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Groups > linux.kernel > #1211940
| From | Jiri Slaby <jslaby@suse.cz> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.12 59/82] x86/nmi/64: Switch stacks on userspace NMI entry |
| Date | 2015-08-24 11:20 +0200 |
| Message-ID | <q0W54-3om-13@gated-at.bofh.it> (permalink) |
| References | <q0VVn-3cH-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Andy Lutomirski <luto@kernel.org> 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 9b6e6a8334d56354853f9c255d1395c2ba570e0a upstream. Returning to userspace is tricky: IRET can fail, and ESPFIX can rearrange the stack prior to IRET. The NMI nesting fixup relies on a precise stack layout and atomic IRET. Rather than trying to teach the NMI nesting fixup to handle ESPFIX and failed IRET, punt: run NMIs that came from user mode on the normal kernel stack. This will make some nested NMIs visible to C code, but the C code is okay with that. As a side effect, this should speed up perf: it eliminates an RDMSR when NMIs come from user mode. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> --- arch/x86/kernel/entry_64.S | 65 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 61 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index fd27e5b86d7b..691337073e1f 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1706,19 +1706,76 @@ ENTRY(nmi) * a nested NMI that updated the copy interrupt stack frame, a * jump will be made to the repeat_nmi code that will handle the second * NMI. + * + * However, espfix prevents us from directly returning to userspace + * with a single IRET instruction. Similarly, IRET to user mode + * can fault. We therefore handle NMIs from user space like + * other IST entries. */ /* Use %rdx as out temp variable throughout */ pushq_cfi %rdx CFI_REL_OFFSET rdx, 0 + testb $3, CS-RIP+8(%rsp) + jz .Lnmi_from_kernel + + /* + * NMI from user mode. We need to run on the thread stack, but we + * can't go through the normal entry paths: NMIs are masked, and + * we don't want to enable interrupts, because then we'll end + * up in an awkward situation in which IRQs are on but NMIs + * are off. + */ + + SWAPGS + cld + movq %rsp, %rdx + movq PER_CPU_VAR(kernel_stack), %rsp + addq $KERNEL_STACK_OFFSET, %rsp + pushq 5*8(%rdx) /* pt_regs->ss */ + pushq 4*8(%rdx) /* pt_regs->rsp */ + pushq 3*8(%rdx) /* pt_regs->flags */ + pushq 2*8(%rdx) /* pt_regs->cs */ + pushq 1*8(%rdx) /* pt_regs->rip */ + pushq $-1 /* pt_regs->orig_ax */ + pushq %rdi /* pt_regs->di */ + pushq %rsi /* pt_regs->si */ + pushq (%rdx) /* pt_regs->dx */ + pushq %rcx /* pt_regs->cx */ + pushq %rax /* pt_regs->ax */ + pushq %r8 /* pt_regs->r8 */ + pushq %r9 /* pt_regs->r9 */ + pushq %r10 /* pt_regs->r10 */ + pushq %r11 /* pt_regs->r11 */ + pushq %rbx /* pt_regs->rbx */ + pushq %rbp /* pt_regs->rbp */ + pushq %r12 /* pt_regs->r12 */ + pushq %r13 /* pt_regs->r13 */ + pushq %r14 /* pt_regs->r14 */ + pushq %r15 /* pt_regs->r15 */ + /* - * If %cs was not the kernel segment, then the NMI triggered in user - * space, which means it is definitely not nested. + * At this point we no longer need to worry about stack damage + * due to nesting -- we're on the normal thread stack and we're + * done with the NMI stack. */ - cmpl $__KERNEL_CS, 16(%rsp) - jne first_nmi + movq %rsp, %rdi + movq $-1, %rsi + call do_nmi + + /* + * Return back to user mode. We must *not* do the normal exit + * work, because we don't want to enable interrupts. Fortunately, + * do_nmi doesn't modify pt_regs. + */ + SWAPGS + + addq $6*8, %rsp /* skip bx, bp, and r12-r15 */ + jmp restore_args + +.Lnmi_from_kernel: /* * Check the special variable on the stack to see if NMIs are * executing. -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH 3.12 01/82] efi: fix 32bit kernel boot failed problem using efi Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:10 +0200
[PATCH 3.12 67/82] signalfd: fix information leak in signalfd_copyinfo Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 54/82] ipc: modify message queue accounting to not take kernel data structures into account Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 75/82] mm/hwpoison: fix page refcount of unknown non LRU page Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 64/82] x86/ldt: Correct LDT access in single stepping logic Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 44/82] ipmi: fix timeout calculation when bmc is disconnected Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 07/82] ARC: make sure instruction_pointer() returns unsigned value Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 59/82] x86/nmi/64: Switch stacks on userspace NMI entry Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 62/82] rcu: Move lockless_dereference() out of rcupdate.h Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 55/82] ocfs2: fix BUG in ocfs2_downconvert_thread_do_work() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 60/82] arch: Introduce smp_load_acquire(), smp_store_release() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 57/82] x86/nmi: Enable nested do_nmi() handling for 64-bit kernels Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 71/82] md/bitmap: return an error when bitmap superblock is corrupt. Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 76/82] xen-blkfront: don't add indirect pages to list when !feature_persistent Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 45/82] sparc64: Fix userspace FPU register corruptions. Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 74/82] ipc,sem: fix use after free on IPC_RMID after a task using same semaphore set exits Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 05/82] freeing unlinked file indefinitely delayed Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 66/82] x86/ldt: Further fix FPU emulation Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 69/82] signal: fix information leak in copy_siginfo_from_user32 Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 80/82] EDAC, ppc4xx: Access mci->csrows array elements properly Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 56/82] md/raid1: extend spinlock to protect raid1_end_read_request against inconsistencies Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 77/82] perf: Fix fasync handling on inherited events Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 63/82] x86/ldt: Make modify_ldt synchronous Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 82/82] rbd: fix copyup completion race Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 78/82] dm thin metadata: delete btrees when releasing metadata snapshot Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 73/82] ipc/sem.c: update/correct memory barriers Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 65/82] x86/ldt: Correct FPU emulation access to LDT Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 68/82] signal: fix information leak in copy_siginfo_to_user Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 81/82] drm/radeon: add new OLAND pci id Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 58/82] x86/nmi/64: Remove asm code that saves CR2 Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 79/82] localmodconfig: Use Kbuild files too Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 61/82] rcu: Provide counterpart to rcu_dereference() for non-RCU situations Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 72/82] mm, vmscan: Do not wait for page writeback for GFP_NOFS allocations Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 46/82] md: use kzalloc() when bitmap is disabled Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 70/82] path_openat(): fix double fput() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:20 +0200
[PATCH 3.12 39/82] ipr: Fix invalid array indexing for HRRQ Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 38/82] ipr: Fix incorrect trace indexing Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 51/82] ARM: OMAP2+: hwmod: Fix _wait_target_ready() for hwmods without sysc Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 32/82] ARM: realview: fix sparsemem build Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 31/82] hwrng: via-rng - Mark device ID table as __maybe_unused Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 10/82] ALSA: usb-audio: add dB range mapping for some devices Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 33/82] MIPS: Fix sched_getaffinity with MT FPAFF enabled Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 43/82] ima: extend "mask" policy matching support Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 41/82] USB: sierra: add 1199:68AB device ID Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 30/82] 3w-xxxx: fix mis-aligned struct accesses Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 40/82] xhci: fix off by one error in TRB DMA address boundary check Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 53/82] ALSA: hda - fix cs4210_spdif_automute() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 08/82] genirq: Prevent resend to interrupts marked IRQ_NESTED_THREAD Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 52/82] iscsi-target: Fix iscsit_start_kthreads failure OOPs Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 27/82] vhost: actually track log eventfd file Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 35/82] fsnotify: fix oops in fsnotify_clear_marks_by_group_flags() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 37/82] ipr: Fix locking for unit attention handling Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 36/82] drm/radeon/combios: add some validation of lvds values Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 47/82] ASoC: pcm1681: Fix setting de-emphasis sampling rate selection Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 50/82] crypto: ixp4xx - Remove bogus BUG_ON on scattered dst buffer Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 29/82] iscsi-target: Fix iser explicit logout TX kthread leak Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 48/82] x86/xen: Probe target addresses in set_aliased_prot() before the hypercall Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
Re: [PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Luis Henriques <luis.henriques@canonical.com> - 2015-08-25 13:40 +0200
Re: [PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> - 2015-08-25 14:00 +0200
Re: [PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Jiri Slaby <jslaby@suse.cz> - 2015-08-25 15:20 +0200
Re: [PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> - 2015-08-25 16:10 +0200
Re: [PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release() Jiri Slaby <jslaby@suse.cz> - 2015-08-27 10:10 +0200
[PATCH 3.12 42/82] ima: add support for new "euid" policy condition Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 34/82] MIPS: Make set_pte() SMP safe. Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:30 +0200
[PATCH 3.12 02/82] futex: Fix a race condition between REQUEUE_PI and task death Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 28/82] iscsi-target: Fix use-after-free during TPG session shutdown Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 09/82] ALSA: usb-audio: Add MIDI support for Steinberg MI2/MI4 Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 15/82] mmc: sdhci-pxav3: fix platform_data is not initialized Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 19/82] blkcg: fix gendisk reference leak in blkg_conf_prep() Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 26/82] rds: rds_ib_device.refcount overflow Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 23/82] xhci: report U3 when link is in resume state Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 03/82] HID: usbhid: add Chicony/Pixart usb optical mouse that needs QUIRK_ALWAYS_POLL Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 18/82] Input: usbtouchscreen - avoid unresponsive TSC-30 touch screen Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 25/82] xhci: do not report PLC when link is in internal resume state Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 22/82] xhci: Calculate old endpoints correctly on device reset Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 24/82] xhci: prevent bus_suspend if SS port resuming in phase 1 Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 06/82] s390/sclp: clear upper register halves in _sclp_print_early Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 17/82] tile: use free_bootmem_late() for initrd Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 04/82] mm: avoid setting up anonymous pages into file mapping Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 16/82] md/raid1: fix test for 'was read error from last working device'. Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 20/82] ata: pmp: add quirk for Marvell 4140 SATA PMP Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 11/82] ALSA: hda - Fix MacBook Pro 5,2 quirk Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 13/82] mac80211: clear subdir_stations when removing debugfs Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 21/82] usb-storage: ignore ZTE MF 823 card reader in mode 0x1225 Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 14/82] mmc: sdhci-esdhc: Make 8BIT bus work Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
[PATCH 3.12 12/82] st: null pointer dereference panic caused by use after kref_put by st_open Jiri Slaby <jslaby@suse.cz> - 2015-08-24 11:40 +0200
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