kernel/git/stable/linux.git/arch/powerpc/include, branch linux-4.13.y

Revert "powerpc64/elfv1: Only dereference function descriptor for non-text symbols"

2017-11-08T09:17:18+00:00

commit 63be1a81e40733ecd175713b6a7558dc43f00851 upstream. This reverts commit 83e840c770f2c5 ("powerpc64/elfv1: Only dereference function descriptor for non-text symbols"). Chandan reported that on newer kernels, trying to enable function_graph tracer on ppc64 (BE) locks up the system with the following trace: Unable to handle kernel paging request for data at address 0x600000002fa30010 Faulting instruction address: 0xc0000000001f1300 Thread overran stack, or stack corrupted Oops: Kernel access of bad area, sig: 11 [#1] BE SMP NR_CPUS=2048 DEBUG_PAGEALLOC NUMA pSeries Modules linked in: CPU: 1 PID: 6586 Comm: bash Not tainted 4.14.0-rc3-00162-g6e51f1f-dirty #20 task: c000000625c07200 task.stack: c000000625c07310 NIP: c0000000001f1300 LR: c000000000121cac CTR: c000000000061af8 REGS: c000000625c088c0 TRAP: 0380 Not tainted (4.14.0-rc3-00162-g6e51f1f-dirty) MSR: 8000000000001032 CR: 28002848 XER: 00000000 CFAR: c0000000001f1320 SOFTE: 0 ... NIP [c0000000001f1300] .__is_insn_slot_addr+0x30/0x90 LR [c000000000121cac] .kernel_text_address+0x18c/0x1c0 Call Trace: [c000000625c08b40] [c0000000001bd040] .is_module_text_address+0x20/0x40 (unreliable) [c000000625c08bc0] [c000000000121cac] .kernel_text_address+0x18c/0x1c0 [c000000625c08c50] [c000000000061960] .prepare_ftrace_return+0x50/0x130 [c000000625c08cf0] [c000000000061b10] .ftrace_graph_caller+0x14/0x34 [c000000625c08d60] [c000000000121b40] .kernel_text_address+0x20/0x1c0 [c000000625c08df0] [c000000000061960] .prepare_ftrace_return+0x50/0x130 ... [c000000625c0ab30] [c000000000061960] .prepare_ftrace_return+0x50/0x130 [c000000625c0abd0] [c000000000061b10] .ftrace_graph_caller+0x14/0x34 [c000000625c0ac40] [c000000000121b40] .kernel_text_address+0x20/0x1c0 [c000000625c0acd0] [c000000000061960] .prepare_ftrace_return+0x50/0x130 [c000000625c0ad70] [c000000000061b10] .ftrace_graph_caller+0x14/0x34 [c000000625c0ade0] [c000000000121b40] .kernel_text_address+0x20/0x1c0 This is because ftrace is using ppc_function_entry() for obtaining the address of return_to_handler() in prepare_ftrace_return(). The call to kernel_text_address() itself gets traced and we end up in a recursive loop. Fixes: 83e840c770f2 ("powerpc64/elfv1: Only dereference function descriptor for non-text symbols") Reported-by: Chandan Rajendra Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

KVM: update to new mmu_notifier semantic v2

2017-08-31T23:13:00+00:00

Calls to mmu_notifier_invalidate_page() were replaced by calls to mmu_notifier_invalidate_range() and are now bracketed by calls to mmu_notifier_invalidate_range_start()/end() Remove now useless invalidate_page callback. Changed since v1 (Linus Torvalds) - remove now useless kvm_arch_mmu_notifier_invalidate_page() Signed-off-by: Jérôme Glisse Tested-by: Mike Galbraith Tested-by: Adam Borowski Cc: Paolo Bonzini Cc: Radim Krčmář Cc: kvm@vger.kernel.org Cc: Kirill A. Shutemov Cc: Andrew Morton Cc: Andrea Arcangeli Signed-off-by: Linus Torvalds

Merge tag 'powerpc-4.13-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2017-08-26T00:32:35+00:00

Pull powerpc fix from Michael Ellerman: "Just one fix, to add a barrier in the switch_mm() code to make sure the mm cpumask update is ordered vs the MMU starting to load translations. As far as we know no one's actually hit the bug, but that's just luck. Thanks to Benjamin Herrenschmidt, Nicholas Piggin" * tag 'powerpc-4.13-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/mm: Ensure cpumask update is ordered

powerpc/mm: Ensure cpumask update is ordered

2017-08-18T03:07:16+00:00

There is no guarantee that the various isync's involved with the context switch will order the update of the CPU mask with the first TLB entry for the new context being loaded by the HW. Be safe here and add a memory barrier to order any subsequent load/store which may bring entries into the TLB. The corresponding barrier on the other side already exists as pte updates use pte_xchg() which uses __cmpxchg_u64 which has a sync after the atomic operation. Cc: stable@vger.kernel.org Signed-off-by: Benjamin Herrenschmidt Reviewed-by: Nicholas Piggin [mpe: Add comments in the code] Signed-off-by: Michael Ellerman

Merge tag 'powerpc-4.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2017-08-04T16:56:54+00:00

Pull powerpc fixes from Michael Ellerman: "Fixes for recently merged code: - a fix for the _PAGE_DEVMAP support, which was breaking KVM on Power9 radix - avoid a (harmless) lockdep warning in the early SMP code - return failure for some uses of dma_set_mask() rather than falling back to 32-bits - fix stack setup in watchdog soft_nmi_common() to use emergency stack - fix of_irq_to_resource() error check in of_fsl_spi_probe() Two fixes going to stable: - fix saving of Transactional Memory SPRs in core dump - fix __check_irq_replay missing decrementer interrupt And two misc: - fix 64-bit boot wrapper build with non-biarch compiler - work around a POWER9 PMU hang after state-loss idle Thanks to: Alistair Popple, Aneesh Kumar K.V, Cyril Bur, Gustavo Romero, Jose Ricardo Ziviani, Laurent Vivier, Nicholas Piggin, Oliver O'Halloran, Sergei Shtylyov, Suraj Jitindar Singh, Thomas Gleixner" * tag 'powerpc-4.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64: Fix __check_irq_replay missing decrementer interrupt powerpc/perf: POWER9 PMU stops after idle workaround powerpc/83xx/mpc832x_rdb: fix of_irq_to_resource() error check powerpc/64s: Fix stack setup in watchdog soft_nmi_common() powerpc/powernv/pci: Return failure for some uses of dma_set_mask() powerpc/boot: Fix 64-bit boot wrapper build with non-biarch compiler powerpc/smp: Call smp_ops->setup_cpu() directly on the boot CPU powerpc/tm: Fix saving of TM SPRs in core dump powerpc/mm: Fix pmd/pte_devmap() on non-leaf entries

Merge tag 'v4.13-rc1' into fixes

2017-07-31T10:20:29+00:00

The fixes branch is based off a random pre-rc1 commit, because we had some fixes that needed to go in before rc1 was released. However we now need to fix some code that went in after that point, but before rc1, so merge rc1 to get that code into fixes so we can fix it!

Merge tag 'powerpc-4.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2017-07-28T20:25:15+00:00

Pull powerpc fixes from Michael Ellerman: "The highlight is Ben's patch to work around a host killing bug when running KVM guests with the Radix MMU on Power9. See the long change log of that commit for more detail. And then three fairly minor fixes: - fix of_node_put() underflow during reconfig remove, using old DLPAR tools. - fix recently introduced ld version check with 64-bit LE-only toolchain. - free the subpage_prot_table correctly, avoiding a memory leak. Thanks to: Aneesh Kumar K.V, Benjamin Herrenschmidt, Laurent Vivier" * tag 'powerpc-4.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/mm/hash: Free the subpage_prot_table correctly powerpc/Makefile: Fix ld version check with 64-bit LE-only toolchain powerpc/pseries: Fix of_node_put() underflow during reconfig remove powerpc/mm/radix: Workaround prefetch issue with KVM

powerpc/mm: Fix pmd/pte_devmap() on non-leaf entries

2017-07-28T05:55:30+00:00

The Radix MMU translation tree as defined in ISA v3.0 contains two different types of entry, directories and leaves. Leaves are identified by _PAGE_PTE being set. The formats of the two entries are different, with the directory entries containing no spare bits for use by software. In particular the bit we use for _PAGE_DEVMAP is not reserved for software, and is part of the NLB (Next Level Base) field, essentially the address of the next level in the tree. Note that the Linux pte_t is not == _PAGE_PTE. A huge page pmd entry (or devmap!) is also a leaf and so has _PAGE_PTE set, even though we use a pmd_t for it in Linux. The fix is to ensure that the pmd/pte_devmap() confirm they are looking at a leaf entry (_PAGE_PTE) as well as checking _PAGE_DEVMAP. Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64") Signed-off-by: Oliver O'Halloran Tested-by: Laurent Vivier Tested-by: Jose Ricardo Ziviani Reviewed-by: Suraj Jitindar Singh Reviewed-by: Aneesh Kumar K.V [mpe: Add a comment in the code and flesh out change log] Signed-off-by: Michael Ellerman

powerpc/mm/radix: Workaround prefetch issue with KVM

2017-07-26T06:41:52+00:00

There's a somewhat architectural issue with Radix MMU and KVM. When coming out of a guest with AIL (Alternate Interrupt Location, ie, MMU enabled), we start executing hypervisor code with the PID register still containing whatever the guest has been using. The problem is that the CPU can (and will) then start prefetching or speculatively load from whatever host context has that same PID (if any), thus bringing translations for that context into the TLB, which Linux doesn't know about. This can cause stale translations and subsequent crashes. Fixing this in a way that is neither racy nor a huge performance impact is difficult. We could just make the host invalidations always use broadcast forms but that would hurt single threaded programs for example. We chose to fix it instead by partitioning the PID space between guest and host. This is possible because today Linux only use 19 out of the 20 bits of PID space, so existing guests will work if we make the host use the top half of the 20 bits space. We additionally add support for a property to indicate to Linux the size of the PID register which will be useful if we eventually have processors with a larger PID space available. There is still an issue with malicious guests purposefully setting the PID register to a value in the hosts PID range. Hopefully future HW can prevent that, but in the meantime, we handle it with a pair of kludges: - On the way out of a guest, before we clear the current VCPU in the PACA, we check the PID and if it's outside of the permitted range we flush the TLB for that PID. - When context switching, if the mm is "new" on that CPU (the corresponding bit was set for the first time in the mm cpumask), we check if any sibling thread is in KVM (has a non-NULL VCPU pointer in the PACA). If that is the case, we also flush the PID for that CPU (core). This second part is needed to handle the case where a process is migrated (or starts a new pthread) on a sibling thread of the CPU coming out of KVM, as there's a window where stale translations can exist before we detect it and flush them out. A future optimization could be added by keeping track of whether the PID has ever been used and avoid doing that for completely fresh PIDs. We could similarily mark PIDs that have been the subject of a global invalidation as "fresh". But for now this will do. Signed-off-by: Benjamin Herrenschmidt [mpe: Rework the asm to build with CONFIG_PPC_RADIX_MMU=n, drop unneeded include of kvm_book3s_asm.h] Signed-off-by: Michael Ellerman

Merge tag 'tty-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2017-07-22T16:00:24+00:00

Pull tty/serial fixes from Greg KH: "Here are some small tty and serial driver fixes for 4.13-rc2. Nothing huge at all, a revert of a patch that turned out to break things, a fix up for a new tty ioctl we added in 4.13-rc1 to get the uapi definition correct, and a few minor serial driver fixes for reported issues. All of these have been in linux-next for a while with no reported issues" * tag 'tty-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: tty: Fix TIOCGPTPEER ioctl definition tty: hide unused pty_get_peer function tty: serial: lpuart: Fix the logic for detecting the 32-bit type UART serial: imx: Prevent TX buffer PIO write when a DMA has been started Revert "serial: imx-serial - move DMA buffer configuration to DT" serial: sh-sci: Uninitialized variables in sysfs files serial: st-asc: Potential error pointer dereference