5.15-stable review patch. If anyone has any objections, please let me know.
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From: David Hildenbrand david@redhat.com
[ Upstream commit 53d38316ab2017a7c0d733765b521700aa357ec9 ]
Patch series "mm/memory_hotplug: full support for add_memory_driver_managed() with CONFIG_ARCH_KEEP_MEMBLOCK", v2.
Architectures that require CONFIG_ARCH_KEEP_MEMBLOCK=y, such as arm64, don't cleanly support add_memory_driver_managed() yet. Most prominently, kexec_file can still end up placing kexec images on such driver-managed memory, resulting in undesired behavior, for example, having kexec images located on memory not part of the firmware-provided memory map.
Teaching kexec to not place images on driver-managed memory is especially relevant for virtio-mem. Details can be found in commit 7b7b27214bba ("mm/memory_hotplug: introduce add_memory_driver_managed()").
Extend memblock with a new flag and set it from memory hotplug code when applicable. This is required to fully support virtio-mem on arm64, making also kexec_file behave like on x86-64.
This patch (of 2):
If memblock_add_node() fails, we're most probably running out of memory. While this is unlikely to happen, it can happen and having memory added without a memblock can be problematic for architectures that use memblock to detect valid memory. Let's fail in a nice way instead of silently ignoring the error.
Link: https://lkml.kernel.org/r/20211004093605.5830-1-david@redhat.com Link: https://lkml.kernel.org/r/20211004093605.5830-2-david@redhat.com Signed-off-by: David Hildenbrand david@redhat.com Cc: Mike Rapoport rppt@kernel.org Cc: Michal Hocko mhocko@suse.com Cc: Oscar Salvador osalvador@suse.de Cc: Jianyong Wu Jianyong.Wu@arm.com Cc: "Aneesh Kumar K . V" aneesh.kumar@linux.ibm.com Cc: Vineet Gupta vgupta@kernel.org Cc: Geert Uytterhoeven geert@linux-m68k.org Cc: Huacai Chen chenhuacai@kernel.org Cc: Jiaxun Yang jiaxun.yang@flygoat.com Cc: Thomas Bogendoerfer tsbogend@alpha.franken.de Cc: Heiko Carstens hca@linux.ibm.com Cc: Vasily Gorbik gor@linux.ibm.com Cc: Christian Borntraeger borntraeger@de.ibm.com Cc: Eric Biederman ebiederm@xmission.com Cc: Arnd Bergmann arnd@arndb.de Cc: Shahab Vahedi shahab@synopsys.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Stable-dep-of: c7206e7bd214 ("MIPS: Loongson64: Handle more memory types passed from firmware") Signed-off-by: Sasha Levin sashal@kernel.org --- mm/memory_hotplug.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index bf611c55fc66b..bc52a9d201ea6 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1384,8 +1384,11 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
mem_hotplug_begin();
- if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) - memblock_add_node(start, size, nid); + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { + ret = memblock_add_node(start, size, nid); + if (ret) + goto error_mem_hotplug_end; + }
ret = __try_online_node(nid, false); if (ret < 0) @@ -1458,6 +1461,7 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) rollback_node_hotadd(nid); if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) memblock_remove(start, size); +error_mem_hotplug_end: mem_hotplug_done(); return ret; }