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2007-10-19pid namespaces: define is_global_init() and is_container_init()Serge E. Hallyn1-1/+1
is_init() is an ambiguous name for the pid==1 check. Split it into is_global_init() and is_container_init(). A cgroup init has it's tsk->pid == 1. A global init also has it's tsk->pid == 1 and it's active pid namespace is the init_pid_ns. But rather than check the active pid namespace, compare the task structure with 'init_pid_ns.child_reaper', which is initialized during boot to the /sbin/init process and never changes. Changelog: 2.6.22-rc4-mm2-pidns1: - Use 'init_pid_ns.child_reaper' to determine if a given task is the global init (/sbin/init) process. This would improve performance and remove dependence on the task_pid(). 2.6.21-mm2-pidns2: - [Sukadev Bhattiprolu] Changed is_container_init() calls in {powerpc, ppc,avr32}/traps.c for the _exception() call to is_global_init(). This way, we kill only the cgroup if the cgroup's init has a bug rather than force a kernel panic. [akpm@linux-foundation.org: fix comment] [sukadev@us.ibm.com: Use is_global_init() in arch/m32r/mm/fault.c] [bunk@stusta.de: kernel/pid.c: remove unused exports] [sukadev@us.ibm.com: Fix capability.c to work with threaded init] Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Acked-by: Pavel Emelianov <xemul@openvz.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Herbert Poetzel <herbert@13thfloor.at> Cc: Kirill Korotaev <dev@sw.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-22[POWERPC] Allow exec faults on readable areas on classic 32-bit PowerPCPaul Mackerras1-1/+7
Classic 32-bit PowerPC CPUs, and the early 64-bit PowerPC CPUs, don't provide a way to prevent execution from readable pages, that is, the MMU doesn't distinguish between data reads and instruction reads, although a different exception is taken for faults in data accesses and instruction accesses. Commit 9ba4ace39fdfe22268daca9f28c5df384ae462cf, in the course of fixing another bug, added a check that meant that a page fault due to an instruction access would fail if the vma did not have the VM_EXEC flag set. This gives an inconsistent enforcement on these CPUs of the no-execute status of the vma (since reading from the page is sufficient to allow subsequent execution from it), and causes old versions of ppc32 glibc (2.2 and earlier) to fail, since they rely on executing the word before the GOT but don't have it marked executable. This fixes the problem by allowing execution from readable (or writable) areas on CPUs which do not provide separate control over data and instruction reads. Signed-off-by: Paul Mackerras <paulus@samba.org> Acked-by: Jon Loeliger <jdl@freescale.com>
2007-07-19mm: fault feedback #2Nick Piggin1-15/+11
This patch completes Linus's wish that the fault return codes be made into bit flags, which I agree makes everything nicer. This requires requires all handle_mm_fault callers to be modified (possibly the modifications should go further and do things like fault accounting in handle_mm_fault -- however that would be for another patch). [akpm@linux-foundation.org: fix alpha build] [akpm@linux-foundation.org: fix s390 build] [akpm@linux-foundation.org: fix sparc build] [akpm@linux-foundation.org: fix sparc64 build] [akpm@linux-foundation.org: fix ia64 build] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ian Molton <spyro@f2s.com> Cc: Bryan Wu <bryan.wu@analog.com> Cc: Mikael Starvik <starvik@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Greg Ungerer <gerg@uclinux.org> Cc: Matthew Wilcox <willy@debian.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp> Cc: Richard Curnow <rc@rc0.org.uk> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp> Cc: Chris Zankel <chris@zankel.net> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Still apparently needs some ARM and PPC loving - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-11Merge branch 'for-2.6.23' into mergePaul Mackerras1-1/+1
2007-06-20[POWERPC] PowerPC: Prevent data exception in kernel space (32-bit)Segher Boessenkool1-3/+2
The "is_exec" branch of the protection check in do_page_fault() didn't do anything on 32-bit PowerPC. So if a userland program jumps to a page with Linux protection flags "---p", all the tests happily fall through, and handle_mm_fault() is called, which in turn calls handle_pte_fault(), which calls update_mmu_cache(), which goes flush the dcache to a page with no access rights. Boom. This fixes it. Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org> Cc: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14[POWERPC] During VM oom condition, kill all threads in process groupwill schmidt1-1/+1
We have had complaints where a threaded application is left in a bad state after one of it's threads is killed when we hit a VM: out_of_memory condition. Killing just one of the process threads can leave the application in a bad state, whereas killing the entire process group would allow for the application to restart, or be otherwise handled, and makes it very obvious that something has gone wrong. This change allows the entire process group to be taken down, rather than just the one thread. lightly tested on powerpc Signed-off-by: Will <will_schmidt@vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-05-08Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpcLinus Torvalds1-27/+15
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (77 commits) [POWERPC] Abolish powerpc_flash_init() [POWERPC] Early serial debug support for PPC44x [POWERPC] Support for the Ebony 440GP reference board in arch/powerpc [POWERPC] Add device tree for Ebony [POWERPC] Add powerpc/platforms/44x, disable platforms/4xx for now [POWERPC] MPIC U3/U4 MSI backend [POWERPC] MPIC MSI allocator [POWERPC] Enable MSI mappings for MPIC [POWERPC] Tell Phyp we support MSI [POWERPC] RTAS MSI implementation [POWERPC] PowerPC MSI infrastructure [POWERPC] Rip out the existing powerpc msi stubs [POWERPC] Remove use of 4level-fixup.h for ppc32 [POWERPC] Add powerpc PCI-E reset API implementation [POWERPC] Holly bootwrapper [POWERPC] Holly DTS [POWERPC] Holly defconfig [POWERPC] Add support for 750CL Holly board [POWERPC] Generalize tsi108 PCI setup [POWERPC] Generalize tsi108 PHY types ... Fixed conflict in include/asm-powerpc/kdebug.h manually Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08move die notifier handling to common codeChristoph Hellwig1-1/+1
This patch moves the die notifier handling to common code. Previous various architectures had exactly the same code for it. Note that the new code is compiled unconditionally, this should be understood as an appel to the other architecture maintainer to implement support for it aswell (aka sprinkling a notify_die or two in the proper place) arm had a notifiy_die that did something totally different, I renamed it to arm_notify_die as part of the patch and made it static to the file it's declared and used at. avr32 used to pass slightly less information through this interface and I brought it into line with the other architectures. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix vmalloc_sync_all bustage] [bryan.wu@analog.com: fix vmalloc_sync_all in nommu] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: <linux-arch@vger.kernel.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Bryan Wu <bryan.wu@analog.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-02[POWERPC] Minor fault path optimizationChristoph Hellwig1-27/+15
Call the kprobes pagefault handler directly instead of going through the complex notifier chain. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-11-13[PATCH] Do a single one-line printk in bad_page_fault()Michael Ellerman1-11/+14
bad_page_fault() prints a message telling the user what type of bad fault we took. The first line of this message is currently implemented as two separate printks. This has the unfortunate effect that if several cpus simultaneously take a bad fault, the first and second parts of the printk get jumbled up, which looks dodge and is hard to read. So do a single one-line printk for each fault type. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-09-29[PATCH] pidspace: is_init()Sukadev Bhattiprolu1-1/+1
This is an updated version of Eric Biederman's is_init() patch. (http://lkml.org/lkml/2006/2/6/280). It applies cleanly to 2.6.18-rc3 and replaces a few more instances of ->pid == 1 with is_init(). Further, is_init() checks pid and thus removes dependency on Eric's other patches for now. Eric's original description: There are a lot of places in the kernel where we test for init because we give it special properties. Most significantly init must not die. This results in code all over the kernel test ->pid == 1. Introduce is_init to capture this case. With multiple pid spaces for all of the cases affected we are looking for only the first process on the system, not some other process that has pid == 1. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: <lxc-devel@lists.sourceforge.net> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] make PROT_WRITE imply PROT_READJason Baron1-1/+1
Make PROT_WRITE imply PROT_READ for a number of architectures which don't support write only in hardware. While looking at this, I noticed that some architectures which do not support write only mappings already take the exact same approach. For example, in arch/alpha/mm/fault.c: " if (cause < 0) { if (!(vma->vm_flags & VM_EXEC)) goto bad_area; } else if (!cause) { /* Allow reads even for write-only mappings */ if (!(vma->vm_flags & (VM_READ | VM_WRITE))) goto bad_area; } else { if (!(vma->vm_flags & VM_WRITE)) goto bad_area; } " Thus, this patch brings other architectures which do not support write only mappings in-line and consistent with the rest. I've verified the patch on ia64, x86_64 and x86. Additional discussion: Several architectures, including x86, can not support write-only mappings. The pte for x86 reserves a single bit for protection and its two states are read only or read/write. Thus, write only is not supported in h/w. Currently, if i 'mmap' a page write-only, the first read attempt on that page creates a page fault and will SEGV. That check is enforced in arch/blah/mm/fault.c. However, if i first write that page it will fault in and the pte will be set to read/write. Thus, any subsequent reads to the page will succeed. It is this inconsistency in behavior that this patch is attempting to address. Furthermore, if the page is swapped out, and then brought back the first read will also cause a SEGV. Thus, any arbitrary read on a page can potentially result in a SEGV. According to the SuSv3 spec, "if the application requests only PROT_WRITE, the implementation may also allow read access." Also as mentioned, some archtectures, such as alpha, shown above already take the approach that i am suggesting. The counter-argument to this raised by Arjan, is that the kernel is enforcing the write only mapping the best it can given the h/w limitations. This is true, however Alan Cox, and myself would argue that the inconsitency in behavior, that is applications can sometimes work/sometimes fails is highly undesireable. If you read through the thread, i think people, came to an agreement on the last patch i posted, as nobody has objected to it... Signed-off-by: Jason Baron <jbaron@redhat.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Andi Kleen <ak@muc.de> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp> Cc: Ian Molton <spyro@f2s.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel1-1/+0
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-26[PATCH] Notify page fault call chain for powerpcAnil S Keshavamurthy1-1/+35
Overloading of page fault notification with the notify_die() has performance issues(since the only interested components for page fault is kprobes and/or kdb) and hence this patch introduces the new notifier call chain exclusively for page fault notifications their by avoiding notifying unnecessary components in the do_page_fault() code path. Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-01[PATCH] powerpc: trivial spelling fixes in fault.cAnton Blanchard1-3/+3
This comment exceeded my bad spelling threshold :) Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-29[PATCH] lock PTE before updating it in 440/BookE page fault handlerEugene Surovegin1-13/+17
Fix 44x and BookE page fault handler to correctly lock PTE before trying to pte_update() it, otherwise this PTE might be swapped out after pte_present() check but before pte_uptdate() call, resulting in corrupted PTE. This can happen with enabled preemption and low memory condition. Signed-off-by: Eugene Surovegin <ebs@ebshome.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-02-10[PATCH] powerpc: trivial: modify comments to refer to new location of filesJon Mason1-2/+0
This patch removes all self references and fixes references to files in the now defunct arch/ppc64 tree. I think this accomplises everything wanted, though there might be a few references I missed. Signed-off-by: Jon Mason <jdmason@us.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09[PATCH] powerpc: DABR exceptions should report the address not the PCAnton Blanchard1-3/+4
When taking a DABR exception we were reporting the PC. It makes more sense to report the address that caused the exception, and the gdb guys would like it that way. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-07[PATCH] powerpc: Nicer printing of address at oopsOlof Johansson1-0/+17
Add nicer printing of faulting address on unresolvable kernel faults. Makes life a little easier for those who don't know how to decode our register contents at oops time. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-27[PATCH] powerpc: Fix warning related to do_dabrKumar Gala1-0/+2
do_dabr() is not relevant on 40x or Book-E processors so dont build it Signed-off-by: Kumar K. Gala <kumar.gala@freescale.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-09-26powerpc: Merge enough to start building in arch/powerpc.Paul Mackerras1-0/+391
This creates the directory structure under arch/powerpc and a bunch of Kconfig files. It does a first-cut merge of arch/powerpc/mm, arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough to build a 32-bit powermac kernel with ARCH=powerpc. For now we are getting some unmerged files from arch/ppc/kernel and arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes to files in those directories and files outside arch/powerpc. The boot directory is still not merged. That's going to be interesting. Signed-off-by: Paul Mackerras <paulus@samba.org>