linux/mm
Linus Torvalds 644473e9c6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace enhancements from Eric Biederman:
 "This is a course correction for the user namespace, so that we can
  reach an inexpensive, maintainable, and reasonably complete
  implementation.

  Highlights:
   - Config guards make it impossible to enable the user namespace and
     code that has not been converted to be user namespace safe.

   - Use of the new kuid_t type ensures the if you somehow get past the
     config guards the kernel will encounter type errors if you enable
     user namespaces and attempt to compile in code whose permission
     checks have not been updated to be user namespace safe.

   - All uids from child user namespaces are mapped into the initial
     user namespace before they are processed.  Removing the need to add
     an additional check to see if the user namespace of the compared
     uids remains the same.

   - With the user namespaces compiled out the performance is as good or
     better than it is today.

   - For most operations absolutely nothing changes performance or
     operationally with the user namespace enabled.

   - The worst case performance I could come up with was timing 1
     billion cache cold stat operations with the user namespace code
     enabled.  This went from 156s to 164s on my laptop (or 156ns to
     164ns per stat operation).

   - (uid_t)-1 and (gid_t)-1 are reserved as an internal error value.
     Most uid/gid setting system calls treat these value specially
     anyway so attempting to use -1 as a uid would likely cause
     entertaining failures in userspace.

   - If setuid is called with a uid that can not be mapped setuid fails.
     I have looked at sendmail, login, ssh and every other program I
     could think of that would call setuid and they all check for and
     handle the case where setuid fails.

   - If stat or a similar system call is called from a context in which
     we can not map a uid we lie and return overflowuid.  The LFS
     experience suggests not lying and returning an error code might be
     better, but the historical precedent with uids is different and I
     can not think of anything that would break by lying about a uid we
     can't map.

   - Capabilities are localized to the current user namespace making it
     safe to give the initial user in a user namespace all capabilities.

  My git tree covers all of the modifications needed to convert the core
  kernel and enough changes to make a system bootable to runlevel 1."

Fix up trivial conflicts due to nearby independent changes in fs/stat.c

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits)
  userns:  Silence silly gcc warning.
  cred: use correct cred accessor with regards to rcu read lock
  userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq
  userns: Convert cgroup permission checks to use uid_eq
  userns: Convert tmpfs to use kuid and kgid where appropriate
  userns: Convert sysfs to use kgid/kuid where appropriate
  userns: Convert sysctl permission checks to use kuid and kgids.
  userns: Convert proc to use kuid/kgid where appropriate
  userns: Convert ext4 to user kuid/kgid where appropriate
  userns: Convert ext3 to use kuid/kgid where appropriate
  userns: Convert ext2 to use kuid/kgid where appropriate.
  userns: Convert devpts to use kuid/kgid where appropriate
  userns: Convert binary formats to use kuid/kgid where appropriate
  userns: Add negative depends on entries to avoid building code that is userns unsafe
  userns: signal remove unnecessary map_cred_ns
  userns: Teach inode_capable to understand inodes whose uids map to other namespaces.
  userns: Fail exec for suid and sgid binaries with ids outside our user namespace.
  userns: Convert stat to return values mapped from kuids and kgids
  userns: Convert user specfied uids and gids in chown into kuids and kgid
  userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs
  ...
2012-05-23 17:42:39 -07:00
..
backing-dev.c backing-dev: fix wakeup timer races with bdi_unregister() 2012-02-01 16:52:49 +08:00
bootmem.c bootmem/sparsemem: remove limit constraint in alloc_bootmem_section 2012-03-21 17:54:58 -07:00
bounce.c mm: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:27 +08:00
cleancache.c mm: cleancache: Use __read_mostly as appropiate. 2012-01-23 16:08:09 -05:00
compaction.c mm: compaction: make compact_control order signed 2012-03-21 17:54:56 -07:00
debug-pagealloc.c mm, x86: Remove debug_pagealloc_enabled 2011-12-06 09:24:07 +01:00
dmapool.c mm: fix implicit stat.h usage in dmapool.c 2011-10-31 09:20:12 -04:00
fadvise.c fadvise: only initiate writeback for specified range with FADV_DONTNEED 2012-01-10 16:30:43 -08:00
failslab.c switch debugfs to umode_t 2012-01-03 22:54:56 -05:00
filemap_xip.c mm/filemap_xip.c: fix race condition in xip_file_fault() 2012-02-03 16:16:41 -08:00
filemap.c radix-tree: use iterators in find_get_pages* functions 2012-03-28 17:14:37 -07:00
fremap.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
highmem.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
huge_memory.c thp: optimize away unnecessary page table locking 2012-03-21 17:54:57 -07:00
hugetlb.c hugetlb: prevent BUG_ON in hugetlb_fault() -> hugetlb_cow() 2012-05-10 15:06:44 -07:00
hwpoison-inject.c HWPOISON: Clean up memory_failure() vs. __memory_failure() 2012-01-03 12:06:32 -08:00
init-mm.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
internal.h mm: thp: tail page refcounting fix 2011-11-02 16:06:57 -07:00
Kconfig Merge branch 'master' into x86/memblock 2011-11-28 09:46:22 -08:00
Kconfig.debug mm: more intensive memory corruption debugging 2012-01-10 16:30:42 -08:00
kmemcheck.c
kmemleak-test.c kmemleak: remove memset by using kzalloc 2011-01-27 18:31:51 +00:00
kmemleak.c kmemleak: Disable early logging when kmemleak is off by default 2012-01-20 16:57:05 +00:00
ksm.c ksm: cleanup: introduce find_mergeable_vma() 2012-03-21 17:54:59 -07:00
maccess.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
madvise.c coredump: add VM_NODUMP, MADV_NODUMP, MADV_CLEAR_NODUMP 2012-03-23 16:58:42 -07:00
Makefile Cross Memory Attach 2011-10-31 17:30:44 -07:00
memblock.c memblock: memblock should be able to handle zero length operations 2012-04-20 11:18:46 -07:00
memcontrol.c Merge branch 'for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2012-05-22 17:40:19 -07:00
memory_hotplug.c mm: compaction: introduce sync-light migration for use by compaction 2012-01-12 20:13:09 -08:00
memory-failure.c Merge branch 'x86-mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-22 09:42:04 -07:00
memory.c vm: remove 'nr_accounted' calculations from the unmap_vmas() interfaces 2012-05-06 14:05:17 -07:00
mempolicy.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
mempool.c mempool: fix first round failure behavior 2012-01-10 16:30:45 -08:00
migrate.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
mincore.c mm: thp: fix pmd_bad() triggering in code paths holding mmap_sem read mode 2012-03-21 17:54:54 -07:00
mlock.c vm: avoid using find_vma_prev() unnecessarily 2012-03-06 18:23:36 -08:00
mm_init.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
mmap.c vm: remove 'nr_accounted' calculations from the unmap_vmas() interfaces 2012-05-06 14:05:17 -07:00
mmu_context.c mm, counters: remove task argument to sync_mm_rss() and __sync_task_rss_stat() 2012-03-21 17:54:59 -07:00
mmu_notifier.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
mmzone.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
mprotect.c Merge branch 'akpm' (Andrew's patch-bomb) 2012-03-22 09:04:48 -07:00
mremap.c mm: collapse security_vm_enough_memory() variants into a single function 2012-02-14 10:45:39 +11:00
msync.c
nobootmem.c mm: nobootmem: fix sign extend problem in __free_pages_memory() 2012-05-10 15:06:44 -07:00
nommu.c kill mm argument of vm_munmap() 2012-04-21 01:58:20 -04:00
oom_kill.c userns: Store uid and gid values in struct cred with kuid_t and kgid_t types 2012-05-03 03:28:38 -07:00
page_alloc.c Driver core pull for 3.5-rc1 2012-05-22 16:02:13 -07:00
page_cgroup.c page_cgroup: fix horrid swap accounting regression 2012-03-06 08:18:23 -08:00
page_io.c block: kill off REQ_UNPLUG 2011-03-10 08:52:27 +01:00
page_isolation.c mm: page_isolation: codeclean fix comment and rm unneeded val init 2010-10-26 16:52:11 -07:00
page-writeback.c Ext4 commits for 3.3 merge window; mostly cleanups and bug fixes 2012-03-28 10:02:55 -07:00
pagewalk.c mm: thp: fix pmd_bad() triggering in code paths holding mmap_sem read mode 2012-03-21 17:54:54 -07:00
percpu-km.c percpu: clear memory allocated with the km allocator 2010-10-02 10:28:42 +03:00
percpu-vm.c percpu: use bitmap_clear 2012-01-20 09:23:16 -08:00
percpu.c kmemleak: Fix the kmemleak tracking of the percpu areas with !SMP 2012-05-09 10:13:29 -07:00
pgtable-generic.c thp: add HPAGE_PMD_* definitions for !CONFIG_TRANSPARENT_HUGEPAGE 2012-03-21 17:55:02 -07:00
prio_tree.c sanitize <linux/prefetch.h> usage 2011-05-20 12:50:29 -07:00
process_vm_access.c Fix race in process_vm_rw_core 2012-02-02 12:55:17 -08:00
quicklist.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
readahead.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
rmap.c memcg: use new logic for page stat accounting 2012-03-21 17:55:01 -07:00
shmem.c userns: Convert tmpfs to use kuid and kgid where appropriate 2012-05-15 14:59:29 -07:00
slab.c Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux 2012-03-28 15:04:26 -07:00
slob.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
slub.c slub: missing test for partial pages flush work in flush_all() 2012-05-17 18:00:51 -07:00
sparse-vmemmap.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
sparse.c bootmem/sparsemem: remove limit constraint in alloc_bootmem_section 2012-03-21 17:54:58 -07:00
swap_state.c mm: fix s390 BUG by __set_page_dirty_no_writeback on swap 2012-04-23 18:19:22 -07:00
swap.c mm: drain percpu lru add/rotate page-vectors on cpu hot-unplug 2012-03-21 17:54:58 -07:00
swapfile.c swapon: check validity of swap_flags 2012-03-28 17:14:35 -07:00
thrash.c mm/thrash.c: quiet sparse noise 2011-10-31 17:30:50 -07:00
truncate.c mm for fs: add truncate_pagecache_range() 2012-03-28 17:14:35 -07:00
util.c procfs: mark thread stack correctly in proc/<pid>/maps 2012-03-21 17:54:58 -07:00
vmalloc.c mm: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:27 +08:00
vmscan.c mm: fix up the vmscan stat in vmstat 2012-04-25 21:26:33 -07:00
vmstat.c mm: fix up the vmscan stat in vmstat 2012-04-25 21:26:33 -07:00