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2024-01-25powerpc/pseries/memhp: Fix access beyond end of drmem arrayNathan Lynch
[ Upstream commit bd68ffce69f6cf8ddd3a3c32549d1d2275e49fc5 ] dlpar_memory_remove_by_index() may access beyond the bounds of the drmem lmb array when the LMB lookup fails to match an entry with the given DRC index. When the search fails, the cursor is left pointing to &drmem_info->lmbs[drmem_info->n_lmbs], which is one element past the last valid entry in the array. The debug message at the end of the function then dereferences this pointer: pr_debug("Failed to hot-remove memory at %llx\n", lmb->base_addr); This was found by inspection and confirmed with KASAN: pseries-hotplug-mem: Attempting to hot-remove LMB, drc index 1234 ================================================================== BUG: KASAN: slab-out-of-bounds in dlpar_memory+0x298/0x1658 Read of size 8 at addr c000000364e97fd0 by task bash/949 dump_stack_lvl+0xa4/0xfc (unreliable) print_report+0x214/0x63c kasan_report+0x140/0x2e0 __asan_load8+0xa8/0xe0 dlpar_memory+0x298/0x1658 handle_dlpar_errorlog+0x130/0x1d0 dlpar_store+0x18c/0x3e0 kobj_attr_store+0x68/0xa0 sysfs_kf_write+0xc4/0x110 kernfs_fop_write_iter+0x26c/0x390 vfs_write+0x2d4/0x4e0 ksys_write+0xac/0x1a0 system_call_exception+0x268/0x530 system_call_vectored_common+0x15c/0x2ec Allocated by task 1: kasan_save_stack+0x48/0x80 kasan_set_track+0x34/0x50 kasan_save_alloc_info+0x34/0x50 __kasan_kmalloc+0xd0/0x120 __kmalloc+0x8c/0x320 kmalloc_array.constprop.0+0x48/0x5c drmem_init+0x2a0/0x41c do_one_initcall+0xe0/0x5c0 kernel_init_freeable+0x4ec/0x5a0 kernel_init+0x30/0x1e0 ret_from_kernel_user_thread+0x14/0x1c The buggy address belongs to the object at c000000364e80000 which belongs to the cache kmalloc-128k of size 131072 The buggy address is located 0 bytes to the right of allocated 98256-byte region [c000000364e80000, c000000364e97fd0) ================================================================== pseries-hotplug-mem: Failed to hot-remove memory at 0 Log failed lookups with a separate message and dereference the cursor only when it points to a valid entry. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Fixes: 51925fb3c5c9 ("powerpc/pseries: Implement memory hotplug remove in the kernel") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20231114-pseries-memhp-fixes-v1-1-fb8f2bb7c557@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25powerpc/pseries/memhotplug: Quieten some DLPAR operationsLaurent Dufour
[ Upstream commit 20e9de85edae3a5866f29b6cce87c9ec66d62a1b ] When attempting to remove by index a set of LMBs a lot of messages are displayed on the console, even when everything goes fine: pseries-hotplug-mem: Attempting to hot-remove LMB, drc index 8000002d Offlined Pages 4096 pseries-hotplug-mem: Memory at 2d0000000 was hot-removed The 2 messages prefixed by "pseries-hotplug-mem" are not really helpful for the end user, they should be debug outputs. In case of error, because some of the LMB's pages couldn't be offlined, the following is displayed on the console: pseries-hotplug-mem: Attempting to hot-remove LMB, drc index 8000003e pseries-hotplug-mem: Failed to hot-remove memory at 3e0000000 dlpar: Could not handle DLPAR request "memory remove index 0x8000003e" Again, the 2 messages prefixed by "pseries-hotplug-mem" are useless, and the generic DLPAR prefixed message should be enough. These 2 first changes are mainly triggered by the changes introduced in drmgr: https://groups.google.com/g/powerpc-utils-devel/c/Y6ef4NB3EzM/m/9cu5JHRxAQAJ Also, when adding a bunch of LMBs, a message is displayed in the console per LMB like these ones: pseries-hotplug-mem: Memory at 7e0000000 (drc index 8000007e) was hot-added pseries-hotplug-mem: Memory at 7f0000000 (drc index 8000007f) was hot-added pseries-hotplug-mem: Memory at 800000000 (drc index 80000080) was hot-added pseries-hotplug-mem: Memory at 810000000 (drc index 80000081) was hot-added When adding 1TB of memory and LMB size is 256MB, this leads to 4096 messages to be displayed on the console. These messages are not really helpful for the end user, so moving them to the DEBUG level. Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> [mpe: Tweak change log wording] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201211145954.90143-1-ldufour@linux.ibm.com Stable-dep-of: bd68ffce69f6 ("powerpc/pseries/memhp: Fix access beyond end of drmem array") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-01-25powerpc: remove redundant 'default n' from Kconfig-sBartlomiej Zolnierkiewicz
[ Upstream commit 719736e1cc12b2fc28eba2122893a449eee66d08 ] 'default n' is the default value for any bool or tristate Kconfig setting so there is no need to write it explicitly. Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO is not set' for visible symbols") the Kconfig behavior is the same regardless of 'default n' being present or not: ... One side effect of (and the main motivation for) this change is making the following two definitions behave exactly the same: config FOO bool config FOO bool default n With this change, neither of these will generate a '# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied). That might make it clearer to people that a bare 'default n' is redundant. ... Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Stable-dep-of: 4a74197b65e6 ("powerpc/44x: select I2C for CURRITUCK") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-23powerpc/pseries: fix possible memory leak in ibmebus_bus_init()ruanjinjie
[ Upstream commit afda85b963c12947e298ad85d757e333aa40fd74 ] If device_register() returns error in ibmebus_bus_init(), name of kobject which is allocated in dev_set_name() called in device_add() is leaked. As comment of device_add() says, it should call put_device() to drop the reference count that was set in device_initialize() when it fails, so the name can be freed in kobject_cleanup(). Signed-off-by: ruanjinjie <ruanjinjie@huawei.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20221110011929.3709774-1-ruanjinjie@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11powerpc/pseries/lparcfg: add missing RTAS retry status handlingNathan Lynch
[ Upstream commit 5d08633e5f6564b60f1cbe09af3af40a74d66431 ] The ibm,get-system-parameter RTAS function may return -2 or 990x, which indicate that the caller should try again. lparcfg's parse_system_parameter_string() ignores this, making it possible to intermittently report incorrect SPLPAR characteristics. Move the RTAS call into a coventional rtas_busy_delay()-based loop. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-4-26929c8cce78@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-02powerpc/pseries: wire up rng during setup_arch()Jason A. Donenfeld
commit e561e472a3d441753bd012333b057f48fef1045b upstream. The platform's RNG must be available before random_init() in order to be useful for initial seeding, which in turn means that it needs to be called from setup_arch(), rather than from an init call. Fortunately, each platform already has a setup_arch function pointer, which means it's easy to wire this up. This commit also removes some noisy log messages that don't add much. Fixes: a489043f4626 ("powerpc/pseries: Implement arch_get_random_long() based on H_RANDOM") Cc: stable@vger.kernel.org # v3.13+ Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220611151015.548325-4-Jason@zx2c4.com Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-04powerpc/pseries: Fix regression while building external modulesSrikar Dronamraju
commit 333cf507465fbebb3727f5b53e77538467df312a upstream. With commit c9f3401313a5 ("powerpc: Always enable queued spinlocks for 64s, disable for others") CONFIG_PPC_QUEUED_SPINLOCKS is always enabled on ppc64le, external modules that use spinlock APIs are failing. ERROR: modpost: GPL-incompatible module XXX.ko uses GPL-only symbol 'shared_processor' Before the above commit, modules were able to build without any issues. Also this problem is not seen on other architectures. This problem can be workaround if CONFIG_UNINLINE_SPIN_UNLOCK is enabled in the config. However CONFIG_UNINLINE_SPIN_UNLOCK is not enabled by default and only enabled in certain conditions like CONFIG_DEBUG_SPINLOCKS is set in the kernel config. #include <linux/module.h> spinlock_t spLock; static int __init spinlock_test_init(void) { spin_lock_init(&spLock); spin_lock(&spLock); spin_unlock(&spLock); return 0; } static void __exit spinlock_test_exit(void) { printk("spinlock_test unloaded\n"); } module_init(spinlock_test_init); module_exit(spinlock_test_exit); MODULE_DESCRIPTION ("spinlock_test"); MODULE_LICENSE ("non-GPL"); MODULE_AUTHOR ("Srikar Dronamraju"); Given that spin locks are one of the basic facilities for module code, this effectively makes it impossible to build/load almost any non GPL modules on ppc64le. This was first reported at https://github.com/openzfs/zfs/issues/11172 Currently shared_processor is exported as GPL only symbol. Fix this for parity with other architectures by exposing shared_processor to non-GPL modules too. Fixes: 14c73bd344da ("powerpc/vcpu: Assume dedicated processors as non-preempt") Cc: stable@vger.kernel.org # v5.5+ Reported-by: marc.c.dionne@gmail.com Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210729060449.292780-1-srikar@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-22powerpc/pseries: Stop calling printk in rtas_stop_self()Michael Ellerman
[ Upstream commit ed8029d7b472369a010a1901358567ca3b6dbb0d ] RCU complains about us calling printk() from an offline CPU: ============================= WARNING: suspicious RCU usage 5.12.0-rc7-02874-g7cf90e481cb8 #1 Not tainted ----------------------------- kernel/locking/lockdep.c:3568 RCU-list traversed in non-reader section!! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 2, debug_locks = 1 no locks held by swapper/0/0. stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.12.0-rc7-02874-g7cf90e481cb8 #1 Call Trace: dump_stack+0xec/0x144 (unreliable) lockdep_rcu_suspicious+0x124/0x144 __lock_acquire+0x1098/0x28b0 lock_acquire+0x128/0x600 _raw_spin_lock_irqsave+0x6c/0xc0 down_trylock+0x2c/0x70 __down_trylock_console_sem+0x60/0x140 vprintk_emit+0x1a8/0x4b0 vprintk_func+0xcc/0x200 printk+0x40/0x54 pseries_cpu_offline_self+0xc0/0x120 arch_cpu_idle_dead+0x54/0x70 do_idle+0x174/0x4a0 cpu_startup_entry+0x38/0x40 rest_init+0x268/0x388 start_kernel+0x748/0x790 start_here_common+0x1c/0x614 Which happens because by the time we get to rtas_stop_self() we are already offline. In addition the message can be spammy, and is not that helpful for users, so remove it. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210418135413.1204031-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-22powerpc/pseries: extract host bridge from pci_bus prior to bus removalTyrel Datwyler
[ Upstream commit 38d0b1c9cec71e6d0f3bddef0bbce41d05a3e796 ] The pci_bus->bridge reference may no longer be valid after pci_bus_remove() resulting in passing a bad value to device_unregister() for the associated bridge device. Store the host_bridge reference in a separate variable prior to pci_bus_remove(). Fixes: 7340056567e3 ("powerpc/pci: Reorder pci bus/bridge unregistration during PHB removal") Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210211182435.47968-1-tyreld@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04powerpc/pseries/dlpar: handle ibm, configure-connector delay statusNathan Lynch
[ Upstream commit 768d70e19ba525debd571b36e6d0ab19956c63d7 ] dlpar_configure_connector() has two problems in its handling of ibm,configure-connector's return status: 1. When the status is -2 (busy, call again), we call ibm,configure-connector again immediately without checking whether to schedule, which can result in monopolizing the CPU. 2. Extended delay status (9900..9905) goes completely unhandled, causing the configuration to unnecessarily terminate. Fix both of these issues by using rtas_busy_delay(). Fixes: ab519a011caa ("powerpc/pseries: Kernel DLPAR Infrastructure") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210107025900.410369-1-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30powerpc/pseries/hibernation: remove redundant cacheinfo updateNathan Lynch
[ Upstream commit b866459489fe8ef0e92cde3cbd6bbb1af6c4e99b ] Partitions with cache nodes in the device tree can encounter the following warning on resume: CPU 0 already accounted in PowerPC,POWER9@0(Data) WARNING: CPU: 0 PID: 3177 at arch/powerpc/kernel/cacheinfo.c:197 cacheinfo_cpu_online+0x640/0x820 These calls to cacheinfo_cpu_offline/online have been redundant since commit e610a466d16a ("powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration"). Fixes: e610a466d16a ("powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migration") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-25-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30powerpc/pseries/hibernation: drop pseries_suspend_begin() from suspend opsNathan Lynch
[ Upstream commit 52719fce3f4c7a8ac9eaa191e8d75a697f9fbcbc ] There are three ways pseries_suspend_begin() can be reached: 1. When "mem" is written to /sys/power/state: kobj_attr_store() -> state_store() -> pm_suspend() -> suspend_devices_and_enter() -> pseries_suspend_begin() This never works because there is no way to supply a valid stream id using this interface, and H_VASI_STATE is called with a stream id of zero. So this call path is useless at best. 2. When a stream id is written to /sys/devices/system/power/hibernate. pseries_suspend_begin() is polled directly from store_hibernate() until the stream is in the "Suspending" state (i.e. the platform is ready for the OS to suspend execution): dev_attr_store() -> store_hibernate() -> pseries_suspend_begin() 3. When a stream id is written to /sys/devices/system/power/hibernate (continued). After #2, pseries_suspend_begin() is called once again from the pm core: dev_attr_store() -> store_hibernate() -> pm_suspend() -> suspend_devices_and_enter() -> pseries_suspend_begin() This is redundant because the VASI suspend state is already known to be Suspending. The begin() callback of platform_suspend_ops is optional, so we can simply remove that assignment with no loss of function. Fixes: 32d8ad4e621d ("powerpc/pseries: Partition hibernation support") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201207215200.1785968-18-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-22powerpc/64s: flush L1D after user accessesNicholas Piggin
commit 9a32a7e78bd0cd9a9b6332cbdc345ee5ffd0c5de upstream. IBM Power9 processors can speculatively operate on data in the L1 cache before it has been completely validated, via a way-prediction mechanism. It is not possible for an attacker to determine the contents of impermissible memory using this method, since these systems implement a combination of hardware and software security measures to prevent scenarios where protected data could be leaked. However these measures don't address the scenario where an attacker induces the operating system to speculatively execute instructions using data that the attacker controls. This can be used for example to speculatively bypass "kernel user access prevention" techniques, as discovered by Anthony Steinhauser of Google's Safeside Project. This is not an attack by itself, but there is a possibility it could be used in conjunction with side-channels or other weaknesses in the privileged code to construct an attack. This issue can be mitigated by flushing the L1 cache between privilege boundaries of concern. This patch flushes the L1 cache after user accesses. This is part of the fix for CVE-2020-4788. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-22powerpc/64s: flush L1D on kernel entryNicholas Piggin
commit f79643787e0a0762d2409b7b8334e83f22d85695 upstream. IBM Power9 processors can speculatively operate on data in the L1 cache before it has been completely validated, via a way-prediction mechanism. It is not possible for an attacker to determine the contents of impermissible memory using this method, since these systems implement a combination of hardware and software security measures to prevent scenarios where protected data could be leaked. However these measures don't address the scenario where an attacker induces the operating system to speculatively execute instructions using data that the attacker controls. This can be used for example to speculatively bypass "kernel user access prevention" techniques, as discovered by Anthony Steinhauser of Google's Safeside Project. This is not an attack by itself, but there is a possibility it could be used in conjunction with side-channels or other weaknesses in the privileged code to construct an attack. This issue can be mitigated by flushing the L1 cache between privilege boundaries of concern. This patch flushes the L1 cache on kernel entry. This is part of the fix for CVE-2020-4788. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-29powerpc/pseries: Fix missing of_node_put() in rng_init()Nicholas Mc Guire
[ Upstream commit 67c3e59443f5fc77be39e2ce0db75fbfa78c7965 ] The call to of_find_compatible_node() returns a node pointer with refcount incremented thus it must be explicitly decremented here before returning. Fixes: a489043f4626 ("powerpc/pseries: Implement arch_get_random_long() based on H_RANDOM") Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1530522496-14816-1-git-send-email-hofrat@osadl.org Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26powerpc/pseries: Do not initiate shutdown when system is running on UPSVasant Hegde
commit 90a9b102eddf6a3f987d15f4454e26a2532c1c98 upstream. As per PAPR we have to look for both EPOW sensor value and event modifier to identify the type of event and take appropriate action. In LoPAPR v1.1 section 10.2.2 includes table 136 "EPOW Action Codes": SYSTEM_SHUTDOWN 3 The system must be shut down. An EPOW-aware OS logs the EPOW error log information, then schedules the system to be shut down to begin after an OS defined delay internal (default is 10 minutes.) Then in section 10.3.2.2.8 there is table 146 "Platform Event Log Format, Version 6, EPOW Section", which includes the "EPOW Event Modifier": For EPOW sensor value = 3 0x01 = Normal system shutdown with no additional delay 0x02 = Loss of utility power, system is running on UPS/Battery 0x03 = Loss of system critical functions, system should be shutdown 0x04 = Ambient temperature too high All other values = reserved We have a user space tool (rtas_errd) on LPAR to monitor for EPOW_SHUTDOWN_ON_UPS. Once it gets an event it initiates shutdown after predefined time. It also starts monitoring for any new EPOW events. If it receives "Power restored" event before predefined time it will cancel the shutdown. Otherwise after predefined time it will shutdown the system. Commit 79872e35469b ("powerpc/pseries: All events of EPOW_SYSTEM_SHUTDOWN must initiate shutdown") changed our handling of the "on UPS/Battery" case, to immediately shutdown the system. This breaks existing setups that rely on the userspace tool to delay shutdown and let the system run on the UPS. Fixes: 79872e35469b ("powerpc/pseries: All events of EPOW_SYSTEM_SHUTDOWN must initiate shutdown") Cc: stable@vger.kernel.org # v4.0+ Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com> [mpe: Massage change log and add PAPR references] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200820061844.306460-1-hegdevasant@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21pseries: Fix 64 bit logical memory block panicAnton Blanchard
commit 89c140bbaeee7a55ed0360a88f294ead2b95201b upstream. Booting with a 4GB LMB size causes us to panic: qemu-system-ppc64: OS terminated: OS panic: Memory block size not suitable: 0x0 Fix pseries_memory_block_size() to handle 64 bit LMBs. Cc: stable@vger.kernel.org Signed-off-by: Anton Blanchard <anton@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200715000820.1255764-1-anton@ozlabs.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-25powerpc/pseries/ras: Fix FWNMI_VALID off by oneNicholas Piggin
[ Upstream commit deb70f7a35a22dffa55b2c3aac71bc6fb0f486ce ] This was discovered developing qemu fwnmi sreset support. This off-by-one bug means the last 16 bytes of the rtas area can not be used for a 16 byte save area. It's not a serious bug, and QEMU implementation has to retain a workaround for old kernels, but it's good to tighten it. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Mahesh Salgaonkar <mahesh@linux.ibm.com> Link: https://lore.kernel.org/r/20200508043408.886394-7-npiggin@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-04-17powerpc/pseries: Avoid NULL pointer dereference when drmem is unavailableLibor Pechacek
commit a83836dbc53e96f13fec248ecc201d18e1e3111d upstream. In guests without hotplugagble memory drmem structure is only zero initialized. Trying to manipulate DLPAR parameters results in a crash. $ echo "memory add count 1" > /sys/kernel/dlpar Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries ... NIP: c0000000000ff294 LR: c0000000000ff248 CTR: 0000000000000000 REGS: c0000000fb9d3880 TRAP: 0300 Tainted: G E (5.5.0-rc6-2-default) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 28242428 XER: 20000000 CFAR: c0000000009a6c10 DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0 ... NIP dlpar_memory+0x6e4/0xd00 LR dlpar_memory+0x698/0xd00 Call Trace: dlpar_memory+0x698/0xd00 (unreliable) handle_dlpar_errorlog+0xc0/0x190 dlpar_store+0x198/0x4a0 kobj_attr_store+0x30/0x50 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1b0/0x290 __vfs_write+0x3c/0x70 vfs_write+0xd0/0x260 ksys_write+0xdc/0x130 system_call+0x5c/0x68 Taking closer look at the code, I can see that for_each_drmem_lmb is a macro expanding into `for (lmb = &drmem_info->lmbs[0]; lmb <= &drmem_info->lmbs[drmem_info->n_lmbs - 1]; lmb++)`. When drmem_info->lmbs is NULL, the loop would iterate through the whole address range if it weren't stopped by the NULL pointer dereference on the next line. This patch aligns for_each_drmem_lmb and for_each_drmem_lmb_in_range macro behavior with the common C semantics, where the end marker does not belong to the scanned range, and alters get_lmb_range() semantics. As a side effect, the wraparound observed in the crash is prevented. Fixes: 6c6ea53725b3 ("powerpc/mm: Separate ibm, dynamic-memory data from DT format") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Libor Pechacek <lpechacek@suse.cz> Signed-off-by: Michal Suchanek <msuchanek@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200131132829.10281-1-msuchanek@suse.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-17powerpc/pseries: Drop pointless static qualifier in vpa_debugfs_init()YueHaibing
commit 11dd34f3eae5a468013bb161a1dcf1fecd2ca321 upstream. There is no need to have the 'struct dentry *vpa_dir' variable static since new value always be assigned before use it. Fixes: c6c26fb55e8e ("powerpc/pseries: Export raw per-CPU VPA data via debugfs") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190218125644.87448-1-yuehaibing@huawei.com Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14powerpc/pseries: Allow not having ibm, hypertas-functions::hcall-multi-tce ↵Alexey Kardashevskiy
for DDW commit 7559d3d295f3365ea7ac0c0274c05e633fe4f594 upstream. By default a pseries guest supports a H_PUT_TCE hypercall which maps a single IOMMU page in a DMA window. Additionally the hypervisor may support H_PUT_TCE_INDIRECT/H_STUFF_TCE which update multiple TCEs at once; this is advertised via the device tree /rtas/ibm,hypertas-functions property which Linux converts to FW_FEATURE_MULTITCE. FW_FEATURE_MULTITCE is checked when dma_iommu_ops is used; however the code managing the huge DMA window (DDW) ignores it and calls H_PUT_TCE_INDIRECT even if it is explicitly disabled via the "multitce=off" kernel command line parameter. This adds FW_FEATURE_MULTITCE checking to the DDW code path. This changes tce_build_pSeriesLP to take liobn and page size as the huge window does not have iommu_table descriptor which usually the place to store these numbers. Fixes: 4e8b0cf46b25 ("powerpc/pseries: Add support for dynamic dma windows") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191216041924.42318-3-aik@ozlabs.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-14powerpc/pseries/vio: Fix iommu_table use-after-free refcount warningTyrel Datwyler
commit aff8c8242bc638ba57247ae1ec5f272ac3ed3b92 upstream. Commit e5afdf9dd515 ("powerpc/vfio_spapr_tce: Add reference counting to iommu_table") missed an iommu_table allocation in the pseries vio code. The iommu_table is allocated with kzalloc and as a result the associated kref gets a value of zero. This has the side effect that during a DLPAR remove of the associated virtual IOA the iommu_tce_table_put() triggers a use-after-free underflow warning. Call Trace: [c0000002879e39f0] [c00000000071ecb4] refcount_warn_saturate+0x184/0x190 (unreliable) [c0000002879e3a50] [c0000000000500ac] iommu_tce_table_put+0x9c/0xb0 [c0000002879e3a70] [c0000000000f54e4] vio_dev_release+0x34/0x70 [c0000002879e3aa0] [c00000000087cfa4] device_release+0x54/0xf0 [c0000002879e3b10] [c000000000d64c84] kobject_cleanup+0xa4/0x240 [c0000002879e3b90] [c00000000087d358] put_device+0x28/0x40 [c0000002879e3bb0] [c0000000007a328c] dlpar_remove_slot+0x15c/0x250 [c0000002879e3c50] [c0000000007a348c] remove_slot_store+0xac/0xf0 [c0000002879e3cd0] [c000000000d64220] kobj_attr_store+0x30/0x60 [c0000002879e3cf0] [c0000000004ff13c] sysfs_kf_write+0x6c/0xa0 [c0000002879e3d10] [c0000000004fde4c] kernfs_fop_write+0x18c/0x260 [c0000002879e3d60] [c000000000410f3c] __vfs_write+0x3c/0x70 [c0000002879e3d80] [c000000000415408] vfs_write+0xc8/0x250 [c0000002879e3dd0] [c0000000004157dc] ksys_write+0x7c/0x120 [c0000002879e3e20] [c00000000000b278] system_call+0x5c/0x68 Further, since the refcount was always zero the iommu_tce_table_put() fails to call the iommu_table release function resulting in a leak. Fix this issue be initilizing the iommu_table kref immediately after allocation. Fixes: e5afdf9dd515 ("powerpc/vfio_spapr_tce: Add reference counting to iommu_table") Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1579558202-26052-1-git-send-email-tyreld@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-11powerpc/pseries: Advance pfn if section is not present in lmb_is_removable()Pingfan Liu
commit fbee6ba2dca30d302efe6bddb3a886f5e964a257 upstream. In lmb_is_removable(), if a section is not present, it should continue to test the rest of the sections in the block. But the current code fails to do so. Fixes: 51925fb3c5c9 ("powerpc/pseries: Implement memory hotplug remove in the kernel") Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1578632042-12415-1-git-send-email-kernelfans@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-29mm/memory_hotplug: make remove_memory() take the device_hotplug_lockDavid Hildenbrand
commit d15e59260f62bd5e0f625cf5f5240f6ffac78ab6 upstream. Patch series "mm: online/offline_pages called w.o. mem_hotplug_lock", v3. Reading through the code and studying how mem_hotplug_lock is to be used, I noticed that there are two places where we can end up calling device_online()/device_offline() - online_pages()/offline_pages() without the mem_hotplug_lock. And there are other places where we call device_online()/device_offline() without the device_hotplug_lock. While e.g. echo "online" > /sys/devices/system/memory/memory9/state is fine, e.g. echo 1 > /sys/devices/system/memory/memory9/online Will not take the mem_hotplug_lock. However the device_lock() and device_hotplug_lock. E.g. via memory_probe_store(), we can end up calling add_memory()->online_pages() without the device_hotplug_lock. So we can have concurrent callers in online_pages(). We e.g. touch in online_pages() basically unprotected zone->present_pages then. Looks like there is a longer history to that (see Patch #2 for details), and fixing it to work the way it was intended is not really possible. We would e.g. have to take the mem_hotplug_lock in device/base/core.c, which sounds wrong. Summary: We had a lock inversion on mem_hotplug_lock and device_lock(). More details can be found in patch 3 and patch 6. I propose the general rules (documentation added in patch 6): 1. add_memory/add_memory_resource() must only be called with device_hotplug_lock. 2. remove_memory() must only be called with device_hotplug_lock. This is already documented and holds for all callers. 3. device_online()/device_offline() must only be called with device_hotplug_lock. This is already documented and true for now in core code. Other callers (related to memory hotplug) have to be fixed up. 4. mem_hotplug_lock is taken inside of add_memory/remove_memory/ online_pages/offline_pages. To me, this looks way cleaner than what we have right now (and easier to verify). And looking at the documentation of remove_memory, using lock_device_hotplug also for add_memory() feels natural. This patch (of 6): remove_memory() is exported right now but requires the device_hotplug_lock, which is not exported. So let's provide a variant that takes the lock and only export that one. The lock is already held in arch/powerpc/platforms/pseries/hotplug-memory.c drivers/acpi/acpi_memhotplug.c arch/powerpc/platforms/powernv/memtrace.c Apart from that, there are not other users in the tree. Link: http://lkml.kernel.org/r/20180925091457.28651-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Rashmica Gupta <rashmica.g@gmail.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com> Cc: Mathieu Malaterre <malat@debian.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Juergen Gross <jgross@suse.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-27powerpc/pseries/mobility: rebuild cacheinfo hierarchy post-migrationNathan Lynch
[ Upstream commit e610a466d16a086e321f0bd421e2fc75cff28605 ] It's common for the platform to replace the cache device nodes after a migration. Since the cacheinfo code is never informed about this, it never drops its references to the source system's cache nodes, causing it to wind up in an inconsistent state resulting in warnings and oopses as soon as CPU online/offline occurs after the migration, e.g. cache for /cpus/l3-cache@3113(Unified) refers to cache for /cpus/l2-cache@200d(Unified) WARNING: CPU: 15 PID: 86 at arch/powerpc/kernel/cacheinfo.c:176 release_cache+0x1bc/0x1d0 [...] NIP release_cache+0x1bc/0x1d0 LR release_cache+0x1b8/0x1d0 Call Trace: release_cache+0x1b8/0x1d0 (unreliable) cacheinfo_cpu_offline+0x1c4/0x2c0 unregister_cpu_online+0x1b8/0x260 cpuhp_invoke_callback+0x114/0xf40 cpuhp_thread_fun+0x270/0x310 smpboot_thread_fn+0x2c8/0x390 kthread+0x1b8/0x1c0 ret_from_kernel_thread+0x5c/0x68 Using device tree notifiers won't work since we want to rebuild the hierarchy only after all the removals and additions have occurred and the device tree is in a consistent state. Call cacheinfo_teardown() before processing device tree updates, and rebuild the hierarchy afterward. Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27powerpc/pseries/memory-hotplug: Fix return value type of find_aa_indexYueHaibing
[ Upstream commit b45e9d761ba2d60044b610297e3ef9f947ac157f ] The variable 'aa_index' is defined as an unsigned value in update_lmb_associativity_index(), but find_aa_index() may return -1 when dlpar_clone_property() fails. So change find_aa_index() to return a bool, which indicates whether 'aa_index' was found or not. Fixes: c05a5a40969e ("powerpc/pseries: Dynamic add entires to associativity lookup array") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Nathan Fontenot nfont@linux.vnet.ibm.com> [mpe: Tweak changelog, rename is_found to just found] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-12powerpc/vcpu: Assume dedicated processors as non-preemptSrikar Dronamraju
commit 14c73bd344da60abaf7da3ea2e7733ddda35bbac upstream. With commit 247f2f6f3c70 ("sched/core: Don't schedule threads on pre-empted vCPUs"), the scheduler avoids preempted vCPUs to schedule tasks on wakeup. This leads to wrong choice of CPU, which in-turn leads to larger wakeup latencies. Eventually, it leads to performance regression in latency sensitive benchmarks like soltp, schbench etc. On Powerpc, vcpu_is_preempted() only looks at yield_count. If the yield_count is odd, the vCPU is assumed to be preempted. However yield_count is increased whenever the LPAR enters CEDE state (idle). So any CPU that has entered CEDE state is assumed to be preempted. Even if vCPU of dedicated LPAR is preempted/donated, it should have right of first-use since they are supposed to own the vCPU. On a Power9 System with 32 cores: # lscpu Architecture: ppc64le Byte Order: Little Endian CPU(s): 128 On-line CPU(s) list: 0-127 Thread(s) per core: 8 Core(s) per socket: 1 Socket(s): 16 NUMA node(s): 2 Model: 2.2 (pvr 004e 0202) Model name: POWER9 (architected), altivec supported Hypervisor vendor: pHyp Virtualization type: para L1d cache: 32K L1i cache: 32K L2 cache: 512K L3 cache: 10240K NUMA node0 CPU(s): 0-63 NUMA node1 CPU(s): 64-127 # perf stat -a -r 5 ./schbench v5.4 v5.4 + patch Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 45 75.0000th: 62 75.0th: 63 90.0000th: 71 90.0th: 74 95.0000th: 77 95.0th: 78 *99.0000th: 91 *99.0th: 82 99.5000th: 707 99.5th: 83 99.9000th: 6920 99.9th: 86 min=0, max=10048 min=0, max=96 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 46 75.0000th: 61 75.0th: 64 90.0000th: 72 90.0th: 75 95.0000th: 79 95.0th: 79 *99.0000th: 691 *99.0th: 83 99.5000th: 3972 99.5th: 85 99.9000th: 8368 99.9th: 91 min=0, max=16606 min=0, max=117 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 46 75.0000th: 61 75.0th: 64 90.0000th: 71 90.0th: 75 95.0000th: 77 95.0th: 79 *99.0000th: 106 *99.0th: 83 99.5000th: 2364 99.5th: 84 99.9000th: 7480 99.9th: 90 min=0, max=10001 min=0, max=95 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 47 75.0000th: 62 75.0th: 65 90.0000th: 72 90.0th: 75 95.0000th: 78 95.0th: 79 *99.0000th: 93 *99.0th: 84 99.5000th: 108 99.5th: 85 99.9000th: 6792 99.9th: 90 min=0, max=17681 min=0, max=117 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 46 50.0th: 45 75.0000th: 62 75.0th: 64 90.0000th: 73 90.0th: 75 95.0000th: 79 95.0th: 79 *99.0000th: 113 *99.0th: 82 99.5000th: 2724 99.5th: 83 99.9000th: 6184 99.9th: 93 min=0, max=9887 min=0, max=111 Performance counter stats for 'system wide' (5 runs): context-switches 43,373 ( +- 0.40% ) 44,597 ( +- 0.55% ) cpu-migrations 1,211 ( +- 5.04% ) 220 ( +- 6.23% ) page-faults 15,983 ( +- 5.21% ) 15,360 ( +- 3.38% ) Waiman Long suggested using static_keys. Fixes: 247f2f6f3c70 ("sched/core: Don't schedule threads on pre-empted vCPUs") Cc: stable@vger.kernel.org # v4.18+ Reported-by: Parth Shah <parth@linux.ibm.com> Reported-by: Ihor Pasichnyk <Ihor.Pasichnyk@ibm.com> Tested-by: Juri Lelli <juri.lelli@redhat.com> Acked-by: Waiman Long <longman@redhat.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Phil Auld <pauld@redhat.com> Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.ibm.com> Tested-by: Parth Shah <parth@linux.ibm.com> [mpe: Move the key and setting of the key to pseries/setup.c] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191213035036.6913-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-09powerpc/pseries/hvconsole: Fix stack overread via udbgDaniel Axtens
[ Upstream commit 934bda59f286d0221f1a3ebab7f5156a996cc37d ] While developing KASAN for 64-bit book3s, I hit the following stack over-read. It occurs because the hypercall to put characters onto the terminal takes 2 longs (128 bits/16 bytes) of characters at a time, and so hvc_put_chars() would unconditionally copy 16 bytes from the argument buffer, regardless of supplied length. However, udbg_hvc_putc() can call hvc_put_chars() with a single-byte buffer, leading to the error. ================================================================== BUG: KASAN: stack-out-of-bounds in hvc_put_chars+0xdc/0x110 Read of size 8 at addr c0000000023e7a90 by task swapper/0 CPU: 0 PID: 0 Comm: swapper Not tainted 5.2.0-rc2-next-20190528-02824-g048a6ab4835b #113 Call Trace: dump_stack+0x104/0x154 (unreliable) print_address_description+0xa0/0x30c __kasan_report+0x20c/0x224 kasan_report+0x18/0x30 __asan_report_load8_noabort+0x24/0x40 hvc_put_chars+0xdc/0x110 hvterm_raw_put_chars+0x9c/0x110 udbg_hvc_putc+0x154/0x200 udbg_write+0xf0/0x240 console_unlock+0x868/0xd30 register_console+0x970/0xe90 register_early_udbg_console+0xf8/0x114 setup_arch+0x108/0x790 start_kernel+0x104/0x784 start_here_common+0x1c/0x534 Memory state around the buggy address: c0000000023e7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c0000000023e7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 >c0000000023e7a80: f1 f1 01 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 ^ c0000000023e7b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c0000000023e7b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Document that a 16-byte buffer is requred, and provide it in udbg. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-04Revert "powerpc/vcpu: Assume dedicated processors as non-preempt"Greg Kroah-Hartman
This reverts commit 4ba32bdbd8c66d9c7822aea8dcf4e51410df84a8 which is commit 14c73bd344da60abaf7da3ea2e7733ddda35bbac upstream. It breaks the build. Cc: Guenter Roeck <linux@roeck-us.net> Cc: Parth Shah <parth@linux.ibm.com> Cc: Ihor Pasichnyk <Ihor.Pasichnyk@ibm.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Waiman Long <longman@redhat.com> Cc: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Phil Auld <pauld@redhat.com> Cc: Vaidyanathan Srinivasan <svaidy@linux.ibm.com> Cc: Parth Shah <parth@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-04powerpc/pseries/cmm: Implement release() function for sysfs deviceDavid Hildenbrand
[ Upstream commit 7d8212747435c534c8d564fbef4541a463c976ff ] When unloading the module, one gets ------------[ cut here ]------------ Device 'cmm0' does not have a release() function, it is broken and must be fixed. See Documentation/kobject.txt. WARNING: CPU: 0 PID: 19308 at drivers/base/core.c:1244 .device_release+0xcc/0xf0 ... We only have one static fake device. There is nothing to do when releasing the device (via cmm_exit()). Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191031142933.10779-2-david@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31powerpc/vcpu: Assume dedicated processors as non-preemptSrikar Dronamraju
commit 14c73bd344da60abaf7da3ea2e7733ddda35bbac upstream. With commit 247f2f6f3c70 ("sched/core: Don't schedule threads on pre-empted vCPUs"), the scheduler avoids preempted vCPUs to schedule tasks on wakeup. This leads to wrong choice of CPU, which in-turn leads to larger wakeup latencies. Eventually, it leads to performance regression in latency sensitive benchmarks like soltp, schbench etc. On Powerpc, vcpu_is_preempted() only looks at yield_count. If the yield_count is odd, the vCPU is assumed to be preempted. However yield_count is increased whenever the LPAR enters CEDE state (idle). So any CPU that has entered CEDE state is assumed to be preempted. Even if vCPU of dedicated LPAR is preempted/donated, it should have right of first-use since they are supposed to own the vCPU. On a Power9 System with 32 cores: # lscpu Architecture: ppc64le Byte Order: Little Endian CPU(s): 128 On-line CPU(s) list: 0-127 Thread(s) per core: 8 Core(s) per socket: 1 Socket(s): 16 NUMA node(s): 2 Model: 2.2 (pvr 004e 0202) Model name: POWER9 (architected), altivec supported Hypervisor vendor: pHyp Virtualization type: para L1d cache: 32K L1i cache: 32K L2 cache: 512K L3 cache: 10240K NUMA node0 CPU(s): 0-63 NUMA node1 CPU(s): 64-127 # perf stat -a -r 5 ./schbench v5.4 v5.4 + patch Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 45 75.0000th: 62 75.0th: 63 90.0000th: 71 90.0th: 74 95.0000th: 77 95.0th: 78 *99.0000th: 91 *99.0th: 82 99.5000th: 707 99.5th: 83 99.9000th: 6920 99.9th: 86 min=0, max=10048 min=0, max=96 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 46 75.0000th: 61 75.0th: 64 90.0000th: 72 90.0th: 75 95.0000th: 79 95.0th: 79 *99.0000th: 691 *99.0th: 83 99.5000th: 3972 99.5th: 85 99.9000th: 8368 99.9th: 91 min=0, max=16606 min=0, max=117 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 46 75.0000th: 61 75.0th: 64 90.0000th: 71 90.0th: 75 95.0000th: 77 95.0th: 79 *99.0000th: 106 *99.0th: 83 99.5000th: 2364 99.5th: 84 99.9000th: 7480 99.9th: 90 min=0, max=10001 min=0, max=95 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 45 50.0th: 47 75.0000th: 62 75.0th: 65 90.0000th: 72 90.0th: 75 95.0000th: 78 95.0th: 79 *99.0000th: 93 *99.0th: 84 99.5000th: 108 99.5th: 85 99.9000th: 6792 99.9th: 90 min=0, max=17681 min=0, max=117 Latency percentiles (usec) Latency percentiles (usec) 50.0000th: 46 50.0th: 45 75.0000th: 62 75.0th: 64 90.0000th: 73 90.0th: 75 95.0000th: 79 95.0th: 79 *99.0000th: 113 *99.0th: 82 99.5000th: 2724 99.5th: 83 99.9000th: 6184 99.9th: 93 min=0, max=9887 min=0, max=111 Performance counter stats for 'system wide' (5 runs): context-switches 43,373 ( +- 0.40% ) 44,597 ( +- 0.55% ) cpu-migrations 1,211 ( +- 5.04% ) 220 ( +- 6.23% ) page-faults 15,983 ( +- 5.21% ) 15,360 ( +- 3.38% ) Waiman Long suggested using static_keys. Fixes: 247f2f6f3c70 ("sched/core: Don't schedule threads on pre-empted vCPUs") Cc: stable@vger.kernel.org # v4.18+ Reported-by: Parth Shah <parth@linux.ibm.com> Reported-by: Ihor Pasichnyk <Ihor.Pasichnyk@ibm.com> Tested-by: Juri Lelli <juri.lelli@redhat.com> Acked-by: Waiman Long <longman@redhat.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Phil Auld <pauld@redhat.com> Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.ibm.com> Tested-by: Parth Shah <parth@linux.ibm.com> [mpe: Move the key and setting of the key to pseries/setup.c] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20191213035036.6913-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-05powerpc/pseries/dlpar: Fix a missing check in dlpar_parse_cc_property()Gen Zhang
[ Upstream commit efa9ace68e487ddd29c2b4d6dd23242158f1f607 ] In dlpar_parse_cc_property(), 'prop->name' is allocated by kstrdup(). kstrdup() may return NULL, so it should be checked and handle error. And prop should be freed if 'prop->name' is NULL. Signed-off-by: Gen Zhang <blackgod016574@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05powerpc/pseries: Fix node leak in update_lmb_associativity_index()Michael Ellerman
[ Upstream commit 47918bc68b7427e961035949cc1501a864578a69 ] In update_lmb_associativity_index() we lookup dr_node using of_find_node_by_path() which takes a reference for us. In the non-error case we forget to drop the reference. Note that find_aa_index() does modify properties of the node, but doesn't need an extra reference held once it's returned. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01mm/memory_hotplug: make add_memory() take the device_hotplug_lockDavid Hildenbrand
[ Upstream commit 8df1d0e4a265f25dc1e7e7624ccdbcb4a6630c89 ] add_memory() currently does not take the device_hotplug_lock, however is aleady called under the lock from arch/powerpc/platforms/pseries/hotplug-memory.c drivers/acpi/acpi_memhotplug.c to synchronize against CPU hot-remove and similar. In general, we should hold the device_hotplug_lock when adding memory to synchronize against online/offline request (e.g. from user space) - which already resulted in lock inversions due to device_lock() and mem_hotplug_lock - see 30467e0b3be ("mm, hotplug: fix concurrent memory hot-add deadlock"). add_memory()/add_memory_resource() will create memory block devices, so this really feels like the right thing to do. Holding the device_hotplug_lock makes sure that a memory block device can really only be accessed (e.g. via .online/.state) from user space, once the memory has been fully added to the system. The lock is not held yet in drivers/xen/balloon.c arch/powerpc/platforms/powernv/memtrace.c drivers/s390/char/sclp_cmd.c drivers/hv/hv_balloon.c So, let's either use the locked variants or take the lock. Don't export add_memory_resource(), as it once was exported to be used by XEN, which is never built as a module. If somebody requires it, we also have to export a locked variant (as device_hotplug_lock is never exported). Link: http://lkml.kernel.org/r/20180925091457.28651-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mathieu Malaterre <malat@debian.org> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01powerpc/pseries: Export raw per-CPU VPA data via debugfsAravinda Prasad
[ Upstream commit c6c26fb55e8e4b3fc376be5611685990a17de27a ] This patch exports the raw per-CPU VPA data via debugfs. A per-CPU file is created which exports the VPA data of that CPU to help debug some of the VPA related issues or to analyze the per-CPU VPA related statistics. v3: Removed offline CPU check. v2: Included offline CPU check and other review comments. Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-24powerpc/pseries: Fix how we iterate over the DTL entriesNaveen N. Rao
[ Upstream commit 9258227e9dd1da8feddb07ad9702845546a581c9 ] When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not set, we look up dtl_idx in the lppaca to determine the number of entries in the buffer. Since lppaca is in big endian, we need to do an endian conversion before using this in our calculation to determine the number of entries in the buffer. Without this, we do not iterate over the existing entries in the DTL buffer properly. Fixes: 7c105b63bd98 ("powerpc: Add CONFIG_CPU_LITTLE_ENDIAN kernel config option.") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-24powerpc/pseries: Fix DTL buffer registrationNaveen N. Rao
[ Upstream commit db787af1b8a6b4be428ee2ea7d409dafcaa4a43c ] When CONFIG_VIRT_CPU_ACCOUNTING_NATIVE is not set, we register the DTL buffer for a cpu when the associated file under powerpc/dtl in debugfs is opened. When doing so, we need to set the size of the buffer being registered in the second u32 word of the buffer. This needs to be in big endian, but we are not doing the conversion resulting in the below error showing up in dmesg: dtl_start: DTL registration for cpu 0 (hw 0) failed with -4 Fix this in the obvious manner. Fixes: 7c105b63bd98 ("powerpc: Add CONFIG_CPU_LITTLE_ENDIAN kernel config option.") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20powerpc/pseries/memory-hotplug: Only update DT once per memory DLPAR requestNathan Fontenot
[ Upstream commit 063b8b1251fd069f3740339fca56119d218f11ba ] The updates to powerpc numa and memory hotplug code now use the in-kernel LMB array instead of the device tree. This change allows the pseries memory DLPAR code to only update the device tree once after successfully handling a DLPAR request. Prior to the in-kernel LMB array, the numa code looked up the affinity for memory being added in the device tree, the code now looks this up in the LMB array. This change means the memory hotplug code can just update the affinity for an LMB in the LMB array instead of updating the device tree. This also provides a savings in kernel memory. When updating the device tree old properties are never free'ed since there is no usecount on properties. This behavior leads to a new copy of the property being allocated every time a LMB is added or removed (i.e. a request to add 100 LMBs creates 100 new copies of the property). With this update only a single new property is created when a DLPAR request completes successfully. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-11powerpc/pseries: Fix cpu_hotplug_lock acquisition in resize_hpt()Gautham R. Shenoy
[ Upstream commit c784be435d5dae28d3b03db31753dd7a18733f0c ] The calls to arch_add_memory()/arch_remove_memory() are always made with the read-side cpu_hotplug_lock acquired via memory_hotplug_begin(). On pSeries, arch_add_memory()/arch_remove_memory() eventually call resize_hpt() which in turn calls stop_machine() which acquires the read-side cpu_hotplug_lock again, thereby resulting in the recursive acquisition of this lock. In the absence of CONFIG_PROVE_LOCKING, we hadn't observed a system lockup during a memory hotplug operation because cpus_read_lock() is a per-cpu rwsem read, which, in the fast-path (in the absence of the writer, which in our case is a CPU-hotplug operation) simply increments the read_count on the semaphore. Thus a recursive read in the fast-path doesn't cause any problems. However, we can hit this problem in practice if there is a concurrent CPU-Hotplug operation in progress which is waiting to acquire the write-side of the lock. This will cause the second recursive read to block until the writer finishes. While the writer is blocked since the first read holds the lock. Thus both the reader as well as the writers fail to make any progress thereby blocking both CPU-Hotplug as well as Memory Hotplug operations. Memory-Hotplug CPU-Hotplug CPU 0 CPU 1 ------ ------ 1. down_read(cpu_hotplug_lock.rw_sem) [memory_hotplug_begin] 2. down_write(cpu_hotplug_lock.rw_sem) [cpu_up/cpu_down] 3. down_read(cpu_hotplug_lock.rw_sem) [stop_machine()] Lockdep complains as follows in these code-paths. swapper/0/1 is trying to acquire lock: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: stop_machine+0x2c/0x60 but task is already holding lock: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: mem_hotplug_begin+0x20/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(cpu_hotplug_lock.rw_sem); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by swapper/0/1: #0: (____ptrval____) (&dev->mutex){....}, at: __driver_attach+0x12c/0x1b0 #1: (____ptrval____) (cpu_hotplug_lock.rw_sem){++++}, at: mem_hotplug_begin+0x20/0x50 #2: (____ptrval____) (mem_hotplug_lock.rw_sem){++++}, at: percpu_down_write+0x54/0x1a0 stack backtrace: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc5-58373-gbc99402235f3-dirty #166 Call Trace: dump_stack+0xe8/0x164 (unreliable) __lock_acquire+0x1110/0x1c70 lock_acquire+0x240/0x290 cpus_read_lock+0x64/0xf0 stop_machine+0x2c/0x60 pseries_lpar_resize_hpt+0x19c/0x2c0 resize_hpt_for_hotplug+0x70/0xd0 arch_add_memory+0x58/0xfc devm_memremap_pages+0x5e8/0x8f0 pmem_attach_disk+0x764/0x830 nvdimm_bus_probe+0x118/0x240 really_probe+0x230/0x4b0 driver_probe_device+0x16c/0x1e0 __driver_attach+0x148/0x1b0 bus_for_each_dev+0x90/0x130 driver_attach+0x34/0x50 bus_add_driver+0x1a8/0x360 driver_register+0x108/0x170 __nd_driver_register+0xd0/0xf0 nd_pmem_driver_init+0x34/0x48 do_one_initcall+0x1e0/0x45c kernel_init_freeable+0x540/0x64c kernel_init+0x2c/0x160 ret_from_kernel_thread+0x5c/0x68 Fix this issue by 1) Requiring all the calls to pseries_lpar_resize_hpt() be made with cpu_hotplug_lock held. 2) In pseries_lpar_resize_hpt() invoke stop_machine_cpuslocked() as a consequence of 1) 3) To satisfy 1), in hpt_order_set(), call mmu_hash_ops.resize_hpt() with cpu_hotplug_lock held. Fixes: dbcf929c0062 ("powerpc/pseries: Add support for hash table resizing") Cc: stable@vger.kernel.org # v4.11+ Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1557906352-29048-1-git-send-email-ego@linux.vnet.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-07powerpc/pseries: correctly track irq state in default idleNathan Lynch
[ Upstream commit 92c94dfb69e350471473fd3075c74bc68150879e ] prep_irq_for_idle() is intended to be called before entering H_CEDE (and it is used by the pseries cpuidle driver). However the default pseries idle routine does not call it, leading to mismanaged lazy irq state when the cpuidle driver isn't in use. Manifestations of this include: * Dropped IPIs in the time immediately after a cpu comes online (before it has installed the cpuidle handler), making the online operation block indefinitely waiting for the new cpu to respond. * Hitting this WARN_ON in arch_local_irq_restore(): /* * We should already be hard disabled here. We had bugs * where that wasn't the case so let's dbl check it and * warn if we are wrong. Only do that when IRQ tracing * is enabled as mfmsr() can be costly. */ if (WARN_ON_ONCE(mfmsr() & MSR_EE)) __hard_irq_disable(); Call prep_irq_for_idle() from pseries_lpar_idle() and honor its result. Fixes: 363edbe2614a ("powerpc: Default arch idle could cede processor on pseries") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190910225244.25056-1-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-07powerpc/pseries/mobility: use cond_resched when updating device treeNathan Lynch
[ Upstream commit ccfb5bd71d3d1228090a8633800ae7cdf42a94ac ] After a partition migration, pseries_devicetree_update() processes changes to the device tree communicated from the platform to Linux. This is a relatively heavyweight operation, with multiple device tree searches, memory allocations, and conversations with partition firmware. There's a few levels of nested loops which are bounded only by decisions made by the platform, outside of Linux's control, and indeed we have seen RCU stalls on large systems while executing this call graph. Use cond_resched() in these loops so that the cpu is yielded when needed. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190802192926.19277-4-nathanl@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-31powerpc/pseries/mobility: prevent cpu hotplug during DT updateNathan Lynch
[ Upstream commit e59a175faa8df9d674247946f2a5a9c29c835725 ] CPU online/offline code paths are sensitive to parts of the device tree (various cpu node properties, cache nodes) that can be changed as a result of a migration. Prevent CPU hotplug while the device tree potentially is inconsistent. Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-26powerpc/pseries: Fix oops in hotplug memory notifierNathan Lynch
commit 0aa82c482ab2ece530a6f44897b63b274bb43c8e upstream. During post-migration device tree updates, we can oops in pseries_update_drconf_memory() if the source device tree has an ibm,dynamic-memory-v2 property and the destination has a ibm,dynamic_memory (v1) property. The notifier processes an "update" for the ibm,dynamic-memory property but it's really an add in this scenario. So make sure the old property object is there before dereferencing it. Fixes: 2b31e3aec1db ("powerpc/drmem: Add support for ibm, dynamic-memory-v2 property") Cc: stable@vger.kernel.org # v4.16+ Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-04jump_label: move 'asm goto' support test to KconfigMasahiro Yamada
commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream. Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Sedat Dilek <sedat.dilek@gmail.com> [nc: Fix trivial conflicts in 4.19 arch/xtensa/kernel/jump_label.c doesn't exist yet Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently eliminated] Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-05powerpc/pseries: Perform full re-add of CPU for topology update post-migrationNathan Fontenot
[ Upstream commit 81b61324922c67f73813d8a9c175f3c153f6a1c6 ] On pseries systems, performing a partition migration can result in altering the nodes a CPU is assigned to on the destination system. For exampl, pre-migration on the source system CPUs are in node 1 and 3, post-migration on the destination system CPUs are in nodes 2 and 3. Handling the node change for a CPU can cause corruption in the slab cache if we hit a timing where a CPUs node is changed while cache_reap() is invoked. The corruption occurs because the slab cache code appears to rely on the CPU and slab cache pages being on the same node. The current dynamic updating of a CPUs node done in arch/powerpc/mm/numa.c does not prevent us from hitting this scenario. Changing the device tree property update notification handler that recognizes an affinity change for a CPU to do a full DLPAR remove and add of the CPU instead of dynamically changing its node resolves this issue. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com> Tested-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-03powerpc/pseries/energy: Use OF accessor functions to read ibm,drc-indexesGautham R. Shenoy
commit ce9afe08e71e3f7d64f337a6e932e50849230fc2 upstream. In cpu_to_drc_index() in the case when FW_FEATURE_DRC_INFO is absent, we currently use of_read_property() to obtain the pointer to the array corresponding to the property "ibm,drc-indexes". The elements of this array are of type __be32, but are accessed without any conversion to the OS-endianness, which is buggy on a Little Endian OS. Fix this by using of_property_read_u32_index() accessor function to safely read the elements of the array. Fixes: e83636ac3334 ("pseries/drc-info: Search DRC properties for CPU indexes") Cc: stable@vger.kernel.org # v4.16+ Reported-by: Pavithra R. Prakash <pavrampu@in.ibm.com> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> [mpe: Make the WARN_ON a WARN_ON_ONCE so it's not retriggerable] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12powerpc/fadump: Do not allow hot-remove memory from fadump reserved area.Mahesh Salgaonkar
[ Upstream commit 0db6896ff6332ba694f1e61b93ae3b2640317633 ] For fadump to work successfully there should not be any holes in reserved memory ranges where kernel has asked firmware to move the content of old kernel memory in event of crash. Now that fadump uses CMA for reserved area, this memory area is now not protected from hot-remove operations unless it is cma allocated. Hence, fadump service can fail to re-register after the hot-remove operation, if hot-removed memory belongs to fadump reserved region. To avoid this make sure that memory from fadump reserved area is not hot-removable if fadump is registered. However, if user still wants to remove that memory, he can do so by manually stopping fadump service before hot-remove operation. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-12powerpc/pseries: add of_node_put() in dlpar_detach_node()Frank Rowand
[ Upstream commit 5b3f5c408d8cc59b87e47f1ab9803dbd006e4a91 ] The previous commit, "of: overlay: add missing of_node_get() in __of_attach_node_sysfs" added a missing of_node_get() to __of_attach_node_sysfs(). This results in a refcount imbalance for nodes attached with dlpar_attach_node(). The calling sequence from dlpar_attach_node() to __of_attach_node_sysfs() is: dlpar_attach_node() of_attach_node() __of_attach_node_sysfs() For more detailed description of the node refcount, see commit 68baf692c435 ("powerpc/pseries: Fix of_node_put() underflow during DLPAR remove"). Tested-by: Alan Tull <atull@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2018-08-17Merge tag 'powerpc-4.19-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Notable changes: - A fix for a bug in our page table fragment allocator, where a page table page could be freed and reallocated for something else while still in use, leading to memory corruption etc. The fix reuses pt_mm in struct page (x86 only) for a powerpc only refcount. - Fixes to our pkey support. Several are user-visible changes, but bring us in to line with x86 behaviour and/or fix outright bugs. Thanks to Florian Weimer for reporting many of these. - A series to improve the hvc driver & related OPAL console code, which have been seen to cause hardlockups at times. The hvc driver changes in particular have been in linux-next for ~month. - Increase our MAX_PHYSMEM_BITS to 128TB when SPARSEMEM_VMEMMAP=y. - Remove Power8 DD1 and Power9 DD1 support, neither chip should be in use anywhere other than as a paper weight. - An optimised memcmp implementation using Power7-or-later VMX instructions - Support for barrier_nospec on some NXP CPUs. - Support for flushing the count cache on context switch on some IBM CPUs (controlled by firmware), as a Spectre v2 mitigation. - A series to enhance the information we print on unhandled signals to bring it into line with other arches, including showing the offending VMA and dumping the instructions around the fault. Thanks to: Aaro Koskinen, Akshay Adiga, Alastair D'Silva, Alexey Kardashevskiy, Alexey Spirkov, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Arnd Bergmann, Bartosz Golaszewski, Benjamin Herrenschmidt, Bharat Bhushan, Bjoern Noetel, Boqun Feng, Breno Leitao, Bryant G. Ly, Camelia Groza, Christophe Leroy, Christoph Hellwig, Cyril Bur, Dan Carpenter, Daniel Klamt, Darren Stevens, Dave Young, David Gibson, Diana Craciun, Finn Thain, Florian Weimer, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geoff Levand, Guenter Roeck, Gustavo Romero, Haren Myneni, Hari Bathini, Joel Stanley, Jonathan Neuschäfer, Kees Cook, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring, Mathieu Malaterre, Mauro S. M. Rodrigues, Michael Hanselmann, Michael Neuling, Michael Schmitz, Mukesh Ojha, Murilo Opsfelder Araujo, Nicholas Piggin, Parth Y Shah, Paul Mackerras, Paul Menzel, Ram Pai, Randy Dunlap, Rashmica Gupta, Reza Arbab, Rodrigo R. Galvao, Russell Currey, Sam Bobroff, Scott Wood, Shilpasri G Bhat, Simon Guo, Souptick Joarder, Stan Johnson, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vasant Hegde, Venkat Rao, zhong jiang" * tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (234 commits) powerpc/mm/book3s/radix: Add mapping statistics powerpc/uaccess: Enable get_user(u64, *p) on 32-bit powerpc/mm/hash: Remove unnecessary do { } while(0) loop powerpc/64s: move machine check SLB flushing to mm/slb.c powerpc/powernv/idle: Fix build error powerpc/mm/tlbflush: update the mmu_gather page size while iterating address range powerpc/mm: remove warning about ‘type’ being set powerpc/32: Include setup.h header file to fix warnings powerpc: Move `path` variable inside DEBUG_PROM powerpc/powermac: Make some functions static powerpc/powermac: Remove variable x that's never read cxl: remove a dead branch powerpc/powermac: Add missing include of header pmac.h powerpc/kexec: Use common error handling code in setup_new_fdt() powerpc/xmon: Add address lookup for percpu symbols powerpc/mm: remove huge_pte_offset_and_shift() prototype powerpc/lib: Use patch_site to patch copy_32 functions once cache is enabled powerpc/pseries: Fix endianness while restoring of r3 in MCE handler. powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements powerpc/fadump: handle crash memory ranges array index overflow ...
2018-08-10powerpc/pseries: Fix endianness while restoring of r3 in MCE handler.Mahesh Salgaonkar
During Machine Check interrupt on pseries platform, register r3 points RTAS extended event log passed by hypervisor. Since hypervisor uses r3 to pass pointer to rtas log, it stores the original r3 value at the start of the memory (first 8 bytes) pointed by r3. Since hypervisor stores this info and rtas log is in BE format, linux should make sure to restore r3 value in correct endian format. Without this patch when MCE handler, after recovery, returns to code that that caused the MCE may end up with Data SLB access interrupt for invalid address followed by kernel panic or hang. Severe Machine check interrupt [Recovered] NIP [d00000000ca301b8]: init_module+0x1b8/0x338 [bork_kernel] Initiator: CPU Error type: SLB [Multihit] Effective address: d00000000ca70000 cpu 0xa: Vector: 380 (Data SLB Access) at [c0000000fc7775b0] pc: c0000000009694c0: vsnprintf+0x80/0x480 lr: c0000000009698e0: vscnprintf+0x20/0x60 sp: c0000000fc777830 msr: 8000000002009033 dar: a803a30c000000d0 current = 0xc00000000bc9ef00 paca = 0xc00000001eca5c00 softe: 3 irq_happened: 0x01 pid = 8860, comm = insmod vscnprintf+0x20/0x60 vprintk_emit+0xb4/0x4b0 vprintk_func+0x5c/0xd0 printk+0x38/0x4c init_module+0x1c0/0x338 [bork_kernel] do_one_initcall+0x54/0x230 do_init_module+0x8c/0x248 load_module+0x12b8/0x15b0 sys_finit_module+0xa8/0x110 system_call+0x58/0x6c --- Exception: c00 (System Call) at 00007fff8bda0644 SP (7fffdfbfe980) is in userspace This patch fixes this issue. Fixes: a08a53ea4c97 ("powerpc/le: Enable RTAS events support") Cc: stable@vger.kernel.org # v3.15+ Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>