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2012-09-19xen/setup: Fix one-off error when adding for-balloon PFNs to the P2M.Konrad Rzeszutek Wilk
commit c96aae1f7f393387d160211f60398d58463a7e65 upstream. When we are finished with return PFNs to the hypervisor, then populate it back, and also mark the E820 MMIO and E820 gaps as IDENTITY_FRAMEs, we then call P2M to set areas that can be used for ballooning. We were off by one, and ended up over-writting a P2M entry that most likely was an IDENTITY_FRAME. For example: 1-1 mapping on 40000->40200 1-1 mapping on bc558->bc5ac 1-1 mapping on bc5b4->bc8c5 1-1 mapping on bc8c6->bcb7c 1-1 mapping on bcd00->100000 Released 614 pages of unused memory Set 277889 page(s) to 1-1 mapping Populating 40200-40466 pfn range: 614 pages added => here we set from 40466 up to bc559 P2M tree to be INVALID_P2M_ENTRY. We should have done it up to bc558. The end result is that if anybody is trying to construct a PTE for PFN bc558 they end up with ~PAGE_PRESENT. Reported-by-and-Tested-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-09-12mm: hugetlbfs: correctly populate shared pmdMichal Hocko
commit eb48c071464757414538c68a6033c8f8c15196f8 upstream. Each page mapped in a process's address space must be correctly accounted for in _mapcount. Normally the rules for this are straightforward but hugetlbfs page table sharing is different. The page table pages at the PMD level are reference counted while the mapcount remains the same. If this accounting is wrong, it causes bugs like this one reported by Larry Woodman: kernel BUG at mm/filemap.c:135! invalid opcode: 0000 [#1] SMP CPU 22 Modules linked in: bridge stp llc sunrpc binfmt_misc dcdbas microcode pcspkr acpi_pad acpi] Pid: 18001, comm: mpitest Tainted: G W 3.3.0+ #4 Dell Inc. PowerEdge R620/07NDJ2 RIP: 0010:[<ffffffff8112cfed>] [<ffffffff8112cfed>] __delete_from_page_cache+0x15d/0x170 Process mpitest (pid: 18001, threadinfo ffff880428972000, task ffff880428b5cc20) Call Trace: delete_from_page_cache+0x40/0x80 truncate_hugepages+0x115/0x1f0 hugetlbfs_evict_inode+0x18/0x30 evict+0x9f/0x1b0 iput_final+0xe3/0x1e0 iput+0x3e/0x50 d_kill+0xf8/0x110 dput+0xe2/0x1b0 __fput+0x162/0x240 During fork(), copy_hugetlb_page_range() detects if huge_pte_alloc() shared page tables with the check dst_pte == src_pte. The logic is if the PMD page is the same, they must be shared. This assumes that the sharing is between the parent and child. However, if the sharing is with a different process entirely then this check fails as in this diagram: parent | ------------>pmd src_pte----------> data page ^ other--------->pmd--------------------| ^ child-----------| dst_pte For this situation to occur, it must be possible for Parent and Other to have faulted and failed to share page tables with each other. This is possible due to the following style of race. PROC A PROC B copy_hugetlb_page_range copy_hugetlb_page_range src_pte == huge_pte_offset src_pte == huge_pte_offset !src_pte so no sharing !src_pte so no sharing (time passes) hugetlb_fault hugetlb_fault huge_pte_alloc huge_pte_alloc huge_pmd_share huge_pmd_share LOCK(i_mmap_mutex) find nothing, no sharing UNLOCK(i_mmap_mutex) LOCK(i_mmap_mutex) find nothing, no sharing UNLOCK(i_mmap_mutex) pmd_alloc pmd_alloc LOCK(instantiation_mutex) fault UNLOCK(instantiation_mutex) LOCK(instantiation_mutex) fault UNLOCK(instantiation_mutex) These two processes are not poing to the same data page but are not sharing page tables because the opportunity was missed. When either process later forks, the src_pte == dst pte is potentially insufficient. As the check falls through, the wrong PTE information is copied in (harmless but wrong) and the mapcount is bumped for a page mapped by a shared page table leading to the BUG_ON. This patch addresses the issue by moving pmd_alloc into huge_pmd_share which guarantees that the shared pud is populated in the same critical section as pmd. This also means that huge_pte_offset test in huge_pmd_share is serialized correctly now which in turn means that the success of the sharing will be higher as the racing tasks see the pud and pmd populated together. Race identified and changelog written mostly by Mel Gorman. {akpm@linux-foundation.org: attempt to make the huge_pmd_share() comment comprehensible, clean up coding style] Reported-by: Larry Woodman <lwoodman@redhat.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Ken Chen <kenchen@google.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-19KVM: VMX: Advertise CPU_BASED_RDPMC_EXITING for nested guestsStefan Bader
Based on commit fee84b079d5ddee2247b5c1f53162c330c622902 upstream. Intercept RDPMC and forward it to the PMU emulation code. Newer vmx support will only allow to load the kvm_intel module if RDPMC_EXITING is supported. Even without the actual support this part of the change is required on 3.2 hosts. BugLink: http://bugs.launchpad.net/bugs/1031090 Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-10x86, nops: Missing break resulting in incorrect selection on IntelAlan Cox
commit d6250a3f12edb3a86db9598ffeca3de8b4a219e9 upstream. The Intel case falls through into the generic case which then changes the values. For cases like the P6 it doesn't do the right thing so this seems to be a screwup. Signed-off-by: Alan Cox <alan@linux.intel.com> Link: http://lkml.kernel.org/n/tip-lww2uirad4skzjlmrm0vru8o@git.kernel.org Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-10xen: mark local pages as FOREIGN in the m2p_overrideStefano Stabellini
commit b9e0d95c041ca2d7ad297ee37c2e9cfab67a188f upstream. When the frontend and the backend reside on the same domain, even if we add pages to the m2p_override, these pages will never be returned by mfn_to_pfn because the check "get_phys_to_machine(pfn) != mfn" will always fail, so the pfn of the frontend will be returned instead (resulting in a deadlock because the frontend pages are already locked). INFO: task qemu-system-i38:1085 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. qemu-system-i38 D ffff8800cfc137c0 0 1085 1 0x00000000 ffff8800c47ed898 0000000000000282 ffff8800be4596b0 00000000000137c0 ffff8800c47edfd8 ffff8800c47ec010 00000000000137c0 00000000000137c0 ffff8800c47edfd8 00000000000137c0 ffffffff82213020 ffff8800be4596b0 Call Trace: [<ffffffff81101ee0>] ? __lock_page+0x70/0x70 [<ffffffff81a0fdd9>] schedule+0x29/0x70 [<ffffffff81a0fe80>] io_schedule+0x60/0x80 [<ffffffff81101eee>] sleep_on_page+0xe/0x20 [<ffffffff81a0e1ca>] __wait_on_bit_lock+0x5a/0xc0 [<ffffffff81101ed7>] __lock_page+0x67/0x70 [<ffffffff8106f750>] ? autoremove_wake_function+0x40/0x40 [<ffffffff811867e6>] ? bio_add_page+0x36/0x40 [<ffffffff8110b692>] set_page_dirty_lock+0x52/0x60 [<ffffffff81186021>] bio_set_pages_dirty+0x51/0x70 [<ffffffff8118c6b4>] do_blockdev_direct_IO+0xb24/0xeb0 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff8118ca95>] __blockdev_direct_IO+0x55/0x60 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff811e91c8>] ext3_direct_IO+0xf8/0x390 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00 [<ffffffff81004b60>] ? xen_mc_flush+0xb0/0x1b0 [<ffffffff81104027>] generic_file_aio_read+0x737/0x780 [<ffffffff813bedeb>] ? gnttab_map_refs+0x15b/0x1e0 [<ffffffff811038f0>] ? find_get_pages+0x150/0x150 [<ffffffff8119736c>] aio_rw_vect_retry+0x7c/0x1d0 [<ffffffff811972f0>] ? lookup_ioctx+0x90/0x90 [<ffffffff81198856>] aio_run_iocb+0x66/0x1a0 [<ffffffff811998b8>] do_io_submit+0x708/0xb90 [<ffffffff81199d50>] sys_io_submit+0x10/0x20 [<ffffffff81a18d69>] system_call_fastpath+0x16/0x1b The explanation is in the comment within the code: We need to do this because the pages shared by the frontend (xen-blkfront) can be already locked (lock_page, called by do_read_cache_page); when the userspace backend tries to use them with direct_IO, mfn_to_pfn returns the pfn of the frontend, so do_blockdev_direct_IO is going to try to lock the same pages again resulting in a deadlock. A simplified call graph looks like this: pygrub QEMU ----------------------------------------------- do_read_cache_page io_submit | | lock_page ext3_direct_IO | bio_add_page | lock_page Internally the xen-blkback uses m2p_add_override to swizzle (temporarily) a 'struct page' to have a different MFN (so that it can point to another guest). It also can easily find out whether another pfn corresponding to the mfn exists in the m2p, and can set the FOREIGN bit in the p2m, making sure that mfn_to_pfn returns the pfn of the backend. This allows the backend to perform direct_IO on these pages, but as a side effect prevents the frontend from using get_user_pages_fast on them while they are being shared with the backend. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-04x86: Simplify code by removing a !SMP #ifdefs from 'struct cpuinfo_x86'Kevin Winchester
commit 141168c36cdee3ff23d9c7700b0edc47cb65479f and commit 3f806e50981825fa56a7f1938f24c0680816be45 upstream. Several fields in struct cpuinfo_x86 were not defined for the !SMP case, likely to save space. However, those fields still have some meaning for UP, and keeping them allows some #ifdef removal from other files. The additional size of the UP kernel from this change is not significant enough to worry about keeping up the distinction: text data bss dec hex filename 4737168 506459 972040 6215667 5ed7f3 vmlinux.o.before 4737444 506459 972040 6215943 5ed907 vmlinux.o.after for a difference of 276 bytes for an example UP config. If someone wants those 276 bytes back badly then it should be implemented in a cleaner way. Signed-off-by: Kevin Winchester <kjwinchester@gmail.com> Cc: Steffen Persvold <sp@numascale.com> Link: http://lkml.kernel.org/r/1324428742-12498-1-git-send-email-kjwinchester@gmail.com Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-02x86, microcode: Sanitize per-cpu microcode reloading interfaceBorislav Petkov
commit c9fc3f778a6a215ace14ee556067c73982b6d40f upstream. Microcode reloading in a per-core manner is a very bad idea for both major x86 vendors. And the thing is, we have such interface with which we can end up with different microcode versions applied on different cores of an otherwise homogeneous wrt (family,model,stepping) system. So turn off the possibility of doing that per core and allow it only system-wide. This is a minimal fix which we'd like to see in stable too thus the more-or-less arbitrary decision to allow system-wide reloading only on the BSP: $ echo 1 > /sys/devices/system/cpu/cpu0/microcode/reload ... and disable the interface on the other cores: $ echo 1 > /sys/devices/system/cpu/cpu23/microcode/reload -bash: echo: write error: Invalid argument Also, allowing the reload only from one CPU (the BSP in that case) doesn't allow the reload procedure to degenerate into an O(n^2) deal when triggering reloads from all /sys/devices/system/cpu/cpuX/microcode/reload sysfs nodes simultaneously. A more generic fix will follow. Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Link: http://lkml.kernel.org/r/1340280437-7718-2-git-send-email-bp@amd64.org Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-02x86, microcode: microcode_core.c simple_strtoul cleanupShuah Khan
commit e826abd523913f63eb03b59746ffb16153c53dc4 upstream. Change reload_for_cpu() in kernel/microcode_core.c to call kstrtoul() instead of calling obsoleted simple_strtoul(). Signed-off-by: Shuah Khan <shuahkhan@gmail.com> Reviewed-by: Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/1336324264.2897.9.camel@lorien2 Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-08-02x86: Fix boot on Twinhead H12YAlan Cox
commit 80b3e557371205566a71e569fbfcce5b11f92dbe upstream. Despite lots of investigation into why this is needed we don't know or have an elegant cure. The only answer found on this laptop is to mark a problem region as used so that Linux doesn't put anything there. Currently all the users add reserve= command lines and anyone not knowing this needs to find the magic page that documents it. Automate it instead. Signed-off-by: Alan Cox <alan@linux.intel.com> Tested-and-bugfixed-by: Arne Fitzenreiter <arne@fitzenreiter.de> Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=10231 Link: http://lkml.kernel.org/r/20120515174347.5109.94551.stgit@bluebook Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-07-25ACPI, x86: fix Dell M6600 ACPI reboot regression via DMIZhang Rui
commit 76eb9a30db4bc8fd172f9155247264b5f2686d7b upstream. Dell Precision M6600 is known to require PCI reboot, so add it to the reboot blacklist in pci_reboot_dmi_table[]. https://bugzilla.kernel.org/show_bug.cgi?id=42749 cc: x86@kernel.org Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-07-25ACPI: Add a quirk for "AMILO PRO V2030" to ignore the timer overridingFeng Tang
commit b939c2acf1dc42b08407ef5174f2e8d6f43dd5ea upstream. commit f6b54f083cc66cf9b11d2120d8df3c2ad4e0836d upstream. This is the 2nd part of fix for kernel bugzilla 40002: "IRQ 0 assigned to VGA" https://bugzilla.kernel.org/show_bug.cgi?id=40002 The root cause is the buggy FW, whose ACPI tables assign the GSI 16 to 2 irqs 0 and 16(VGA), and the VGA is the right owner of GSI 16. So add a quirk to ignore the irq0 overriding GSI 16 for the FUJITSU SIEMENS AMILO PRO V2030 platform will solve this issue. Reported-and-tested-by: Szymon Kowalczyk <fazerxlo@o2.pl> Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-07-25ACPI: Remove one board specific WARN when ignoring timer overridingFeng Tang
commit 5752cdb805ff89942d99d12118e2844e7db34df8 upstream. commit 7f68b4c2e158019c2ec494b5cfbd9c83b4e5b253 upstream. Current WARN msg is only for the ati_ixp4x0 board, while this function is used by mulitple platforms. So this one board specific warning is not appropriate any more. Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-07-25ACPI: Make acpi_skip_timer_override cover all source_irq==0 casesFeng Tang
commit ae10ccdc3093486f8c2369d227583f9d79f628e5 upstream. Currently when acpi_skip_timer_override is set, it only cover the (source_irq == 0 && global_irq == 2) cases. While there is also platform which need use this option and its global_irq is not 2. This patch will extend acpi_skip_timer_override to cover all timer overriding cases as long as the source irq is 0. This is the first part of a fix to kernel bug bugzilla 40002: "IRQ 0 assigned to VGA" https://bugzilla.kernel.org/show_bug.cgi?id=40002 Reported-and-tested-by: Szymon Kowalczyk <fazerxlo@o2.pl> Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-07-04x86, cpufeature: Rename X86_FEATURE_DTS to X86_FEATURE_DTHERMH. Peter Anvin
commit 4ad33411308596f2f918603509729922a1ec4411 upstream. It makes sense to label "Digital Thermal Sensor" as "DTS", but unfortunately the string "dts" was already used for "Debug Store", and /proc/cpuinfo is a user space ABI. Therefore, rename this to "dtherm". This conflict went into mainline via the hwmon tree without any x86 maintainer ack, and without any kind of hint in the subject. a4659053 x86/hwmon: fix initialization of coretemp Reported-by: Jean Delvare <khali@linux-fr.org> Link: http://lkml.kernel.org/r/4FE34BCB.5050305@linux.intel.com Cc: Jan Beulich <JBeulich@suse.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> [bwh: Backported to 3.2: drop the coretemp device table change] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-07-04thp: avoid atomic64_read in pmd_read_atomic for 32bit PAEAndrea Arcangeli
commit e4eed03fd06578571c01d4f1478c874bb432c815 upstream. In the x86 32bit PAE CONFIG_TRANSPARENT_HUGEPAGE=y case while holding the mmap_sem for reading, cmpxchg8b cannot be used to read pmd contents under Xen. So instead of dealing only with "consistent" pmdvals in pmd_none_or_trans_huge_or_clear_bad() (which would be conceptually simpler) we let pmd_none_or_trans_huge_or_clear_bad() deal with pmdvals where the low 32bit and high 32bit could be inconsistent (to avoid having to use cmpxchg8b). The only guarantee we get from pmd_read_atomic is that if the low part of the pmd was found null, the high part will be null too (so the pmd will be considered unstable). And if the low part of the pmd is found "stable" later, then it means the whole pmd was read atomically (because after a pmd is stable, neither MADV_DONTNEED nor page faults can alter it anymore, and we read the high part after the low part). In the 32bit PAE x86 case, it is enough to read the low part of the pmdval atomically to declare the pmd as "stable" and that's true for THP and no THP, furthermore in the THP case we also have a barrier() that will prevent any inconsistent pmdvals to be cached by a later re-read of the *pmd. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Jonathan Nieder <jrnieder@gmail.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Tested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-07-04mm: pmd_read_atomic: fix 32bit PAE pmd walk vs pmd_populate SMP race conditionAndrea Arcangeli
commit 26c191788f18129af0eb32a358cdaea0c7479626 upstream. When holding the mmap_sem for reading, pmd_offset_map_lock should only run on a pmd_t that has been read atomically from the pmdp pointer, otherwise we may read only half of it leading to this crash. PID: 11679 TASK: f06e8000 CPU: 3 COMMAND: "do_race_2_panic" #0 [f06a9dd8] crash_kexec at c049b5ec #1 [f06a9e2c] oops_end at c083d1c2 #2 [f06a9e40] no_context at c0433ded #3 [f06a9e64] bad_area_nosemaphore at c043401a #4 [f06a9e6c] __do_page_fault at c0434493 #5 [f06a9eec] do_page_fault at c083eb45 #6 [f06a9f04] error_code (via page_fault) at c083c5d5 EAX: 01fb470c EBX: fff35000 ECX: 00000003 EDX: 00000100 EBP: 00000000 DS: 007b ESI: 9e201000 ES: 007b EDI: 01fb4700 GS: 00e0 CS: 0060 EIP: c083bc14 ERR: ffffffff EFLAGS: 00010246 #7 [f06a9f38] _spin_lock at c083bc14 #8 [f06a9f44] sys_mincore at c0507b7d #9 [f06a9fb0] system_call at c083becd start len EAX: ffffffda EBX: 9e200000 ECX: 00001000 EDX: 6228537f DS: 007b ESI: 00000000 ES: 007b EDI: 003d0f00 SS: 007b ESP: 62285354 EBP: 62285388 GS: 0033 CS: 0073 EIP: 00291416 ERR: 000000da EFLAGS: 00000286 This should be a longstanding bug affecting x86 32bit PAE without THP. Only archs with 64bit large pmd_t and 32bit unsigned long should be affected. With THP enabled the barrier() in pmd_none_or_trans_huge_or_clear_bad() would partly hide the bug when the pmd transition from none to stable, by forcing a re-read of the *pmd in pmd_offset_map_lock, but when THP is enabled a new set of problem arises by the fact could then transition freely in any of the none, pmd_trans_huge or pmd_trans_stable states. So making the barrier in pmd_none_or_trans_huge_or_clear_bad() unconditional isn't good idea and it would be a flakey solution. This should be fully fixed by introducing a pmd_read_atomic that reads the pmd in order with THP disabled, or by reading the pmd atomically with cmpxchg8b with THP enabled. Luckily this new race condition only triggers in the places that must already be covered by pmd_none_or_trans_huge_or_clear_bad() so the fix is localized there but this bug is not related to THP. NOTE: this can trigger on x86 32bit systems with PAE enabled with more than 4G of ram, otherwise the high part of the pmd will never risk to be truncated because it would be zero at all times, in turn so hiding the SMP race. This bug was discovered and fully debugged by Ulrich, quote: ---- [..] pmd_none_or_trans_huge_or_clear_bad() loads the content of edx and eax. 496 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd) 497 { 498 /* depend on compiler for an atomic pmd read */ 499 pmd_t pmdval = *pmd; // edi = pmd pointer 0xc0507a74 <sys_mincore+548>: mov 0x8(%esp),%edi ... // edx = PTE page table high address 0xc0507a84 <sys_mincore+564>: mov 0x4(%edi),%edx ... // eax = PTE page table low address 0xc0507a8e <sys_mincore+574>: mov (%edi),%eax [..] Please note that the PMD is not read atomically. These are two "mov" instructions where the high order bits of the PMD entry are fetched first. Hence, the above machine code is prone to the following race. - The PMD entry {high|low} is 0x0000000000000000. The "mov" at 0xc0507a84 loads 0x00000000 into edx. - A page fault (on another CPU) sneaks in between the two "mov" instructions and instantiates the PMD. - The PMD entry {high|low} is now 0x00000003fda38067. The "mov" at 0xc0507a8e loads 0xfda38067 into eax. ---- Reported-by: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-06-19xen/setup: filter APERFMPERF cpuid feature outAndre Przywara
commit 5e626254206a709c6e937f3dda69bf26c7344f6f upstream. Xen PV kernels allow access to the APERF/MPERF registers to read the effective frequency. Access to the MSRs is however redirected to the currently scheduled physical CPU, making consecutive read and compares unreliable. In addition each rdmsr traps into the hypervisor. So to avoid bogus readouts and expensive traps, disable the kernel internal feature flag for APERF/MPERF if running under Xen. This will a) remove the aperfmperf flag from /proc/cpuinfo b) not mislead the power scheduler (arch/x86/kernel/cpu/sched.c) to use the feature to improve scheduling (by default disabled) c) not mislead the cpufreq driver to use the MSRs This does not cover userland programs which access the MSRs via the device file interface, but this will be addressed separately. Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-06-19crypto: aesni-intel - fix unaligned cbc decrypt for x86-32Mathias Krause
commit 7c8d51848a88aafdb68f42b6b650c83485ea2f84 upstream. The 32 bit variant of cbc(aes) decrypt is using instructions requiring 128 bit aligned memory locations but fails to ensure this constraint in the code. Fix this by loading the data into intermediate registers with load unaligned instructions. This fixes reported general protection faults related to aesni. References: https://bugzilla.kernel.org/show_bug.cgi?id=43223 Reported-by: Daniel <garkein@mailueberfall.de> Signed-off-by: Mathias Krause <minipli@googlemail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-06-19x86/amd: Re-enable CPU topology extensions in case BIOS has disabled itAndreas Herrmann
BIOS will switch off the corresponding feature flag on family 15h models 10h-1fh non-desktop CPUs. The topology extension CPUID leafs are required to detect which cores belong to the same compute unit. (thread siblings mask is set accordingly and also correct information about L1i and L2 cache sharing depends on this). W/o this patch we wouldn't see which cores belong to the same compute unit and also cache sharing information for L1i and L2 would be incorrect on such systems. Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> (cherry picked from commit f7f286a910221ae18b21c18d9d0f4cd88965829f) Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-06-19x86, MCE, AMD: Make APIC LVT thresholding interrupt optionalBorislav Petkov
commit f227d4306cf30e1d5b6f231e8ef9006c34f3d186 upstream. Currently, the APIC LVT interrupt for error thresholding is implicitly enabled. However, there are models in the F15h range which do not enable it. Make the code machinery which sets up the APIC interrupt support an optional setting and add an ->interrupt_capable member to the bank representation mirroring that capability and enable the interrupt offset programming only if it is true. Simplify code and fixup comment style while at it. This patch is for stable kernels v3.0 to v3.2. Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-06-19x86/uv: Fix UV2 BAU legacy modeCliff Wickman
commit d5d2d2eea84b0d8450b082edbc3dbde41fb8bfd8 upstream. The SGI Altix UV2 BAU (Broadcast Assist Unit) as used for tlb-shootdown (selective broadcast mode) always uses UV2 broadcast descriptor format. There is no need to clear the 'legacy' (UV1) mode, because the hardware always uses UV2 mode for selective broadcast. But the BIOS uses general broadcast and legacy mode, and the hardware pays attention to the legacy mode bit for general broadcast. So the kernel must not clear that mode bit. Signed-off-by: Cliff Wickman <cpw@sgi.com> Link: http://lkml.kernel.org/r/E1SccoO-0002Lh-Cb@eag09.americas.sgi.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-06-10x86, amd, xen: Avoid NULL pointer paravirt referencesKonrad Rzeszutek Wilk
commit 1ab46fd319bcf1fcd9fb6311727d532b580e4eba upstream. Stub out MSR methods that aren't actually needed. This fixes a crash as Xen Dom0 on AMD Trinity systems. A bigger patch should be added to remove the paravirt machinery completely for the methods which apparently have no users! Reported-by: Andre Przywara <andre.przywara@amd.com> Link: http://lkml.kernel.org/r/20120530222356.GA28417@andromeda.dapyr.net Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31x86, relocs: Add jiffies and jiffies_64 to the relative whitelistH. Peter Anvin
commit ea17e7414bc62e8d3bde8d08e3df1d921c518c17 upstream. The symbol jiffies is created in the linker script as an alias to jiffies_64. Unfortunately this is done outside any section, and apparently GNU ld 2.21 doesn't carry the section with it, so we end up with an absolute symbol and therefore a broken kernel. Add jiffies and jiffies_64 to the whitelist. The most disturbing bit with this discovery is that it shows that we have had multiple linker bugs in this area crossing multiple generations, and have been silently building bad kernels for some time. Link: http://lkml.kernel.org/r/20120524171604.0d98284f3affc643e9714470@canb.auug.org.au Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31x86-32, relocs: Whitelist more symbols for ld bug workaroundH. Peter Anvin
commit fd952815307f0f272bf49fd364a7fd2f9992bc42 upstream. As noted in checkin: a3e854d95 x86, relocs: Workaround for binutils 2.22.52.0.1 section bug ld version 2.22.52.0.[12] can incorrectly promote relative symbols to absolute, if the output section they appear in is otherwise empty. Since checkin: 6520fe55 x86, realmode: 16-bit real-mode code support for relocs tool we actually check for this and error out rather than silently creating a kernel which will malfunction if relocated. Ingo found a configuration in which __start_builtin_fw triggered the warning. Go through the linker script sources and look for more symbols that could plausibly get bogusly promoted to absolute, and add them to the whitelist. In general, if the following error triggers: Invalid absolute R_386_32 relocation: <symbol> ... then we should verify that <symbol> is really meant to be relocated, and add it and any related symbols manually to the S_REL regexp. Please note that 6520fe55 does not introduce the error, only the check for the error -- without 6520fe55 this version of ld will simply produce a corrupt kernel if CONFIG_RELOCATABLE is set on x86-32. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31x86, relocs: Build clean fixJarkko Sakkinen
commit b2d668da9307c4c163dd603d2bb3cadb10f9fd37 upstream. relocs was not cleaned up when "make clean" is issued. This patch fixes the issue. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1337622684-6834-1-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31x86, relocs: When printing an error, say relative or absoluteH. Peter Anvin
commit 24ab82bd9bf18f3efc69a131d73577940941e1b7 upstream. When the relocs tool throws an error, let the error message say if it is an absolute or relative symbol. This should make it a lot more clear what action the programmer needs to take and should help us find the reason if additional symbol bugs show up. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31x86, relocs: Workaround for binutils 2.22.52.0.1 section bugH. Peter Anvin
commit a3e854d95a76862cd37937e0b0438f540536771a upstream. GNU ld 2.22.52.0.1 has a bug that it blindly changes symbols from section-relative to absolute if they are in a section of zero length. This turns the symbols __init_begin and __init_end into absolute symbols. Let the relocs program know that those should be treated as relative symbols. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31x86, realmode: 16-bit real-mode code support for relocs toolH. Peter Anvin
commit 6520fe5564acf07ade7b18a1272db1184835c487 upstream. A new option is added to the relocs tool called '--realmode'. This option causes the generation of 16-bit segment relocations and 32-bit linear relocations for the real-mode code. When the real-mode code is moved to the low-memory during kernel initialization, these relocation entries can be used to relocate the code properly. In the assembly code 16-bit segment relocations must be relative to the 'real_mode_seg' absolute symbol. Linear relocations must be relative to a symbol prefixed with 'pa_'. 16-bit segment relocation is used to load cs:ip in 16-bit code. Linear relocations are used in the 32-bit code for relocatable data references. They are declared in the linker script of the real-mode code. The relocs tool is moved to arch/x86/tools/relocs.c, and added new target archscripts that can be used to build scripts needed building an architecture. be compiled before building the arch/x86 tree. [ hpa: accelerating this because it detects invalid absolute relocations, a serious bug in binutils 2.22.52.0.x which currently produces bad kernels. ] Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-2-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: <stable@vger.kernel.org> [bwh: Backported to 3.2: - Adjust context (no archheaders; no insn_sanity) - Expand put_unaligned_le32()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31x86/mce: Fix check for processor context when machine check was taken.Tony Luck
commit 875e26648cf9b6db9d8dc07b7959d7c61fb3f49c upstream. Linus pointed out that there was no value is checking whether m->ip was zero - because zero is a legimate value. If we have a reliable (or faked in the VM86 case) "m->cs" we can use it to tell whether we were in user mode or kernelwhen the machine check hit. Reported-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31MCE: Fix vm86 handling for 32bit mce handlerAndi Kleen
commit a129a7c84582629741e5fa6f40026efcd7a65bd4 upstream. When running on 32bit the mce handler could misinterpret vm86 mode as ring 0. This can affect whether it does recovery or not; it was possible to panic when recovery was actually possible. Fix this by always forcing vm86 to look like ring 3. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31xen: do not map the same GSI twice in PVHVM guests.Stefano Stabellini
commit 68c2c39a76b094e9b2773e5846424ea674bf2c46 upstream. PV on HVM guests map GSIs into event channels. At restore time the event channels are resumed by restore_pirqs. Device drivers might try to register the same GSI again through ACPI at restore time, but the GSI has already been mapped and bound by restore_pirqs. This patch detects these situations and avoids mapping the same GSI multiple times. Without this patch we get: (XEN) irq.c:2235: dom4: pirq 23 or emuirq 28 already mapped and waste a pirq. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31perf/x86: Update event scheduling constraints for AMD family 15h modelsRobert Richter
commit 5bcdf5e4fee3c45e1281c25e4941f2163cb28c65 upstream. This update is for newer family 15h cpu models from 0x02 to 0x1f. Signed-off-by: Robert Richter <robert.richter@amd.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1337337642-1621-1-git-send-email-robert.richter@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31KVM: VMX: vmx_set_cr0 expects kvm->srcu lockedMarcelo Tosatti
(cherry picked from commit 7a4f5ad051e02139a9f1c0f7f4b1acb88915852b) vmx_set_cr0 is called from vcpu run context, therefore it expects kvm->srcu to be held (for setting up the real-mode TSS). Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31KVM: nVMX: Fix erroneous exception bitmap checkNadav Har'El
(cherry picked from commit 9587190107d0c0cbaccbf7bf6b0245d29095a9ae) The code which checks whether to inject a pagefault to L1 or L2 (in nested VMX) was wrong, incorrect in how it checked the PF_VECTOR bit. Thanks to Dan Carpenter for spotting this. Signed-off-by: Nadav Har'El <nyh@il.ibm.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-31KVM: Ensure all vcpus are consistent with in-kernel irqchip settingsAvi Kivity
(cherry picked from commit 3e515705a1f46beb1c942bb8043c16f8ac7b1e9e) If some vcpus are created before KVM_CREATE_IRQCHIP, then irqchip_in_kernel() and vcpu->arch.apic will be inconsistent, leading to potential NULL pointer dereferences. Fix by: - ensuring that no vcpus are installed when KVM_CREATE_IRQCHIP is called - ensuring that a vcpu has an apic if it is installed after KVM_CREATE_IRQCHIP This is somewhat long winded because vcpu->arch.apic is created without kvm->lock held. Based on earlier patch by Michael Ellerman. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-11percpu, x86: don't use PMD_SIZE as embedded atom_size on 32bitTejun Heo
commit d5e28005a1d2e67833852f4c9ea8ec206ea3ff85 upstream. With the embed percpu first chunk allocator, x86 uses either PAGE_SIZE or PMD_SIZE for atom_size. PMD_SIZE is used when CPU supports PSE so that percpu areas are aligned to PMD mappings and possibly allow using PMD mappings in vmalloc areas in the future. Using larger atom_size doesn't waste actual memory; however, it does require larger vmalloc space allocation later on for !first chunks. With reasonably sized vmalloc area, PMD_SIZE shouldn't be a problem but x86_32 at this point is anything but reasonable in terms of address space and using larger atom_size reportedly leads to frequent percpu allocation failures on certain setups. As there is no reason to not use PMD_SIZE on x86_64 as vmalloc space is aplenty and most x86_64 configurations support PSE, fix the issue by always using PMD_SIZE on x86_64 and PAGE_SIZE on x86_32. v2: drop cpu_has_pse test and make x86_64 always use PMD_SIZE and x86_32 PAGE_SIZE as suggested by hpa. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Yanmin Zhang <yanmin.zhang@intel.com> Reported-by: ShuoX Liu <shuox.liu@intel.com> Acked-by: H. Peter Anvin <hpa@zytor.com> LKML-Reference: <4F97BA98.6010001@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-11xen/pci: don't use PCI BIOS service for configuration space accessesDavid Vrabel
commit 76a8df7b49168509df02461f83fab117a4a86e08 upstream. The accessing PCI configuration space with the PCI BIOS32 service does not work in PV guests. On systems without MMCONFIG or where the BIOS hasn't marked the MMCONFIG region as reserved in the e820 map, the BIOS service is probed (even though direct access is preferred) and this hangs. Acked-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> [v1: Fixed compile error when CONFIG_PCI is not set] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-11xen/pte: Fix crashes when trying to see non-existent PGD/PMD/PUD/PTEsKonrad Rzeszutek Wilk
commit b7e5ffe5d83fa40d702976d77452004abbe35791 upstream. If I try to do "cat /sys/kernel/debug/kernel_page_tables" I end up with: BUG: unable to handle kernel paging request at ffffc7fffffff000 IP: [<ffffffff8106aa51>] ptdump_show+0x221/0x480 PGD 0 Oops: 0000 [#1] SMP CPU 0 .. snip.. RAX: 0000000000000000 RBX: ffffc00000000fff RCX: 0000000000000000 RDX: 0000800000000000 RSI: 0000000000000000 RDI: ffffc7fffffff000 which is due to the fact we are trying to access a PFN that is not accessible to us. The reason (at least in this case) was that PGD[256] is set to __HYPERVISOR_VIRT_START which was setup (by the hypervisor) to point to a read-only linear map of the MFN->PFN array. During our parsing we would get the MFN (a valid one), try to look it up in the MFN->PFN tree and find it invalid and return ~0 as PFN. Then pte_mfn_to_pfn would happilly feed that in, attach the flags and return it back to the caller. 'ptdump_show' bitshifts it and gets and invalid value that it tries to dereference. Instead of doing all of that, we detect the ~0 case and just return !_PAGE_PRESENT. This bug has been in existence .. at least until 2.6.37 (yikes!) Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-11x86, relocs: Remove an unused variableKusanagi Kouichi
commit 7c77cda0fe742ed07622827ce80963bbeebd1e3f upstream. sh_symtab is set but not used. [ hpa: putting this in urgent because of the sheer harmlessness of the patch: it quiets a build warning but does not change any generated code. ] Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp> Link: http://lkml.kernel.org/r/20120401082932.D5E066FC03D@msa105.auone-net.jp Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-11xen/smp: Fix crash when booting with ACPI hotplug CPUs.Konrad Rzeszutek Wilk
commit cf405ae612b0f7e2358db7ff594c0e94846137aa upstream. When we boot on a machine that can hotplug CPUs and we are using 'dom0_max_vcpus=X' on the Xen hypervisor line to clip the amount of CPUs available to the initial domain, we get this: (XEN) Command line: com1=115200,8n1 dom0_mem=8G noreboot dom0_max_vcpus=8 sync_console mce_verbosity=verbose console=com1,vga loglvl=all guest_loglvl=all .. snip.. DMI: Intel Corporation S2600CP/S2600CP, BIOS SE5C600.86B.99.99.x032.072520111118 07/25/2011 .. snip. SMP: Allowing 64 CPUs, 32 hotplug CPUs installing Xen timer for CPU 7 cpu 7 spinlock event irq 361 NMI watchdog: disabled (cpu7): hardware events not enabled Brought up 8 CPUs .. snip.. [acpi processor finds the CPUs are not initialized and starts calling arch_register_cpu, which creates /sys/devices/system/cpu/cpu8/online] CPU 8 got hotplugged CPU 9 got hotplugged CPU 10 got hotplugged .. snip.. initcall 1_acpi_battery_init_async+0x0/0x1b returned 0 after 406 usecs calling erst_init+0x0/0x2bb @ 1 [and the scheduler sticks newly started tasks on the new CPUs, but said CPUs cannot be initialized b/c the hypervisor has limited the amount of vCPUS to 8 - as per the dom0_max_vcpus=8 flag. The spinlock tries to kick the other CPU, but the structure for that is not initialized and we crash.] BUG: unable to handle kernel paging request at fffffffffffffed8 IP: [<ffffffff81035289>] xen_spin_lock+0x29/0x60 PGD 180d067 PUD 180e067 PMD 0 Oops: 0002 [#1] SMP CPU 7 Modules linked in: Pid: 1, comm: swapper/0 Not tainted 3.4.0-rc2upstream-00001-gf5154e8 #1 Intel Corporation S2600CP/S2600CP RIP: e030:[<ffffffff81035289>] [<ffffffff81035289>] xen_spin_lock+0x29/0x60 RSP: e02b:ffff8801fb9b3a70 EFLAGS: 00010282 With this patch, we cap the amount of vCPUS that the initial domain can run, to exactly what dom0_max_vcpus=X has specified. In the future, if there is a hypercall that will allow a running domain to expand past its initial set of vCPUS, this patch should be re-evaluated. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-11xen: correctly check for pending events when restoring irq flagsDavid Vrabel
commit 7eb7ce4d2e8991aff4ecb71a81949a907ca755ac upstream. In xen_restore_fl_direct(), xen_force_evtchn_callback() was being called even if no events were pending. This resulted in (depending on workload) about a 100 times as many xen_version hypercalls as necessary. Fix this by correcting the sense of the conditional jump. This seems to give a significant performance benefit for some workloads. There is some subtle tricksy "..since the check here is trying to check both pending and masked in a single cmpw, but I think this is correct. It will call check_events now only when the combined mask+pending word is 0x0001 (aka unmasked, pending)." (Ian) Acked-by: Ian Campbell <ian.campbell@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-11x86, apic: APIC code touches invalid MSR on P5 class machinesBryan O'Donoghue
commit cbf2829b61c136edcba302a5e1b6b40e97d32c00 upstream. Current APIC code assumes MSR_IA32_APICBASE is present for all systems. Pentium Classic P5 and friends didn't have this MSR. MSR_IA32_APICBASE was introduced as an architectural MSR by Intel @ P6. Code paths that can touch this MSR invalidly are when vendor == Intel && cpu-family == 5 and APIC bit is set in CPUID - or when you simply pass lapic on the kernel command line, on a P5. The below patch stops Linux incorrectly interfering with the MSR_IA32_APICBASE for P5 class machines. Other code paths exist that touch the MSR - however those paths are not currently reachable for a conformant P5. Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linux.intel.com> Link: http://lkml.kernel.org/r/4F8EEDD3.1080404@linux.intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-05-11x86, microcode: Fix sysfs warning during module unload on unsupported CPUsAndreas Herrmann
commit a956bd6f8583326b18348ab1452b4686778f785d upstream. Loading the microcode driver on an unsupported CPU and subsequently unloading the driver causes WARNING: at fs/sysfs/group.c:138 mc_device_remove+0x5f/0x70 [microcode]() Hardware name: 01972NG sysfs group ffffffffa00013d0 not found for kobject 'cpu0' Modules linked in: snd_hda_codec_hdmi snd_hda_codec_conexant snd_hda_intel btusb snd_hda_codec bluetooth thinkpad_acpi rfkill microcode(-) [last unloaded: cfg80211] Pid: 4560, comm: modprobe Not tainted 3.4.0-rc2-00002-g258f742 #5 Call Trace: [<ffffffff8103113b>] ? warn_slowpath_common+0x7b/0xc0 [<ffffffff81031235>] ? warn_slowpath_fmt+0x45/0x50 [<ffffffff81120e74>] ? sysfs_remove_group+0x34/0x120 [<ffffffffa00000ef>] ? mc_device_remove+0x5f/0x70 [microcode] [<ffffffff81331eb9>] ? subsys_interface_unregister+0x69/0xa0 [<ffffffff81563526>] ? mutex_lock+0x16/0x40 [<ffffffffa0000c3e>] ? microcode_exit+0x50/0x92 [microcode] [<ffffffff8107051d>] ? sys_delete_module+0x16d/0x260 [<ffffffff810a0065>] ? wait_iff_congested+0x45/0x110 [<ffffffff815656af>] ? page_fault+0x1f/0x30 [<ffffffff81565ba2>] ? system_call_fastpath+0x16/0x1b on recent kernels. This is due to commit 8a25a2fd126c ("cpu: convert 'cpu' and 'machinecheck' sysdev_class to a regular subsystem") which renders commit 6c53cbfced04 ("x86, microcode: Correct sysdev_add error path") useless. See http://marc.info/?l=linux-kernel&m=133416246406478 Avoid above warning by restoring the old driver behaviour before 6c53cbfced04 ("x86, microcode: Correct sysdev_add error path"). Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: http://lkml.kernel.org/r/20120411163849.GE4794@alberich.amd.com Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> [bwh: Backported to 3.2: deleted line uses sys_dev, not dev] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-04-13sched/x86: Fix overflow in cyc2ns_offsetSalman Qazi
commit 9993bc635d01a6ee7f6b833b4ee65ce7c06350b1 upstream. When a machine boots up, the TSC generally gets reset. However, when kexec is used to boot into a kernel, the TSC value would be carried over from the previous kernel. The computation of cycns_offset in set_cyc2ns_scale is prone to an overflow, if the machine has been up more than 208 days prior to the kexec. The overflow happens when we multiply *scale, even though there is enough room to store the final answer. We fix this issue by decomposing tsc_now into the quotient and remainder of division by CYC2NS_SCALE_FACTOR and then performing the multiplication separately on the two components. Refactor code to share the calculation with the previous fix in __cycles_2_ns(). Signed-off-by: Salman Qazi <sqazi@google.com> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Turner <pjt@google.com> Cc: john stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/20120310004027.19291.88460.stgit@dungbeetle.mtv.corp.google.com Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13Revert "x86/ioapic: Add register level checks to detect bogus io-apic entries"Greg Kroah-Hartman
This reverts commit 273fb194e86b795b08a724c7646d0f694949070b [73d63d038ee9f769f5e5b46792d227fe20e442c5 upstream] It causes problems, so needs to be reverted from 3.2-stable for now. Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jon Dufresne <jon@jondufresne.org> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: <yinghai@kernel.org> Cc: Josh Boyer <jwboyer@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Teck Choon Giam <giamteckchoon@gmail.com> Cc: Ben Guthro <ben@guthro.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13x86/PCI: do not tie MSI MS-7253 use_crs quirk to BIOS versionJonathan Nieder
commit a97f4f5e524bcd09a85ef0b8821a14d35e69335f upstream. Carlos was getting WARNING: at drivers/pci/pci.c:118 pci_ioremap_bar+0x24/0x52() when probing his sound card, and sound did not work. After adding pci=use_crs to the kernel command line, no more trouble. Ok, we can add a quirk. dmidecode output reveals that this is an MSI MS-7253, for which we already have a quirk, but the short-sighted author tied the quirk to a single BIOS version, making it not kick in on Carlos's machine with BIOS V1.2. If a later BIOS update makes it no longer necessary to look at the _CRS info it will still be harmless, so let's stop trying to guess which versions have and don't have accurate _CRS tables. Addresses https://bugtrack.alsa-project.org/alsa-bug/view.php?id=5533 Also see <https://bugzilla.kernel.org/show_bug.cgi?id=42619>. Reported-by: Carlos Luna <caralu74@gmail.com> Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13x86/PCI: use host bridge _CRS info on MSI MS-7253Jonathan Nieder
commit 8411371709610c826bf65684f886bfdfb5780ca1 upstream. In the spirit of commit 29cf7a30f8a0 ("x86/PCI: use host bridge _CRS info on ASUS M2V-MX SE"), this DMI quirk turns on "pci_use_crs" by default on a board that needs it. This fixes boot failures and oopses introduced in 3e3da00c01d0 ("x86/pci: AMD one chain system to use pci read out res"). The quirk is quite targetted (to a specific board and BIOS version) for two reasons: (1) to emphasize that this method of tackling the problem one quirk at a time is a little insane (2) to give BIOS vendors an opportunity to use simpler tables and allow us to return to generic behavior (whatever that happens to be) with a later BIOS update In other words, I am not at all happy with having quirks like this. But it is even worse for the kernel not to work out of the box on these machines, so... Reference: https://bugzilla.kernel.org/show_bug.cgi?id=42619 Reported-by: Svante Signell <svante.signell@telia.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13x86,kgdb: Fix DEBUG_RODATA limitation using text_poke()Jason Wessel
commit 3751d3e85cf693e10e2c47c03c8caa65e171099b upstream. There has long been a limitation using software breakpoints with a kernel compiled with CONFIG_DEBUG_RODATA going back to 2.6.26. For this particular patch, it will apply cleanly and has been tested all the way back to 2.6.36. The kprobes code uses the text_poke() function which accommodates writing a breakpoint into a read-only page. The x86 kgdb code can solve the problem similarly by overriding the default breakpoint set/remove routines and using text_poke() directly. The x86 kgdb code will first attempt to use the traditional probe_kernel_write(), and next try using a the text_poke() function. The break point install method is tracked such that the correct break point removal routine will get called later on. Cc: x86@kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Inspried-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-13x86 bpf_jit: fix a bug in emitting the 16-bit immediate operand of ANDzhuangfeiran@ict.ac.cn
[ Upstream commit 1d24fb3684f347226747c6b11ea426b7b992694e ] When K >= 0xFFFF0000, AND needs the two least significant bytes of K as its operand, but EMIT2() gives it the least significant byte of K and 0x2. EMIT() should be used here to replace EMIT2(). Signed-off-by: Feiran Zhuang <zhuangfeiran@ict.ac.cn> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02x86, tls: Off by one limit checkDan Carpenter
commit 8f0750f19789cf352d7e24a6cc50f2ab1b4f1372 upstream. These are used as offsets into an array of GDT_ENTRY_TLS_ENTRIES members so GDT_ENTRY_TLS_ENTRIES is one past the end of the array. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: http://lkml.kernel.org/r/20120324075250.GA28258@elgon.mountain Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>