| Age | Commit message (Collapse) | Author |
|---|
|
AMD K7/K8 CPUs only save/restore the FOP/FIP/FDP x87 registers in FXSAVE
when an exception is pending. This means the value leak through context
switches and allow processes to observe some x87 instruction state of
other processes.
This was actually documented by AMD, but nobody recognized it as being
different from Intel before.
The fix first adds an optimization: instead of unconditionally calling
FNCLEX after each FXSAVE test if ES is pending and skip it when not
needed. Then do a x87 load from a kernel variable to clear FOP/FIP/FDP.
This means other processes always will only see a constant value defined
by the kernel in their FP state.
I took some pain to make sure to chose a variable that's already in L1
during context switch to make the overhead of this low.
Also alternative() is used to patch away the new code on CPUs who don't
need it.
Patch for both i386/x86-64.
The problem was discovered originally by Jan Beulich. Richard Brunner
provided the basic code for the workarounds, with contribution from Jan.
This is CVE-2006-1056
Cc: richard.brunner@amd.com
Cc: jbeulich@novell.com
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
|
|
Define it for i386 too.
This is a synthetic flag that signifies that the CPU's TSC runs
at a constant P state invariant frequency.
Fix up the logic on x86-64/i386 to set it on all known CPUs.
Use the AMD defined bit to set it on future AMD CPUs.
Cc: venkatesh.pallipadi@intel.com
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
The recent support for K8 multicore was misported from x86-64 to i386, due
to an unnecessary inconsistency between the CPUID code. Sure, there is are
no x86-64 VIA chips yet, but it should happen eventually.
This patch fixes the i386 bug as well as makes x86-64 match i386 in the
handing of the CPUID array.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
|
|
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
|
