From 53d38316ab2017a7c0d733765b521700aa357ec9 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Fri, 5 Nov 2021 13:44:42 -0700 Subject: mm/memory_hotplug: handle memblock_add_node() failures in add_memory_resource() 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 Cc: Mike Rapoport Cc: Michal Hocko Cc: Oscar Salvador Cc: Jianyong Wu Cc: "Aneesh Kumar K . V" Cc: Vineet Gupta Cc: Geert Uytterhoeven Cc: Huacai Chen Cc: Jiaxun Yang Cc: Thomas Bogendoerfer Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Eric Biederman Cc: Arnd Bergmann Cc: Shahab Vahedi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory_hotplug.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 0aa7ca3dfbc9..9d254e88221e 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1369,8 +1369,11 @@ 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) @@ -1443,6 +1446,7 @@ error: rollback_node_hotadd(nid); if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) memblock_remove(start, size); +error_mem_hotplug_end: mem_hotplug_done(); return ret; } -- cgit v1.2.3