kernel.git/arch/powerpc/platforms/pseries, branch linux-4.8.y

powerpc/pseries: Fix stack corruption in htpe code

2016-10-28T07:45:22Z

commit 05af40e885955065aee8bb7425058eb3e1adca08 upstream. This commit fixes a stack corruption in the pseries specific code dealing with the huge pages. In __pSeries_lpar_hugepage_invalidate() the buffer used to pass arguments to the hypervisor is not large enough. This leads to a stack corruption where a previously saved register could be corrupted leading to unexpected result in the caller, like the following panic: Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=2048 NUMA pSeries Modules linked in: virtio_balloon ip_tables x_tables autofs4 virtio_blk 8139too virtio_pci virtio_ring 8139cp virtio CPU: 11 PID: 1916 Comm: mmstress Not tainted 4.8.0 #76 task: c000000005394880 task.stack: c000000005570000 NIP: c00000000027bf6c LR: c00000000027bf64 CTR: 0000000000000000 REGS: c000000005573820 TRAP: 0300 Not tainted (4.8.0) MSR: 8000000000009033 CR: 84822884 XER: 20000000 CFAR: c00000000010a924 DAR: 420000000014e5e0 DSISR: 40000000 SOFTE: 1 GPR00: c00000000027bf64 c000000005573aa0 c000000000e02800 c000000004447964 GPR04: c00000000404de18 c000000004d38810 00000000042100f5 00000000f5002104 GPR08: e0000000f5002104 0000000000000001 042100f5000000e0 00000000042100f5 GPR12: 0000000000002200 c00000000fe02c00 c00000000404de18 0000000000000000 GPR16: c1ffffffffffe7ff 00003fff62000000 420000000014e5e0 00003fff63000000 GPR20: 0008000000000000 c0000000f7014800 0405e600000000e0 0000000000010000 GPR24: c000000004d38810 c000000004447c10 c00000000404de18 c000000004447964 GPR28: c000000005573b10 c000000004d38810 00003fff62000000 420000000014e5e0 NIP [c00000000027bf6c] zap_huge_pmd+0x4c/0x470 LR [c00000000027bf64] zap_huge_pmd+0x44/0x470 Call Trace: [c000000005573aa0] [c00000000027bf64] zap_huge_pmd+0x44/0x470 (unreliable) [c000000005573af0] [c00000000022bbd8] unmap_page_range+0xcf8/0xed0 [c000000005573c30] [c00000000022c2d4] unmap_vmas+0x84/0x120 [c000000005573c80] [c000000000235448] unmap_region+0xd8/0x1b0 [c000000005573d80] [c0000000002378f0] do_munmap+0x2d0/0x4c0 [c000000005573df0] [c000000000237be4] SyS_munmap+0x64/0xb0 [c000000005573e30] [c000000000009560] system_call+0x38/0x108 Instruction dump: fbe1fff8 fb81ffe0 7c7f1b78 7ca32b78 7cbd2b78 f8010010 7c9a2378 f821ffb1 7cde3378 4bfffea9 7c7b1b79 41820298 48000130 7fa5eb78 7fc4f378 Most of the time, the bug is surfacing in a caller up in the stack from __pSeries_lpar_hugepage_invalidate() which is quite confusing. This bug is pending since v3.11 but was hidden if a caller of the caller of __pSeries_lpar_hugepage_invalidate() has pushed the corruped register (r18 in this case) in the stack and is not using it until restoring it. GCC 6.2.0 seems to raise it more frequently. This commit also change the definition of the parameter buffer in pSeries_lpar_flush_hash_range() to rely on the global define PLPAR_HCALL9_BUFSIZE (no functional change here). Fixes: 1a5272866f87 ("powerpc: Optimize hugepage invalidate") Signed-off-by: Laurent Dufour Reviewed-by: Aneesh Kumar K.V Acked-by: Balbir Singh Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Fix little endian build with CONFIG_KEXEC=n

2016-09-06T04:54:08Z

On ppc64le, builds with CONFIG_KEXEC=n fail with: arch/powerpc/platforms/pseries/setup.c: In function ‘pseries_big_endian_exceptions’: arch/powerpc/platforms/pseries/setup.c:403:13: error: implicit declaration of function ‘kdump_in_progress’ if (rc && !kdump_in_progress()) This is because pseries/setup.c includes , but kdump_in_progress() is defined in . This is a problem because the former only includes the latter if CONFIG_KEXEC_CORE=y. Fix it by including directly, as is done in powernv/setup.c. Fixes: d3cbff1b5a90 ("powerpc: Put exception configuration in a common place") Signed-off-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman

powerpc/pseries: use pci_host_bridge.release_fn() to kfree(phb)

2016-08-22T01:09:33Z

This patch leverages 'struct pci_host_bridge' from the PCI subsystem in order to free the pci_controller only after the last reference to its devices is dropped (avoiding an oops in pcibios_release_device() if the last reference is dropped after pcibios_free_controller()). The patch relies on pci_host_bridge.release_fn() (and .release_data), which is called automatically by the PCI subsystem when the root bus is released (i.e., the last reference is dropped). Those fields are set via pci_set_host_bridge_release() (e.g. in the platform-specific implementation of pcibios_root_bridge_prepare()). It introduces the 'pcibios_free_controller_deferred()' .release_fn() and it expects .release_data to hold a pointer to the pci_controller. The function implictly calls 'pcibios_free_controller()', so an user must *NOT* explicitly call it if using the new _deferred() callback. The functionality is enabled for pseries (although it isn't platform specific, and may be used by cxl). Details on not-so-elegant design choices: - Use 'pci_host_bridge.release_data' field as pointer to associated 'struct pci_controller' so *not* to 'pci_bus_to_host(bridge->bus)' in pcibios_free_controller_deferred(). That's because pci_remove_root_bus() sets 'host_bridge->bus = NULL' (so, if the last reference is released after pci_remove_root_bus() runs, which eventually reaches pcibios_free_controller_deferred(), that would hit a null pointer dereference). The cxl/vphb.c code calls pci_remove_root_bus(), and the cxl folks are interested in this fix. Test-case #1 (hold references) # ls -ld /sys/block/sd* | grep -m1 0021:01:00.0 <...> /sys/block/sdaa -> ../devices/pci0021:01/0021:01:00.0/<...> # ls -ld /sys/block/sd* | grep -m1 0021:01:00.1 <...> /sys/block/sdab -> ../devices/pci0021:01/0021:01:00.1/<...> # cat >/dev/sdaa & pid1=$! # cat >/dev/sdab & pid2=$! # drmgr -w 5 -d 1 -c phb -s 'PHB 33' -r Validating PHB DLPAR capability...yes. [ 594.306719] pci_hp_remove_devices: PCI: Removing devices on bus 0021:01 [ 594.306738] pci_hp_remove_devices: Removing 0021:01:00.0... ... [ 598.236381] pci_hp_remove_devices: Removing 0021:01:00.1... ... [ 611.972077] pci_bus 0021:01: busn_res: [bus 01-ff] is released [ 611.972140] rpadlpar_io: slot PHB 33 removed # kill -9 $pid1 # kill -9 $pid2 [ 632.918088] pcibios_free_controller_deferred: domain 33, dynamic 1 Test-case #2 (don't hold references) # drmgr -w 5 -d 1 -c phb -s 'PHB 33' -r Validating PHB DLPAR capability...yes. [ 916.357363] pci_hp_remove_devices: PCI: Removing devices on bus 0021:01 [ 916.357386] pci_hp_remove_devices: Removing 0021:01:00.0... ... [ 920.566527] pci_hp_remove_devices: Removing 0021:01:00.1... ... [ 933.955873] pci_bus 0021:01: busn_res: [bus 01-ff] is released [ 933.955977] pcibios_free_controller_deferred: domain 33, dynamic 1 [ 933.955999] rpadlpar_io: slot PHB 33 removed Suggested-By: Gavin Shan Signed-off-by: Mauricio Faria de Oliveira Reviewed-by: Gavin Shan Reviewed-by: Andrew Donnellan Tested-by: Andrew Donnellan # cxl Signed-off-by: Benjamin Herrenschmidt

powerpc: Fix unused function warning 'lmb_to_memblock'

2016-08-09T06:52:00Z

This patch fixes the following warning: arch/powerpc/platforms/pseries/hotplug-memory.c:323:29: error: 'lmb_to_memblock' defined but not used [-Werror=unused-function] static struct memory_block *lmb_to_memblock(struct of_drconf_cell *lmb) ^~~~~~~~~~~~~~~ The only consumer of this function is 'dlpar_remove_lmb', which is enabled with CONFIG_MEMORY_HOTREMOVE, so move it into the same ifdef block. Signed-off-by: Michael Ellerman

dma-mapping: use unsigned long for dma_attrs

2016-08-04T12:50:07Z

The dma-mapping core and the implementations do not change the DMA attributes passed by pointer. Thus the pointer can point to const data. However the attributes do not have to be a bitfield. Instead unsigned long will do fine: 1. This is just simpler. Both in terms of reading the code and setting attributes. Instead of initializing local attributes on the stack and passing pointer to it to dma_set_attr(), just set the bits. 2. It brings safeness and checking for const correctness because the attributes are passed by value. Semantic patches for this change (at least most of them): virtual patch virtual context @r@ identifier f, attrs; @@ f(..., - struct dma_attrs *attrs + unsigned long attrs , ...) { ... } @@ identifier r.f; @@ f(..., - NULL + 0 ) and // Options: --all-includes virtual patch virtual context @r@ identifier f, attrs; type t; @@ t f(..., struct dma_attrs *attrs); @@ identifier r.f; @@ f(..., - NULL + 0 ) Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.com Signed-off-by: Krzysztof Kozlowski Acked-by: Vineet Gupta Acked-by: Robin Murphy Acked-by: Hans-Christian Noren Egtvedt Acked-by: Mark Salter [c6x] Acked-by: Jesper Nilsson [cris] Acked-by: Daniel Vetter [drm] Reviewed-by: Bart Van Assche Acked-by: Joerg Roedel [iommu] Acked-by: Fabien Dessenne [bdisp] Reviewed-by: Marek Szyprowski [vb2-core] Acked-by: David Vrabel [xen] Acked-by: Konrad Rzeszutek Wilk [xen swiotlb] Acked-by: Joerg Roedel [iommu] Acked-by: Richard Kuo [hexagon] Acked-by: Geert Uytterhoeven [m68k] Acked-by: Gerald Schaefer [s390] Acked-by: Bjorn Andersson Acked-by: Hans-Christian Noren Egtvedt [avr32] Acked-by: Vineet Gupta [arc] Acked-by: Robin Murphy [arm64 and dma-iommu] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

powerpc/mm: Rename hpte_init_lpar() and move the fallback to a header

2016-07-26T04:16:18Z

hpte_init_lpar() is part of the pseries platform, so name it as such. Move the fallback implementation for when PSERIES=n into the header, dropping the weak implementation. The panic() is now handled by the calling code. Signed-off-by: Michael Ellerman

powerpc: Get rid of ppc_md.init_early()

2016-07-21T09:07:26Z

It is now called right after platform probe, so the probe function can just do the job. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman

powerpc/64: Move 64-bit probe_machine() to later in the boot process

2016-07-21T08:59:22Z

We no long need the machine type that early, so we can move probe_machine() to after the device-tree has been expanded. This will allow further consolidation. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman

powerpc/mm: Move hash table ops to a separate structure

2016-07-21T08:59:09Z

Moving probe_machine() to after mmu init will cause the ppc_md fields relative to the hash table management to be overwritten. Since we have essentially disconnected the machine type from the hash backend ops, finish the job by moving them to a different structure. The only callback that didn't quite fix is update_partition_table since this is not specific to hash, so I moved it to a standalone variable for now. We can revisit later if needed. Signed-off-by: Benjamin Herrenschmidt [mpe: Fix ppc64e build failure in kexec] Signed-off-by: Michael Ellerman

powerpc/64: Move MMU backend selection out of platform code

2016-07-21T08:56:38Z

We move it into early_mmu_init() based on firmware features. For PS3, we have to move the setting of these into early_init_devtree(). Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman