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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2018-02-26 21:04:49 +0300
committerIngo Molnar <mingo@kernel.org>2018-03-12 09:37:25 +0100
commitfb5268354d20b82c12569e325b0d051c09f983f7 (patch)
tree2fb2e6d3037ae0ed36a0bb6a2b31671c6f0df261 /arch/x86/boot/compressed/head_64.S
parent3548e131ec6a82208f36e68d31947b0fe244c7a7 (diff)
downloadblackbird-op-linux-fb5268354d20b82c12569e325b0d051c09f983f7.tar.gz
blackbird-op-linux-fb5268354d20b82c12569e325b0d051c09f983f7.zip
x86/boot/compressed/64: Save and restore trampoline memory
The memory area we found for trampoline shouldn't contain anything useful. But let's preserve the data anyway. Just to be on safe side. paging_prepare() would save the data into a buffer. cleanup_trampoline() would restore it back once we are done with the trampoline. Tested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180226180451.86788-4-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/boot/compressed/head_64.S')
-rw-r--r--arch/x86/boot/compressed/head_64.S10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index d598d65db32c..8ba0582c65d5 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -355,6 +355,16 @@ ENTRY(startup_64)
lretq
lvl5:
+ /*
+ * cleanup_trampoline() would restore trampoline memory.
+ *
+ * RSI holds real mode data and needs to be preserved across
+ * this function call.
+ */
+ pushq %rsi
+ call cleanup_trampoline
+ popq %rsi
+
/* Zero EFLAGS */
pushq $0
popfq
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