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path: root/include/asm-x86_64/cpufeature.h
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2006-04-20[PATCH] i386/x86-64: Fix x87 information leak between processesAndi Kleen
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: Linus Torvalds <torvalds@osdl.org>
2006-02-04[PATCH] x86_64: Undo the earlier changes to remove unrolled copy/memset ↵Andi Kleen
functions They cause quite bad performance regressions on Netburst This is temporary until we can get new optimized functions for these CPUs. This undoes changes that were done in 2.6.15 and in 2.6.16-rc1, essentially bringing the code back to 2.6.14 level. Only change is I renamed the X86_FEATURE_K8_C flag to X86_FEATURE_REP_GOOD and fixed the check for the flag and also fixed some comments. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11[PATCH] x86_64: Remove unused AMD K8 C stepping flagAndi Kleen
X86_FEATURE_K8_C was a synthetic Linux CPUID flag that was used for some code optimizations in Opteron C stepping or later. But support for pre C stepping optimizations has been removed, so this isn't needed anymore. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11[PATCH] x86_64: On Intel CPUs don't do an additional CPU sync before RDTSCAndi Kleen
RDTSC serialization using cpuid is not needed for Intel platforms. This increases gettimeofday performance. Cc: vojtech@suse.cz Cc: rohit.seth@intel.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01[PATCH] CPUID bug and inconsistency fixH. Peter Anvin
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>
2005-04-16[PATCH] x86_64: Support constantly ticking TSCsAndi Kleen
On Intel Noconas the TSC ticks with a constant frequency. Don't scale the factor used by udelay when cpufreq changes the frequency. This generalizes an earlier patch by Intel for this. Cc: <venkatesh.pallipadi@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
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!