linux/init, branch v2.6.39

slub: Revert "[PARISC] slub: fix panic with DISCONTIGMEM"

2011-05-11T00:37:34Z

This reverts commit 4a5fa3590f09, which did not allow SLUB to be used on architectures that use DISCONTIGMEM without compiling NUMA support without CONFIG_BROKEN also set. The slub panic that it was intended to prevent is addressed by d9b41e0b54fd ("[PARISC] set memory ranges in N_NORMAL_MEMORY when onlined") on parisc so there is no further slub issues with such a configuration. The reverts allows SLUB now to be used on such architectures since there haven't been any reports of additional errors. Cc: James Bottomley Signed-off-by: David Rientjes Signed-off-by: Linus Torvalds

Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/parisc-2.6

2011-04-27T22:20:33Z

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/parisc-2.6: [PARISC] slub: fix panic with DISCONTIGMEM [PARISC] set memory ranges in N_NORMAL_MEMORY when onlined

init/Kconfig: fix EXPERT menu list

2011-04-27T03:48:37Z

The EXPERT menu list was recently broken by the insertion of a kconfig symbol (EMBEDDED) at the beginning of the EXPERT list of kconfig items. Broken by: commit 6a108a14fa356ef607be308b68337939e56ea94e Author: David Rientjes Date: Thu Jan 20 14:44:16 2011 -0800 kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT Restore the EXPERT menu list -- don't inject a symbol (EMBEDDED) that does not depend on EXPERT into the list. Signed-off-by: Randy Dunlap Cc: David Rientjes Cc: Peter Foley Signed-off-by: Linus Torvalds

[PARISC] slub: fix panic with DISCONTIGMEM

2011-04-22T20:42:46Z

Slub makes assumptions about page_to_nid() which are violated by DISCONTIGMEM and !NUMA. This violation results in a panic because page_to_nid() can be non-zero for pages in the discontiguous ranges and this leads to a null return by get_node(). The assertion by the maintainer is that DISCONTIGMEM should only be allowed when NUMA is also defined. However, at least six architectures: alpha, ia64, m32r, m68k, mips, parisc violate this. The panic is a regression against slab, so just mark slub broken in the problem configuration to prevent users reporting these panics. Cc: stable@kernel.org Acked-by: David Rientjes Acked-by: Pekka Enberg Signed-off-by: James Bottomley

Fix common misspellings

2011-03-31T14:26:23Z

Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi

userns: add a user_namespace as creator/owner of uts_namespace

2011-03-24T02:46:59Z

The expected course of development for user namespaces targeted capabilities is laid out at https://wiki.ubuntu.com/UserNamespace. Goals: - Make it safe for an unprivileged user to unshare namespaces. They will be privileged with respect to the new namespace, but this should only include resources which the unprivileged user already owns. - Provide separate limits and accounting for userids in different namespaces. Status: Currently (as of 2.6.38) you can clone with the CLONE_NEWUSER flag to get a new user namespace if you have the CAP_SYS_ADMIN, CAP_SETUID, and CAP_SETGID capabilities. What this gets you is a whole new set of userids, meaning that user 500 will have a different 'struct user' in your namespace than in other namespaces. So any accounting information stored in struct user will be unique to your namespace. However, throughout the kernel there are checks which - simply check for a capability. Since root in a child namespace has all capabilities, this means that a child namespace is not constrained. - simply compare uid1 == uid2. Since these are the integer uids, uid 500 in namespace 1 will be said to be equal to uid 500 in namespace 2. As a result, the lxc implementation at lxc.sf.net does not use user namespaces. This is actually helpful because it leaves us free to develop user namespaces in such a way that, for some time, user namespaces may be unuseful. Bugs aside, this patchset is supposed to not at all affect systems which are not actively using user namespaces, and only restrict what tasks in child user namespace can do. They begin to limit privilege to a user namespace, so that root in a container cannot kill or ptrace tasks in the parent user namespace, and can only get world access rights to files. Since all files currently belong to the initila user namespace, that means that child user namespaces can only get world access rights to *all* files. While this temporarily makes user namespaces bad for system containers, it starts to get useful for some sandboxing. I've run the 'runltplite.sh' with and without this patchset and found no difference. This patch: copy_process() handles CLONE_NEWUSER before the rest of the namespaces. So in the case of clone(CLONE_NEWUSER|CLONE_NEWUTS) the new uts namespace will have the new user namespace as its owner. That is what we want, since we want root in that new userns to be able to have privilege over it. Changelog: Feb 15: don't set uts_ns->user_ns if we didn't create a new uts_ns. Feb 23: Move extern init_user_ns declaration from init/version.c to utsname.h. Signed-off-by: Serge E. Hallyn Acked-by: "Eric W. Biederman" Acked-by: Daniel Lezcano Acked-by: David Howells Cc: James Morris Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pid: remove the child_reaper special case in init/main.c

2011-03-24T02:46:57Z

This patchset is a cleanup and a preparation to unshare the pid namespace. These prerequisites prepare for Eric's patchset to give a file descriptor to a namespace and join an existing namespace. This patch: It turns out that the existing assignment in copy_process of the child_reaper can handle the initial assignment of child_reaper we just need to generalize the test in kernel/fork.c Signed-off-by: Eric W. Biederman Signed-off-by: Daniel Lezcano Cc: Oleg Nesterov Cc: Alexey Dobriyan Acked-by: Serge E. Hallyn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

init: return proper error code in do_mounts_rd()

2011-03-23T00:44:15Z

In do_mounts_rd() if memory cannot be allocated, return -ENOMEM. Signed-off-by: Davidlohr Bueso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

calibrate: retry with wider bounds when converge seems to fail

2011-03-23T00:44:12Z

Systems with unmaskable interrupts such as SMIs may massively underestimate loops_per_jiffy, and fail to converge anywhere near the real value. A case seen on x86_64 was an initial estimate of 256<<12, which converged to 511<<12 where the real value should have been over 630<<12. This admitedly requires bypassing the TSC calibration (lpj_fine), and a failure to settle in the direct calibration too, but is physically possible. This failure does not depend on my previous calibration optimisation, but by luck is easy to fix with the optimisation in place with a trivial retry loop. In the context of the optimised converging method, as we can no longer trust the starting estimate, enlarge the search bounds exponentially so that the number of retries is logarithmically bounded. [akpm@linux-foundation.org: mention x86_64 SMIs in comment] Signed-off-by: Phil Carmody Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Tested-by: Stephen Boyd Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

calibrate: home in on correct lpj value more quickly

2011-03-23T00:44:11Z

Binary chop with a jiffy-resync on each step to find an upper bound is slow, so just race in a tight-ish loop to find an underestimate. If done with lots of individual steps, sometimes several hundreds of iterations would be required, which would impose a significant overhead, and make the initial estimate very low. By taking slowly increasing steps there will be less overhead. E.g. an x86_64 2.67GHz could have fitted in 613 individual small delays, but in reality should have been able to fit in a single delay 644 times longer, so underestimated by 31 steps. To reach the equivalent of 644 small delays with the accelerating scheme now requires about 130 iterations, so has <1/4th of the overhead, and can therefore be expected to underestimate by only 7 steps. As now we have a better initial estimate we can binary chop over a smaller range. With the loop overhead in the initial estimate kept low, and the step sizes moderate, we won't have under-estimated by much, so chose as tight a range as we can. Signed-off-by: Phil Carmody Cc: Ingo Molnar Cc: Thomas Gleixner Cc: "H. Peter Anvin" Tested-by: Stephen Boyd Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds