Commit 4710e4fc authored by Christophe JAILLET's avatar Christophe JAILLET Committed by Sean Christopherson
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KVM: SVM: Remove a useless zeroing of allocated memory 



Remove KVM's unnecessary zeroing of memory when allocating the pages array
in sev_pin_memory() via __vmalloc(), as the array is only used to hold
kernel pointers.  The kmalloc() path for "small" regions doesn't zero the
array, and if KVM leaks state and/or accesses uninitialized data, then the
kernel has bigger problems.

Signed-off-by: default avatarChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/c7619a3d3cbb36463531a7c73ccbde9db587986c.1710004509.git.christophe.jaillet@wanadoo.fr


[sean: massage changelog]
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent fec50db7

arch/x86/kvm/svm/sev.c

+1 −1
Original line number Diff line number Diff line
@@ -434,7 +434,7 @@ static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr, 
	/* Avoid using vmalloc for smaller buffers. */

	size = npages * sizeof(struct page *);

	if (size > PAGE_SIZE)

		pages = __vmalloc(size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);

		pages = __vmalloc(size, GFP_KERNEL_ACCOUNT);

	else

		pages = kmalloc(size, GFP_KERNEL_ACCOUNT);