: fold link_path_walk() call into path_init() path_init(): don't bother with LOOKUP_PARENT in argument fs/namei.c: new helper (path_cleanup()) path_init(): store the "base" pointer to file in nameidata itself make default ->i_fop have ->open() fail with ENXIO make nameidata completely opaque outside of fs/namei.c kill proc_ns completely take the targets of /proc/*/ns/* symlinks to separate fs bury struct proc_ns in fs/proc copy address of proc_ns_ops into ns_common new helpers: ns_alloc_inum/ns_free_inum make proc_ns_operations work with struct ns_common * instead of void * switch the rest of proc_ns_operations to working with &...->ns netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns common object embedded into various struct ....ns
| * \ \ Merge branch 'nsfs' into for-nextAl Viro2014-12-103-149/+16
| |\ \ \
| | * | | kill proc_ns completelyAl Viro2014-12-103-11/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | procfs inodes need only the ns_ops part; nsfs inodes don't need it at all Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| | * | | take the targets of /proc/*/ns/* symlinks to separate fsAl Viro2014-12-102-144/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | New pseudo-filesystem: nsfs. Targets of /proc/*/ns/* live there now. It's not mountable (not even registered, so it's not in /proc/filesystems, etc.). Files on it *are* bindable - we explicitly permit that in do_loopback(). This stuff lives in fs/nsfs.c now; proc_ns_fget() moved there as well. get_proc_ns() is a macro now (it's simply returning ->i_private; would have been an inline, if not for header ordering headache). proc_ns_inode() is an ex-parrot. The interface used in procfs is ns_get_path(path, task, ops) and ns_get_name(buf, size, task, ops). Dentries and inodes are never hashed; a non-counting reference to dentry is stashed in ns_common (removed by ->d_prune()) and reused by ns_get_path() if present. See ns_get_path()/ns_prune_dentry/nsfs_evict() for details of that mechanism. As the result, proc_ns_follow_link() has stopped poking in nd->path.mnt; it does nd_jump_link() on a consistent <vfsmount,dentry> pair it gets from ns_get_path(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| | * | | bury struct proc_ns in fs/procAl Viro2014-12-042-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | a) make get_proc_ns() return a pointer to struct ns_common b) mirror ns_ops in dentry->d_fsdata of ns dentries, so that is_mnt_ns_file() could get away with fewer dereferences. That way struct proc_ns becomes invisible outside of fs/proc/*.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| | * | | copy address of proc_ns_ops into ns_commonAl Viro2014-12-041-4/+2
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| | * | | make proc_ns_operations work with struct ns_common * instead of void *Al Viro2014-12-042-5/+5
| | |/ / | | | | | | | | | | | | | | | | | | | | | | | | We can do that now. And kill ->inum(), while we are at it - all instances are identical. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | Merge branch 'akpm' (patchbomb from Andrew)Linus Torvalds2014-12-107-125/+205
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge first patchbomb from Andrew Morton: - a few minor cifs fixes - dma-debug upadtes - ocfs2 - slab - about half of MM - procfs - kernel/exit.c - panic.c tweaks - printk upates - lib/ updates - checkpatch updates - fs/binfmt updates - the drivers/rtc tree - nilfs - kmod fixes - more kernel/exit.c - various other misc tweaks and fixes * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits) exit: pidns: fix/update the comments in zap_pid_ns_processes() exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting exit: exit_notify: re-use "dead" list to autoreap current exit: reparent: call forget_original_parent() under tasklist_lock exit: reparent: avoid find_new_reaper() if no children exit: reparent: introduce find_alive_thread() exit: reparent: introduce find_child_reaper() exit: reparent: document the ->has_child_subreaper checks exit: reparent: s/while_each_thread/for_each_thread/ in find_new_reaper() exit: reparent: fix the cross-namespace PR_SET_CHILD_SUBREAPER reparenting exit: reparent: fix the dead-parent PR_SET_CHILD_SUBREAPER reparenting exit: proc: don't try to flush /proc/tgid/task/tgid exit: release_task: fix the comment about group leader accounting exit: wait: drop tasklist_lock before psig->c* accounting exit: wait: don't use zombie->real_parent exit: wait: cleanup the ptrace_reparented() checks usermodehelper: kill the kmod_thread_locker logic usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper() fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp nilfs2: fix the nilfs_iget() vs. nilfs_new_inode() races ...
| * | | | exit: proc: don't try to flush /proc/tgid/task/tgidOleg Nesterov2014-12-101-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | proc_flush_task_mnt() always tries to flush task/pid, but this is pointless if we reap the leader. d_invalidate() is recursive, and if nothing else the next d_hash_and_lookup(tgid) should fail anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Rik van Riel <riel@redhat.com> Cc: Sterling Alexander <stalexan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | proc: task_state: ptrace_parent() doesn't need pid_alive() checkOleg Nesterov2014-12-101-7/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | p->ptrace != 0 means that release_task(p) was not called, so pid_alive() buys nothing and we can remove this check. Other callers already use it directly without additional checks. Note: with or without this patch ptrace_parent() can return the pointer to the freed task, this will be explained/fixed later. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com>, Cc: Sterling Alexander <stalexan@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roland McGrath <roland@hack.frob.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | proc: task_state: move the main seq_printf() outside of rcu_read_lock()Oleg Nesterov2014-12-101-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | task_state() does seq_printf() under rcu_read_lock(), but this is only needed for task_tgid_nr_ns() and task_numa_group_id(). We can calculate tgid/ngid and drop rcu lock. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com>, Cc: Sterling Alexander <stalexan@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roland McGrath <roland@hack.frob.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | proc: task_state: deuglify the max_fds calculationOleg Nesterov2014-12-101-12/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1. The usage of fdt looks very ugly, it can't be NULL if ->files is not NULL. We can use "unsigned int max_fds" instead. 2. This also allows to move seq_printf(max_fds) outside of task_lock() and join it with the previous seq_printf(). See also the next patch. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com>, Cc: Sterling Alexander <stalexan@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roland McGrath <roland@hack.frob.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | proc: task_state: read cred->group_info outside of task_lock()Oleg Nesterov2014-12-101-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | task_state() reads cred->group_info under task_lock() because a long ago it was task_struct->group_info and it was actually protected by task->alloc_lock. Today this task_unlock() after rcu_read_unlock() just adds the confusion, move task_unlock() up. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com>, Cc: Sterling Alexander <stalexan@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roland McGrath <roland@hack.frob.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | fs/proc.c: use rb_entry_safe() instead of rb_entry()Nicolas Dichtel2014-12-101-12/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Better to use existing macro that rewriting them. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | procfs: fix error handling of proc_register()Debabrata Banerjee2014-12-101-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | proc_register() error paths are leaking inodes and directory refcounts. Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | fs/proc: use a rb tree for the directory entriesNicolas Dichtel2014-12-104-64/+113
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a lot of netdevices are created, one of the bottleneck is the creation of proc entries. This serie aims to accelerate this part. The current implementation for the directories in /proc is using a single linked list. This is slow when handling directories with large numbers of entries (eg netdevice-related entries when lots of tunnels are opened). This patch replaces this linked list by a red-black tree. Here are some numbers: dummy30000.batch contains 30 000 times 'link add type dummy'. Before the patch: $ time ip -b dummy30000.batch real 2m31.950s user 0m0.440s sys 2m21.440s $ time rmmod dummy real 1m35.764s user 0m0.000s sys 1m24.088s After the patch: $ time ip -b dummy30000.batch real 2m0.874s user 0m0.448s sys 1m49.720s $ time rmmod dummy real 1m13.988s user 0m0.000s sys 1m1.008s The idea of improving this part was suggested by Thierry Herbelot. [akpm@linux-foundation.org: initialise proc_root.subdir at compile time] Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: Thierry Herbelot <thierry.herbelot@6wind.com>. Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * | | | mm: fix huge zero page accounting in smaps reportKirill A. Shutemov2014-12-101-36/+68
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As a small zero page, huge zero page should not be accounted in smaps report as normal page. For small pages we rely on vm_normal_page() to filter out zero page, but vm_normal_page() is not designed to handle pmds. We only get here due hackish cast pmd to pte in smaps_pte_range() -- pte and pmd format is not necessary compatible on each and every architecture. Let's add separate codepath to handle pmds. follow_trans_huge_pmd() will detect huge zero page for us. We would need pmd_dirty() helper to do this properly. The patch adds it to THP-enabled architectures which don't yet have one. [akpm@linux-foundation.org: use do_div to fix 32-bit build] Signed-off-by: "Kirill A. Shutemov" <kirill@shutemov.name> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Fengwei Yin <yfw.kernel@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge branch 'for-linus' of ↵Linus Torvalds2014-12-102-3/+4
|\ \ \ \ | |/ / / |/| / / | |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull VFS changes from Al Viro: "First pile out of several (there _definitely_ will be more). Stuff in this one: - unification of d_splice_alias()/d_materialize_unique() - iov_iter rewrite - killing a bunch of ->f_path.dentry users (and f_dentry macro). Getting that completed will make life much simpler for unionmount/overlayfs, since then we'll be able to limit the places sensitive to file _dentry_ to reasonably few. Which allows to have file_inode(file) pointing to inode in a covered layer, with dentry pointing to (negative) dentry in union one. Still not complete, but much closer now. - crapectomy in lustre (dead code removal, mostly) - "let's make seq_printf return nothing" preparations - assorted cleanups and fixes There _definitely_ will be more piles" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) copy_from_iter_nocache() new helper: iov_iter_kvec() csum_and_copy_..._iter() iov_iter.c: handle ITER_KVEC directly iov_iter.c: convert copy_to_iter() to iterate_and_advance iov_iter.c: convert copy_from_iter() to iterate_and_advance iov_iter.c: get rid of bvec_copy_page_{to,from}_iter() iov_iter.c: convert iov_iter_zero() to iterate_and_advance iov_iter.c: convert iov_iter_get_pages_alloc() to iterate_all_kinds iov_iter.c: convert iov_iter_get_pages() to iterate_all_kinds iov_iter.c: convert iov_iter_npages() to iterate_all_kinds iov_iter.c: iterate_and_advance iov_iter.c: macros for iterating over iov_iter kill f_dentry macro dcache: fix kmemcheck warning in switch_names new helper: audit_file() nfsd_vfs_write(): use file_inode() ncpfs: use file_inode() kill f_dentry uses lockd: get rid of ->f_path.dentry->d_sb ...
| * | Merge tag 'trace-seq-file-cleanup' of ↵Al Viro2014-11-191-1/+2
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into for-next Pull the beginning of seq_file cleanup from Steven: "I'm looking to clean up the seq_file code and to eventually merge the trace_seq code with seq_file as well, since they basically do the same thing. Part of this process is to remove the return code of seq_printf() and friends as they are rather inconsistent. It is better to use the new function seq_has_overflowed() if you want to stop processing when the buffer is full. Note, if the buffer is full, the seq_file code will throw away the contents, allocate a bigger buffer, and then call your code again to fill in the data. The only thing that breaking out of the function early does is to save a little time which is probably never noticed. I started with patches from Joe Perches and modified them as well. There's many more places that need to be updated before we can convert seq_printf() and friends to return void. But this patch set introduces the seq_has_overflowed() and does some initial updates."
| | * | fs: Convert show_fdinfo functions to voidJoe Perches2014-11-051-1/+2
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | seq_printf functions shouldn't really check the return value. Checking seq_has_overflowed() occasionally is used instead. Update vfs documentation. Link: http://lkml.kernel.org/p/e37e6e7b76acbdcc3bb4ab2a57c8f8ca1ae11b9a.1412031505.git.joe@perches.com Cc: David S. Miller <davem@davemloft.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Joe Perches <joe@perches.com> [ did a few clean ups ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * / procfs: get rid of ->f_dentryAl Viro2014-11-191-2/+2
| |/ | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* / x86, mpx: Introduce VM_MPX to indicate that a VMA is MPX specificQiaowei Ren2014-11-181-0/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | MPX-enabled applications using large swaths of memory can potentially have large numbers of bounds tables in process address space to save bounds information. These tables can take up huge swaths of memory (as much as 80% of the memory on the system) even if we clean them up aggressively. In the worst-case scenario, the tables can be 4x the size of the data structure being tracked. IOW, a 1-page structure can require 4 bounds-table pages. Being this huge, our expectation is that folks using MPX are going to be keen on figuring out how much memory is being dedicated to it. So we need a way to track memory use for MPX. If we want to specifically track MPX VMAs we need to be able to distinguish them from normal VMAs, and keep them from getting merged with normal VMAs. A new VM_ flag set only on MPX VMAs does both of those things. With this flag, MPX bounds-table VMAs can be distinguished from other VMAs, and userspace can also walk /proc/$pid/smaps to get memory usage for MPX. In addition to this flag, we also introduce a special ->vm_ops specific to MPX VMAs (see the patch "add MPX specific mmap interface"), but currently different ->vm_ops do not by themselves prevent VMA merging, so we still need this flag. We understand that VM_ flags are scarce and are open to other options. Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-mm@kvack.org Cc: linux-mips@linux-mips.org Cc: Dave Hansen <dave@sr71.net> Link: http://lkml.kernel.org/r/20141114151825.565625B3@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY clearedPeter Feiner2014-10-141-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For VMAs that don't want write notifications, PTEs created for read faults have their write bit set. If the read fault happens after VM_SOFTDIRTY is cleared, then the PTE's softdirty bit will remain clear after subsequent writes. Here's a simple code snippet to demonstrate the bug: char* m = mmap(NULL, getpagesize(), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); system("echo 4 > /proc/$PPID/clear_refs"); /* clear VM_SOFTDIRTY */ assert(*m == '\0'); /* new PTE allows write access */ assert(!soft_dirty(x)); *m = 'x'; /* should dirty the page */ assert(soft_dirty(x)); /* fails */ With this patch, write notifications are enabled when VM_SOFTDIRTY is cleared. Furthermore, to avoid unnecessary faults, write notifications are disabled when VM_SOFTDIRTY is set. As a side effect of enabling and disabling write notifications with care, this patch fixes a bug in mprotect where vm_page_prot bits set by drivers were zapped on mprotect. An analogous bug was fixed in mmap by commit c9d0bf241451 ("mm: uncached vma support with writenotify"). Signed-off-by: Peter Feiner <pfeiner@google.com> Reported-by: Peter Feiner <pfeiner@google.com> Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Jamie Liu <jamieliu@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2014-10-132-10/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "The big thing in this pile is Eric's unmount-on-rmdir series; we finally have everything we need for that. The final piece of prereqs is delayed mntput() - now filesystem shutdown always happens on shallow stack. Other than that, we have several new primitives for iov_iter (Matt Wilcox, culled from his XIP-related series) pushing the conversion to ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c cleanups and fixes (including the external name refcounting, which gives consistent behaviour of d_move() wrt procfs symlinks for long and short names alike) and assorted cleanups and fixes all over the place. This is just the first pile; there's a lot of stuff from various people that ought to go in this window. Starting with unionmount/overlayfs mess... ;-/" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits) fs/file_table.c: Update alloc_file() comment vfs: Deduplicate code shared by xattr system calls operating on paths reiserfs: remove pointless forward declaration of struct nameidata don't need that forward declaration of struct nameidata in dcache.h anymore take dname_external() into fs/dcache.c let path_init() failures treated the same way as subsequent link_path_walk() fix misuses of f_count() in ppp and netlink ncpfs: use list_for_each_entry() for d_subdirs walk vfs: move getname() from callers to do_mount() gfs2_atomic_open(): skip lookups on hashed dentry [infiniband] remove pointless assignments gadgetfs: saner API for gadgetfs_create_file() f_fs: saner API for ffs_sb_create_file() jfs: don't hash direct inode [s390] remove pointless assignment of ->f_op in vmlogrdr ->open() ecryptfs: ->f_op is never NULL android: ->f_op is never NULL nouveau: __iomem misannotations missing annotation in fs/file.c fs: namespace: suppress 'may be used uninitialized' warnings ...
| * proc: Update proc_flush_task_mnt to use d_invalidateEric W. Biederman2014-10-091-4/+2
| | | | | | | | | | | | | | | | | | | | | | Now that d_invalidate always succeeds and flushes mount points use it in stead of a combination of shrink_dcache_parent and d_drop in proc_flush_task_mnt. This removes the danger of a mount point under /proc/<pid>/... becoming unreachable after the d_drop. Reviewed-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * vfs: Remove d_drop calls from d_revalidate implementationsEric W. Biederman2014-10-092-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that d_invalidate always succeeds it is not longer necessary or desirable to hard code d_drop calls into filesystem specific d_revalidate implementations. Remove the unnecessary d_drop calls and rely on d_invalidate to drop the dentries. Using d_invalidate ensures that paths to mount points will not be dropped. Reviewed-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'for-3.18' of ↵Linus Torvalds2014-10-101-35/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Nothing too interesting. Just a handful of cleanup patches" * 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: Revert "cgroup: remove redundant variable in cgroup_mount()" cgroup: remove redundant variable in cgroup_mount() cgroup: fix missing unlock in cgroup_release_agent() cgroup: remove CGRP_RELEASABLE flag perf/cgroup: Remove perf_put_cgroup() cgroup: remove redundant check in cgroup_ino() cpuset: simplify proc_cpuset_show() cgroup: simplify proc_cgroup_show() cgroup: use a per-cgroup work for release agent cgroup: remove bogus comments cgroup: remove redundant code in cgroup_rmdir() cgroup: remove some useless forward declarations cgroup: fix a typo in comment.
| * | cpuset: simplify proc_cpuset_show()Zefan Li2014-09-181-18/+2
| | | | | | | | | | | | | | | | | | | | | Use the ONE macro instead of REG, and we can simplify proc_cpuset_show(). Signed-off-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: simplify proc_cgroup_show()Zefan Li2014-09-181-17/+2
| | | | | | | | | | | | | | | | | | | | | Use the ONE macro instead of REG, and we can simplify proc_cgroup_show(). Signed-off-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | | mm/balloon_compaction: add vmstat counters and kpageflags bitKonstantin Khlebnikov2014-10-091-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Always mark pages with PageBalloon even if balloon compaction is disabled and expose this mark in /proc/kpageflags as KPF_BALLOON. Also this patch adds three counters into /proc/vmstat: "balloon_inflate", "balloon_deflate" and "balloon_migrate". They accumulate balloon activity. Current size of balloon is (balloon_inflate - balloon_deflate) pages. All generic balloon code now gathered under option CONFIG_MEMORY_BALLOON. It should be selected by ballooning driver which wants use this feature. Currently virtio-balloon is the only user. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: softdirty: unmapped addresses between VMAs are cleanPeter Feiner2014-10-091-21/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a /proc/pid/pagemap read spans a [VMA, an unmapped region, then a VM_SOFTDIRTY VMA], the virtual pages in the unmapped region are reported as softdirty. Here's a program to demonstrate the bug: int main() { const uint64_t PAGEMAP_SOFTDIRTY = 1ul << 55; uint64_t pme[3]; int fd = open("/proc/self/pagemap", O_RDONLY);; char *m = mmap(NULL, 3 * getpagesize(), PROT_READ, MAP_ANONYMOUS | MAP_SHARED, -1, 0); munmap(m + getpagesize(), getpagesize()); pread(fd, pme, 24, (unsigned long) m / getpagesize() * 8); assert(pme[0] & PAGEMAP_SOFTDIRTY); /* passes */ assert(!(pme[1] & PAGEMAP_SOFTDIRTY)); /* fails */ assert(pme[2] & PAGEMAP_SOFTDIRTY); /* passes */ return 0; } (Note that all pages in new VMAs are softdirty until cleared). Tested: Used the program given above. I'm going to include this code in a selftest in the future. [n-horiguchi@ah.jp.nec.com: prevent pagemap_pte_range() from overrunning] Signed-off-by: Peter Feiner <pfeiner@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Jamie Liu <jamieliu@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mempolicy: fix show_numa_map() vs exec() + do_set_mempolicy() raceOleg Nesterov2014-10-091-24/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 9e7814404b77 "hold task->mempolicy while numa_maps scans." fixed the race with the exiting task but this is not enough. The current code assumes that get_vma_policy(task) should either see task->mempolicy == NULL or it should be equal to ->task_mempolicy saved by hold_task_mempolicy(), so we can never race with __mpol_put(). But this can only work if we can't race with do_set_mempolicy(), and thus we can't race with another do_set_mempolicy() or do_exit() after that. However, do_set_mempolicy()->down_write(mmap_sem) can not prevent this race. This task can exec, change it's ->mm, and call do_set_mempolicy() after that; in this case they take 2 different locks. Change hold_task_mempolicy() to use get_task_policy(), it never returns NULL, and change show_numa_map() to use __get_vma_policy() or fall back to proc_priv->task_mempolicy. Note: this is the minimal fix, we will cleanup this code later. I think hold_task_mempolicy() and release_task_mempolicy() should die, we can move this logic into show_numa_map(). Or we can move get_task_policy() outside of ->mmap_sem and !CONFIG_NUMA code at least. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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