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2015-10-28x86: Init per-cpu shadow copy of CR4 on 32-bit CPUs tooSteven Rostedt
[ Upstream commit 5b2bdbc84556774afbe11bcfd24c2f6411cfa92b ] Commit: 1e02ce4cccdc ("x86: Store a per-cpu shadow copy of CR4") added a shadow CR4 such that reads and writes that do not modify the CR4 execute much faster than always reading the register itself. The change modified cpu_init() in common.c, so that the shadow CR4 gets initialized before anything uses it. Unfortunately, there's two cpu_init()s in common.c. There's one for 64-bit and one for 32-bit. The commit only added the shadow init to the 64-bit path, but the 32-bit path needs the init too. Link: http://lkml.kernel.org/r/20150227125208.71c36402@gandalf.local.home Fixes: 1e02ce4cccdc "x86: Store a per-cpu shadow copy of CR4" Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Acked-by: Andy Lutomirski <luto@amacapital.net> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20150227145019.2bdd4354@gandalf.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/nmi/64: Fix a paravirt stack-clobbering bug in the NMI codeAndy Lutomirski
[ Upstream commit 83c133cf11fb0e68a51681447e372489f052d40e ] The NMI entry code that switches to the normal kernel stack needs to be very careful not to clobber any extra stack slots on the NMI stack. The code is fine under the assumption that SWAPGS is just a normal instruction, but that assumption isn't really true. Use SWAPGS_UNSAFE_STACK instead. This is part of a fix for some random crashes that Sasha saw. Fixes: 9b6e6a8334d5 ("x86/nmi/64: Switch stacks on userspace NMI entry") Reported-and-tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/974bc40edffdb5c2950a5c4977f821a446b76178.1442791737.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27ARM: OMAP2+: DRA7: clockdomain: change l4per2_7xx_clkdm to SW_WKUPVignesh R
[ Upstream commit b9e23f321940d2db2c9def8ff723b8464fb86343 ] Legacy IPs like PWMSS, present under l4per2_7xx_clkdm, cannot support smart-idle when its clock domain is in HW_AUTO on DRA7 SoCs. Hence, program clock domain to SW_WKUP. Signed-off-by: Vignesh R <vigneshr@ti.com> Acked-by: Tero Kristo <t-kristo@ti.com> Reviewed-by: Paul Walmsley <paul@pwsan.com> Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: <stable@vger.kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27xtensa: fix kernel register spillingMax Filippov
[ Upstream commit 77d6273e79e3a86552fcf10cdd31a69b46ed2ce6 ] call12 can't be safely used as the first call in the inline function, because the compiler does not extend the stack frame of the bounding function accordingly, which may result in corruption of local variables. If a call needs to be done, do call8 first followed by call12. For pure assembly code in _switch_to increase stack frame size of the bounding function. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27xtensa: fix threadptr reload on return to userspaceMax Filippov
[ Upstream commit 4229fb12a03e5da5882b420b0aa4a02e77447b86 ] Userspace return code may skip restoring THREADPTR register if there are no registers that need to be zeroed. This leads to spurious failures in libc NPTL tests. Always restore THREADPTR on return to userspace. Cc: stable@vger.kernel.org Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27KVM: MMU: fix validation of mmio page faultXiao Guangrong
[ Upstream commit 6f691251c0350ac52a007c54bf3ef62e9d8cdc5e ] 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> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27crypto: ghash-clmulni: specify context size for ghash async algorithmAndrey Ryabinin
[ Upstream commit 71c6da846be478a61556717ef1ee1cea91f5d6a8 ] 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. Cc: stable@vger.kernel.org Signed-off-by: Andrey Ryabinin <aryabinin@odin.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27m68k: Define asmlinkage_protectAndreas Schwab
[ Upstream commit 8474ba74193d302e8340dddd1e16c85cc4b98caf ] 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> Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27arm64: readahead: fault retry breaks mmap file read random detectionMark Salyzyn
[ Upstream commit 569ba74a7ba69f46ce2950bf085b37fea2408385 ] This is the arm64 portion of commit 45cac65b0fcd ("readahead: fault retry breaks mmap file read random detection"), which was absent from the initial port and has since gone unnoticed. The original commit says: > .fault now can retry. The retry can break state machine of .fault. In > filemap_fault, if page is miss, ra->mmap_miss is increased. In the second > try, since the page is in page cache now, ra->mmap_miss is decreased. And > these are done in one fault, so we can't detect random mmap file access. > > Add a new flag to indicate .fault is tried once. In the second try, skip > ra->mmap_miss decreasing. The filemap_fault state machine is ok with it. With this change, Mark reports that: > Random read improves by 250%, sequential read improves by 40%, and > random write by 400% to an eMMC device with dm crypto wrapped around it. Cc: Shaohua Li <shli@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Mark Salyzyn <salyzyn@android.com> Signed-off-by: Riley Andrews <riandrews@android.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27arm64: ftrace: fix function_graph tracer panicLi Bin
[ Upstream commit ee556d00cf20012e889344a0adbbf809ab5015a3 ] When function graph tracer is enabled, the following operation will trigger panic: mount -t debugfs nodev /sys/kernel echo next_tgid > /sys/kernel/tracing/set_ftrace_filter echo function_graph > /sys/kernel/tracing/current_tracer ls /proc/ ------------[ cut here ]------------ [ 198.501417] Unable to handle kernel paging request at virtual address cb88537fdc8ba316 [ 198.506126] pgd = ffffffc008f79000 [ 198.509363] [cb88537fdc8ba316] *pgd=00000000488c6003, *pud=00000000488c6003, *pmd=0000000000000000 [ 198.517726] Internal error: Oops: 94000005 [#1] SMP [ 198.518798] Modules linked in: [ 198.520582] CPU: 1 PID: 1388 Comm: ls Tainted: G [ 198.521800] Hardware name: linux,dummy-virt (DT) [ 198.522852] task: ffffffc0fa9e8000 ti: ffffffc0f9ab0000 task.ti: ffffffc0f9ab0000 [ 198.524306] PC is at next_tgid+0x30/0x100 [ 198.525205] LR is at return_to_handler+0x0/0x20 [ 198.526090] pc : [<ffffffc0002a1070>] lr : [<ffffffc0000907c0>] pstate: 60000145 [ 198.527392] sp : ffffffc0f9ab3d40 [ 198.528084] x29: ffffffc0f9ab3d40 x28: ffffffc0f9ab0000 [ 198.529406] x27: ffffffc000d6a000 x26: ffffffc000b786e8 [ 198.530659] x25: ffffffc0002a1900 x24: ffffffc0faf16c00 [ 198.531942] x23: ffffffc0f9ab3ea0 x22: 0000000000000002 [ 198.533202] x21: ffffffc000d85050 x20: 0000000000000002 [ 198.534446] x19: 0000000000000002 x18: 0000000000000000 [ 198.535719] x17: 000000000049fa08 x16: ffffffc000242efc [ 198.537030] x15: 0000007fa472b54c x14: ffffffffff000000 [ 198.538347] x13: ffffffc0fada84a0 x12: 0000000000000001 [ 198.539634] x11: ffffffc0f9ab3d70 x10: ffffffc0f9ab3d70 [ 198.540915] x9 : ffffffc0000907c0 x8 : ffffffc0f9ab3d40 [ 198.542215] x7 : 0000002e330f08f0 x6 : 0000000000000015 [ 198.543508] x5 : 0000000000000f08 x4 : ffffffc0f9835ec0 [ 198.544792] x3 : cb88537fdc8ba316 x2 : cb88537fdc8ba306 [ 198.546108] x1 : 0000000000000002 x0 : ffffffc000d85050 [ 198.547432] [ 198.547920] Process ls (pid: 1388, stack limit = 0xffffffc0f9ab0020) [ 198.549170] Stack: (0xffffffc0f9ab3d40 to 0xffffffc0f9ab4000) [ 198.582568] Call trace: [ 198.583313] [<ffffffc0002a1070>] next_tgid+0x30/0x100 [ 198.584359] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70 [ 198.585503] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70 [ 198.586574] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70 [ 198.587660] [<ffffffc0000907bc>] ftrace_graph_caller+0x6c/0x70 [ 198.588896] Code: aa0003f5 2a0103f4 b4000102 91004043 (885f7c60) [ 198.591092] ---[ end trace 6a346f8f20949ac8 ]--- This is because when using function graph tracer, if the traced function return value is in multi regs ([x0-x7]), return_to_handler may corrupt them. So in return_to_handler, the parameter regs should be protected properly. Cc: <stable@vger.kernel.org> # 3.18+ Signed-off-by: Li Bin <huawei.libin@huawei.com> Acked-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27powerpc/MSI: Fix race condition in tearing down MSI interruptsPaul Mackerras
[ Upstream commit e297c939b745e420ef0b9dc989cb87bda617b399 ] 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") Cc: stable@vger.kernel.org # v2.6.22+ Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27MIPS: dma-default: Fix 32-bit fall back to GFP_DMAJames Hogan
[ Upstream commit 53960059d56ecef67d4ddd546731623641a3d2d1 ] 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 Cc: <stable@vger.kernel.org> # 2.6.36+ Patchwork: https://patchwork.linux-mips.org/patch/9610/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27dts: imx25: fix sd card gpio polarity specified in device treeDong Aisheng
[ Upstream commit cf75eb15be2bdd054a76aeef6458beaa4a6ab770 ] cd-gpios polarity should be changed to GPIO_ACTIVE_LOW and wp-gpios should be changed to GPIO_ACTIVE_HIGH. Otherwise, the SD may not work properly due to wrong polarity inversion specified in DT after switch to common parsing function mmc_of_parse(). Signed-off-by: Dong Aisheng <aisheng.dong@freescale.com> Acked-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27dts: imx53: fix sd card gpio polarity specified in device treeDong Aisheng
[ Upstream commit 94d76946859b4bcfa0da373357f14feda2af0622 ] cd-gpios polarity should be changed to GPIO_ACTIVE_LOW and wp-gpios should be changed to GPIO_ACTIVE_HIGH. Otherwise, the SD may not work properly due to wrong polarity inversion specified in DT after switch to common parsing function mmc_of_parse(). Signed-off-by: Dong Aisheng <aisheng.dong@freescale.com> Acked-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27dts: imx51: fix sd card gpio polarity specified in device treeDong Aisheng
[ Upstream commit aca45c0e95dad1c4ba4d38da192756b0e10cbbbd ] cd-gpios polarity should be changed to GPIO_ACTIVE_LOW and wp-gpios should be changed to GPIO_ACTIVE_HIGH. Otherwise, the SD may not work properly due to wrong polarity inversion specified in DT after switch to common parsing function mmc_of_parse(). Signed-off-by: Dong Aisheng <aisheng.dong@freescale.com> Acked-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27s390/boot/decompression: disable floating point in decompressorChristian Borntraeger
[ Upstream commit adc0b7fbf6fe9967505c0254d9535ec7288186ae ] my gcc 5.1 used an ldgr instruction with a register != 0,2,4,6 for spilling/filling into a floating point register in our decompressor. This will cause an AFP-register data exception as the decompressor did not setup the additional floating point registers via cr0. That causes a program check loop that looked like a hang with one "Uncompressing Linux... " message (directly booted via kvm) or a loop of "Uncompressing Linux... " messages (when booted via zipl boot loader). The offending code in my build was 48e400: e3 c0 af ff ff 71 lay %r12,-1(%r10) -->48e406: b3 c1 00 1c ldgr %f1,%r12 48e40a: ec 6c 01 22 02 7f clij %r6,2,12,0x48e64e but gcc could do spilling into an fpr at any function. We can simply disable floating point support at that early stage. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27s390/compat: correct uc_sigmask of the compat signal frameMartin Schwidefsky
[ Upstream commit 8d4bd0ed0439dfc780aab801a085961925ed6838 ] 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. Cc: <stable@vger.kernel.org> Reported-by: Stefan Liebler <stli@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/xen: Support kexec/kdump in HVM guests by doing a soft resetVitaly Kuznetsov
[ Upstream commit 0b34a166f291d255755be46e43ed5497cdd194f2 ] Currently there is a number of issues preventing PVHVM Xen guests from doing successful kexec/kdump: - Bound event channels. - Registered vcpu_info. - PIRQ/emuirq mappings. - shared_info frame after XENMAPSPACE_shared_info operation. - Active grant mappings. Basically, newly booted kernel stumbles upon already set up Xen interfaces and there is no way to reestablish them. In Xen-4.7 a new feature called 'soft reset' is coming. A guest performing kexec/kdump operation is supposed to call SCHEDOP_shutdown hypercall with SHUTDOWN_soft_reset reason before jumping to new kernel. Hypervisor (with some help from toolstack) will do full domain cleanup (but keeping its memory and vCPU contexts intact) returning the guest to the state it had when it was first booted and thus allowing it to start over. Doing SHUTDOWN_soft_reset on Xen hypervisors which don't support it is probably OK as by default all unknown shutdown reasons cause domain destroy with a message in toolstack log: 'Unknown shutdown reason code 5. Destroying domain.' which gives a clue to what the problem is and eliminates false expectations. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/mm: Set NX on gap between __ex_table and rodataStephen Smalley
[ Upstream commit ab76f7b4ab2397ffdd2f1eb07c55697d19991d10 ] Unused space between the end of __ex_table and the start of rodata can be left W+x in the kernel page tables. Extend the setting of the NX bit to cover this gap by starting from text_end rather than rodata_start. Before: ---[ High Kernel Mapping ]--- 0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd 0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte 0xffffffff81754000-0xffffffff81800000 688K RW GLB x pte 0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd 0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte 0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte 0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd 0xffffffff82200000-0xffffffffa0000000 478M pmd After: ---[ High Kernel Mapping ]--- 0xffffffff80000000-0xffffffff81000000 16M pmd 0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd 0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte 0xffffffff81754000-0xffffffff81800000 688K RW GLB NX pte 0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd 0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte 0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte 0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd 0xffffffff82200000-0xffffffffa0000000 478M pmd Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443704662-3138-1-git-send-email-sds@tycho.nsa.gov Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/process: Add proper bound checks in 64bit get_wchan()Thomas Gleixner
[ Upstream commit eddd3826a1a0190e5235703d1e666affa4d13b96 ] 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> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20150930083302.694788319@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/asm/entry: Create and use a 'TOP_OF_KERNEL_STACK_PADDING' macroAndy Lutomirski
[ Upstream commit 3ee4298f440c81638cbb5ec06f2497fb7a9a9eb4 ] x86_32, unlike x86_64, pads the top of the kernel stack, because the hardware stack frame formats are variable in size. Document this padding and give it a name. This should make no change whatsoever to the compiled kernel image. It also doesn't fix any of the current bugs in this area. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/02bf2f54b8dcb76a62a142b6dfe07d4ef7fc582e.1426009661.git.luto@amacapital.net [ Fixed small details, such as a missed magic constant in entry_32.S pointed out by Denys Vlasenko. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/kexec: Fix kexec crash in syscall kexec_file_load()Lee, Chun-Yi
[ Upstream commit e3c41e37b0f4b18cbd4dac76cbeece5a7558b909 ] The original bug is a page fault crash that sometimes happens on big machines when preparing ELF headers: BUG: unable to handle kernel paging request at ffffc90613fc9000 IP: [<ffffffff8103d645>] prepare_elf64_ram_headers_callback+0x165/0x260 The bug is caused by us under-counting the number of memory ranges and subsequently not allocating enough ELF header space for them. The bug is typically masked on smaller systems, because the ELF header allocation is rounded up to the next page. This patch modifies the code in fill_up_crash_elf_data() by using walk_system_ram_res() instead of walk_system_ram_range() to correctly count the max number of crash memory ranges. That's because the walk_system_ram_range() filters out small memory regions that reside in the same page, but walk_system_ram_res() does not. Here's how I found the bug: After tracing prepare_elf64_headers() and prepare_elf64_ram_headers_callback(), the code uses walk_system_ram_res() to fill-in crash memory regions information to the program header, so it counts those small memory regions that reside in a page area. But, when the kernel was using walk_system_ram_range() in fill_up_crash_elf_data() to count the number of crash memory regions, it filters out small regions. I printed those small memory regions, for example: kexec: Get nr_ram ranges. vaddr=0xffff880077592258 paddr=0x77592258, sz=0xdc0 Based on the code in walk_system_ram_range(), this memory region will be filtered out: pfn = (0x77592258 + 0x1000 - 1) >> 12 = 0x77593 end_pfn = (0x77592258 + 0xfc0 -1 + 1) >> 12 = 0x77593 end_pfn - pfn = 0x77593 - 0x77593 = 0 <=== if (end_pfn > pfn) is FALSE So, the max_nr_ranges that's counted by the kernel doesn't include small memory regions - causing us to under-allocate the required space. That causes the page fault crash that happens in a later code path when preparing ELF headers. This bug is not easy to reproduce on small machines that have few CPUs, because the allocated page aligned ELF buffer has more free space to cover those small memory regions' PT_LOAD headers. Signed-off-by: Lee, Chun-Yi <jlee@suse.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Takashi Iwai <tiwai@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/1443531537-29436-1-git-send-email-jlee@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, ↵Matt Fleming
instead of top-down [ Upstream commit a5caa209ba9c29c6421292e7879d2387a2ef39c9 ] Beginning with UEFI v2.5 EFI_PROPERTIES_TABLE was introduced that signals that the firmware PE/COFF loader supports splitting code and data sections of PE/COFF images into separate EFI memory map entries. This allows the kernel to map those regions with strict memory protections, e.g. EFI_MEMORY_RO for code, EFI_MEMORY_XP for data, etc. Unfortunately, an unwritten requirement of this new feature is that the regions need to be mapped with the same offsets relative to each other as observed in the EFI memory map. If this is not done crashes like this may occur, BUG: unable to handle kernel paging request at fffffffefe6086dd IP: [<fffffffefe6086dd>] 0xfffffffefe6086dd Call Trace: [<ffffffff8104c90e>] efi_call+0x7e/0x100 [<ffffffff81602091>] ? virt_efi_set_variable+0x61/0x90 [<ffffffff8104c583>] efi_delete_dummy_variable+0x63/0x70 [<ffffffff81f4e4aa>] efi_enter_virtual_mode+0x383/0x392 [<ffffffff81f37e1b>] start_kernel+0x38a/0x417 [<ffffffff81f37495>] x86_64_start_reservations+0x2a/0x2c [<ffffffff81f37582>] x86_64_start_kernel+0xeb/0xef Here 0xfffffffefe6086dd refers to an address the firmware expects to be mapped but which the OS never claimed was mapped. The issue is that included in these regions are relative addresses to other regions which were emitted by the firmware toolchain before the "splitting" of sections occurred at runtime. Needless to say, we don't satisfy this unwritten requirement on x86_64 and instead map the EFI memory map entries in reverse order. The above crash is almost certainly triggerable with any kernel newer than v3.13 because that's when we rewrote the EFI runtime region mapping code, in commit d2f7cbe7b26a ("x86/efi: Runtime services virtual mapping"). For kernel versions before v3.13 things may work by pure luck depending on the fragmentation of the kernel virtual address space at the time we map the EFI regions. Instead of mapping the EFI memory map entries in reverse order, where entry N has a higher virtual address than entry N+1, map them in the same order as they appear in the EFI memory map to preserve this relative offset between regions. This patch has been kept as small as possible with the intention that it should be applied aggressively to stable and distribution kernels. It is very much a bugfix rather than support for a new feature, since when EFI_PROPERTIES_TABLE is enabled we must map things as outlined above to even boot - we have no way of asking the firmware not to split the code/data regions. In fact, this patch doesn't even make use of the more strict memory protections available in UEFI v2.5. That will come later. Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Cc: <stable@vger.kernel.org> Cc: Borislav Petkov <bp@suse.de> Cc: Chun-Yi <jlee@suse.com> Cc: Dave Young <dyoung@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: James Bottomley <JBottomley@Odin.com> Cc: Lee, Chun-Yi <jlee@suse.com> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/1443218539-7610-2-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27Use WARN_ON_ONCE for missing X86_FEATURE_NRIPSDirk Müller
[ Upstream commit d2922422c48df93f3edff7d872ee4f3191fefb08 ] The cpu feature flags are not ever going to change, so warning everytime can cause a lot of kernel log spam (in our case more than 10GB/hour). The warning seems to only occur when nested virtualization is enabled, so it's probably triggered by a KVM bug. This is a sensible and safe change anyway, and the KVM bug fix might not be suitable for stable releases anyway. Cc: stable@vger.kernel.org Signed-off-by: Dirk Mueller <dmueller@suse.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/paravirt: Replace the paravirt nop with a bona fide empty functionAndy Lutomirski
[ Upstream commit fc57a7c68020dcf954428869eafd934c0ab1536f ] 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> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/8f5d2ba295f9d73751c33d97fda03e0495d9ade0.1442791737.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/platform: Fix Geode LX timekeeping in the generic x86 buildDavid Woodhouse
[ Upstream commit 03da3ff1cfcd7774c8780d2547ba0d995f7dc03d ] 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> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1442409003.131189.87.camel@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/apic: Serialize LVTT and TSC_DEADLINE writesShaohua Li
[ Upstream commit 5d7c631d926b59aa16f3c56eaeb83f1036c81dc7 ] The APIC LVTT register is MMIO mapped but the TSC_DEADLINE register is an MSR. The write to the TSC_DEADLINE MSR is not serializing, so it's not guaranteed that the write to LVTT has reached the APIC before the TSC_DEADLINE MSR is written. In such a case the write to the MSR is ignored and as a consequence the local timer interrupt never fires. The SDM decribes this issue for xAPIC and x2APIC modes. The serialization methods recommended by the SDM differ. xAPIC: "1. Memory-mapped write to LVT Timer Register, setting bits 18:17 to 10b. 2. WRMSR to the IA32_TSC_DEADLINE MSR a value much larger than current time-stamp counter. 3. If RDMSR of the IA32_TSC_DEADLINE MSR returns zero, go to step 2. 4. WRMSR to the IA32_TSC_DEADLINE MSR the desired deadline." x2APIC: "To allow for efficient access to the APIC registers in x2APIC mode, the serializing semantics of WRMSR are relaxed when writing to the APIC registers. Thus, system software should not use 'WRMSR to APIC registers in x2APIC mode' as a serializing instruction. Read and write accesses to the APIC registers will occur in program order. A WRMSR to an APIC register may complete before all preceding stores are globally visible; software can prevent this by inserting a serializing instruction, an SFENCE, or an MFENCE before the WRMSR." The xAPIC method is to just wait for the memory mapped write to hit the LVTT by checking whether the MSR write has reached the hardware. There is no reason why a proper MFENCE after the memory mapped write would not do the same. Andi Kleen confirmed that MFENCE is sufficient for the xAPIC case as well. Issue MFENCE before writing to the TSC_DEADLINE MSR. This can be done unconditionally as all CPUs which have TSC_DEADLINE also have MFENCE support. [ tglx: Massaged the changelog ] Signed-off-by: Shaohua Li <shli@fb.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: <Kernel-team@fb.com> Cc: <lenb@kernel.org> Cc: <fenghua.yu@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: stable@vger.kernel.org #v3.7+ Link: http://lkml.kernel.org/r/20150909041352.GA2059853@devbig257.prn2.facebook.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27ARM: dts: fix usb pin control for imx-rex dtsFelipe F. Tonello
[ Upstream commit 0af822110871400908d5b6f83a8908c45f881d8f ] This fixes a duplicated pin control causing this error: imx6q-pinctrl 20e0000.iomuxc: pin MX6Q_PAD_GPIO_1 already requested by regulators:regulator@2; cannot claim for 2184000.usb imx6q-pinctrl 20e0000.iomuxc: pin-137 (2184000.usb) status -22 imx6q-pinctrl 20e0000.iomuxc: could not request pin 137 (MX6Q_PAD_GPIO_1) from group usbotggrp on device 20e0000.iomuxc imx_usb 2184000.usb: Error applying setting, reverse things back imx6q-pinctrl 20e0000.iomuxc: pin MX6Q_PAD_EIM_D31 already requested by regulators:regulator@1; cannot claim for 2184200.usb imx6q-pinctrl 20e0000.iomuxc: pin-52 (2184200.usb) status -22 imx6q-pinctrl 20e0000.iomuxc: could not request pin 52 (MX6Q_PAD_EIM_D31) from group usbh1grp on device 20e0000.iomuxc imx_usb 2184200.usb: Error applying setting, reverse things back Signed-off-by: Felipe F. Tonello <eu@felipetonello.com> Fixes: e2047e33f2bd ("ARM: dts: add initial Rex Pro board support") Cc: <stable@vger.kernel.org> Signed-off-by: Shawn Guo <shawnguo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27ARM: dts: omap3-beagle: make i2c3, ddc and tfp410 gpio work againCarl Frederik Werner
[ Upstream commit 3a2fa775bd1d0579113666c1a2e37654a34018a0 ] Let's fix pinmux address of gpio 170 used by tfp410 powerdown-gpio. According to the OMAP35x Technical Reference Manual CONTROL_PADCONF_I2C3_SDA[15:0] 0x480021C4 mode0: i2c3_sda CONTROL_PADCONF_I2C3_SDA[31:16] 0x480021C4 mode4: gpio_170 the pinmux address of gpio 170 must be 0x480021C6. The former wrong address broke i2c3 (used by hdmi ddc), resulting in kernel message: omap_i2c 48060000.i2c: controller timed out Fixes: 8cecf52befd7 ("ARM: omap3-beagle.dts: add display information") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Carl Frederik Werner <frederik@cfbw.eu> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27ARM: dts: omap5-uevm.dts: fix i2c5 pinctrl offsetsGrazvydas Ignotas
[ Upstream commit 1dbdad75074d16c3e3005180f81a01cdc04a7872 ] The i2c5 pinctrl offsets are wrong. If the bootloader doesn't set the pins up, communication with tca6424a doesn't work (controller timeouts) and it is not possible to enable HDMI. Fixes: 9be495c42609 ("ARM: dts: omap5-evm: Add I2c pinctrl data") Signed-off-by: Grazvydas Ignotas <notasas@gmail.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27ARM: 8429/1: disable GCC SRA optimizationArd Biesheuvel
[ Upstream commit a077224fd35b2f7fbc93f14cf67074fc792fbac2 ] 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. Cc: <stable@vger.kernel.org> 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: Sasha Levin <sasha.levin@oracle.com>
2015-10-27ARM: fix Thumb2 signal handling when ARMv6 is enabledRussell King
[ Upstream commit 9b55613f42e8d40d5c9ccb8970bde6af4764b2ab ] 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. Cc: <stable@vger.kernel.org> 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: Sasha Levin <sasha.levin@oracle.com>
2015-10-27arm: KVM: Fix incorrect device to IPA mappingMarek Majtyka
[ Upstream commit ca09f02f122b2ecb0f5ddfc5fd47b29ed657d4fd ] A critical bug has been found in device memory stage1 translation for VMs with more then 4GB of address space. Once vm_pgoff size is smaller then pa (which is true for LPAE case, u32 and u64 respectively) some more significant bits of pa may be lost as a shift operation is performed on u32 and later cast onto u64. Example: vm_pgoff(u32)=0x00210030, PAGE_SHIFT=12 expected pa(u64): 0x0000002010030000 produced pa(u64): 0x0000000010030000 The fix is to change the order of operations (casting first onto phys_addr_t and then shifting). Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> [maz: fixed changelog and patch formatting] Cc: stable@vger.kernel.org Signed-off-by: Marek Majtyka <marek.majtyka@tieto.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/nmi/64: Use DF to avoid userspace RSP confusing nested NMI detectionAndy Lutomirski
[ Upstream commit 810bc075f78ff2c221536eb3008eac6a492dba2d ] We have a tricky bug in the nested NMI code: if we see RSP pointing to the NMI stack on NMI entry from kernel mode, we assume that we are executing a nested NMI. This isn't quite true. A malicious userspace program can point RSP at the NMI stack, issue SYSCALL, and arrange for an NMI to happen while RSP is still pointing at the NMI stack. Fix it with a sneaky trick. Set DF in the region of code that the RSP check is intended to detect. IRET will clear DF atomically. ( Note: other than paravirt, there's little need for all this complexity. We could check RIP instead of RSP. ) Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/nmi/64: Reorder nested NMI checksAndy Lutomirski
[ Upstream commit a27507ca2d796cfa8d907de31ad730359c8a6d06 ] Check the repeat_nmi .. end_repeat_nmi special case first. The next patch will rework the RSP check and, as a side effect, the RSP check will no longer detect repeat_nmi .. end_repeat_nmi, so we'll need this ordering of the checks. Note: this is more subtle than it appears. The check for repeat_nmi .. end_repeat_nmi jumps straight out of the NMI code instead of adjusting the "iret" frame to force a repeat. This is necessary, because the code between repeat_nmi and end_repeat_nmi sets "NMI executing" and then writes to the "iret" frame itself. If a nested NMI comes in and modifies the "iret" frame while repeat_nmi is also modifying it, we'll end up with garbage. The old code got this right, as does the new code, but the new code is a bit more explicit. If we were to move the check right after the "NMI executing" check, then we'd get it wrong and have random crashes. ( Because the "NMI executing" check would jump to the code that would modify the "iret" frame without checking if the interrupted NMI was currently modifying it. ) Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-27x86/nmi/64: Improve nested NMI commentsAndy Lutomirski
[ Upstream commit 0b22930ebad563ae97ff3f8d7b9f12060b4c6e6b ] I found the nested NMI documentation to be difficult to follow. Improve the comments. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07parisc: Filter out spurious interrupts in PA-RISC irq handlerHelge Deller
[ Upstream commit b1b4e435e4ef7de77f07bf2a42c8380b960c2d44 ] 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 Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07parisc: Use double word condition in 64bit CAS operationJohn David Anglin
[ Upstream commit 1b59ddfcf1678de38a1f8ca9fb8ea5eebeff1843 ] The attached change fixes the condition used in the "sub" instruction. A double word comparison is needed. This fixes the 64-bit LWS CAS operation on 64-bit kernels. I can now enable 64-bit atomic support in GCC. Cc: <stable@vger.kernel.org> Signed-off-by: John David Anglin <dave.anglin> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07x86/mm: Initialize pmd_idx in page_table_range_init_count()Minfei Huang
[ Upstream commit 9962eea9e55f797f05f20ba6448929cab2a9f018 ] The variable pmd_idx is not initialized for the first iteration of the for loop. Assign the proper value which indexes the start address. Fixes: 719272c45b82 'x86, mm: only call early_ioremap_page_table_range_init() once' Signed-off-by: Minfei Huang <mnfhuang@gmail.com> Cc: tony.luck@intel.com Cc: wangnan0@huawei.com Cc: david.vrabel@citrix.com Reviewed-by: yinghai@kernel.org Link: http://lkml.kernel.org/r/1436703522-29552-1-git-send-email-mhuang@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07powerpc/mm: Recompute hash value after a failed updateAneesh Kumar K.V
[ Upstream commit 36b35d5d807b7e57aff7d08e63de8b17731ee211 ] If we had secondary hash flag set, we ended up modifying hash value in the updatepp code path. Hence with a failed updatepp we will be using a wrong hash value for the following hash insert. Fix this by recomputing hash before insert. Without this patch we can end up with using wrong slot number in linux pte. That can result in us missing an hash pte update or invalidate which can cause memory corruption or even machine check. Fixes: 6d492ecc6489 ("powerpc/THP: Add code to handle HPTE faults for hugepages") Cc: stable@vger.kernel.org # v3.11+ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07powerpc/rtas: Introduce rtas_get_sensor_fast() for IRQ handlersThomas Huth
[ Upstream commit 1c2cb594441d02815d304cccec9742ff5c707495 ] The EPOW interrupt handler uses rtas_get_sensor(), which in turn uses rtas_busy_delay() to wait for RTAS becoming ready in case it is necessary. But rtas_busy_delay() is annotated with might_sleep() and thus may not be used by interrupts handlers like the EPOW handler! This leads to the following BUG when CONFIG_DEBUG_ATOMIC_SLEEP is enabled: BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:496 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.2.0-rc2-thuth #6 Call Trace: [c00000007ffe7b90] [c000000000807670] dump_stack+0xa0/0xdc (unreliable) [c00000007ffe7bc0] [c0000000000e1f14] ___might_sleep+0x134/0x180 [c00000007ffe7c20] [c00000000002aec0] rtas_busy_delay+0x30/0xd0 [c00000007ffe7c50] [c00000000002bde4] rtas_get_sensor+0x74/0xe0 [c00000007ffe7ce0] [c000000000083264] ras_epow_interrupt+0x44/0x450 [c00000007ffe7d90] [c000000000120260] handle_irq_event_percpu+0xa0/0x300 [c00000007ffe7e70] [c000000000120524] handle_irq_event+0x64/0xc0 [c00000007ffe7eb0] [c000000000124dbc] handle_fasteoi_irq+0xec/0x260 [c00000007ffe7ef0] [c00000000011f4f0] generic_handle_irq+0x50/0x80 [c00000007ffe7f20] [c000000000010f3c] __do_irq+0x8c/0x200 [c00000007ffe7f90] [c0000000000236cc] call_do_irq+0x14/0x24 [c00000007e6f39e0] [c000000000011144] do_IRQ+0x94/0x110 [c00000007e6f3a30] [c000000000002594] hardware_interrupt_common+0x114/0x180 Fix this issue by introducing a new rtas_get_sensor_fast() function that does not use rtas_busy_delay() - and thus can only be used for sensors that do not cause a BUSY condition - known as "fast" sensors. The EPOW sensor is defined to be "fast" in sPAPR - mpe. Fixes: 587f83e8dd50 ("powerpc/pseries: Use rtas_get_sensor in RAS code") Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07powerpc/mm: Fix pte_pagesize_index() crash on 4K w/64K hashMichael Ellerman
[ Upstream commit 74b5037baa2011a2799e2c43adde7d171b072f9e ] The powerpc kernel can be built to have either a 4K PAGE_SIZE or a 64K PAGE_SIZE. However when built with a 4K PAGE_SIZE there is an additional config option which can be enabled, PPC_HAS_HASH_64K, which means the kernel also knows how to hash a 64K page even though the base PAGE_SIZE is 4K. This is used in one obscure configuration, to support 64K pages for SPU local store on the Cell processor when the rest of the kernel is using 4K pages. In this configuration, pte_pagesize_index() is defined to just pass through its arguments to get_slice_psize(). However pte_pagesize_index() is called for both user and kernel addresses, whereas get_slice_psize() only knows how to handle user addresses. This has been broken forever, however until recently it happened to work. That was because in get_slice_psize() the large kernel address would cause the right shift of the slice mask to return zero. However in commit 7aa0727f3302 ("powerpc/mm: Increase the slice range to 64TB"), the get_slice_psize() code was changed so that instead of a right shift we do an array lookup based on the address. When passed a kernel address this means we index way off the end of the slice array and return random junk. That is only fatal if we happen to hit something non-zero, but when we do return a non-zero value we confuse the MMU code and eventually cause a check stop. This fix is ugly, but simple. When we're called for a kernel address we return 4K, which is always correct in this configuration, otherwise we use the slice mask. Fixes: 7aa0727f3302 ("powerpc/mm: Increase the slice range to 64TB") Reported-by: Cyril Bur <cyrilbur@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07arm64: KVM: Disable virtual timer even if the guest is not using itMarc Zyngier
[ Upstream commit c4cbba9fa078f55d9f6d081dbb4aec7cf969e7c7 ] When running a guest with the architected timer disabled (with QEMU and the kernel_irqchip=off option, for example), it is important to make sure the timer gets turned off. Otherwise, the guest may try to enable it anyway, leading to a screaming HW interrupt. The fix is to unconditionally turn off the virtual timer on guest exit. Cc: stable@vger.kernel.org Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07arm64: errata: add module build workaround for erratum #843419Will Deacon
[ Upstream commit df057cc7b4fa59e9b55f07ffdb6c62bf02e99a00 ] Cortex-A53 processors <= r0p4 are affected by erratum #843419 which can lead to a memory access using an incorrect address in certain sequences headed by an ADRP instruction. There is a linker fix to generate veneers for ADRP instructions, but this doesn't work for kernel modules which are built as unlinked ELF objects. This patch adds a new config option for the erratum which, when enabled, builds kernel modules with the mcmodel=large flag. This uses absolute addressing for all kernel symbols, thereby removing the use of ADRP as a PC-relative form of addressing. The ADRP relocs are removed from the module loader so that we fail to load any potentially affected modules. Cc: <stable@vger.kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07arm64: head.S: initialise mdcr_el2 in el2_setupWill Deacon
[ Upstream commit d10bcd473301888f957ec4b6b12aa3621be78d59 ] When entering the kernel at EL2, we fail to initialise the MDCR_EL2 register which controls debug access and PMU capabilities at EL1. This patch ensures that the register is initialised so that all traps are disabled and all the PMU counters are available to the host. When a guest is scheduled, KVM takes care to configure trapping appropriately. Cc: <stable@vger.kernel.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07arm64: compat: fix vfp save/restore across signal handlers in big-endianWill Deacon
[ Upstream commit bdec97a855ef1e239f130f7a11584721c9a1bf04 ] When saving/restoring the VFP registers from a compat (AArch32) signal frame, we rely on the compat registers forming a prefix of the native register file and therefore make use of copy_{to,from}_user to transfer between the native fpsimd_state and the compat_vfp_sigframe. Unfortunately, this doesn't work so well in a big-endian environment. Our fpsimd save/restore code operates directly on 128-bit quantities (Q registers) whereas the compat_vfp_sigframe represents the registers as an array of 64-bit (D) registers. The architecture packs the compat D registers into the Q registers, with the least significant bytes holding the lower register. Consequently, we need to swap the 64-bit halves when converting between these two representations on a big-endian machine. This patch replaces the __copy_{to,from}_user invocations in our compat VFP signal handling code with explicit __put_user loops that operate on 64-bit values and swap them accordingly. Cc: <stable@vger.kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-10-07arm64: kconfig: Move LIST_POISON to a safe valueJeff Vander Stoep
[ Upstream commit bf0c4e04732479f650ff59d1ee82de761c0071f0 ] Move the poison pointer offset to 0xdead000000000000, a recognized value that is not mappable by user-space exploits. Cc: <stable@vger.kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Thierry Strudel <tstrudel@google.com> Signed-off-by: Jeff Vander Stoep <jeffv@google.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-09-27x86/ldt: Correct LDT access in single stepping logicJuergen Gross
[ Upstream commit 136d9d83c07c5e30ac49fc83b27e8c4842f108fc ] 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: <stable@vger.kernel.org> # On top of: 37868fe113ff: x86/ldt: Make modify_ldt synchronous 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: Sasha Levin <sasha.levin@oracle.com>
2015-09-27x86/ldt: Make modify_ldt synchronousAndy Lutomirski
[ Upstream commit 37868fe113ff2ba814b3b4eb12df214df555f8dc ] 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: <stable@vger.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> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
2015-09-27x86/nmi/64: Switch stacks on userspace NMI entryAndy Lutomirski
[ Upstream commit 9b6e6a8334d56354853f9c255d1395c2ba570e0a ] 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> Cc: stable@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>