kernel.git/arch/powerpc/platforms/pseries/hotplug-memory.c, branch linux-5.5.y

powerpc/pseries: Avoid NULL pointer dereference when drmem is unavailable

2020-04-17T14:12:14Z

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 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 Signed-off-by: Michal Suchanek Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200131132829.10281-1-msuchanek@suse.de Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Advance pfn if section is not present in lmb_is_removable()

2020-02-11T12:36:49Z

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 Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1578632042-12415-1-git-send-email-kernelfans@gmail.com Signed-off-by: Greg Kroah-Hartman

powerpc/pseries/hotplug-memory: Change rc variable to bool

2019-11-13T05:58:10Z

Changes the return variable to bool (as the return value) and avoids doing a ternary operation before returning. Signed-off-by: Leonardo Bras Reviewed-by: David Hildenbrand Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190802133914.30413-1-leonardo@linux.ibm.com

powerpc/pseries/hotplug-memory.c: Replace nested ifs by switch-case

2019-08-05T08:53:04Z

I noticed these nested ifs can be easily replaced by switch-cases, which can improve readability. Signed-off-by: Leonardo Bras Reviewed-by: David Hildenbrand Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190801225251.17864-1-leonardo@linux.ibm.com

Merge tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2019-07-13T23:08:36Z

Pull powerpc updates from Michael Ellerman: "Notable changes: - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver, as well as some other functions only used by drivers that haven't (yet?) made it upstream. - A fix for a bug in our handling of hardware watchpoints (eg. perf record -e mem: ...) which could lead to register corruption and kernel crashes. - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for vmalloc when using the Radix MMU. - A large but incremental rewrite of our exception handling code to use gas macros rather than multiple levels of nested CPP macros. And the usual small fixes, cleanups and improvements. Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Cédric Le Goater, Christian Lamparter, Christophe Leroy, Christophe Lombard, Christoph Hellwig, Daniel Axtens, Denis Efremov, Enrico Weigelt, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg Kurz, Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi Bangoria, Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher Boessenkool, Shaokun Zhang, Shawn Anastasio, Stewart Smith, Suraj Jitindar Singh, Thiago Jung Bauermann, YueHaibing" * tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (163 commits) powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state. powerpc/eeh: Handle hugepages in ioremap space ocxl: Update for AFU descriptor template version 1.1 powerpc/boot: pass CONFIG options in a simpler and more robust way powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h powerpc/irq: Don't WARN continuously in arch_local_irq_restore() powerpc/module64: Use symbolic instructions names. powerpc/module32: Use symbolic instructions names. powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h powerpc/module64: Fix comment in R_PPC64_ENTRY handling powerpc/boot: Add lzo support for uImage powerpc/boot: Add lzma support for uImage powerpc/boot: don't force gzipped uImage powerpc/8xx: Add microcode patch to move SMC parameter RAM. powerpc/8xx: Use IO accessors in microcode programming. powerpc/8xx: replace #ifdefs by IS_ENABLED() in microcode.c powerpc/8xx: refactor programming of microcode CPM params. powerpc/8xx: refactor printing of microcode patch name. powerpc/8xx: Refactor microcode write powerpc/8xx: refactor writing of CPM microcode arrays ...

powerpc/pseries: Fix oops in hotplug memory notifier

2019-06-14T05:36:33Z

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 Signed-off-by: Michael Ellerman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: Track LMB nid instead of using device tree

2019-04-29T12:27:16Z

When removing memory we need to remove the memory from the node it was added to instead of looking up the node it should be in in the device tree. During testing we have seen scenarios where the affinity for a LMB changes due to a partition migration or PRRN event. In these cases the node the LMB exists in may not match the node the device tree indicates it belongs in. This can lead to a system crash when trying to DLPAR remove the LMB after a migration or PRRN event. The current code looks up the node in the device tree to remove the LMB from, the crash occurs when we try to offline this node and it does not have any data, i.e. node_data[nid] == NULL. 36:mon> e cpu 0x36: Vector: 300 (Data Access) at [c0000001828b7810] pc: c00000000036d08c: try_offline_node+0x2c/0x1b0 lr: c0000000003a14ec: remove_memory+0xbc/0x110 sp: c0000001828b7a90 msr: 800000000280b033 dar: 9a28 dsisr: 40000000 current = 0xc0000006329c4c80 paca = 0xc000000007a55200 softe: 0 irq_happened: 0x01 pid = 76926, comm = kworker/u320:3 36:mon> t [link register ] c0000000003a14ec remove_memory+0xbc/0x110 [c0000001828b7a90] c00000000006a1cc arch_remove_memory+0x9c/0xd0 (unreliable) [c0000001828b7ad0] c0000000003a14e0 remove_memory+0xb0/0x110 [c0000001828b7b20] c0000000000c7db4 dlpar_remove_lmb+0x94/0x160 [c0000001828b7b60] c0000000000c8ef8 dlpar_memory+0x7e8/0xd10 [c0000001828b7bf0] c0000000000bf828 handle_dlpar_errorlog+0xf8/0x160 [c0000001828b7c60] c0000000000bf8cc pseries_hp_work_fn+0x3c/0xa0 [c0000001828b7c90] c000000000128cd8 process_one_work+0x298/0x5a0 [c0000001828b7d20] c000000000129068 worker_thread+0x88/0x620 [c0000001828b7dc0] c00000000013223c kthread+0x1ac/0x1c0 [c0000001828b7e30] c00000000000b45c ret_from_kernel_thread+0x5c/0x80 To resolve this we need to track the node a LMB belongs to when it is added to the system so we can remove it from that node instead of the node that the device tree indicates it should belong to. Signed-off-by: Nathan Fontenot Signed-off-by: Michael Ellerman

powerpc/pseries: Fix node leak in update_lmb_associativity_index()

2018-12-22T10:04:22Z

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

powerpc/fadump: Do not allow hot-remove memory from fadump reserved area.

2018-12-21T00:32:49Z

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 Signed-off-by: Michael Ellerman