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2012-05-07i387: ptrace breaks the lazy-fpu-restore logicOleg Nesterov
commit 089f9fba56faf33cc6dd2a6442b7ac92c58b8209 upstream. Starting from 7e16838d "i387: support lazy restore of FPU state" we assume that fpu_owner_task doesn't need restore_fpu_checking() on the context switch, its FPU state should match what we already have in the FPU on this CPU. However, debugger can change the tracee's FPU state, in this case we should reset fpu.last_cpu to ensure fpu_lazy_restore() can't return true. Change init_fpu() to do this, it is called by user_regset->set() methods. Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Link: http://lkml.kernel.org/r/20120416204815.GB24884@redhat.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86/platform: Remove incorrect error message in x86_default_fixup_cpu_id()Andreas Herrmann
commit 68894632afb2729a1d8785c877840953894c7283 upstream. It's only called from amd.c:srat_detect_node(). The introduced condition for calling the fixup code is true for all AMD multi-node processors, e.g. Magny-Cours and Interlagos. There we have 2 NUMA nodes on one socket. Thus there are cores having different numa-node-id but with equal phys_proc_id. There is no point to print error messages in such a situation. The confusing/misleading error message was introduced with commit 64be4c1c2428e148de6081af235e2418e6a66dda ("x86: Add x86_init platform override to fix up NUMA core numbering"). Remove the default fixup function (especially the error message) and replace it by a NULL pointer check, move the Numascale-specific condition for calling the fixup into the fixup-function itself and slightly adapt the comment. Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Acked-by: Borislav Petkov <borislav.petkov@amd.com> Cc: <sp@numascale.com> Cc: <bp@amd64.org> Cc: <daniel@numascale-asia.com> Link: http://lkml.kernel.org/r/20120402160648.GR27684@alberich.amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, microcode: Ensure that module is only loaded on supported AMD CPUsAndreas Herrmann
commit 283c1f2558ef4a4411fe908364b15b73b6ab44cf upstream. Exit early when there's no support for a particular CPU family. Also, fixup the "no support for this CPU vendor" to be issued only when the driver is attempted to be loaded on an unsupported vendor. 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 [Boris: add a commit msg because Andreas is lazy] Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07x86, 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 a998dc2fa76f496d2944f0602b920d1d10d7467d [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,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>
2012-04-02x86, 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>
2012-04-02x86, tsc: Skip refined tsc calibration on systems with reliable TSCAlok Kataria
commit 57779dc2b3b75bee05ef5d1ada47f615f7a13932 upstream. While running the latest Linux as guest under VMware in highly over-committed situations, we have seen cases when the refined TSC algorithm fails to get a valid tsc_start value in tsc_refine_calibration_work from multiple attempts. As a result the kernel keeps on scheduling the tsc_irqwork task for later. Subsequently after several attempts when it gets a valid start value it goes through the refined calibration and either bails out or uses the new results. Given that the kernel originally read the TSC frequency from the platform, which is the best it can get, I don't think there is much value in refining it. So for systems which get the TSC frequency from the platform we should skip the refined tsc algorithm. We can use the TSC_RELIABLE cpu cap flag to detect this, right now it is set only on VMware and for Moorestown Penwell both of which have there own TSC calibration methods. Signed-off-by: Alok N Kataria <akataria@vmware.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: Dirk Brandewie <dirk.brandewie@gmail.com> Cc: Alan Cox <alan@linux.intel.com> [jstultz: Reworked to simply not schedule the refining work, rather then scheduling the work and bombing out later] Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02x86-32: Fix endless loop when processing signals for kernel tasksDmitry Adamushko
commit 29a2e2836ff9ea65a603c89df217f4198973a74f upstream. The problem occurs on !CONFIG_VM86 kernels [1] when a kernel-mode task returns from a system call with a pending signal. A real-life scenario is a child of 'khelper' returning from a failed kernel_execve() in ____call_usermodehelper() [ kernel/kmod.c ]. kernel_execve() fails due to a pending SIGKILL, which is the result of "kill -9 -1" (at least, busybox's init does it upon reboot). The loop is as follows: * syscall_exit_work: - work_pending: // start_of_the_loop - work_notify_sig: - do_notify_resume() - do_signal() - if (!user_mode(regs)) return; - resume_userspace // TIF_SIGPENDING is still set - work_pending // so we call work_pending => goto // start_of_the_loop More information can be found in another LKML thread: http://www.serverphorums.com/read.php?12,457826 [1] the problem was also seen on MIPS. Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Link: http://lkml.kernel.org/r/1332448765.2299.68.camel@dimm Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02mm: thp: fix pmd_bad() triggering in code paths holding mmap_sem read modeAndrea Arcangeli
commit 1a5a9906d4e8d1976b701f889d8f35d54b928f25 upstream. In some cases it may happen that pmd_none_or_clear_bad() is called with the mmap_sem hold in read mode. In those cases the huge page faults can allocate hugepmds under pmd_none_or_clear_bad() and that can trigger a false positive from pmd_bad() that will not like to see a pmd materializing as trans huge. It's not khugepaged causing the problem, khugepaged holds the mmap_sem in write mode (and all those sites must hold the mmap_sem in read mode to prevent pagetables to go away from under them, during code review it seems vm86 mode on 32bit kernels requires that too unless it's restricted to 1 thread per process or UP builds). The race is only with the huge pagefaults that can convert a pmd_none() into a pmd_trans_huge(). Effectively all these pmd_none_or_clear_bad() sites running with mmap_sem in read mode are somewhat speculative with the page faults, and the result is always undefined when they run simultaneously. This is probably why it wasn't common to run into this. For example if the madvise(MADV_DONTNEED) runs zap_page_range() shortly before the page fault, the hugepage will not be zapped, if the page fault runs first it will be zapped. Altering pmd_bad() not to error out if it finds hugepmds won't be enough to fix this, because zap_pmd_range would then proceed to call zap_pte_range (which would be incorrect if the pmd become a pmd_trans_huge()). The simplest way to fix this is to read the pmd in the local stack (regardless of what we read, no need of actual CPU barriers, only compiler barrier needed), and be sure it is not changing under the code that computes its value. Even if the real pmd is changing under the value we hold on the stack, we don't care. If we actually end up in zap_pte_range it means the pmd was not none already and it was not huge, and it can't become huge from under us (khugepaged locking explained above). All we need is to enforce that there is no way anymore that in a code path like below, pmd_trans_huge can be false, but pmd_none_or_clear_bad can run into a hugepmd. The overhead of a barrier() is just a compiler tweak and should not be measurable (I only added it for THP builds). I don't exclude different compiler versions may have prevented the race too by caching the value of *pmd on the stack (that hasn't been verified, but it wouldn't be impossible considering pmd_none_or_clear_bad, pmd_bad, pmd_trans_huge, pmd_none are all inlines and there's no external function called in between pmd_trans_huge and pmd_none_or_clear_bad). if (pmd_trans_huge(*pmd)) { if (next-addr != HPAGE_PMD_SIZE) { VM_BUG_ON(!rwsem_is_locked(&tlb->mm->mmap_sem)); split_huge_page_pmd(vma->vm_mm, pmd); } else if (zap_huge_pmd(tlb, vma, pmd, addr)) continue; /* fall through */ } if (pmd_none_or_clear_bad(pmd)) Because this race condition could be exercised without special privileges this was reported in CVE-2012-1179. The race was identified and fully explained by Ulrich who debugged it. I'm quoting his accurate explanation below, for reference. ====== start quote ======= mapcount 0 page_mapcount 1 kernel BUG at mm/huge_memory.c:1384! At some point prior to the panic, a "bad pmd ..." message similar to the following is logged on the console: mm/memory.c:145: bad pmd ffff8800376e1f98(80000000314000e7). The "bad pmd ..." message is logged by pmd_clear_bad() before it clears the page's PMD table entry. 143 void pmd_clear_bad(pmd_t *pmd) 144 { -> 145 pmd_ERROR(*pmd); 146 pmd_clear(pmd); 147 } After the PMD table entry has been cleared, there is an inconsistency between the actual number of PMD table entries that are mapping the page and the page's map count (_mapcount field in struct page). When the page is subsequently reclaimed, __split_huge_page() detects this inconsistency. 1381 if (mapcount != page_mapcount(page)) 1382 printk(KERN_ERR "mapcount %d page_mapcount %d\n", 1383 mapcount, page_mapcount(page)); -> 1384 BUG_ON(mapcount != page_mapcount(page)); The root cause of the problem is a race of two threads in a multithreaded process. Thread B incurs a page fault on a virtual address that has never been accessed (PMD entry is zero) while Thread A is executing an madvise() system call on a virtual address within the same 2 MB (huge page) range. virtual address space .---------------------. | | | | .-|---------------------| | | | | | |<-- B(fault) | | | 2 MB | |/////////////////////|-. huge < |/////////////////////| > A(range) page | |/////////////////////|-' | | | | | | '-|---------------------| | | | | '---------------------' - Thread A is executing an madvise(..., MADV_DONTNEED) system call on the virtual address range "A(range)" shown in the picture. sys_madvise // Acquire the semaphore in shared mode. down_read(&current->mm->mmap_sem) ... madvise_vma switch (behavior) case MADV_DONTNEED: madvise_dontneed zap_page_range unmap_vmas unmap_page_range zap_pud_range zap_pmd_range // // Assume that this huge page has never been accessed. // I.e. content of the PMD entry is zero (not mapped). // if (pmd_trans_huge(*pmd)) { // We don't get here due to the above assumption. } // // Assume that Thread B incurred a page fault and .---------> // sneaks in here as shown below. | // | if (pmd_none_or_clear_bad(pmd)) | { | if (unlikely(pmd_bad(*pmd))) | pmd_clear_bad | { | pmd_ERROR | // Log "bad pmd ..." message here. | pmd_clear | // Clear the page's PMD entry. | // Thread B incremented the map count | // in page_add_new_anon_rmap(), but | // now the page is no longer mapped | // by a PMD entry (-> inconsistency). | } | } | v - Thread B is handling a page fault on virtual address "B(fault)" shown in the picture. ... do_page_fault __do_page_fault // Acquire the semaphore in shared mode. down_read_trylock(&mm->mmap_sem) ... handle_mm_fault if (pmd_none(*pmd) && transparent_hugepage_enabled(vma)) // We get here due to the above assumption (PMD entry is zero). do_huge_pmd_anonymous_page alloc_hugepage_vma // Allocate a new transparent huge page here. ... __do_huge_pmd_anonymous_page ... spin_lock(&mm->page_table_lock) ... page_add_new_anon_rmap // Here we increment the page's map count (starts at -1). atomic_set(&page->_mapcount, 0) set_pmd_at // Here we set the page's PMD entry which will be cleared // when Thread A calls pmd_clear_bad(). ... spin_unlock(&mm->page_table_lock) The mmap_sem does not prevent the race because both threads are acquiring it in shared mode (down_read). Thread B holds the page_table_lock while the page's map count and PMD table entry are updated. However, Thread A does not synchronize on that lock. ====== end quote ======= [akpm@linux-foundation.org: checkpatch fixes] Reported-by: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Jones <davej@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Mark Salter <msalter@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02x86/ioapic: Add register level checks to detect bogus io-apic entriesSuresh Siddha
commit 73d63d038ee9f769f5e5b46792d227fe20e442c5 upstream. With the recent changes to clear_IO_APIC_pin() which tries to clear remoteIRR bit explicitly, some of the users started to see "Unable to reset IRR for apic .." messages. Close look shows that these are related to bogus IO-APIC entries which return's all 1's for their io-apic registers. And the above mentioned error messages are benign. But kernel should have ignored such io-apic's in the first place. Check if register 0, 1, 2 of the listed io-apic are all 1's and ignore such io-apic. Reported-by: Álvaro Castillo <midgoon@gmail.com> Tested-by: Jon Dufresne <jon@jondufresne.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: yinghai@kernel.org Cc: kernel-team@fedoraproject.org Cc: Josh Boyer <jwboyer@redhat.com> Link: http://lkml.kernel.org/r/1331577393.31585.94.camel@sbsiddha-desk.sc.intel.com [ Performed minor cleanup of affected code. ] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-12perf/x86: Fix local vs remote memory events for NHM/WSMPeter Zijlstra
Verified using the below proglet.. before: [root@westmere ~]# perf stat -e node-stores -e node-store-misses ./numa 0 remote write Performance counter stats for './numa 0': 2,101,554 node-stores 2,096,931 node-store-misses 5.021546079 seconds time elapsed [root@westmere ~]# perf stat -e node-stores -e node-store-misses ./numa 1 local write Performance counter stats for './numa 1': 501,137 node-stores 199 node-store-misses 5.124451068 seconds time elapsed After: [root@westmere ~]# perf stat -e node-stores -e node-store-misses ./numa 0 remote write Performance counter stats for './numa 0': 2,107,516 node-stores 2,097,187 node-store-misses 5.012755149 seconds time elapsed [root@westmere ~]# perf stat -e node-stores -e node-store-misses ./numa 1 local write Performance counter stats for './numa 1': 2,063,355 node-stores 165 node-store-misses 5.082091494 seconds time elapsed #define _GNU_SOURCE #include <sched.h> #include <stdio.h> #include <errno.h> #include <sys/mman.h> #include <sys/types.h> #include <dirent.h> #include <signal.h> #include <unistd.h> #include <numaif.h> #include <stdlib.h> #define SIZE (32*1024*1024) volatile int done; void sig_done(int sig) { done = 1; } int main(int argc, char **argv) { cpu_set_t *mask, *mask2; size_t size; int i, err, t; int nrcpus = 1024; char *mem; unsigned long nodemask = 0x01; /* node 0 */ DIR *node; struct dirent *de; int read = 0; int local = 0; if (argc < 2) { printf("usage: %s [0-3]\n", argv[0]); printf(" bit0 - local/remote\n"); printf(" bit1 - read/write\n"); exit(0); } switch (atoi(argv[1])) { case 0: printf("remote write\n"); break; case 1: printf("local write\n"); local = 1; break; case 2: printf("remote read\n"); read = 1; break; case 3: printf("local read\n"); local = 1; read = 1; break; } mask = CPU_ALLOC(nrcpus); size = CPU_ALLOC_SIZE(nrcpus); CPU_ZERO_S(size, mask); node = opendir("/sys/devices/system/node/node0/"); if (!node) perror("opendir"); while ((de = readdir(node))) { int cpu; if (sscanf(de->d_name, "cpu%d", &cpu) == 1) CPU_SET_S(cpu, size, mask); } closedir(node); mask2 = CPU_ALLOC(nrcpus); CPU_ZERO_S(size, mask2); for (i = 0; i < size; i++) CPU_SET_S(i, size, mask2); CPU_XOR_S(size, mask2, mask2, mask); // invert if (!local) mask = mask2; err = sched_setaffinity(0, size, mask); if (err) perror("sched_setaffinity"); mem = mmap(0, SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); err = mbind(mem, SIZE, MPOL_BIND, &nodemask, 8*sizeof(nodemask), MPOL_MF_MOVE); if (err) perror("mbind"); signal(SIGALRM, sig_done); alarm(5); if (!read) { while (!done) { for (i = 0; i < SIZE; i++) mem[i] = 0x01; } } else { while (!done) { for (i = 0; i < SIZE; i++) t += *(volatile char *)(mem + i); } } return 0; } Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Cc: <stable@kernel.org> Link: http://lkml.kernel.org/n/tip-tq73sxus35xmqpojf7ootxgs@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-03-02perf/x86/kvm: Fix Host-Only/Guest-Only counting with SVM disabledJoerg Roedel
It turned out that a performance counter on AMD does not count at all when the GO or HO bit is set in the control register and SVM is disabled in EFER. This patch works around this issue by masking out the HO bit in the performance counter control register when SVM is not enabled. The GO bit is not touched because it is only set when the user wants to count in guest-mode only. So when SVM is disabled the counter should not run at all and the not-counting is the intended behaviour. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Avi Kivity <avi@redhat.com> Cc: Stephane Eranian <eranian@google.com> Cc: David Ahern <dsahern@gmail.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Robert Richter <robert.richter@amd.com> Cc: stable@vger.kernel.org # v3.2 Link: http://lkml.kernel.org/r/1330523852-19566-1-git-send-email-joerg.roedel@amd.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-27Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce/AMD: Fix UP build error x86: Specify a size for the cmp in the NMI handler x86/nmi: Test saved %cs in NMI to determine nested NMI case x86/amd: Fix L1i and L2 cache sharing information for AMD family 15h processors x86/microcode: Remove noisy AMD microcode warning
2012-02-22x86/mce/AMD: Fix UP build errorBorislav Petkov
141168c36cde ("x86: Simplify code by removing a !SMP #ifdefs from 'struct cpuinfo_x86'") removed a bunch of CONFIG_SMP ifdefs around code touching struct cpuinfo_x86 members but also caused the following build error with Randy's randconfigs: mce_amd.c:(.cpuinit.text+0x4723): undefined reference to `cpu_llc_shared_map' Restore the #ifdef in threshold_create_bank() which creates symlinks on the non-BSP CPUs. There's a better patch series being worked on by Kevin Winchester which will solve this in a cleaner fashion, but that series is too ambitious for v3.3 merging - so we first queue up this trivial fix and then do the rest for v3.4. Signed-off-by: Borislav Petkov <bp@alien8.de> Acked-by: Kevin Winchester <kjwinchester@gmail.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Nick Bowler <nbowler@elliptictech.com> Link: http://lkml.kernel.org/r/20120203191801.GA2846@x1.osrc.amd.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-20i387: export 'fpu_owner_task' per-cpu variableLinus Torvalds
(And define it properly for x86-32, which had its 'current_task' declaration in separate from x86-64) Bitten by my dislike for modules on the machines I use, and the fact that apparently nobody else actually wanted to test the patches I sent out. Snif. Nobody else cares. Anyway, we probably should uninline the 'kernel_fpu_begin()' function that is what modules actually use and that references this, but this is the minimal fix for now. Reported-by: Josh Boyer <jwboyer@gmail.com> Reported-and-tested-by: Jongman Heo <jongman.heo@samsung.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-20x86: Specify a size for the cmp in the NMI handlerSteven Rostedt
Linus noticed that the cmp used to check if the code segment is __KERNEL_CS or not did not specify a size. Perhaps it does not matter as H. Peter Anvin noted that user space can not set the bottom two bits of the %cs register. But it's best not to let the assembly choose and change things between different versions of gas, but instead just pick the size. Four bytes are used to compare the saved code segment against __KERNEL_CS. Perhaps this might mess up Xen, but we can fix that when the time comes. Also I noticed that there was another non-specified cmp that checks the special stack variable if it is 1 or 0. This too probably doesn't matter what cmp is used, but this patch uses cmpl just to make it non ambiguous. Link: http://lkml.kernel.org/r/CA+55aFxfAn9MWRgS3O5k2tqN5ys1XrhSFVO5_9ZAoZKDVgNfGA@mail.gmail.com Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-02-20i387: support lazy restore of FPU stateLinus Torvalds
This makes us recognize when we try to restore FPU state that matches what we already have in the FPU on this CPU, and avoids the restore entirely if so. To do this, we add two new data fields: - a percpu 'fpu_owner_task' variable that gets written any time we update the "has_fpu" field, and thus acts as a kind of back-pointer to the task that owns the CPU. The exception is when we save the FPU state as part of a context switch - if the save can keep the FPU state around, we leave the 'fpu_owner_task' variable pointing at the task whose FP state still remains on the CPU. - a per-thread 'last_cpu' field, that indicates which CPU that thread used its FPU on last. We update this on every context switch (writing an invalid CPU number if the last context switch didn't leave the FPU in a lazily usable state), so we know that *that* thread has done nothing else with the FPU since. These two fields together can be used when next switching back to the task to see if the CPU still matches: if 'fpu_owner_task' matches the task we are switching to, we know that no other task (or kernel FPU usage) touched the FPU on this CPU in the meantime, and if the current CPU number matches the 'last_cpu' field, we know that this thread did no other FP work on any other CPU, so the FPU state on the CPU must match what was saved on last context switch. In that case, we can avoid the 'f[x]rstor' entirely, and just clear the CR0.TS bit. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-20i387: use 'restore_fpu_checking()' directly in task switching codeLinus Torvalds
This inlines what is usually just a couple of instructions, but more importantly it also fixes the theoretical error case (can that FPU restore really ever fail? Maybe we should remove the checking). We can't start sending signals from within the scheduler, we're much too deep in the kernel and are holding the runqueue lock etc. So don't bother even trying. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-20i387: fix up some fpu_counter confusionLinus Torvalds
This makes sure we clear the FPU usage counter for newly created tasks, just so that we start off in a known state (for example, don't try to preload the FPU state on the first task switch etc). It also fixes a thinko in when we increment the fpu_counter at task switch time, introduced by commit 34ddc81a230b ("i387: re-introduce FPU state preloading at context switch time"). We should increment the *new* task fpu_counter, not the old task, and only if we decide to use that state (whether lazily or preloaded). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-20x86/nmi: Test saved %cs in NMI to determine nested NMI caseSteven Rostedt
Currently, the NMI handler tests if it is nested by checking the special variable saved on the stack (set during NMI handling) and whether the saved stack is the NMI stack as well (to prevent the race when the variable is set to zero). But userspace may set their %rsp to any value as long as they do not derefence it, and it may make it point to the NMI stack, which will prevent NMIs from triggering while the userspace app is running. (I tested this, and it is indeed the case) Add another check to determine nested NMIs by looking at the saved %cs (code segment register) and making sure that it is the kernel code segment. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@kernel.org> Link: http://lkml.kernel.org/r/1329687817.1561.27.camel@acer.local.home Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-18i387: re-introduce FPU state preloading at context switch timeLinus Torvalds
After all the FPU state cleanups and finally finding the problem that caused all our FPU save/restore problems, this re-introduces the preloading of FPU state that was removed in commit b3b0870ef3ff ("i387: do not preload FPU state at task switch time"). However, instead of simply reverting the removal, this reimplements preloading with several fixes, most notably - properly abstracted as a true FPU state switch, rather than as open-coded save and restore with various hacks. In particular, implementing it as a proper FPU state switch allows us to optimize the CR0.TS flag accesses: there is no reason to set the TS bit only to then almost immediately clear it again. CR0 accesses are quite slow and expensive, don't flip the bit back and forth for no good reason. - Make sure that the same model works for both x86-32 and x86-64, so that there are no gratuitous differences between the two due to the way they save and restore segment state differently due to architectural differences that really don't matter to the FPU state. - Avoid exposing the "preload" state to the context switch routines, and in particular allow the concept of lazy state restore: if nothing else has used the FPU in the meantime, and the process is still on the same CPU, we can avoid restoring state from memory entirely, just re-expose the state that is still in the FPU unit. That optimized lazy restore isn't actually implemented here, but the infrastructure is set up for it. Of course, older CPU's that use 'fnsave' to save the state cannot take advantage of this, since the state saving also trashes the state. In other words, there is now an actual _design_ to the FPU state saving, rather than just random historical baggage. Hopefully it's easier to follow as a result. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-18i387: move TS_USEDFPU flag from thread_info to task_structLinus Torvalds
This moves the bit that indicates whether a thread has ownership of the FPU from the TS_USEDFPU bit in thread_info->status to a word of its own (called 'has_fpu') in task_struct->thread.has_fpu. This fixes two independent bugs at the same time: - changing 'thread_info->status' from the scheduler causes nasty problems for the other users of that variable, since it is defined to be thread-synchronous (that's what the "TS_" part of the naming was supposed to indicate). So perfectly valid code could (and did) do ti->status |= TS_RESTORE_SIGMASK; and the compiler was free to do that as separate load, or and store instructions. Which can cause problems with preemption, since a task switch could happen in between, and change the TS_USEDFPU bit. The change to TS_USEDFPU would be overwritten by the final store. In practice, this seldom happened, though, because the 'status' field was seldom used more than once, so gcc would generally tend to generate code that used a read-modify-write instruction and thus happened to avoid this problem - RMW instructions are naturally low fat and preemption-safe. - On x86-32, the current_thread_info() pointer would, during interrupts and softirqs, point to a *copy* of the real thread_info, because x86-32 uses %esp to calculate the thread_info address, and thus the separate irq (and softirq) stacks would cause these kinds of odd thread_info copy aliases. This is normally not a problem, since interrupts aren't supposed to look at thread information anyway (what thread is running at interrupt time really isn't very well-defined), but it confused the heck out of irq_fpu_usable() and the code that tried to squirrel away the FPU state. (It also caused untold confusion for us poor kernel developers). It also turns out that using 'task_struct' is actually much more natural for most of the call sites that care about the FPU state, since they tend to work with the task struct for other reasons anyway (ie scheduling). And the FPU data that we are going to save/restore is found there too. Thanks to Arjan Van De Ven <arjan@linux.intel.com> for pointing us to the %esp issue. Cc: Arjan van de Ven <arjan@linux.intel.com> Reported-and-tested-by: Raphael Prevost <raphael@buro.asia> Acked-and-tested-by: Suresh Siddha <suresh.b.siddha@intel.com> Tested-by: Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-16i387: move AMD K7/K8 fpu fxsave/fxrstor workaround from save to restoreLinus Torvalds
The AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception is pending. In order to not leak FIP state from one process to another, we need to do a floating point load after the fxsave of the old process, and before the fxrstor of the new FPU state. That resets the state to the (uninteresting) kernel load, rather than some potentially sensitive user information. We used to do this directly after the FPU state save, but that is actually very inconvenient, since it (a) corrupts what is potentially perfectly good FPU state that we might want to lazy avoid restoring later and (b) on x86-64 it resulted in a very annoying ordering constraint, where "__unlazy_fpu()" in the task switch needs to be delayed until after the DS segment has been reloaded just to get the new DS value. Coupling it to the fxrstor instead of the fxsave automatically avoids both of these issues, and also ensures that we only do it when actually necessary (the FP state after a save may never actually get used). It's simply a much more natural place for the leaked state cleanup. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-16i387: do not preload FPU state at task switch timeLinus Torvalds
Yes, taking the trap to re-load the FPU/MMX state is expensive, but so is spending several days looking for a bug in the state save/restore code. And the preload code has some rather subtle interactions with both paravirtualization support and segment state restore, so it's not nearly as simple as it should be. Also, now that we no longer necessarily depend on a single bit (ie TS_USEDFPU) for keeping track of the state of the FPU, we migth be able to do better. If we are really switching between two processes that keep touching the FP state, save/restore is inevitable, but in the case of having one process that does most of the FPU usage, we may actually be able to do much better than the preloading. In particular, we may be able to keep track of which CPU the process ran on last, and also per CPU keep track of which process' FP state that CPU has. For modern CPU's that don't destroy the FPU contents on save time, that would allow us to do a lazy restore by just re-enabling the existing FPU state - with no restore cost at all! Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-16i387: don't ever touch TS_USEDFPU directly, use helper functionsLinus Torvalds
This creates three helper functions that do the TS_USEDFPU accesses, and makes everybody that used to do it by hand use those helpers instead. In addition, there's a couple of helper functions for the "change both CR0.TS and TS_USEDFPU at the same time" case, and the places that do that together have been changed to use those. That means that we have fewer random places that open-code this situation. The intent is partly to clarify the code without actually changing any semantics yet (since we clearly still have some hard to reproduce bug in this area), but also to make it much easier to use another approach entirely to caching the CR0.TS bit for software accesses. Right now we use a bit in the thread-info 'status' variable (this patch does not change that), but we might want to make it a full field of its own or even make it a per-cpu variable. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-16i387: fix x86-64 preemption-unsafe user stack save/restoreLinus Torvalds
Commit 5b1cbac37798 ("i387: make irq_fpu_usable() tests more robust") added a sanity check to the #NM handler to verify that we never cause the "Device Not Available" exception in kernel mode. However, that check actually pinpointed a (fundamental) race where we do cause that exception as part of the signal stack FPU state save/restore code. Because we use the floating point instructions themselves to save and restore state directly from user mode, we cannot do that atomically with testing the TS_USEDFPU bit: the user mode access itself may cause a page fault, which causes a task switch, which saves and restores the FP/MMX state from the kernel buffers. This kind of "recursive" FP state save is fine per se, but it means that when the signal stack save/restore gets restarted, it will now take the '#NM' exception we originally tried to avoid. With preemption this can happen even without the page fault - but because of the user access, we cannot just disable preemption around the save/restore instruction. There are various ways to solve this, including using the "enable/disable_page_fault()" helpers to not allow page faults at all during the sequence, and fall back to copying things by hand without the use of the native FP state save/restore instructions. However, the simplest thing to do is to just allow the #NM from kernel space, but fix the race in setting and clearing CR0.TS that this all exposed: the TS bit changes and the TS_USEDFPU bit absolutely have to be atomic wrt scheduling, so while the actual state save/restore can be interrupted and restarted, the act of actually clearing/setting CR0.TS and the TS_USEDFPU bit together must not. Instead of just adding random "preempt_disable/enable()" calls to what is already excessively ugly code, this introduces some helper functions that mostly mirror the "kernel_fpu_begin/end()" functionality, just for the user state instead. Those helper functions should probably eventually replace the other ad-hoc CR0.TS and TS_USEDFPU tests too, but I'll need to think about it some more: the task switching functionality in particular needs to expose the difference between the 'prev' and 'next' threads, while the new helper functions intentionally were written to only work with 'current'. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-13i387: make irq_fpu_usable() tests more robustLinus Torvalds
Some code - especially the crypto layer - wants to use the x86 FP/MMX/AVX register set in what may be interrupt (typically softirq) context. That *can* be ok, but the tests for when it was ok were somewhat suspect. We cannot touch the thread-specific status bits either, so we'd better check that we're not going to try to save FP state or anything like that. Now, it may be that the TS bit is always cleared *before* we set the USEDFPU bit (and only set when we had already cleared the USEDFP before), so the TS bit test may actually have been sufficient, but it certainly was not obviously so. So this explicitly verifies that we will not touch the TS_USEDFPU bit, and adds a few related sanity-checks. Because it seems that somehow AES-NI is corrupting user FP state. The cause is not clear, and this patch doesn't fix it, but while debugging it I really wanted the code to be more obviously correct and robust. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-13i387: math_state_restore() isn't called from asmLinus Torvalds
It was marked asmlinkage for some really old and stale legacy reasons. Fix that and the equally stale comment. Noticed when debugging the irq_fpu_usable() bugs. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-09x86/amd: Fix L1i and L2 cache sharing information for AMD family 15h processorsAndreas Herrmann
For L1 instruction cache and L2 cache the shared CPU information is wrong. On current AMD family 15h CPUs those caches are shared between both cores of a compute unit. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=42607 Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Petkov Borislav <Borislav.Petkov@amd.com> Cc: Dave Jones <davej@redhat.com> Cc: <stable@kernel.org> Link: http://lkml.kernel.org/r/20120208195229.GA17523@alberich.amd.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-07perf: Fix double start/stop in x86_pmu_start()Stephane Eranian
The following patch fixes a bug introduced by the following commit: e050e3f0a71b ("perf: Fix broken interrupt rate throttling") The patch caused the following warning to pop up depending on the sampling frequency adjustments: ------------[ cut here ]------------ WARNING: at arch/x86/kernel/cpu/perf_event.c:995 x86_pmu_start+0x79/0xd4() It was caused by the following call sequence: perf_adjust_freq_unthr_context.part() { stop() if (delta > 0) { perf_adjust_period() { if (period > 8*...) { stop() ... start() } } } start() } Which caused a double start and a double stop, thus triggering the assert in x86_pmu_start(). The patch fixes the problem by avoiding the double calls. We pass a new argument to perf_adjust_period() to indicate whether or not the event is already stopped. We can't just remove the start/stop from that function because it's called from __perf_event_overflow where the event needs to be reloaded via a stop/start back-toback call. The patch reintroduces the assertion in x86_pmu_start() which was removed by commit: 84f2b9b ("perf: Remove deprecated WARN_ON_ONCE()") In this second version, we've added calls to disable/enable PMU during unthrottling or frequency adjustment based on bug report of spurious NMI interrupts from Eric Dumazet. Reported-and-tested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: markus@trippelsdorf.de Cc: paulus@samba.org Link: http://lkml.kernel.org/r/20120207133956.GA4932@quad [ Minor edits to the changelog and to the code ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-07x86/microcode: Remove noisy AMD microcode warningPrarit Bhargava
AMD processors will never support /dev/cpu/microcode updating so just silently fail instead of printing out a warning for every cpu. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: Borislav Petkov <borislav.petkov@amd.com> Link: http://lkml.kernel.org/r/1328552935-965-1-git-send-email-prarit@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-03perf: Remove deprecated WARN_ON_ONCE()Stephane Eranian
With the new throttling/unthrottling code introduced with commit: e050e3f0a71b ("perf: Fix broken interrupt rate throttling") we occasionally hit two WARN_ON_ONCE() checks in: - intel_pmu_pebs_enable() - intel_pmu_lbr_enable() - x86_pmu_start() The assertions are no longer problematic. There is a valid path where they can trigger but it is harmless. The assertion can be triggered with: $ perf record -e instructions:pp .... Leading to paths: intel_pmu_pebs_enable intel_pmu_enable_event x86_perf_event_set_period x86_pmu_start perf_adjust_freq_unthr_context perf_event_task_tick scheduler_tick And: intel_pmu_lbr_enable intel_pmu_enable_event x86_perf_event_set_period x86_pmu_start perf_adjust_freq_unthr_context. perf_event_task_tick scheduler_tick cpuc->enabled is always on because when we get to perf_adjust_freq_unthr_context() the PMU is not totally disabled. Furthermore when we need to adjust a period, we only stop the event we need to change and not the entire PMU. Thus, when we re-enable, cpuc->enabled is already set. Note that when we stop the event, both pebs and lbr are stopped if necessary (and possible). Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Link: http://lkml.kernel.org/r/20120202110401.GA30911@quad Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-02-02Merge branches 'core-urgent-for-linus', 'perf-urgent-for-linus', ↵Linus Torvalds
'sched-urgent-for-linus' and 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: bugs, x86: Fix printk levels for panic, softlockups and stack dumps * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf top: Fix number of samples displayed perf tools: Fix strlen() bug in perf_event__synthesize_event_type() perf tools: Fix broken build by defining _GNU_SOURCE in Makefile x86/dumpstack: Remove unneeded check in dump_trace() perf: Fix broken interrupt rate throttling * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/rt: Fix task stack corruption under __ARCH_WANT_INTERRUPTS_ON_CTXSW sched: Fix ancient race in do_exit() sched/nohz: Fix nohz cpu idle load balancing state with cpu hotplug sched/s390: Fix compile error in sched/core.c sched: Fix rq->nr_uninterruptible update race * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/reboot: Remove VersaLogic Menlow reboot quirk x86/reboot: Skip DMI checks if reboot set by user x86: Properly parenthesize cmpxchg() macro arguments
2012-01-30x86/reboot: Remove VersaLogic Menlow reboot quirkMichael D Labriola
This commit removes the reboot quirk originally added by commit e19e074 ("x86: Fix reboot problem on VersaLogic Menlow boards"). Testing with a VersaLogic Ocelot (VL-EPMs-21a rev 1.00 w/ BIOS 6.5.102) revealed the following regarding the reboot hang problem: - v2.6.37 reboot=bios was needed. - v2.6.38-rc1: behavior changed, reboot=acpi is needed, reboot=kbd and reboot=bios results in system hang. - v2.6.38: VersaLogic patch (e19e074 "x86: Fix reboot problem on VersaLogic Menlow boards") was applied prior to v2.6.38-rc7. This patch sets a quirk for VersaLogic Menlow boards that forces the use of reboot=bios, which doesn't work anymore. - v3.2: It seems that commit 660e34c ("x86: Reorder reboot method preferences") changed the default reboot method to acpi prior to v3.0-rc1, which means the default behavior is appropriate for the Ocelot. No VersaLogic quirk is required. The Ocelot board used for testing can successfully reboot w/out having to pass any reboot= arguments for all 3 current versions of the BIOS. Signed-off-by: Michael D Labriola <michael.d.labriola@gmail.com> Cc: Matthew Garrett <mjg@redhat.com> Cc: Michael D Labriola <mlabriol@gdeb.com> Cc: Kushal Koolwal <kushalkoolwal@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/87vcnub9hu.fsf@gmail.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-30x86/reboot: Skip DMI checks if reboot set by userMichael D Labriola
Skip DMI checks for vendor specific reboot quirks if the user passed in a reboot= arg on the command line - we should never override user choices. Signed-off-by: Michael D Labriola <michael.d.labriola@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Michael D Labriola <mlabriol@gdeb.com> Cc: Matthew Garrett <mjg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/87wr8ab9od.fsf@gmail.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-28x86/dumpstack: Remove unneeded check in dump_trace()Dan Carpenter
Smatch complains that we have some inconsistent NULL checking. If "task" were NULL then it would lead to a NULL dereference later. We can remove this test because earlier on in the function we have: if (!task) task = current; Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Clemens Ladisch <clemens@ladisch.de> Link: http://lkml.kernel.org/r/20120128105246.GA25092@elgon.mountain Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-26bugs, x86: Fix printk levels for panic, softlockups and stack dumpsPrarit Bhargava
rsyslog will display KERN_EMERG messages on a connected terminal. However, these messages are useless/undecipherable for a general user. For example, after a softlockup we get: Message from syslogd@intel-s3e37-04 at Jan 25 14:18:06 ... kernel:Stack: Message from syslogd@intel-s3e37-04 at Jan 25 14:18:06 ... kernel:Call Trace: Message from syslogd@intel-s3e37-04 at Jan 25 14:18:06 ... kernel:Code: ff ff a8 08 75 25 31 d2 48 8d 86 38 e0 ff ff 48 89 d1 0f 01 c8 0f ae f0 48 8b 86 38 e0 ff ff a8 08 75 08 b1 01 4c 89 e0 0f 01 c9 <e8> ea 69 dd ff 4c 29 e8 48 89 c7 e8 0f bc da ff 49 89 c4 49 89 This happens because the printk levels for these messages are incorrect. Only an informational message should be displayed on a terminal. I modified the printk levels for various messages in the kernel and tested the output by using the drivers/misc/lkdtm.c kernel modules (ie, softlockups, panics, hard lockups, etc.) and confirmed that the console output was still the same and that the output to the terminals was correct. For example, in the case of a softlockup we now see the much more informative: Message from syslogd@intel-s3e37-04 at Jan 25 10:18:06 ... BUG: soft lockup - CPU4 stuck for 60s! instead of the above confusing messages. AFAICT, the messages no longer have to be KERN_EMERG. In the most important case of a panic we set console_verbose(). As for the other less severe cases the correct data is output to the console and /var/log/messages. Successfully tested by me using the drivers/misc/lkdtm.c module. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: dzickus@redhat.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1327586134-11926-1-git-send-email-prarit@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-26x86/microcode_amd: Add support for CPU family specific container filesAndreas Herrmann
We've decided to provide CPU family specific container files (starting with CPU family 15h). E.g. for family 15h we have to load microcode_amd_fam15h.bin instead of microcode_amd.bin Rationale is that starting with family 15h patch size is larger than 2KB which was hard coded as maximum patch size in various microcode loaders (not just Linux). Container files which include patches larger than 2KB cause different kinds of trouble with such old patch loaders. Thus we have to ensure that the default container file provides only patches with size less than 2KB. Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: Borislav Petkov <borislav.petkov@amd.com> Cc: <stable@kernel.org> Link: http://lkml.kernel.org/r/20120120164412.GD24508@alberich.amd.com [ documented the naming convention and tidied the code a bit. ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-19Merge remote-tracking branch 'linus/master' into x86/urgentH. Peter Anvin
2012-01-18Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux This includes initial support for the recently published ACPI 5.0 spec. In particular, support for the "hardware-reduced" bit that eliminates the dependency on legacy hardware. APEI has patches resulting from testing on real hardware. Plus other random fixes. * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux: (52 commits) acpi/apei/einj: Add extensions to EINJ from rev 5.0 of acpi spec intel_idle: Split up and provide per CPU initialization func ACPI processor: Remove unneeded variable passed by acpi_processor_hotadd_init V2 ACPI processor: Remove unneeded cpuidle_unregister_driver call intel idle: Make idle driver more robust intel_idle: Fix a cast to pointer from integer of different size warning in intel_idle ACPI: kernel-parameters.txt : Add intel_idle.max_cstate intel_idle: remove redundant local_irq_disable() call ACPI processor: Fix error path, also remove sysdev link ACPI: processor: fix acpi_get_cpuid for UP processor intel_idle: fix API misuse ACPI APEI: Convert atomicio routines ACPI: Export interfaces for ioremapping/iounmapping ACPI registers ACPI: Fix possible alignment issues with GAS 'address' references ACPI, ia64: Use SRAT table rev to use 8bit or 16/32bit PXM fields (ia64) ACPI, x86: Use SRAT table rev to use 8bit or 32bit PXM fields (x86/x86-64) ACPI: Store SRAT table revision ACPI, APEI, Resolve false conflict between ACPI NVS and APEI ACPI, Record ACPI NVS regions ACPI, APEI, EINJ, Refine the fix of resource conflict ...
2012-01-17x86-32: Fix build failure with AUDIT=y, AUDITSYSCALL=nAl Viro
JONGMAN HEO reports: With current linus git (commit a25a2b84), I got following build error, arch/x86/kernel/vm86_32.c: In function 'do_sys_vm86': arch/x86/kernel/vm86_32.c:340: error: implicit declaration of function '__audit_syscall_exit' make[3]: *** [arch/x86/kernel/vm86_32.o] Error 1 OK, I can reproduce it (32bit allmodconfig with AUDIT=y, AUDITSYSCALL=n) It's due to commit d7e7528bcd45: "Audit: push audit success and retcode into arch ptrace.h". Reported-by: JONGMAN HEO <jongman.heo@samsung.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-17Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit: (29 commits) audit: no leading space in audit_log_d_path prefix audit: treat s_id as an untrusted string audit: fix signedness bug in audit_log_execve_info() audit: comparison on interprocess fields audit: implement all object interfield comparisons audit: allow interfield comparison between gid and ogid audit: complex interfield comparison helper audit: allow interfield comparison in audit rules Kernel: Audit Support For The ARM Platform audit: do not call audit_getname on error audit: only allow tasks to set their loginuid if it is -1 audit: remove task argument to audit_set_loginuid audit: allow audit matching on inode gid audit: allow matching on obj_uid audit: remove audit_finish_fork as it can't be called audit: reject entry,always rules audit: inline audit_free to simplify the look of generic code audit: drop audit_set_macxattr as it doesn't do anything audit: inline checks for not needing to collect aux records audit: drop some potentially inadvisable likely notations ... Use evil merge to fix up grammar mistakes in Kconfig file. Bad speling and horrible grammar (and copious swearing) is to be expected, but let's keep it to commit messages and comments, rather than expose it to users in config help texts or printouts.
2012-01-17x86, tsc: Fix SMI induced variation in quick_pit_calibrate()Linus Torvalds
pit_expect_msb() returns success wrongly in the below SMI scenario: a. pit_verify_msb() has not yet seen the MSB transition. b. we are close to the MSB transition though and got a SMI immediately after returning from pit_verify_msb() which didn't see the MSB transition. PIT MSB transition has happened somewhere during SMI execution. c. returned from SMI and we noted down the 'tsc', saw the pit MSB change now and exited the loop to calculate 'deltatsc'. Instead of noting the TSC at the MSB transition, we are way off because of the SMI. And as the SMI happened between the pit_verify_msb() and before the 'tsc' is recorded in the for loop, 'delattsc' (d1/d2 in quick_pit_calibrate()) will be small and quick_pit_calibrate() will not notice this error. Depending on whether SMI disturbance happens while computing d1 or d2, we will see the TSC calibrated value smaller or bigger than the expected value. As a result, in a cluster we were seeing a variation of approximately +/- 20MHz in the calibrated values, resulting in NTP failures. [ As far as the SMI source is concerned, this is a periodic SMI that gets disabled after ACPI is enabled by the OS. But the TSC calibration happens before the ACPI is enabled. ] To address this, change pit_expect_msb() so that - the 'tsc' is the TSC in between the two reads that read the MSB change from the PIT (same as before) - the 'delta' is the difference in TSC from *before* the MSB changed to *after* the MSB changed. Now the delta is twice as big as before (it covers four PIT accesses, roughly 4us) and quick_pit_calibrate() will loop a bit longer to get the calibrated value with in the 500ppm precision. As the delta (d1/d2) covers four PIT accesses, actual calibrated result might be closer to 250ppm precision. As the loop now takes longer to stabilize, double MAX_QUICK_PIT_MS to 50. SMI disturbance will showup as much larger delta's and the loop will take longer than usual for the result to be with in the accepted precision. Or will fallback to slow PIT calibration if it takes more than 50msec. Also while we are at this, remove the calibration correction that aims to get the result to the middle of the error bars. We really don't know which direction to correct into, so remove it. Reported-and-tested-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1326843337.5291.4.camel@sbsiddha-mobl2 Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-01-17audit: inline audit_syscall_entry to reduce burden on archsEric Paris
Every arch calls: if (unlikely(current->audit_context)) audit_syscall_entry() which requires knowledge about audit (the existance of audit_context) in the arch code. Just do it all in static inline in audit.h so that arch's can remain blissfully ignorant. Signed-off-by: Eric Paris <eparis@redhat.com>
2012-01-17Audit: push audit success and retcode into arch ptrace.hEric Paris
The audit system previously expected arches calling to audit_syscall_exit to supply as arguments if the syscall was a success and what the return code was. Audit also provides a helper AUDITSC_RESULT which was supposed to simplify things by converting from negative retcodes to an audit internal magic value stating success or failure. This helper was wrong and could indicate that a valid pointer returned to userspace was a failed syscall. The fix is to fix the layering foolishness. We now pass audit_syscall_exit a struct pt_reg and it in turns calls back into arch code to collect the return value and to determine if the syscall was a success or failure. We also define a generic is_syscall_success() macro which determines success/failure based on if the value is < -MAX_ERRNO. This works for arches like x86 which do not use a separate mechanism to indicate syscall failure. We make both the is_syscall_success() and regs_return_value() static inlines instead of macros. The reason is because the audit function must take a void* for the regs. (uml calls theirs struct uml_pt_regs instead of just struct pt_regs so audit_syscall_exit can't take a struct pt_regs). Since the audit function takes a void* we need to use static inlines to cast it back to the arch correct structure to dereference it. The other major change is that on some arches, like ia64, MIPS and ppc, we change regs_return_value() to give us the negative value on syscall failure. THE only other user of this macro, kretprobe_example.c, won't notice and it makes the value signed consistently for the audit functions across all archs. In arch/sh/kernel/ptrace_64.c I see that we were using regs[9] in the old audit code as the return value. But the ptrace_64.h code defined the macro regs_return_value() as regs[3]. I have no idea which one is correct, but this patch now uses the regs_return_value() function, so it now uses regs[3]. For powerpc we previously used regs->result but now use the regs_return_value() function which uses regs->gprs[3]. regs->gprs[3] is always positive so the regs_return_value(), much like ia64 makes it negative before calling the audit code when appropriate. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: H. Peter Anvin <hpa@zytor.com> [for x86 portion] Acked-by: Tony Luck <tony.luck@intel.com> [for ia64] Acked-by: Richard Weinberger <richard@nod.at> [for uml] Acked-by: David S. Miller <davem@davemloft.net> [for sparc] Acked-by: Ralf Baechle <ralf@linux-mips.org> [for mips] Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [for ppc]
2012-01-17ACPI, Record ACPI NVS regionsHuang Ying
Some firmware will access memory in ACPI NVS region via APEI. That is, instructions in APEI ERST/EINJ table will read/write ACPI NVS region. The original resource conflict checking in APEI code will check memory/ioport accessed by APEI via general resource management mechanism. But ACPI NVS region is marked as busy already, so that the false resource conflict will prevent APEI ERST/EINJ to work. To fix this, this patch record ACPI NVS regions, so that we can avoid request resources for memory region inside it. Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2012-01-16Merge branch 'x86-syscall-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'x86-syscall-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Move <asm/asm-offsets.h> from trace_syscalls.c to asm/syscall.h x86, um: Fix typo in 32-bit system call modifications um: Use $(srctree) not $(KBUILD_SRC) x86, um: Mark system call tables readonly x86, um: Use the same style generated syscall tables as native um: Generate headers before generating user-offsets.s um: Run host archheaders, allow use of host generated headers kbuild, headers.sh: Don't make archheaders explicitly x86, syscall: Allow syscall offset to be symbolic x86, syscall: Re-fix typo in comment x86: Simplify syscallhdr.sh x86: Generate system call tables and unistd_*.h from tables checksyscalls: Use arch/x86/syscalls/syscall_32.tbl as source x86: Machine-readable syscall tables and scripts to process them trace: Include <asm/asm-offsets.h> in trace_syscalls.c x86-64, ia32: Move compat_ni_syscall into C and its own file x86-64, syscall: Adjust comment spacing and remove typo kbuild: Add support for an "archheaders" target kbuild: Add support for installing generated asm headers