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author | Andy Lutomirski <luto@kernel.org> | 2017-12-04 15:07:19 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2017-12-17 13:59:56 +0100 |
commit | 1a935bc3d4ea61556461a9e92a68ca3556232efd (patch) | |
tree | 149d9019a18e78c7a004d44c2c368923043c38ce /arch/x86/include/asm/processor.h | |
parent | 6e60e583426c2f8751c22c2dfe5c207083b4483a (diff) | |
download | lwn-1a935bc3d4ea61556461a9e92a68ca3556232efd.tar.gz lwn-1a935bc3d4ea61556461a9e92a68ca3556232efd.zip |
x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct
SYSENTER_stack should have reliable overflow detection, which
means that it needs to be at the bottom of a page, not the top.
Move it to the beginning of struct tss_struct and page-align it.
Also add an assertion to make sure that the fixed hardware TSS
doesn't cross a page boundary.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.881827433@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/processor.h')
-rw-r--r-- | arch/x86/include/asm/processor.h | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 555c9478f3df..759051251664 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -332,7 +332,16 @@ struct x86_hw_tss { struct tss_struct { /* - * The hardware state: + * Space for the temporary SYSENTER stack, used for SYSENTER + * and the entry trampoline as well. + */ + unsigned long SYSENTER_stack_canary; + unsigned long SYSENTER_stack[64]; + + /* + * The fixed hardware portion. This must not cross a page boundary + * at risk of violating the SDM's advice and potentially triggering + * errata. */ struct x86_hw_tss x86_tss; @@ -343,15 +352,9 @@ struct tss_struct { * be within the limit. */ unsigned long io_bitmap[IO_BITMAP_LONGS + 1]; +} __aligned(PAGE_SIZE); - /* - * Space for the temporary SYSENTER stack. - */ - unsigned long SYSENTER_stack_canary; - unsigned long SYSENTER_stack[64]; -} ____cacheline_aligned; - -DECLARE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss); +DECLARE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss); /* * sizeof(unsigned long) coming from an extra "long" at the end |