kernel.git/arch/powerpc/platforms/pseries, branch linux-3.12.y

powerpc/pseries: Fix stack corruption in htpe code

2016-10-28T18:30:53Z

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: Jiri Slaby

powerpc/pseries: Fix PCI config address for DDW

2016-07-21T06:35:59Z

commit 8a934efe94347eee843aeea65bdec8077a79e259 upstream. In commit 8445a87f7092 "powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism", the PE address was replaced with the PCI config address in order to remove dependency on EEH. According to PAPR spec, firmware (pHyp or QEMU) should accept "xxBBSSxx" format PCI config address, not "xxxxBBSS" provided by the patch. Note that "BB" is PCI bus number and "SS" is the combination of slot and function number. This fixes the PCI address passed to DDW RTAS calls. Fixes: 8445a87f7092 ("powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism") Reported-by: Guilherme G. Piccoli Signed-off-by: Gavin Shan Tested-by: Guilherme G. Piccoli Signed-off-by: Michael Ellerman Signed-off-by: Jiri Slaby

powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism

2016-07-21T06:35:58Z

commit 8445a87f7092bc8336ea1305be9306f26b846d93 upstream. Commit 39baadbf36ce ("powerpc/eeh: Remove eeh information from pci_dn") changed the pci_dn struct by removing its EEH-related members. As part of this clean-up, DDW mechanism was modified to read the device configuration address from eeh_dev struct. As a consequence, now if we disable EEH mechanism on kernel command-line for example, the DDW mechanism will fail, generating a kernel oops by dereferencing a NULL pointer (which turns to be the eeh_dev pointer). This patch just changes the configuration address calculation on DDW functions to a manual calculation based on pci_dn members instead of using eeh_dev-based address. No functional changes were made. This was tested on pSeries, both in PHyp and qemu guest. Fixes: 39baadbf36ce ("powerpc/eeh: Remove eeh information from pci_dn") Reviewed-by: Gavin Shan Signed-off-by: Guilherme G. Piccoli Signed-off-by: Michael Ellerman Signed-off-by: Jiri Slaby

powerpc/pseries/eeh: Handle RTAS delay requests in configure_bridge

2016-06-23T12:07:56Z

commit 871e178e0f2c4fa788f694721a10b4758d494ce1 upstream. In the "ibm,configure-pe" and "ibm,configure-bridge" RTAS calls, the spec states that values of 9900-9905 can be returned, indicating that software should delay for 10^x (where x is the last digit, i.e. 990x) milliseconds and attempt the call again. Currently, the kernel doesn't know about this, and respecting it fixes some PCI failures when the hypervisor is busy. The delay is capped at 0.2 seconds. Signed-off-by: Russell Currey Acked-by: Gavin Shan Signed-off-by: Michael Ellerman Signed-off-by: Jiri Slaby

powerpc/rtas: Introduce rtas_get_sensor_fast() for IRQ handlers

2015-09-30T09:00:07Z

commit 1c2cb594441d02815d304cccec9742ff5c707495 upstream. 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 Reviewed-by: Nathan Fontenot Signed-off-by: Michael Ellerman Signed-off-by: Jiri Slaby

powerpc/pseries: Little endian fixes for post mobility device tree update

2015-04-21T14:30:02Z

commit f6ff04149637723261aa4738958b0098b929ee9e upstream. We currently use the device tree update code in the kernel after resuming from a suspend operation to re-sync the kernels view of the device tree with that of the hypervisor. The code as it stands is not endian safe as it relies on parsing buffers returned by RTAS calls that thusly contains data in big endian format. This patch annotates variables and structure members with __be types as well as performing necessary byte swaps to cpu endian for data that needs to be parsed. Signed-off-by: Tyrel Datwyler Cc: Nathan Fontenot Cc: Cyril Bur Signed-off-by: Michael Ellerman Signed-off-by: Jiri Slaby

powerpc/pseries: Honor the generic "no_64bit_msi" flag

2014-12-06T14:18:13Z

commit 415072a041bf50dbd6d56934ffc0cbbe14c97be8 upstream. Instead of the arch specific quirk which we are deprecating Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Jiri Slaby

powerpc: use device_online/offline() instead of cpu_up/down()

2014-11-13T18:03:06Z

commit 10ccaf178b2b961d8bca252d647ed7ed8aae2a20 upstream. In powerpc pseries platform dlpar operations, use device_online() and device_offline() instead of cpu_up() and cpu_down(). Calling cpu_up/down() directly does not update the cpu device offline field, which is used to online/offline a cpu from sysfs. Calling device_online/offline() instead keeps the sysfs cpu online value correct. The hotplug lock, which is required to be held when calling device_online/offline(), is already held when dlpar_online/offline_cpu() are called, since they are called only from cpu_probe|release_store(). This patch fixes errors on phyp (PowerVM) systems that have cpu(s) added/removed using dlpar operations; without this patch, the /sys/devices/system/cpu/cpuN/online nodes do not correctly show the online state of added/removed cpus. Signed-off-by: Dan Streetman Cc: Nathan Fontenot Fixes: 0902a9044fa5 ("Driver core: Use generic offline/online for CPU offline/online") Signed-off-by: Michael Ellerman Signed-off-by: Jiri Slaby

powerpc/thp: Don't recompute vsid and ssize in loop on invalidate

2014-09-17T14:55:04Z

commit fa1f8ae80f8bb996594167ff4750a0b0a5a5bb5d upstream. The segment identifier and segment size will remain the same in the loop, So we can compute it outside. We also change the hugepage_invalidate interface so that we can use it the later patch Signed-off-by: Aneesh Kumar K.V Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Jiri Slaby

powerpc/pseries: Avoid deadlock on removing ddw

2014-09-17T14:55:04Z

commit 5efbabe09d986f25c02d19954660238fcd7f008a upstream. Function remove_ddw() could be called in of_reconfig_notifier and we potentially remove the dynamic DMA window property, which invokes of_reconfig_notifier again. Eventually, it leads to the deadlock as following backtrace shows. The patch fixes the above issue by deferring releasing the dynamic DMA window property while releasing the device node. ============================================= [ INFO: possible recursive locking detected ] 3.16.0+ #428 Tainted: G W --------------------------------------------- drmgr/2273 is trying to acquire lock: ((of_reconfig_chain).rwsem){.+.+..}, at: [] \ .__blocking_notifier_call_chain+0x40/0x78 but task is already holding lock: ((of_reconfig_chain).rwsem){.+.+..}, at: [] \ .__blocking_notifier_call_chain+0x40/0x78 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock((of_reconfig_chain).rwsem); lock((of_reconfig_chain).rwsem); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by drmgr/2273: #0: (sb_writers#4){.+.+.+}, at: [] \ .vfs_write+0xb0/0x1f8 #1: ((of_reconfig_chain).rwsem){.+.+..}, at: [] \ .__blocking_notifier_call_chain+0x40/0x78 stack backtrace: CPU: 17 PID: 2273 Comm: drmgr Tainted: G W 3.16.0+ #428 Call Trace: [c0000000137e7000] [c000000000013d9c] .show_stack+0x88/0x148 (unreliable) [c0000000137e70b0] [c00000000083cd34] .dump_stack+0x7c/0x9c [c0000000137e7130] [c0000000000b8afc] .__lock_acquire+0x128c/0x1c68 [c0000000137e7280] [c0000000000b9a4c] .lock_acquire+0xe8/0x104 [c0000000137e7350] [c00000000083588c] .down_read+0x4c/0x90 [c0000000137e73e0] [c000000000091890] .__blocking_notifier_call_chain+0x40/0x78 [c0000000137e7490] [c000000000091900] .blocking_notifier_call_chain+0x38/0x48 [c0000000137e7520] [c000000000682a28] .of_reconfig_notify+0x34/0x5c [c0000000137e75b0] [c000000000682a9c] .of_property_notify+0x4c/0x54 [c0000000137e7650] [c000000000682bf0] .of_remove_property+0x30/0xd4 [c0000000137e76f0] [c000000000052a44] .remove_ddw+0x144/0x168 [c0000000137e7790] [c000000000053204] .iommu_reconfig_notifier+0x30/0xe0 [c0000000137e7820] [c00000000009137c] .notifier_call_chain+0x6c/0xb4 [c0000000137e78c0] [c0000000000918ac] .__blocking_notifier_call_chain+0x5c/0x78 [c0000000137e7970] [c000000000091900] .blocking_notifier_call_chain+0x38/0x48 [c0000000137e7a00] [c000000000682a28] .of_reconfig_notify+0x34/0x5c [c0000000137e7a90] [c000000000682e14] .of_detach_node+0x44/0x1fc [c0000000137e7b40] [c0000000000518e4] .ofdt_write+0x3ac/0x688 [c0000000137e7c20] [c000000000238430] .proc_reg_write+0xb8/0xd4 [c0000000137e7cd0] [c0000000001cbeac] .vfs_write+0xec/0x1f8 [c0000000137e7d70] [c0000000001cc3b0] .SyS_write+0x58/0xa0 [c0000000137e7e30] [c00000000000a064] syscall_exit+0x0/0x98 Signed-off-by: Gavin Shan Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Jiri Slaby