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2015-11-27KVM: svm: unconditionally intercept #DBPaolo Bonzini
commit cbdb967af3d54993f5814f1cee0ed311a055377d upstream. This is needed to avoid the possibility that the guest triggers an infinite stream of #DB exceptions (CVE-2015-8104). VMX is not affected: because it does not save DR6 in the VMCS, it already intercepts #DB unconditionally. Reported-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.2, with thanks to Paolo: - update_db_bp_intercept() was called update_db_intercept() - The remaining call is in svm_guest_debug() rather than through svm_x86_ops] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-11-27x86/cpu: Call verify_cpu() after having entered long mode tooBorislav Petkov
commit 04633df0c43d710e5f696b06539c100898678235 upstream. When we get loaded by a 64-bit bootloader, kernel entry point is startup_64 in head_64.S. We don't trust any and all bootloaders because some will fiddle with CPU configuration so we go ahead and massage each CPU into sanity again. For example, some dell BIOSes have this XD disable feature which set IA32_MISC_ENABLE[34] and disable NX. This might be some dumb workaround for other OSes but Linux sure doesn't need it. A similar thing is present in the Surface 3 firmware - see https://bugzilla.kernel.org/show_bug.cgi?id=106051 - which sets this bit only on the BSP: # rdmsr -a 0x1a0 400850089 850089 850089 850089 I know, right?! There's not even an off switch in there. So fix all those cases by sanitizing the 64-bit entry point too. For that, make verify_cpu() callable in 64-bit mode also. Requested-and-debugged-by: "H. Peter Anvin" <hpa@zytor.com> Reported-and-tested-by: Bastien Nocera <bugzilla@hadess.net> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1446739076-21303-1-git-send-email-bp@alien8.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-11-27MIPS: atomic: Fix comment describing atomic64_add_unless's return value.Ralf Baechle
commit f25319d2cb439249a6859f53ad42ffa332b0acba upstream. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Fixes: f24219b4e90cf70ec4a211b17fbabc725a0ddf3c (cherry picked from commit f0a232cde7be18a207fd057dd79bbac8a0a45dec) Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-11-27ARM: pxa: remove incorrect __init annotation on pxa27x_set_pwrmodeArnd Bergmann
commit 54c09889bff6d99c8733eed4a26c9391b177c88b upstream. The z2 machine calls pxa27x_set_pwrmode() in order to power off the machine, but this function gets discarded early at boot because it is marked __init, as pointed out by kbuild: WARNING: vmlinux.o(.text+0x145c4): Section mismatch in reference from the function z2_power_off() to the function .init.text:pxa27x_set_pwrmode() The function z2_power_off() references the function __init pxa27x_set_pwrmode(). This is often because z2_power_off lacks a __init annotation or the annotation of pxa27x_set_pwrmode is wrong. This removes the __init section modifier to fix rebooting and the build error. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: ba4a90a6d86a ("ARM: pxa/z2: fix building error of pxa27x_cpu_suspend() no longer available") Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-11-17KVM: x86: work around infinite loop in microcode when #AC is deliveredEric Northup
commit 54a20552e1eae07aa240fa370a0293e006b5faed upstream. It was found that a guest can DoS a host by triggering an infinite stream of "alignment check" (#AC) exceptions. This causes the microcode to enter an infinite loop where the core never receives another interrupt. The host kernel panics pretty quickly due to the effects (CVE-2015-5307). Signed-off-by: Eric Northup <digitaleric@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.2: - Add definition of AC_VECTOR - Adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-11-17powerpc/rtas: Validate rtas.entry before calling enter_rtas()Vasant Hegde
commit 8832317f662c06f5c06e638f57bfe89a71c9b266 upstream. Currently we do not validate rtas.entry before calling enter_rtas(). This leads to a kernel oops when user space calls rtas system call on a powernv platform (see below). This patch adds code to validate rtas.entry before making enter_rtas() call. Oops: Exception in kernel mode, sig: 4 [#1] SMP NR_CPUS=1024 NUMA PowerNV task: c000000004294b80 ti: c0000007e1a78000 task.ti: c0000007e1a78000 NIP: 0000000000000000 LR: 0000000000009c14 CTR: c000000000423140 REGS: c0000007e1a7b920 TRAP: 0e40 Not tainted (3.18.17-340.el7_1.pkvm3_1_0.2400.1.ppc64le) MSR: 1000000000081000 <HV,ME> CR: 00000000 XER: 00000000 CFAR: c000000000009c0c SOFTE: 0 NIP [0000000000000000] (null) LR [0000000000009c14] 0x9c14 Call Trace: [c0000007e1a7bba0] [c00000000041a7f4] avc_has_perm_noaudit+0x54/0x110 (unreliable) [c0000007e1a7bd80] [c00000000002ddc0] ppc_rtas+0x150/0x2d0 [c0000007e1a7be30] [c000000000009358] syscall_exit+0x0/0x98 Fixes: 55190f88789a ("powerpc: Add skeleton PowerNV platform") Reported-by: NAGESWARA R. SASTRY <nasastry@in.ibm.com> Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> [mpe: Reword change log, trim oops, and add stable + fixes] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-11-17x86/process: Add proper bound checks in 64bit get_wchan()Thomas Gleixner
commit eddd3826a1a0190e5235703d1e666affa4d13b96 upstream. Dmitry Vyukov reported the following using trinity and the memory error detector AddressSanitizer (https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel). [ 124.575597] ERROR: AddressSanitizer: heap-buffer-overflow on address ffff88002e280000 [ 124.576801] ffff88002e280000 is located 131938492886538 bytes to the left of 28857600-byte region [ffffffff81282e0a, ffffffff82e0830a) [ 124.578633] Accessed by thread T10915: [ 124.579295] inlined in describe_heap_address ./arch/x86/mm/asan/report.c:164 [ 124.579295] #0 ffffffff810dd277 in asan_report_error ./arch/x86/mm/asan/report.c:278 [ 124.580137] #1 ffffffff810dc6a0 in asan_check_region ./arch/x86/mm/asan/asan.c:37 [ 124.581050] #2 ffffffff810dd423 in __tsan_read8 ??:0 [ 124.581893] #3 ffffffff8107c093 in get_wchan ./arch/x86/kernel/process_64.c:444 The address checks in the 64bit implementation of get_wchan() are wrong in several ways: - The lower bound of the stack is not the start of the stack page. It's the start of the stack page plus sizeof (struct thread_info) - The upper bound must be: top_of_stack - TOP_OF_KERNEL_STACK_PADDING - 2 * sizeof(unsigned long). The 2 * sizeof(unsigned long) is required because the stack pointer points at the frame pointer. The layout on the stack is: ... IP FP ... IP FP. So we need to make sure that both IP and FP are in the bounds. Fix the bound checks and get rid of the mix of numeric constants, u64 and unsigned long. Making all unsigned long allows us to use the same function for 32bit as well. Use READ_ONCE() when accessing the stack. This does not prevent a concurrent wakeup of the task and the stack changing, but at least it avoids TOCTOU. Also check task state at the end of the loop. Again that does not prevent concurrent changes, but it avoids walking for nothing. Add proper comments while at it. Reported-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Based-on-patch-from: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@alien8.de> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: kasan-dev <kasan-dev@googlegroups.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de> Link: http://lkml.kernel.org/r/20150930083302.694788319@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [bwh: Backported to 3.2: - s/READ_ONCE/ACCESS_ONCE/ - Remove use of TOP_OF_KERNEL_STACK_PADDING, not defined here and would be defined as 0] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-11-17MIPS: dma-default: Fix 32-bit fall back to GFP_DMAJames Hogan
commit 53960059d56ecef67d4ddd546731623641a3d2d1 upstream. If there is a DMA zone (usually 24bit = 16MB I believe), but no DMA32 zone, as is the case for some 32-bit kernels, then massage_gfp_flags() will cause DMA memory allocated for devices with a 32..63-bit coherent_dma_mask to fall back to using __GFP_DMA, even though there may only be 32-bits of physical address available anyway. Correct that case to compare against a mask the size of phys_addr_t instead of always using a 64-bit mask. Signed-off-by: James Hogan <james.hogan@imgtec.com> Fixes: a2e715a86c6d ("MIPS: DMA: Fix computation of DMA flags from device's coherent_dma_mask.") Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9610/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-11-17x86/xen: Do not clip xen_e820_map to xen_e820_map_entries when sanitizing mapMalcolm Crossley
commit 64c98e7f49100b637cd20a6c63508caed6bbba7a upstream. Sanitizing the e820 map may produce extra E820 entries which would result in the topmost E820 entries being removed. The removed entries would typically include the top E820 usable RAM region and thus result in the domain having signicantly less RAM available to it. Fix by allowing sanitize_e820_map to use the full size of the allocated E820 array. Signed-off-by: Malcolm Crossley <malcolm.crossley@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> [bwh: Backported to 3.2: s/xen_e820_map_entries/memmap.nr_entries/; s/xen_e820_map/map/g] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-11-17m68k: Define asmlinkage_protectAndreas Schwab
commit 8474ba74193d302e8340dddd1e16c85cc4b98caf upstream. Make sure the compiler does not modify arguments of syscall functions. This can happen if the compiler generates a tailcall to another function. For example, without asmlinkage_protect sys_openat is compiled into this function: sys_openat: clr.l %d0 move.w 18(%sp),%d0 move.l %d0,16(%sp) jbra do_sys_open Note how the fourth argument is modified in place, modifying the register %d4 that gets restored from this stack slot when the function returns to user-space. The caller may expect the register to be unmodified across system calls. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-11-17Revert "KVM: MMU: fix validation of mmio page fault"Ben Hutchings
This reverts commit 41e3025eacd6daafc40c3e7850fbcabc8b847805, which was commit 6f691251c0350ac52a007c54bf3ef62e9d8cdc5e upstream. The fix is only needed after commit f8f559422b6c ("KVM: MMU: fast invalidate all mmio sptes"), included in Linux 3.11. Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13parisc: Filter out spurious interrupts in PA-RISC irq handlerHelge Deller
commit b1b4e435e4ef7de77f07bf2a42c8380b960c2d44 upstream. When detecting a serial port on newer PA-RISC machines (with iosapic) we have a long way to go to find the right IRQ line, registering it, then registering the serial port and the irq handler for the serial port. During this phase spurious interrupts for the serial port may happen which then crashes the kernel because the action handler might not have been set up yet. So, basically it's a race condition between the serial port hardware and the CPU which sets up the necessary fields in the irq sructs. The main reason for this race is, that we unmask the serial port irqs too early without having set up everything properly before (which isn't easily possible because we need the IRQ number to register the serial ports). This patch is a work-around for this problem. It adds checks to the CPU irq handler to verify if the IRQ action field has been initialized already. If not, we just skip this interrupt (which isn't critical for a serial port at bootup). The real fix would probably involve rewriting all PA-RISC specific IRQ code (for CPU, IOSAPIC, GSC and EISA) to use IRQ domains with proper parenting of the irq chips and proper irq enabling along this line. This bug has been in the PA-RISC port since the beginning, but the crashes happened very rarely with currently used hardware. But on the latest machine which I bought (a C8000 workstation), which uses the fastest CPUs (4 x PA8900, 1GHz) and which has the largest possible L1 cache size (64MB each), the kernel crashed at every boot because of this race. So, without this patch the machine would currently be unuseable. For the record, here is the flow logic: 1. serial_init_chip() in 8250_gsc.c calls iosapic_serial_irq(). 2. iosapic_serial_irq() calls txn_alloc_irq() to find the irq. 3. iosapic_serial_irq() calls cpu_claim_irq() to register the CPU irq 4. cpu_claim_irq() unmasks the CPU irq (which it shouldn't!) 5. serial_init_chip() then registers the 8250 port. Problems: - In step 4 the CPU irq shouldn't have been registered yet, but after step 5 - If serial irq happens between 4 and 5 have finished, the kernel will crash Cc: linux-parisc@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13x86/paravirt: Replace the paravirt nop with a bona fide empty functionAndy Lutomirski
commit fc57a7c68020dcf954428869eafd934c0ab1536f upstream. PARAVIRT_ADJUST_EXCEPTION_FRAME generates this code (using nmi as an example, trimmed for readability): ff 15 00 00 00 00 callq *0x0(%rip) # 2796 <nmi+0x6> 2792: R_X86_64_PC32 pv_irq_ops+0x2c That's a call through a function pointer to regular C function that does nothing on native boots, but that function isn't protected against kprobes, isn't marked notrace, and is certainly not guaranteed to preserve any registers if the compiler is feeling perverse. This is bad news for a CLBR_NONE operation. Of course, if everything works correctly, once paravirt ops are patched, it gets nopped out, but what if we hit this code before paravirt ops are patched in? This can potentially cause breakage that is very difficult to debug. A more subtle failure is possible here, too: if _paravirt_nop uses the stack at all (even just to push RBP), it will overwrite the "NMI executing" variable if it's called in the NMI prologue. The Xen case, perhaps surprisingly, is fine, because it's already written in asm. Fix all of the cases that default to paravirt_nop (including adjust_exception_frame) with a big hammer: replace paravirt_nop with an asm function that is just a ret instruction. The Xen case may have other problems, so document them. This is part of a fix for some random crashes that Sasha saw. Reported-and-tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Link: http://lkml.kernel.org/r/8f5d2ba295f9d73751c33d97fda03e0495d9ade0.1442791737.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13KVM: x86: trap AMD MSRs for the TSeg base and maskPaolo Bonzini
commit 3afb1121800128aae9f5722e50097fcf1a9d4d88 upstream. These have roughly the same purpose as the SMRR, which we do not need to implement in KVM. However, Linux accesses MSR_K8_TSEG_ADDR at boot, which causes problems when running a Xen dom0 under KVM. Just return 0, meaning that processor protection of SMRAM is not in effect. Reported-by: M A Young <m.a.young@durham.ac.uk> Acked-by: Borislav Petkov <bp@suse.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13s390/compat: correct uc_sigmask of the compat signal frameMartin Schwidefsky
commit 8d4bd0ed0439dfc780aab801a085961925ed6838 upstream. The uc_sigmask in the ucontext structure is an array of words to keep the 64 signal bits (or 1024 if you ask glibc but the kernel sigset_t only has 64 bits). For 64 bit the sigset_t contains a single 8 byte word, but for 31 bit there are two 4 byte words. The compat signal handler code uses a simple copy of the 64 bit sigset_t to the 31 bit compat_sigset_t. As s390 is a big-endian architecture this is incorrect, the two words in the 31 bit sigset_t array need to be swapped. Reported-by: Stefan Liebler <stli@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [bwh: Backported to 3.2: - Introduce local compat_sigset_t in setup_frame32() - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13x86/platform: Fix Geode LX timekeeping in the generic x86 buildDavid Woodhouse
commit 03da3ff1cfcd7774c8780d2547ba0d995f7dc03d upstream. In 2007, commit 07190a08eef36 ("Mark TSC on GeodeLX reliable") bypassed verification of the TSC on Geode LX. However, this code (now in the check_system_tsc_reliable() function in arch/x86/kernel/tsc.c) was only present if CONFIG_MGEODE_LX was set. OpenWRT has recently started building its generic Geode target for Geode GX, not LX, to include support for additional platforms. This broke the timekeeping on LX-based devices, because the TSC wasn't marked as reliable: https://dev.openwrt.org/ticket/20531 By adding a runtime check on is_geode_lx(), we can also include the fix if CONFIG_MGEODEGX1 or CONFIG_X86_GENERIC are set, thus fixing the problem. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Cc: Andres Salomon <dilinger@queued.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marcelo Tosatti <marcelo@kvack.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1442409003.131189.87.camel@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13ARM: fix Thumb2 signal handling when ARMv6 is enabledRussell King
commit 9b55613f42e8d40d5c9ccb8970bde6af4764b2ab upstream. When a kernel is built covering ARMv6 to ARMv7, we omit to clear the IT state when entering a signal handler. This can cause the first few instructions to be conditionally executed depending on the parent context. In any case, the original test for >= ARMv7 is broken - ARMv6 can have Thumb-2 support as well, and an ARMv6T2 specific build would omit this code too. Relax the test back to ARMv6 or greater. This results in us always clearing the IT state bits in the PSR, even on CPUs where these bits are reserved. However, they're reserved for the IT state, so this should cause no harm. Fixes: d71e1352e240 ("Clear the IT state when invoking a Thumb-2 signal handler") Acked-by: Tony Lindgren <tony@atomide.com> Tested-by: H. Nikolaus Schaller <hns@goldelico.com> Tested-by: Grazvydas Ignotas <notasas@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13ARM: 7880/1: Clear the IT state independent of the Thumb-2 modeT.J. Purtell
commit 6ecf830e5029598732e04067e325d946097519cb upstream. The ARM architecture reference specifies that the IT state bits in the PSR must be all zeros in ARM mode or behavior is unspecified. On the Qualcomm Snapdragon S4/Krait architecture CPUs the processor continues to consider the IT state bits while in ARM mode. This makes it so that some instructions are skipped by the CPU. Signed-off-by: T.J. Purtell <tj@mobisocial.us> [rmk+kernel@arm.linux.org.uk: fixed whitespace formatting in patch] Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13powerpc/MSI: Fix race condition in tearing down MSI interruptsPaul Mackerras
commit e297c939b745e420ef0b9dc989cb87bda617b399 upstream. This fixes a race which can result in the same virtual IRQ number being assigned to two different MSI interrupts. The most visible consequence of that is usually a warning and stack trace from the sysfs code about an attempt to create a duplicate entry in sysfs. The race happens when one CPU (say CPU 0) is disposing of an MSI while another CPU (say CPU 1) is setting up an MSI. CPU 0 calls (for example) pnv_teardown_msi_irqs(), which calls msi_bitmap_free_hwirqs() to indicate that the MSI (i.e. its hardware IRQ number) is no longer in use. Then, before CPU 0 gets to calling irq_dispose_mapping() to free up the virtal IRQ number, CPU 1 comes in and calls msi_bitmap_alloc_hwirqs() to allocate an MSI, and gets the same hardware IRQ number that CPU 0 just freed. CPU 1 then calls irq_create_mapping() to get a virtual IRQ number, which sees that there is currently a mapping for that hardware IRQ number and returns the corresponding virtual IRQ number (which is the same virtual IRQ number that CPU 0 was using). CPU 0 then calls irq_dispose_mapping() and frees that virtual IRQ number. Now, if another CPU comes along and calls irq_create_mapping(), it is likely to get the virtual IRQ number that was just freed, resulting in the same virtual IRQ number apparently being used for two different hardware interrupts. To fix this race, we just move the call to msi_bitmap_free_hwirqs() to after the call to irq_dispose_mapping(). Since virq_to_hw() doesn't work for the virtual IRQ number after irq_dispose_mapping() has been called, we need to call it before irq_dispose_mapping() and remember the result for the msi_bitmap_free_hwirqs() call. The pattern of calling msi_bitmap_free_hwirqs() before irq_dispose_mapping() appears in 5 places under arch/powerpc, and appears to have originated in commit 05af7bd2d75e ("[POWERPC] MPIC U3/U4 MSI backend") from 2007. Fixes: 05af7bd2d75e ("[POWERPC] MPIC U3/U4 MSI backend") Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> [bwh: Backported to 3.2: - powernv uses a private functions instead of msi_bitmap_free_hwirqs() - Adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13ARM: 8429/1: disable GCC SRA optimizationArd Biesheuvel
commit a077224fd35b2f7fbc93f14cf67074fc792fbac2 upstream. While working on the 32-bit ARM port of UEFI, I noticed a strange corruption in the kernel log. The following snprintf() statement (in drivers/firmware/efi/efi.c:efi_md_typeattr_format()) snprintf(pos, size, "|%3s|%2s|%2s|%2s|%3s|%2s|%2s|%2s|%2s]", was producing the following output in the log: | | | | | |WB|WT|WC|UC] | | | | | |WB|WT|WC|UC] | | | | | |WB|WT|WC|UC] |RUN| | | | |WB|WT|WC|UC]* |RUN| | | | |WB|WT|WC|UC]* | | | | | |WB|WT|WC|UC] |RUN| | | | |WB|WT|WC|UC]* | | | | | |WB|WT|WC|UC] |RUN| | | | | | | |UC] |RUN| | | | | | | |UC] As it turns out, this is caused by incorrect code being emitted for the string() function in lib/vsprintf.c. The following code if (!(spec.flags & LEFT)) { while (len < spec.field_width--) { if (buf < end) *buf = ' '; ++buf; } } for (i = 0; i < len; ++i) { if (buf < end) *buf = *s; ++buf; ++s; } while (len < spec.field_width--) { if (buf < end) *buf = ' '; ++buf; } when called with len == 0, triggers an issue in the GCC SRA optimization pass (Scalar Replacement of Aggregates), which handles promotion of signed struct members incorrectly. This is a known but as yet unresolved issue. (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65932). In this particular case, it is causing the second while loop to be executed erroneously a single time, causing the additional space characters to be printed. So disable the optimization by passing -fno-ipa-sra. Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13crypto: ghash-clmulni: specify context size for ghash async algorithmAndrey Ryabinin
commit 71c6da846be478a61556717ef1ee1cea91f5d6a8 upstream. Currently context size (cra_ctxsize) doesn't specified for ghash_async_alg. Which means it's zero. Thus crypto_create_tfm() doesn't allocate needed space for ghash_async_ctx, so any read/write to ctx (e.g. in ghash_async_init_tfm()) is not valid. Signed-off-by: Andrey Ryabinin <aryabinin@odin.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13KVM: MMU: fix validation of mmio page faultXiao Guangrong
commit 6f691251c0350ac52a007c54bf3ef62e9d8cdc5e upstream. We got the bug that qemu complained with "KVM: unknown exit, hardware reason 31" and KVM shown these info: [84245.284948] EPT: Misconfiguration. [84245.285056] EPT: GPA: 0xfeda848 [84245.285154] ept_misconfig_inspect_spte: spte 0x5eaef50107 level 4 [84245.285344] ept_misconfig_inspect_spte: spte 0x5f5fadc107 level 3 [84245.285532] ept_misconfig_inspect_spte: spte 0x5141d18107 level 2 [84245.285723] ept_misconfig_inspect_spte: spte 0x52e40dad77 level 1 This is because we got a mmio #PF and the handler see the mmio spte becomes normal (points to the ram page) However, this is valid after introducing fast mmio spte invalidation which increases the generation-number instead of zapping mmio sptes, a example is as follows: 1. QEMU drops mmio region by adding a new memslot 2. invalidate all mmio sptes 3. VCPU 0 VCPU 1 access the invalid mmio spte access the region originally was MMIO before set the spte to the normal ram map mmio #PF check the spte and see it becomes normal ram mapping !!! This patch fixes the bug just by dropping the check in mmio handler, it's good for backport. Full check will be introduced in later patches Reported-by: Pavel Shirshov <ru.pchel@gmail.com> Tested-by: Pavel Shirshov <ru.pchel@gmail.com> Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.2: error code from handle_mmio_page_fault_common() was not named] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13sparc64: Fix userspace FPU register corruptions.David S. Miller
commit 44922150d87cef616fd183220d43d8fde4d41390 upstream. If we have a series of events from userpsace, with %fprs=FPRS_FEF, like follows: ETRAP ETRAP VIS_ENTRY(fprs=0x4) VIS_EXIT RTRAP (kernel FPU restore with fpu_saved=0x4) RTRAP We will not restore the user registers that were clobbered by the FPU using kernel code in the inner-most trap. Traps allocate FPU save slots in the thread struct, and FPU using sequences save the "dirty" FPU registers only. This works at the initial trap level because all of the registers get recorded into the top-level FPU save area, and we'll return to userspace with the FPU disabled so that any FPU use by the user will take an FPU disabled trap wherein we'll load the registers back up properly. But this is not how trap returns from kernel to kernel operate. The simplest fix for this bug is to always save all FPU register state for anything other than the top-most FPU save area. Getting rid of the optimized inner-slot FPU saving code ends up making VISEntryHalf degenerate into plain VISEntry. Longer term we need to do something smarter to reinstate the partial save optimizations. Perhaps the fundament error is having trap entry and exit allocate FPU save slots and restore register state. Instead, the VISEntry et al. calls should be doing that work. This bug is about two decades old. Reported-by: James Y Knight <jyknight@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: - Adjust context - Drop changes to NG4memcpy.S and ksyms.c] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13x86/ldt: Further fix FPU emulationAndy Lutomirski
commit 12e244f4b550498bbaf654a52f93633f7dde2dc7 upstream. The previous fix confused a selector with a segment prefix. Fix it. Compile-tested only. Cc: Juergen Gross <jgross@suse.com> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Fixes: 4809146b86c3 ("x86/ldt: Correct FPU emulation access to LDT") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13x86/ldt: Correct FPU emulation access to LDTJuergen Gross
commit 4809146b86c3d41ce588fdb767d021e2a80600dd upstream. Commit 37868fe113ff ("x86/ldt: Make modify_ldt synchronous") introduced a new struct ldt_struct anchored at mm->context.ldt. Adapt the x86 fpu emulation code to use that new structure. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: billm@melbpc.org.au Link: http://lkml.kernel.org/r/1438883674-1240-1-git-send-email-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13x86/ldt: Correct LDT access in single stepping logicJuergen Gross
commit 136d9d83c07c5e30ac49fc83b27e8c4842f108fc upstream. Commit 37868fe113ff ("x86/ldt: Make modify_ldt synchronous") introduced a new struct ldt_struct anchored at mm->context.ldt. convert_ip_to_linear() was changed to reflect this, but indexing into the ldt has to be changed as the pointer is no longer void *. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Link: http://lkml.kernel.org/r/1438848278-12906-1-git-send-email-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13x86/ldt: Make modify_ldt synchronousAndy Lutomirski
commit 37868fe113ff2ba814b3b4eb12df214df555f8dc upstream. modify_ldt() has questionable locking and does not synchronize threads. Improve it: redesign the locking and synchronize all threads' LDTs using an IPI on all modifications. This will dramatically slow down modify_ldt in multithreaded programs, but there shouldn't be any multithreaded programs that care about modify_ldt's performance in the first place. This fixes some fallout from the CVE-2015-5157 fixes. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: security@kernel.org <security@kernel.org> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/4c6978476782160600471bd865b318db34c7b628.1438291540.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> [bwh: Backported to 3.2: - Adjust context - Drop comment changes in switch_mm() - Drop changes to get_segment_base() in arch/x86/kernel/cpu/perf_event.c - Open-code lockless_dereference(), smp_store_release(), on_each_cpu_mask()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13MIPS: Make set_pte() SMP safe.David Daney
commit 46011e6ea39235e4aca656673c500eac81a07a17 upstream. On MIPS the GLOBAL bit of the PTE must have the same value in any aligned pair of PTEs. These pairs of PTEs are referred to as "buddies". In a SMP system is is possible for two CPUs to be calling set_pte() on adjacent PTEs at the same time. There is a race between setting the PTE and a different CPU setting the GLOBAL bit in its buddy PTE. This race can be observed when multiple CPUs are executing vmap()/vfree() at the same time. Make setting the buddy PTE's GLOBAL bit an atomic operation to close the race condition. The case of CONFIG_64BIT_PHYS_ADDR && CONFIG_CPU_MIPS32 is *not* handled. Signed-off-by: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10835/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-10-13MIPS: Fix sched_getaffinity with MT FPAFF enabledFelix Fietkau
commit 1d62d737555e1378eb62a8bba26644f7d97139d2 upstream. p->thread.user_cpus_allowed is zero-initialized and is only filled on the first sched_setaffinity call. To avoid adding overhead in the task initialization codepath, simply OR the returned mask in sched_getaffinity with p->cpus_allowed. Signed-off-by: Felix Fietkau <nbd@openwrt.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10740/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.2: also convert from obsolete cpumask API] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-12x86/xen: Probe target addresses in set_aliased_prot() before the hypercallAndy Lutomirski
commit aa1acff356bbedfd03b544051f5b371746735d89 upstream. The update_va_mapping hypercall can fail if the VA isn't present in the guest's page tables. Under certain loads, this can result in an OOPS when the target address is in unpopulated vmap space. While we're at it, add comments to help explain what's going on. This isn't a great long-term fix. This code should probably be changed to use something like set_memory_ro. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Vrabel <dvrabel@cantab.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: security@kernel.org <security@kernel.org> Cc: xen-devel <xen-devel@lists.xen.org> Link: http://lkml.kernel.org/r/0b0e55b995cda11e7829f140b833ef932fcabe3a.1438291540.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-12tile: use free_bootmem_late() for initrdChris Metcalf
commit 3f81d2447b37ac697b3c600039f2c6b628c06e21 upstream. We were previously using free_bootmem() and just getting lucky that nothing too bad happened. Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-12s390/process: fix sfpc inline assemblyHeiko Carstens
commit e47994dd44bcb4a77b4152bd0eada585934703c0 upstream. The sfpc inline assembly within execve_tail() may incorrectly set bits 28-31 of the sfpc instruction to a value which is not zero. These bits however are currently unused and therefore should be zero so we won't get surprised if these bits will be used in the future. Therefore remove the second operand from the inline assembly. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-12s390/sclp: clear upper register halves in _sclp_print_earlyMartin Schwidefsky
commit f9c87a6f46d508eae0d9ae640be98d50f237f827 upstream. If the kernel is compiled with gcc 5.1 and the XZ compression option the decompress_kernel function calls _sclp_print_early in 64-bit mode while the content of the upper register half of %r6 is non-zero. This causes a specification exception on the servc instruction in _sclp_servc. The _sclp_print_early function saves and restores the upper registers halves but it fails to clear them for the 31-bit code of the mini sclp driver. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-12KVM: x86: properly restore LVT0Radim Krčmář
commit db1385624c686fe99fe2d1b61a36e1537b915d08 upstream. Legacy NMI watchdog didn't work after migration/resume, because vapics_in_nmi_mode was left at 0. Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.2: - Adjust context - s/kvm_apic_get_reg/apic_get_reg/] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-12KVM: x86: make vapics_in_nmi_mode atomicRadim Krčmář
commit 42720138b06301cc8a7ee8a495a6d021c4b6a9bc upstream. Writes were a bit racy, but hard to turn into a bug at the same time. (Particularly because modern Linux doesn't use this feature anymore.) Signed-off-by: Radim Krčmář <rkrcmar@redhat.com> [Actually the next patch makes it much, much easier to trigger the race so I'm including this one for stable@ as well. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-07sparc32,leon: fix leon buildSam Ravnborg
commit d657784b70ef653350d7aa49da90a8484c29da7d upstream. Minimal fix to allow leon to be built. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Konrad Eisele <konrad@gaisler.com> Cc: Daniel Hellstrom <daniel@gaisler.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-07parisc: Provide __ucmpdi2 to resolve undefined references in 32 bit builds.John David Anglin
commit ca0ad83da17b6ba07f9eb5902e69daac90c4fa61 upstream. The Debian experimental linux source package (3.8.5-1) build fails with the following errors: ... MODPOST 2016 modules ERROR: "__ucmpdi2" [fs/btrfs/btrfs.ko] undefined! ERROR: "__ucmpdi2" [drivers/md/dm-verity.ko] undefined! The attached patch resolves this problem. It is based on the s390 implementation of ucmpdi2.c. Signed-off-by: John David Anglin <dave.anglin@bell.net> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-07MIPS: Octeon: Delete override of cpu_has_mips_r2_exec_hazard.Ralf Baechle
commit f05ff43355e6997c18f82ddcee370a6e5f8643ce upstream. This is no longer needed with the fixed, new and improved definition of cpu_has_mips_r2_exec_hazard in <asm/cpu-features.h>. For a discussion, see http://patchwork.linux-mips.org/patch/9539/. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-07MIPS: Fix cpu_has_mips_r2_exec_hazard.Ralf Baechle
commit 9cdf30bd3bac697fc533988f44a117434a858f69 upstream. Returns a non-zero value if the current processor implementation requires an IHB instruction to deal with an instruction hazard as per MIPS R2 architecture specification, zero otherwise. For a discussion, see http://patchwork.linux-mips.org/patch/9539/. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.2: trim the CPU type list] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-07MIPS: Octeon: Remove udelay() causing huge IRQ latencyAlexander Sverdlin
commit 73bf3c2a500b2db8ac966469591196bf55afb409 upstream. udelay() in PCI/PCIe read/write callbacks cause 30ms IRQ latency on Octeon platforms because these operations are called from PCI_OP_READ() and PCI_OP_WRITE() under raw_spin_lock_irqsave(). Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Cc: linux-mips@linux-mips.org Cc: David Daney <ddaney@cavium.com> Cc: Rob Herring <robh@kernel.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Masanari Iida <standby24x7@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Mathias <mathias.rulf@nokia.com> Patchwork: https://patchwork.linux-mips.org/patch/9576/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-07MIPS: Fix race condition in lazy cache flushing.Lars Persson
commit 4d46a67a3eb827ccf1125959936fd51ba318dabc upstream. The lazy cache flushing implemented in the MIPS kernel suffers from a race condition that is exposed by do_set_pte() in mm/memory.c. A pre-condition is a file-system that writes to the page from the CPU in its readpage method and then calls flush_dcache_page(). One example is ubifs. Another pre-condition is that the dcache flush is postponed in __flush_dcache_page(). Upon a page fault for an executable mapping not existing in the page-cache, the following will happen: 1. Write to the page 2. flush_dcache_page 3. flush_icache_page 4. set_pte_at 5. update_mmu_cache (commits the flush of a dcache-dirty page) Between steps 4 and 5 another thread can hit the same page and it will encounter a valid pte. Because the data still is in the L1 dcache the CPU will fetch stale data from L2 into the icache and execute garbage. This fix moves the commit of the cache flush to step 3 to close the race window. It also reduces the amount of flushes on non-executable mappings because we never enter __flush_dcache_page() for non-aliasing CPUs. Regressions can occur in drivers that mistakenly relies on the flush_dcache_page() in get_user_pages() for DMA operations. [ralf@linux-mips.org: Folded in patch 9346 to fix highmem issue.] Signed-off-by: Lars Persson <larper@axis.com> Cc: linux-mips@linux-mips.org Cc: paul.burton@imgtec.com Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9346/ Patchwork: https://patchwork.linux-mips.org/patch/9738/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-07powerpc+sparc64/mm: Remove hack in mmap randomize layoutDan McGee
commit fa8cbaaf5a68f62db3f9a8444ecbb940b47984cb upstream. Since commit 8a0a9bd4db63bc45e301, this comment in mmap_rnd() does not hold true as the value returned by get_random_int() will in fact be different every single call. Remove the comment and simplify the code back to its original desired form. This reverts commit a5adc91a4b44b5d1 which is no longer necessary and also fixes the sparc code that copied this same adjustment. Signed-off-by: Dan McGee <dpmcgee@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Moritz Mühlenhoff <jmm@inutil.org>
2015-08-07x86/reboot: Fix a warning message triggered by stop_other_cpus()Feng Tang
commit 55c844a4dd16a4d1fdc0cf2a283ec631a02ec448 upstream. When rebooting our 24 CPU Westmere servers with 3.4-rc6, we always see this warning msg: Restarting system. machine restart ------------[ cut here ]------------ WARNING: at arch/x86/kernel/smp.c:125 native_smp_send_reschedule+0x74/0xa7() Hardware name: X8DTN Modules linked in: igb [last unloaded: scsi_wait_scan] Pid: 1, comm: systemd-shutdow Not tainted 3.4.0-rc6+ #22 Call Trace: <IRQ> [<ffffffff8102a41f>] warn_slowpath_common+0x7e/0x96 [<ffffffff8102a44c>] warn_slowpath_null+0x15/0x17 [<ffffffff81018cf7>] native_smp_send_reschedule+0x74/0xa7 [<ffffffff810561c1>] trigger_load_balance+0x279/0x2a6 [<ffffffff81050112>] scheduler_tick+0xe0/0xe9 [<ffffffff81036768>] update_process_times+0x60/0x70 [<ffffffff81062f2f>] tick_sched_timer+0x68/0x92 [<ffffffff81046e33>] __run_hrtimer+0xb3/0x13c [<ffffffff81062ec7>] ? tick_nohz_handler+0xd0/0xd0 [<ffffffff810474f2>] hrtimer_interrupt+0xdb/0x198 [<ffffffff81019a35>] smp_apic_timer_interrupt+0x81/0x94 [<ffffffff81655187>] apic_timer_interrupt+0x67/0x70 <EOI> [<ffffffff8101a3c4>] ? default_send_IPI_mask_allbutself_phys+0xb4/0xc4 [<ffffffff8101c680>] physflat_send_IPI_allbutself+0x12/0x14 [<ffffffff81018db4>] native_nmi_stop_other_cpus+0x8a/0xd6 [<ffffffff810188ba>] native_machine_shutdown+0x50/0x67 [<ffffffff81018926>] machine_shutdown+0xa/0xc [<ffffffff8101897e>] native_machine_restart+0x20/0x32 [<ffffffff810189b0>] machine_restart+0xa/0xc [<ffffffff8103b196>] kernel_restart+0x47/0x4c [<ffffffff8103b2e6>] sys_reboot+0x13e/0x17c [<ffffffff8164e436>] ? _raw_spin_unlock_bh+0x10/0x12 [<ffffffff810fcac9>] ? bdi_queue_work+0xcf/0xd8 [<ffffffff810fe82f>] ? __bdi_start_writeback+0xae/0xb7 [<ffffffff810e0d64>] ? iterate_supers+0xa3/0xb7 [<ffffffff816547a2>] system_call_fastpath+0x16/0x1b ---[ end trace 320af5cb1cb60c5b ]--- The root cause seems to be the default_send_IPI_mask_allbutself_phys() takes quite some time (I measured it could be several ms) to complete sending NMIs to all the other 23 CPUs, and for HZ=250/1000 system, the time is long enough for a timer interrupt to happen, which will in turn trigger to kick load balance to a stopped CPU and cause this warning in native_smp_send_reschedule(). So disabling the local irq before stop_other_cpu() can fix this problem (tested 25 times reboot ok), and it is fine as there should be nobody caring the timer interrupt in such reboot stage. The latest 3.4 kernel slightly changes this behavior by sending REBOOT_VECTOR first and only send NMI_VECTOR if the REBOOT_VCTOR fails, and this patch is still needed to prevent the problem. Signed-off-by: Feng Tang <feng.tang@intel.com> Acked-by: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120530231541.4c13433a@feng-i7 Signed-off-by: Ingo Molnar <mingo@kernel.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Vinson Lee <vlee@twopensource.com>
2015-08-07config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selectedKonrad Rzeszutek Wilk
commit a6dfa128ce5c414ab46b1d690f7a1b8decb8526d upstream. A huge amount of NIC drivers use the DMA API, however if compiled under 32-bit an very important part of the DMA API can be ommitted leading to the drivers not working at all (especially if used with 'swiotlb=force iommu=soft'). As Prashant Sreedharan explains it: "the driver [tg3] uses DEFINE_DMA_UNMAP_ADDR(), dma_unmap_addr_set() to keep a copy of the dma "mapping" and dma_unmap_addr() to get the "mapping" value. On most of the platforms this is a no-op, but ... with "iommu=soft and swiotlb=force" this house keeping is required, ... otherwise we pass 0 while calling pci_unmap_/pci_dma_sync_ instead of the DMA address." As such enable this even when using 32-bit kernels. Reported-by: Ian Jackson <Ian.Jackson@eu.citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Prashant Sreedharan <prashant@broadcom.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Chan <mchan@broadcom.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: boris.ostrovsky@oracle.com Cc: cascardo@linux.vnet.ibm.com Cc: david.vrabel@citrix.com Cc: sanjeevb@broadcom.com Cc: siva.kallam@broadcom.com Cc: vyasevich@gmail.com Cc: xen-devel@lists.xensource.com Link: http://lkml.kernel.org/r/20150417190448.GA9462@l.oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org> [bwh: Backported to 3.2: also change the def_bool (cond) to def_bool y + depends] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-07powerpc: Don't skip ePAPR spin-table CPUsScott Wood
commit 6663a4fa6711050036562ddfd2086edf735fae21 upstream. Commit 59a53afe70fd530040bdc69581f03d880157f15a "powerpc: Don't setup CPUs with bad status" broke ePAPR SMP booting. ePAPR says that CPUs that aren't presently running shall have status of disabled, with enable-method being used to determine whether the CPU can be enabled. Fix by checking for spin-table, which is currently the only supported enable-method. Signed-off-by: Scott Wood <scottwood@freescale.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Emil Medve <Emilian.Medve@Freescale.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Jonathan Toppins <jtoppins@cumulusnetworks.com>
2015-08-07powerpc: Make logical to real cpu mapping code endian safeAnton Blanchard
commit ac13282dff13cd0f4da0f0ccb134bc29bfa10255 upstream. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [jt: fixed up context due to commit 59a53afe70fd530040bdc69581f03d880157f15a already being backported.] Signed-off-by: Jonathan Toppins <jtoppins@cumulusnetworks.com> Reviewed-by: Andy Gospodarek <gospo@cumulusnetworks.com> Acked-by: Curt Brune <curt@cumulusnetworks.com> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-07MIPS: Fix enabling of DEBUG_STACKOVERFLOWJames Hogan
commit 5f35b9cd553fd64415b563497d05a563c988dbd6 upstream. Commit 334c86c494b9 ("MIPS: IRQ: Add stackoverflow detection") added kernel stack overflow detection, however it only enabled it conditional upon the preprocessor definition DEBUG_STACKOVERFLOW, which is never actually defined. The Kconfig option is called DEBUG_STACKOVERFLOW, which manifests to the preprocessor as CONFIG_DEBUG_STACKOVERFLOW, so switch it to using that definition instead. Fixes: 334c86c494b9 ("MIPS: IRQ: Add stackoverflow detection") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Adam Jiang <jiang.adam@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/10531/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-07x86_64: Fix strnlen_user() to not touch memory after specified maximumBen Hutchings
Inspired by commit f18c34e483ff ("lib: Fix strnlen_user() to not touch memory after specified maximum") upstream. This version of strnlen_user(), no longer present upstream, has a similar off-by-one error. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Jan Kara <jack@suse.cz>
2015-08-07x86: bpf_jit: fix compilation of large bpf programsAlexei Starovoitov
commit 3f7352bf21f8fd7ba3e2fcef9488756f188e12be upstream. x86 has variable length encoding. x86 JIT compiler is trying to pick the shortest encoding for given bpf instruction. While doing so the jump targets are changing, so JIT is doing multiple passes over the program. Typical program needs 3 passes. Some very short programs converge with 2 passes. Large programs may need 4 or 5. But specially crafted bpf programs may hit the pass limit and if the program converges on the last iteration the JIT compiler will be producing an image full of 'int 3' insns. Fix this corner case by doing final iteration over bpf program. Fixes: 0a14842f5a3c ("net: filter: Just In Time compiler for x86-64") Reported-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Tested-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2015-08-07crypto: s390/ghash - Fix incorrect ghash icv buffer handling.Harald Freudenberger
commit a1cae34e23b1293eccbcc8ee9b39298039c3952a upstream. Multitheaded tests showed that the icv buffer in the current ghash implementation is not handled correctly. A move of this working ghash buffer value to the descriptor context fixed this. Code is tested and verified with an multithreaded application via af_alg interface. Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> Signed-off-by: Gerald Schaefer <geraldsc@linux.vnet.ibm.com> Reported-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>