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commit 2961298efe1ea1b6fc0d7ee8b76018fa6c0bcef2 We want to expose the hardware features simply in /proc/cpuinfo as "ibrs", "ibpb" and "stibp". Since AMD has separate CPUID bits for those, use them as the user-visible bits. When the Intel SPEC_CTRL bit is set which indicates both IBRS and IBPB capability, set those (AMD) bits accordingly. Likewise if the Intel STIBP bit is set, set the AMD STIBP that's used for the generic hardware capability. Hide the rest from /proc/cpuinfo by putting "" in the comments. Including RETPOLINE and RETPOLINE_AMD which shouldn't be visible there. There are patches to make the sysfs vulnerabilities information non-readable by non-root, and the same should apply to all information about which mitigations are actually in use. Those *shouldn't* appear in /proc/cpuinfo. The feature bit for whether IBPB is actually used, which is needed for ALTERNATIVEs, is renamed to X86_FEATURE_USE_IBPB. Originally-by: Borislav Petkov <bp@suse.de> Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: ak@linux.intel.com Cc: dave.hansen@intel.com Cc: karahmed@amazon.de Cc: arjan@linux.intel.com Cc: torvalds@linux-foundation.org Cc: peterz@infradead.org Cc: bp@alien8.de Cc: pbonzini@redhat.com Cc: tim.c.chen@linux.intel.com Cc: gregkh@linux-foundation.org Link: https://lkml.kernel.org/r/1517070274-12128-2-git-send-email-dwmw@amazon.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.