commit 644c154186386bb1fa6446bc5e037b9ed098db46 upstream. When a cpu enters S3 state, the FPU state is lost. After resuming for S3, if we try to lazy restore the FPU for a process running on the same CPU, this will result in a corrupted FPU context. Ensure that "fpu_owner_task" is properly invalided when (re-)initializing a CPU, so nobody will try to lazy restore a state which doesn't exist in the hardware. Tested with a 64-bit kernel on a 4-core Ivybridge CPU with eagerfpu=off, by doing thousands of suspend/resume cycles with 4 processes doing FPU operations running. Without the patch, a process is killed after a few hundreds cycles by a SIGFPE. Signed-off-by: Vincent Palatin <vpalatin@chromium.org> Cc: Duncan Laurie <dlaurie@chromium.org> Cc: Olof Johansson <olofj@chromium.org> Link: http://lkml.kernel.org/r/1354306532-1014-1-git-send-email-vpalatin@chromium.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1022623842cb72ee4d0dbf02f6937f38c92c3f41 upstream. In 32 bit the stack address provided by kernel_stack_pointer() may point to an invalid range causing NULL pointer access or page faults while in NMI (see trace below). This happens if called in softirq context and if the stack is empty. The address at ®s->sp is then out of range. Fixing this by checking if regs and ®s->sp are in the same stack context. Otherwise return the previous stack pointer stored in struct thread_info. If that address is invalid too, return address of regs. BUG: unable to handle kernel NULL pointer dereference at 0000000a IP: [<c1004237>] print_context_stack+0x6e/0x8d *pde = 00000000 Oops: 0000 [#1] SMP Modules linked in: Pid: 4434, comm: perl Not tainted 3.6.0-rc3-oprofile-i386-standard-g4411a05 #4 Hewlett-Packard HP xw9400 Workstation/0A1Ch EIP: 0060:[<c1004237>] EFLAGS: 00010093 CPU: 0 EIP is at print_context_stack+0x6e/0x8d EAX: ffffe000 EBX: 0000000a ECX: f4435f94 EDX: 0000000a ESI: f4435f94 EDI: f4435f94 EBP: f5409ec0 ESP: f5409ea0 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 CR0: 8005003b CR2: 0000000a CR3: 34ac9000 CR4: 000007d0 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 DR6: ffff0ff0 DR7: 00000400 Process perl (pid: 4434, ti=f5408000 task=f5637850 task.ti=f4434000) Stack: 000003e8 ffffe000 00001ffc f4e39b00 00000000 0000000a f4435f94 c155198c f5409ef0 c1003723 c155198c f5409f04 00000000 f5409edc 00000000 00000000 f5409ee8 f4435f94 f5409fc4 00000001 f5409f1c c12dce1c 00000000 c155198c Call Trace: [<c1003723>] dump_trace+0x7b/0xa1 [<c12dce1c>] x86_backtrace+0x40/0x88 [<c12db712>] ? oprofile_add_sample+0x56/0x84 [<c12db731>] oprofile_add_sample+0x75/0x84 [<c12ddb5b>] op_amd_check_ctrs+0x46/0x260 [<c12dd40d>] profile_exceptions_notify+0x23/0x4c [<c1395034>] nmi_handle+0x31/0x4a [<c1029dc5>] ? ftrace_define_fields_irq_handler_entry+0x45/0x45 [<c13950ed>] do_nmi+0xa0/0x2ff [<c1029dc5>] ? ftrace_define_fields_irq_handler_entry+0x45/0x45 [<c13949e5>] nmi_stack_correct+0x28/0x2d [<c1029dc5>] ? ftrace_define_fields_irq_handler_entry+0x45/0x45 [<c1003603>] ? do_softirq+0x4b/0x7f <IRQ> [<c102a06f>] irq_exit+0x35/0x5b [<c1018f56>] smp_apic_timer_interrupt+0x6c/0x7a [<c1394746>] apic_timer_interrupt+0x2a/0x30 Code: 89 fe eb 08 31 c9 8b 45 0c ff 55 ec 83 c3 04 83 7d 10 00 74 0c 3b 5d 10 73 26 3b 5d e4 73 0c eb 1f 3b 5d f0 76 1a 3b 5d e8 73 15 <8b> 13 89 d0 89 55 e0 e8 ad 42 03 00 85 c0 8b 55 e0 75 a6 eb cc EIP: [<c1004237>] print_context_stack+0x6e/0x8d SS:ESP 0068:f5409ea0 CR2: 000000000000000a ---[ end trace 62afee3481b00012 ]--- Kernel panic - not syncing: Fatal exception in interrupt V2: * add comments to kernel_stack_pointer() * always return a valid stack address by falling back to the address of regs Reported-by: Yang Wei <wei.yang@windriver.com> Signed-off-by: Robert Richter <robert.richter@amd.com> Link: http://lkml.kernel.org/r/20120912135059.GZ8285@erda.amd.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Jun Zhang <jun.zhang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5189c2a7c7769ee9d037d76c1a7b8550ccf3481c upstream. When 32-bit EFI is used with 64-bit kernel (or vice versa), turn off efi_enabled once setup is done. Beyond setup, it is normally used to determine if runtime services are available and we will have none. This will resolve issues stemming from efivars modprobe panicking on a 32/64-bit setup, as well as some reboot issues on similar setups. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=45991 Reported-by: Marko Kohtala <marko.kohtala@gmail.com> Reported-by: Maxim Kammerer <mk@dee.su> Signed-off-by: Olof Johansson <olof@lixom.net> Acked-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Cc: Matthew Garrett <mjg@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 027ef6c87853b0a9df53175063028edb4950d476 upstream. In many places !pmd_present has been converted to pmd_none. For pmds that's equivalent and pmd_none is quicker so using pmd_none is better. However (unless we delete pmd_present) we should provide an accurate pmd_present too. This will avoid the risk of code thinking the pmd is non present because it's under __split_huge_page_map, see the pmd_mknotpresent there and the comment above it. If the page has been mprotected as PROT_NONE, it would also lead to a pmd_present false negative in the same way as the race with split_huge_page. Because the PSE bit stays on at all times (both during split_huge_page and when the _PAGE_PROTNONE bit get set), we could only check for the PSE bit, but checking the PROTNONE bit too is still good to remember pmd_present must always keep PROT_NONE into account. This explains a not reproducible BUG_ON that was seldom reported on the lists. The same issue is in pmd_large, it would go wrong with both PROT_NONE and if it races with split_huge_page. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> 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>
Pull Xen bug-fixes from Konrad Rzeszutek Wilk: - Fix M2P batching re-using the incorrect structure field. In v3.5 we added batching for M2P override (Machine Frame Number -> Physical Frame Number), but the original MFN was saved in an incorrect structure - and we would oops/restore when restoring with the old MFN. - Disable BIOS SMP MP table search. A bootup issue that we had ignored until we found that on DL380 G6 it was needed. * tag 'stable/for-linus-3.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xen/boot: Disable BIOS SMP MP table search. xen/m2p: do not reuse kmap_op->dev_bus_addr
If the caller passes a valid kmap_op to m2p_add_override, we use kmap_op->dev_bus_addr to store the original mfn, but dev_bus_addr is part of the interface with Xen and if we are batching the hypercalls it might not have been written by the hypervisor yet. That means that later on Xen will write to it and we'll think that the original mfn is actually what Xen has written to it. Rather than "stealing" struct members from kmap_op, keep using page->index to store the original mfn and add another parameter to m2p_remove_override to get the corresponding kmap_op instead. It is now responsibility of the caller to keep track of which kmap_op corresponds to a particular page in the m2p_override (gntdev, the only user of this interface that passes a valid kmap_op, is already doing that). CC: stable@kernel.org Reported-and-Tested-By: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This comment is no longer true. We support up to 2^16 CPUs because __ticket_t is an u16 if NR_CPUS is larger than 256. Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 fixes from Ingo Molnar: "Various fixes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86-64, kcmp: The kcmp system call can be common arch/x86/kernel/kdebugfs.c: Ensure a consistent return value in error case x86/mce: Add quirk for instruction recovery on Sandy Bridge processors x86/mce: Move MCACOD defines from mce-severity.c to <asm/mce.h> x86/ioapic: Fix NULL pointer dereference on CPU hotplug after disabling irqs x86, nops: Missing break resulting in incorrect selection on Intel x86: CONFIG_CC_STACKPROTECTOR=y is no longer experimental
Pull perf fixes from Ingo Molnar: "Fix merge window fallout and fix sleep profiling (this was always broken, so it's not a fix for the merge window - we can skip this one from the head of the tree)." * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/trace: Add ability to set a target task for events perf/x86: Fix USER/KERNEL tagging of samples properly perf/x86/intel/uncore: Make UNCORE_PMU_HRTIMER_INTERVAL 64-bit
Pull OLPC platform updates from Andres Salomon: "These move the OLPC Embedded Controller driver out of arch/x86/platform and into drivers/platform/olpc. OLPC machines are now ARM-based (which means lots of x86 and ARM changes), but are typically pretty self-contained.. so it makes more sense to go through a separate OLPC tree after getting the appropriate review/ACKs." * 'for-linus-3.6' of git://dev.laptop.org/users/dilinger/linux-olpc: x86: OLPC: move s/r-related EC cmds to EC driver Platform: OLPC: move global variables into priv struct Platform: OLPC: move debugfs support from x86 EC driver x86: OLPC: switch over to using new EC driver on x86 Platform: OLPC: add a suspended flag to the EC driver Platform: OLPC: turn EC driver into a platform_driver Platform: OLPC: allow EC cmd to be overridden, and create a workqueue to call it drivers: OLPC: update various drivers to include olpc-ec.h Platform: OLPC: add a stub to drivers/platform/ for the OLPC EC driver