kernel/resource: fix kfree() of bootmem memory again
[ Upstream commit0cbcc92917
] Since commitebff7d8f27
("mem hotunplug: fix kfree() of bootmem memory"), we could get a resource allocated during boot via alloc_resource(). And it's required to release the resource using free_resource(). Howerver, many people use kfree directly which will result in kernel BUG. In order to fix this without fixing every call site, just leak a couple of bytes in such corner case. Link: https://lkml.kernel.org/r/20220217083619.19305-1-linmiaohe@huawei.com Fixes:ebff7d8f27
("mem hotunplug: fix kfree() of bootmem memory") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Suggested-by: David Hildenbrand <david@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Alistair Popple <apopple@nvidia.com> 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>
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@ -56,14 +56,6 @@ struct resource_constraint {
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static DEFINE_RWLOCK(resource_lock);
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static DEFINE_RWLOCK(resource_lock);
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/*
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* For memory hotplug, there is no way to free resource entries allocated
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* by boot mem after the system is up. So for reusing the resource entry
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* we need to remember the resource.
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*/
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static struct resource *bootmem_resource_free;
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static DEFINE_SPINLOCK(bootmem_resource_lock);
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static struct resource *next_resource(struct resource *p)
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static struct resource *next_resource(struct resource *p)
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{
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{
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if (p->child)
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if (p->child)
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@ -160,36 +152,19 @@ __initcall(ioresources_init);
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static void free_resource(struct resource *res)
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static void free_resource(struct resource *res)
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{
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{
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if (!res)
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/**
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return;
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* If the resource was allocated using memblock early during boot
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* we'll leak it here: we can only return full pages back to the
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if (!PageSlab(virt_to_head_page(res))) {
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* buddy and trying to be smart and reusing them eventually in
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spin_lock(&bootmem_resource_lock);
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* alloc_resource() overcomplicates resource handling.
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res->sibling = bootmem_resource_free;
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*/
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bootmem_resource_free = res;
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if (res && PageSlab(virt_to_head_page(res)))
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spin_unlock(&bootmem_resource_lock);
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} else {
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kfree(res);
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kfree(res);
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}
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}
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}
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static struct resource *alloc_resource(gfp_t flags)
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static struct resource *alloc_resource(gfp_t flags)
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{
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{
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struct resource *res = NULL;
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return kzalloc(sizeof(struct resource), flags);
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spin_lock(&bootmem_resource_lock);
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if (bootmem_resource_free) {
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res = bootmem_resource_free;
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bootmem_resource_free = res->sibling;
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}
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spin_unlock(&bootmem_resource_lock);
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if (res)
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memset(res, 0, sizeof(struct resource));
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else
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res = kzalloc(sizeof(struct resource), flags);
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return res;
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}
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}
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/* Return the conflict entry if you can't request it */
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/* Return the conflict entry if you can't request it */
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