diff options
| author | Alexander Kuleshov <kuleshovmail@gmail.com> | 2018-07-14 02:27:46 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-17 11:31:45 +0200 |
| commit | a1b00d57298f013e5213dee6c1a5aba6766108ca (patch) | |
| tree | eb4b746f58265444670a5e977929822481f21168 | |
| parent | 7b354f89fd5a538ced93afd5563e77b85eadb669 (diff) | |
x86/boot: Simplify kernel load address alignment check
commit a4733143085d6c782ac1e6c85778655b6bac1d4e upstream
We are using %rax as temporary register to check the kernel
address alignment. We don't really have to since the TEST
instruction does not clobber the destination operand.
Suggested-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Popov <alpopov@ptsecurity.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1453531828-19291-1-git-send-email-kuleshovmail@gmail.com
Link: http://lkml.kernel.org/r/1453842730-28463-11-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Matt Helsley (VMware) <matt.helsley@gmail.com>
Reviewed-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Bo Gan <ganb@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kernel/head_64.S | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 4034e905741a..734ba1d0f686 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -76,9 +76,7 @@ startup_64: subq $_text - __START_KERNEL_map, %rbp /* Is the address not 2M aligned? */ - movq %rbp, %rax - andl $~PMD_PAGE_MASK, %eax - testl %eax, %eax + testl $~PMD_PAGE_MASK, %ebp jnz bad_address /* |