user/sven/linux.git/include/asm-generic, branch v4.4.135

asm-generic: provide generic_pmdp_establish()

2018-05-30T05:48:55Z

[ Upstream commit c58f0bb77ed8bf93dfdde762b01cb67eebbdfc29 ] Patch series "Do not lose dirty bit on THP pages", v4. Vlastimil noted that pmdp_invalidate() is not atomic and we can lose dirty and access bits if CPU sets them after pmdp dereference, but before set_pmd_at(). The bug can lead to data loss, but the race window is tiny and I haven't seen any reports that suggested that it happens in reality. So I don't think it worth sending it to stable. Unfortunately, there's no way to address the issue in a generic way. We need to fix all architectures that support THP one-by-one. All architectures that have THP supported have to provide atomic pmdp_invalidate() that returns previous value. If generic implementation of pmdp_invalidate() is used, architecture needs to provide atomic pmdp_estabish(). pmdp_estabish() is not used out-side generic implementation of pmdp_invalidate() so far, but I think this can change in the future. This patch (of 12): This is an implementation of pmdp_establish() that is only suitable for an architecture that doesn't have hardware dirty/accessed bits. In this case we can't race with CPU which sets these bits and non-atomic approach is fine. Link: http://lkml.kernel.org/r/20171213105756.69879-2-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Cc: Vlastimil Babka Cc: Andrea Arcangeli Cc: Michal Hocko Cc: Aneesh Kumar K.V Cc: Catalin Marinas Cc: David Daney Cc: David Miller Cc: H. Peter Anvin Cc: Hugh Dickins Cc: Ingo Molnar Cc: Martin Schwidefsky Cc: Nitin Gupta Cc: Ralf Baechle Cc: Thomas Gleixner Cc: Vineet Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

futex: Remove duplicated code and fix undefined behaviour

2018-05-26T06:48:50Z

commit 30d6e0a4190d37740e9447e4e4815f06992dd8c3 upstream. There is code duplicated over all architecture's headers for futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr, and comparison of the result. Remove this duplication and leave up to the arches only the needed assembly which is now in arch_futex_atomic_op_inuser. This effectively distributes the Will Deacon's arm64 fix for undefined behaviour reported by UBSAN to all architectures. The fix was done in commit 5f16a046f8e1 (arm64: futex: Fix undefined behaviour with FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump. And as suggested by Thomas, check for negative oparg too, because it was also reported to cause undefined behaviour report. Note that s390 removed access_ok check in d12a29703 ("s390/uaccess: remove pointless access_ok() checks") as access_ok there returns true. We introduce it back to the helper for the sake of simplicity (it gets optimized away anyway). Signed-off-by: Jiri Slaby Signed-off-by: Thomas Gleixner Acked-by: Russell King Acked-by: Michael Ellerman (powerpc) Acked-by: Heiko Carstens [s390] Acked-by: Chris Metcalf [for tile] Reviewed-by: Darren Hart (VMware) Reviewed-by: Will Deacon [core/arm64] Cc: linux-mips@linux-mips.org Cc: Rich Felker Cc: linux-ia64@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: peterz@infradead.org Cc: Benjamin Herrenschmidt Cc: Max Filippov Cc: Paul Mackerras Cc: sparclinux@vger.kernel.org Cc: Jonas Bonn Cc: linux-s390@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: Yoshinori Sato Cc: linux-hexagon@vger.kernel.org Cc: Helge Deller Cc: "James E.J. Bottomley" Cc: Catalin Marinas Cc: Matt Turner Cc: linux-snps-arc@lists.infradead.org Cc: Fenghua Yu Cc: Arnd Bergmann Cc: linux-xtensa@linux-xtensa.org Cc: Stefan Kristiansson Cc: openrisc@lists.librecores.org Cc: Ivan Kokshaysky Cc: Stafford Horne Cc: linux-arm-kernel@lists.infradead.org Cc: Richard Henderson Cc: Chris Zankel Cc: Michal Simek Cc: Tony Luck Cc: linux-parisc@vger.kernel.org Cc: Vineet Gupta Cc: Ralf Baechle Cc: Richard Kuo Cc: linux-alpha@vger.kernel.org Cc: Martin Schwidefsky Cc: linuxppc-dev@lists.ozlabs.org Cc: "David S. Miller" Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

mm/vmalloc: add interfaces to free unmapped page table

2018-03-28T16:40:14Z

commit b6bdb7517c3d3f41f20e5c2948d6bc3f8897394e upstream. On architectures with CONFIG_HAVE_ARCH_HUGE_VMAP set, ioremap() may create pud/pmd mappings. A kernel panic was observed on arm64 systems with Cortex-A75 in the following steps as described by Hanjun Guo. 1. ioremap a 4K size, valid page table will build, 2. iounmap it, pte0 will set to 0; 3. ioremap the same address with 2M size, pgd/pmd is unchanged, then set the a new value for pmd; 4. pte0 is leaked; 5. CPU may meet exception because the old pmd is still in TLB, which will lead to kernel panic. This panic is not reproducible on x86. INVLPG, called from iounmap, purges all levels of entries associated with purged address on x86. x86 still has memory leak. The patch changes the ioremap path to free unmapped page table(s) since doing so in the unmap path has the following issues: - The iounmap() path is shared with vunmap(). Since vmap() only supports pte mappings, making vunmap() to free a pte page is an overhead for regular vmap users as they do not need a pte page freed up. - Checking if all entries in a pte page are cleared in the unmap path is racy, and serializing this check is expensive. - The unmap path calls free_vmap_area_noflush() to do lazy TLB purges. Clearing a pud/pmd entry before the lazy TLB purges needs extra TLB purge. Add two interfaces, pud_free_pmd_page() and pmd_free_pte_page(), which clear a given pud/pmd entry and free up a page for the lower level entries. This patch implements their stub functions on x86 and arm64, which work as workaround. [akpm@linux-foundation.org: fix typo in pmd_free_pte_page() stub] Link: http://lkml.kernel.org/r/20180314180155.19492-2-toshi.kani@hpe.com Fixes: e61ce6ade404e ("mm: change ioremap to set up huge I/O mappings") Reported-by: Lei Li Signed-off-by: Toshi Kani Cc: Catalin Marinas Cc: Wang Xuefeng Cc: Will Deacon Cc: Hanjun Guo Cc: Michal Hocko Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Borislav Petkov Cc: Matthew Wilcox Cc: Chintan Pandya Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [ tweak arm64 portion to rely on CONFIG_ARCH_HAVE_HUGE_VMAP - gregkh] Signed-off-by: Greg Kroah-Hartman

EXPORT_SYMBOL() for asm

2018-01-23T18:50:12Z

commit 22823ab419d8ed884195cfa75483fd3a99bb1462 upstream. Add asm-usable variants of EXPORT_SYMBOL/EXPORT_SYMBOL_GPL. This commit just adds the default implementation; most of the architectures can simply add export.h to asm/Kbuild and start using from assembler. The rest needs to have their define everal macros and then explicitly include One area where the things might diverge from default is the alignment; normally it's 8 bytes on 64bit targets and 4 on 32bit ones, both for unsigned long and for struct kernel_symbol. Unfortunately, amd64 and m68k are unusual - m68k aligns to 2 bytes (for both) and amd64 aligns struct kernel_symbol to 16 bytes. For those we'll need asm/export.h to override the constants used by generic version - KSYM_ALIGN and KCRC_ALIGN for kernel_symbol and unsigned long resp. And no, __alignof__ would not do the trick - on amd64 __alignof__ of struct kernel_symbol is 8, not 16. More serious source of unpleasantness is treatment of function descriptors on architectures that have those. Things like ppc64, parisc, ia64, etc. need more than the address of the first insn to call an arbitrary function. As the result, their representation of pointers to functions is not the typical "address of the entry point" - it's an address of a small static structure containing all the required information (including the entry point, of course). Sadly, the asm-side conventions differ in what the function name refers to - entry point or the function descriptor. On ppc64 we do the latter; bar: .quad foo is what void (*bar)(void) = foo; turns into and the rare places where we need to explicitly work with the label of entry point are dealt with as DOTSYM(foo). For our purposes it's ideal - generic macros are usable. However, parisc would have foo and P%foo used for label of entry point and address of the function descriptor and bar: .long P%foo woudl be used instead. ia64 goes similar to parisc in that respect, except that there it's @fptr(foo) rather than P%foo. Such architectures need to define KSYM_FUNC that would turn a function name into whatever is needed to refer to function descriptor. What's more, on such architectures we need to know whether we are exporting a function or an object - in assembler we have to tell that explicitly, to decide whether we want EXPORT_SYMBOL(foo) produce e.g. __ksymtab_foo: .quad foo or __ksymtab_foo: .quad @fptr(foo) For that reason we introduce EXPORT_DATA_SYMBOL{,_GPL}(), to be used for exports of data objects. On normal architectures it's the same thing as EXPORT_SYMBOL{,_GPL}(), but on parisc-like ones they differ and the right one needs to be used. Most of the exports are functions, so we keep EXPORT_SYMBOL for those... Signed-off-by: Al Viro Signed-off-by: Razvan Ghitulete Signed-off-by: Greg Kroah-Hartman

x86/kbuild: enable modversions for symbols exported from asm

2018-01-23T18:50:11Z

commit 334bb773876403eae3457d81be0b8ea70f8e4ccc upstream. Commit 4efca4ed ("kbuild: modversions for EXPORT_SYMBOL() for asm") adds modversion support for symbols exported from asm files. Architectures must include C-style declarations for those symbols in asm/asm-prototypes.h in order for them to be versioned. Add these declarations for x86, and an architecture-independent file that can be used for common symbols. With f27c2f6 reverting 8ab2ae6 ("default exported asm symbols to zero") we produce a scary warning on x86, this commit fixes that. Signed-off-by: Adam Borowski Tested-by: Kalle Valo Acked-by: Nicholas Piggin Tested-by: Peter Wu Tested-by: Oliver Hartkopp Signed-off-by: Michal Marek Signed-off-by: Razvan Ghitulete Signed-off-by: Greg Kroah-Hartman

kaiser: cleanups while trying for gold link

2018-01-05T14:44:24Z

While trying to get our gold link to work, four cleanups: matched the gdt_page declaration to its definition; in fiddling unsuccessfully with PERCPU_INPUT(), lined up backslashes; lined up the backslashes according to convention in percpu-defs.h; deleted the unused irq_stack_pointer addition to irq_stack_union. Sad to report that aligning backslashes does not appear to help gold align to 8192: but while these did not help, they are worth keeping. Signed-off-by: Hugh Dickins Acked-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman

KAISER: Kernel Address Isolation

2018-01-05T14:44:23Z

This patch introduces our implementation of KAISER (Kernel Address Isolation to have Side-channels Efficiently Removed), a kernel isolation technique to close hardware side channels on kernel address information. More information about the patch can be found on: https://github.com/IAIK/KAISER From: Richard Fellner From: Daniel Gruss X-Subject: [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode Date: Thu, 4 May 2017 14:26:50 +0200 Link: http://marc.info/?l=linux-kernel&m=149390087310405&w=2 Kaiser-4.10-SHA1: c4b1831d44c6144d3762ccc72f0c4e71a0c713e5 To: To: Cc: Cc: Cc: Michael Schwarz Cc: Richard Fellner Cc: Ingo Molnar Cc: Cc: After several recent works [1,2,3] KASLR on x86_64 was basically considered dead by many researchers. We have been working on an efficient but effective fix for this problem and found that not mapping the kernel space when running in user mode is the solution to this problem [4] (the corresponding paper [5] will be presented at ESSoS17). With this RFC patch we allow anybody to configure their kernel with the flag CONFIG_KAISER to add our defense mechanism. If there are any questions we would love to answer them. We also appreciate any comments! Cheers, Daniel (+ the KAISER team from Graz University of Technology) [1] http://www.ieee-security.org/TC/SP2013/papers/4977a191.pdf [2] https://www.blackhat.com/docs/us-16/materials/us-16-Fogh-Using-Undocumented-CPU-Behaviour-To-See-Into-Kernel-Mode-And-Break-KASLR-In-The-Process.pdf [3] https://www.blackhat.com/docs/us-16/materials/us-16-Jang-Breaking-Kernel-Address-Space-Layout-Randomization-KASLR-With-Intel-TSX.pdf [4] https://github.com/IAIK/KAISER [5] https://gruss.cc/files/kaiser.pdf [patch based also on https://raw.githubusercontent.com/IAIK/KAISER/master/KAISER/0001-KAISER-Kernel-Address-Isolation.patch] Signed-off-by: Richard Fellner Signed-off-by: Moritz Lipp Signed-off-by: Daniel Gruss Signed-off-by: Michael Schwarz Acked-by: Jiri Kosina Signed-off-by: Hugh Dickins Signed-off-by: Greg Kroah-Hartman

mm: add PHYS_PFN, use it in __phys_to_pfn()

2017-11-21T08:21:22Z

commit 8f235d1a3eb7198affe7cadf676a10afb8a46a1a upstream. __phys_to_pfn and __pfn_to_phys are symmetric, PHYS_PFN and PFN_PHYS are semmetric: - y = (phys_addr_t)x << PAGE_SHIFT - y >> PAGE_SHIFT = (phys_add_t)x - (unsigned long)(y >> PAGE_SHIFT) = x [akpm@linux-foundation.org: use macro arg name `x'] [arnd@arndb.de: include linux/pfn.h for PHYS_PFN definition] Signed-off-by: Chen Gang Cc: Oleg Nesterov Signed-off-by: Arnd Bergmann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Marcin Nowakowski Signed-off-by: Greg Kroah-Hartman

percpu: make this_cpu_generic_read() atomic w.r.t. interrupts

2017-10-21T15:09:01Z

commit e88d62cd4b2f0b1ae55e9008e79c2794b1fc914d upstream. As raw_cpu_generic_read() is a plain read from a raw_cpu_ptr() address, it's possible (albeit unlikely) that the compiler will split the access across multiple instructions. In this_cpu_generic_read() we disable preemption but not interrupts before calling raw_cpu_generic_read(). Thus, an interrupt could be taken in the middle of the split load instructions. If a this_cpu_write() or RMW this_cpu_*() op is made to the same variable in the interrupt handling path, this_cpu_read() will return a torn value. For native word types, we can avoid tearing using READ_ONCE(), but this won't work in all cases (e.g. 64-bit types on most 32-bit platforms). This patch reworks this_cpu_generic_read() to use READ_ONCE() where possible, otherwise falling back to disabling interrupts. Signed-off-by: Mark Rutland Cc: Arnd Bergmann Cc: Christoph Lameter Cc: Peter Zijlstra Cc: Pranith Kumar Cc: Tejun Heo Cc: Thomas Gleixner Cc: linux-arch@vger.kernel.org Signed-off-by: Tejun Heo [Mark: backport to v4.4.y] Signed-off-by: Mark Rutland Signed-off-by: Greg Kroah-Hartman

cpumask: fix spurious cpumask_of_node() on non-NUMA multi-node configs

2017-09-07T06:34:09Z

commit b339752d054fb32863418452dff350a1086885b1 upstream. When !NUMA, cpumask_of_node(@node) equals cpu_online_mask regardless of @node. The assumption seems that if !NUMA, there shouldn't be more than one node and thus reporting cpu_online_mask regardless of @node is correct. However, that assumption was broken years ago to support DISCONTIGMEM and whether a system has multiple nodes or not is separately controlled by NEED_MULTIPLE_NODES. This means that, on a system with !NUMA && NEED_MULTIPLE_NODES, cpumask_of_node() will report cpu_online_mask for all possible nodes, indicating that the CPUs are associated with multiple nodes which is an impossible configuration. This bug has been around forever but doesn't look like it has caused any noticeable symptoms. However, it triggers a WARN recently added to workqueue to verify NUMA affinity configuration. Fix it by reporting empty cpumask on non-zero nodes if !NUMA. Signed-off-by: Tejun Heo Reported-and-tested-by: Geert Uytterhoeven Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman