kernel/include/linux/set_memory.h, branch linux-5.0.y

x86/memory_failure: Introduce {set, clear}_mce_nospec()

2018-08-20T16:22:45Z

Currently memory_failure() returns zero if the error was handled. On that result mce_unmap_kpfn() is called to zap the page out of the kernel linear mapping to prevent speculative fetches of potentially poisoned memory. However, in the case of dax mapped devmap pages the page may be in active permanent use by the device driver, so it cannot be unmapped from the kernel. Instead of marking the page not present, marking the page UC should be sufficient for preventing poison from being pre-fetched into the cache. Convert mce_unmap_pfn() to set_mce_nospec() remapping the page as UC, to hide it from speculative accesses. Given that that persistent memory errors can be cleared by the driver, include a facility to restore the page to cacheable operation, clear_mce_nospec(). Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Borislav Petkov Cc: Cc: Acked-by: Tony Luck Signed-off-by: Dan Williams Acked-by: Ingo Molnar Signed-off-by: Dave Jiang

set_memory.h: Provide set_memory_{en,de}crypted() stubs

2018-03-20T09:01:58Z

... to make these APIs more universally available. Tested-by: Tom Lendacky Signed-off-by: Christoph Hellwig Reviewed-by: Thomas Gleixner Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Tom Lendacky Cc: David Woodhouse Cc: Joerg Roedel Cc: Jon Mason Cc: Linus Torvalds Cc: Muli Ben-Yehuda Cc: Peter Zijlstra Cc: iommu@lists.linux-foundation.org Link: http://lkml.kernel.org/r/20180319103826.12853-11-hch@lst.de Signed-off-by: Ingo Molnar

provide linux/set_memory.h

2017-07-06T23:24:30Z

Currently code that wants to use set_memory_ro() etc, needs to include asm/set_memory.h, which doesn't exist on all arches. Some code knows it only builds on arches which have the header, other code guards the inclusion with an #ifdef, neither is ideal. So create linux/set_memory.h. This always exists, so users don't need an #ifdef just to include the header. When CONFIG_ARCH_HAS_SET_MEMORY=y it includes asm/set_memory.h, otherwise it provides empty non-failing implementations. Link: http://lkml.kernel.org/r/1498717781-29151-1-git-send-email-mpe@ellerman.id.au Signed-off-by: Michael Ellerman Acked-by: Daniel Borkmann Acked-by: Kees Cook Acked-by: Laura Abbott Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds