linux/fs/proc, branch v3.17

mm: softdirty: addresses before VMAs in PTE holes aren't softdirty

2014-09-26T15:10:35Z

In PTE holes that contain VM_SOFTDIRTY VMAs, unmapped addresses before VM_SOFTDIRTY VMAs are reported as softdirty by /proc/pid/pagemap. This bug was introduced in commit 68b5a6524856 ("mm: softdirty: respect VM_SOFTDIRTY in PTE holes"). That commit made /proc/pid/pagemap look at VM_SOFTDIRTY in PTE holes but neglected to observe the start of VMAs returned by find_vma. Tested: Wrote a selftest that creates a PMD-sized VMA then unmaps the first page and asserts that the page is not softdirty. I'm going to send the pagemap selftest in a later commit. Signed-off-by: Peter Feiner Cc: Cyrill Gorcunov Cc: Pavel Emelyanov Cc: Hugh Dickins Cc: Naoya Horiguchi Cc: "Kirill A. Shutemov" Cc: Jamie Liu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Revert "proc: Point /proc/{mounts,net} at /proc/thread-self/{mounts,net} instead of /proc/self/{mounts,net}"

2014-08-11T04:24:59Z

This reverts commits 344470cac42e and e81324407269. It turns out that the exact path in the symlink matters, if for somewhat unfortunate reasons: some apparmor configurations don't allow dhclient access to the per-thread /proc files. As reported by Jörg Otte: audit: type=1400 audit(1407684227.003:28): apparmor="DENIED" operation="open" profile="/sbin/dhclient" name="/proc/1540/task/1540/net/dev" pid=1540 comm="dhclient" requested_mask="r" denied_mask="r" fsuid=0 ouid=0 so we had better revert this for now. We might be able to work around this in practice by only using the per-thread symlinks if the thread isn't the thread group leader, and if the namespaces differ between threads (which basically never happens). We'll see. In the meantime, the revert was made to be intentionally easy. Reported-by: Jörg Otte Acked-by: Eric W. Biederman Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2014-08-10T00:10:41Z

Pull namespace updates from Eric Biederman: "This is a bunch of small changes built against 3.16-rc6. The most significant change for users is the first patch which makes setns drmatically faster by removing unneded rcu handling. The next chunk of changes are so that "mount -o remount,.." will not allow the user namespace root to drop flags on a mount set by the system wide root. Aks this forces read-only mounts to stay read-only, no-dev mounts to stay no-dev, no-suid mounts to stay no-suid, no-exec mounts to stay no exec and it prevents unprivileged users from messing with a mounts atime settings. I have included my test case as the last patch in this series so people performing backports can verify this change works correctly. The next change fixes a bug in NFS that was discovered while auditing nsproxy users for the first optimization. Today you can oops the kernel by reading /proc/fs/nfsfs/{servers,volumes} if you are clever with pid namespaces. I rebased and fixed the build of the !CONFIG_NFS_FS case yesterday when a build bot caught my typo. Given that no one to my knowledge bases anything on my tree fixing the typo in place seems more responsible that requiring a typo-fix to be backported as well. The last change is a small semantic cleanup introducing /proc/thread-self and pointing /proc/mounts and /proc/net at it. This prevents several kinds of problemantic corner cases. It is a user-visible change so it has a minute chance of causing regressions so the change to /proc/mounts and /proc/net are individual one line commits that can be trivially reverted. Unfortunately I lost and could not find the email of the original reporter so he is not credited. From at least one perspective this change to /proc/net is a refgression fix to allow pthread /proc/net uses that were broken by the introduction of the network namespace" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Point /proc/mounts at /proc/thread-self/mounts instead of /proc/self/mounts proc: Point /proc/net at /proc/thread-self/net instead of /proc/self/net proc: Implement /proc/thread-self to point at the directory of the current thread proc: Have net show up under /proc//task/ NFS: Fix /proc/fs/nfsfs/servers and /proc/fs/nfsfs/volumes mnt: Add tests for unprivileged remount cases that have found to be faulty mnt: Change the default remount atime from relatime to the existing value mnt: Correct permission checks in do_remount mnt: Move the test for MNT_LOCK_READONLY from change_mount_flags into do_remount mnt: Only change user settable mount flags in remount namespaces: Use task_lock and not rcu to protect nsproxy

sysctl: remove typedef ctl_table

2014-08-08T22:57:24Z

Remove the final user, and the typedef itself. Signed-off-by: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fs/proc/vmcore.c:mmap_vmcore: skip non-ram pages reported by hypervisors

2014-08-08T22:57:23Z

We have a special check in read_vmcore() handler to check if the page was reported as ram or not by the hypervisor (pfn_is_ram()). However, when vmcore is read with mmap() no such check is performed. That can lead to unpredictable results, e.g. when running Xen PVHVM guest memcpy() after mmap() on /proc/vmcore will hang processing HVMMEM_mmio_dm pages creating enormous load in both DomU and Dom0. Fix the issue by mapping each non-ram page to the zero page. Keep direct path with remap_oldmem_pfn_range() to avoid looping through all pages on bare metal. The issue can also be solved by overriding remap_oldmem_pfn_range() in xen-specific code, as remap_oldmem_pfn_range() was been designed for. That, however, would involve non-obvious xen code path for all x86 builds with CONFIG_XEN_PVHVM=y and would prevent all other hypervisor-specific code on x86 arch from doing the same override. [fengguang.wu@intel.com: remap_oldmem_pfn_checked() can be static] [akpm@linux-foundation.org: clean up layout] Signed-off-by: Vitaly Kuznetsov Reviewed-by: Andrew Jones Cc: Michael Holzheu Acked-by: Vivek Goyal Cc: David Vrabel Signed-off-by: Fengguang Wu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: remove INF macro

2014-08-08T22:57:23Z

If you're applying this patch, all /proc/$PID/* files were converted to seq_file interface and this code became unused. Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: convert /proc/$PID/hardwall to seq_file interface

2014-08-08T22:57:23Z

Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: convert /proc/$PID/io to seq_file interface

2014-08-08T22:57:23Z

Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: convert /proc/$PID/oom_score to seq_file interface

2014-08-08T22:57:23Z

Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: convert /proc/$PID/schedstat to seq_file interface

2014-08-08T22:57:23Z

Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds