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authorTom Lendacky <thomas.lendacky@amd.com>2017-07-17 16:10:28 -0500
committerIngo Molnar <mingo@kernel.org>2017-07-18 11:38:04 +0200
commitbba4ed011a52d494aa7ef5e08cf226709bbf3f60 (patch)
treee7302e86dd5b1a83356151e1155cec9736ee8ed0 /kernel/kexec_core.c
parentd0ec49d4de90806755e17289bd48464a1a515823 (diff)
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x86/mm, kexec: Allow kexec to be used with SME
Provide support so that kexec can be used to boot a kernel when SME is enabled. Support is needed to allocate pages for kexec without encryption. This is needed in order to be able to reboot in the kernel in the same manner as originally booted. Additionally, when shutting down all of the CPUs we need to be sure to flush the caches and then halt. This is needed when booting from a state where SME was not active into a state where SME is active (or vice-versa). Without these steps, it is possible for cache lines to exist for the same physical location but tagged both with and without the encryption bit. This can cause random memory corruption when caches are flushed depending on which cacheline is written last. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: <kexec@lists.infradead.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brijesh Singh <brijesh.singh@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Toshimitsu Kani <toshi.kani@hpe.com> Cc: kasan-dev@googlegroups.com Cc: kvm@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-efi@vger.kernel.org Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/b95ff075db3e7cd545313f2fb609a49619a09625.1500319216.git.thomas.lendacky@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/kexec_core.c')
-rw-r--r--kernel/kexec_core.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 1ae7c41c33c1..20fef1a38602 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -301,7 +301,7 @@ static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
{
struct page *pages;
- pages = alloc_pages(gfp_mask, order);
+ pages = alloc_pages(gfp_mask & ~__GFP_ZERO, order);
if (pages) {
unsigned int count, i;
@@ -310,6 +310,13 @@ static struct page *kimage_alloc_pages(gfp_t gfp_mask, unsigned int order)
count = 1 << order;
for (i = 0; i < count; i++)
SetPageReserved(pages + i);
+
+ arch_kexec_post_alloc_pages(page_address(pages), count,
+ gfp_mask);
+
+ if (gfp_mask & __GFP_ZERO)
+ for (i = 0; i < count; i++)
+ clear_highpage(pages + i);
}
return pages;
@@ -321,6 +328,9 @@ static void kimage_free_pages(struct page *page)
order = page_private(page);
count = 1 << order;
+
+ arch_kexec_pre_free_pages(page_address(page), count);
+
for (i = 0; i < count; i++)
ClearPageReserved(page + i);
__free_pages(page, order);