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2020-10-02Merge branch 'for-next/mte' into for-next/coreWill Deacon1-0/+118
Add userspace support for the Memory Tagging Extension introduced by Armv8.5. (Catalin Marinas and others) * for-next/mte: (30 commits) arm64: mte: Fix typo in memory tagging ABI documentation arm64: mte: Add Memory Tagging Extension documentation arm64: mte: Kconfig entry arm64: mte: Save tags when hibernating arm64: mte: Enable swap of tagged pages mm: Add arch hooks for saving/restoring tags fs: Handle intra-page faults in copy_mount_options() arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset arm64: mte: ptrace: Add PTRACE_{PEEK,POKE}MTETAGS support arm64: mte: Allow {set,get}_tagged_addr_ctrl() on non-current tasks arm64: mte: Restore the GCR_EL1 register after a suspend arm64: mte: Allow user control of the generated random tags via prctl() arm64: mte: Allow user control of the tag check mode via prctl() mm: Allow arm64 mmap(PROT_MTE) on RAM-based files arm64: mte: Validate the PROT_MTE request via arch_validate_flags() mm: Introduce arch_validate_flags() arm64: mte: Add PROT_MTE support to mmap() and mprotect() mm: Introduce arch_calc_vm_flag_bits() arm64: mte: Tags-aware aware memcmp_pages() implementation arm64: Avoid unnecessary clear_user_page() indirection ...
2020-10-02Merge branch 'for-next/ghostbusters' into for-next/coreWill Deacon1-5/+1
Fix and subsequently rewrite Spectre mitigations, including the addition of support for PR_SPEC_DISABLE_NOEXEC. (Will Deacon and Marc Zyngier) * for-next/ghostbusters: (22 commits) arm64: Add support for PR_SPEC_DISABLE_NOEXEC prctl() option arm64: Pull in task_stack_page() to Spectre-v4 mitigation code KVM: arm64: Allow patching EL2 vectors even with KASLR is not enabled arm64: Get rid of arm64_ssbd_state KVM: arm64: Convert ARCH_WORKAROUND_2 to arm64_get_spectre_v4_state() KVM: arm64: Get rid of kvm_arm_have_ssbd() KVM: arm64: Simplify handling of ARCH_WORKAROUND_2 arm64: Rewrite Spectre-v4 mitigation code arm64: Move SSBD prctl() handler alongside other spectre mitigation code arm64: Rename ARM64_SSBD to ARM64_SPECTRE_V4 arm64: Treat SSBS as a non-strict system feature arm64: Group start_thread() functions together KVM: arm64: Set CSV2 for guests on hardware unaffected by Spectre-v2 arm64: Rewrite Spectre-v2 mitigation code arm64: Introduce separate file for spectre mitigations and reporting arm64: Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2 KVM: arm64: Simplify install_bp_hardening_cb() KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE arm64: Remove Spectre-related CONFIG_* options arm64: Run ARCH_WORKAROUND_2 enabling code on all CPUs ...
2020-09-29arm64: Rewrite Spectre-v4 mitigation codeWill Deacon1-5/+1
Rewrite the Spectre-v4 mitigation handling code to follow the same approach as that taken by Spectre-v2. For now, report to KVM that the system is vulnerable (by forcing 'ssbd_state' to ARM64_SSBD_UNKNOWN), as this will be cleared up in subsequent steps. Signed-off-by: Will Deacon <will@kernel.org>
2020-09-14arm64: hibernate: Remove unused including <linux/version.h>Tian Tao1-1/+0
Remove including <linux/version.h> that don't need it. Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Link: https://lore.kernel.org/r/1600068522-54499-1-git-send-email-tiantao6@hisilicon.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-04arm64: mte: Save tags when hibernatingSteven Price1-0/+118
When hibernating the contents of all pages in the system are written to disk, however the MTE tags are not visible to the generic hibernation code. So just before the hibernation image is created copy the tags out of the physical tag storage into standard memory so they will be included in the hibernation image. After hibernation apply the tags back into the physical tag storage. Signed-off-by: Steven Price <steven.price@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will@kernel.org>
2020-06-09mm: consolidate pte_index() and pte_offset_*() definitionsMike Rapoport1-2/+2
All architectures define pte_index() as (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1) and all architectures define pte_offset_kernel() as an entry in the array of PTEs indexed by the pte_index(). For the most architectures the pte_offset_kernel() implementation relies on the availability of pmd_page_vaddr() that converts a PMD entry value to the virtual address of the page containing PTEs array. Let's move x86 definitions of the PTE accessors to the generic place in <linux/pgtable.h> and then simply drop the respective definitions from the other architectures. The architectures that didn't provide pmd_page_vaddr() are updated to have that defined. The generic implementation of pte_offset_kernel() can be overridden by an architecture and alpha makes use of this because it has special ordering requirements for its version of pte_offset_kernel(). [rppt@linux.ibm.com: v2] Link: http://lkml.kernel.org/r/20200514170327.31389-11-rppt@kernel.org [rppt@linux.ibm.com: update] Link: http://lkml.kernel.org/r/20200514170327.31389-12-rppt@kernel.org [rppt@linux.ibm.com: update] Link: http://lkml.kernel.org/r/20200514170327.31389-13-rppt@kernel.org [akpm@linux-foundation.org: fix x86 warning] [sfr@canb.auug.org.au: fix powerpc build] Link: http://lkml.kernel.org/r/20200607153443.GB738695@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-10-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mm: don't include asm/pgtable.h if linux/mm.h is already includedMike Rapoport1-1/+0
Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04arm64: add support for folded p4d page tablesMike Rapoport1-7/+37
Implement primitives necessary for the 4th level folding, add walks of p4d level where appropriate, replace 5level-fixup.h with pgtable-nop4d.h and remove __ARCH_USE_5LEVEL_HACK. [arnd@arndb.de: fix gcc-10 shift warning] Link: http://lkml.kernel.org/r/20200429185657.4085975-1-arnd@arndb.de Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: James Morse <james.morse@arm.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200414153455.21744-4-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-03-25arm64: hibernate: Use bringup_hibernate_cpu()Qais Yousef1-8/+5
Use bringup_hibernate_cpu() instead of open coding it. [ tglx: Split out the core change ] Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/20200323135110.30522-9-qais.yousef@arm.com
2020-01-08arm64: hibernate: add trans_pgd public functionsPavel Tatashin1-33/+60
trans_pgd_create_copy() and trans_pgd_map_page() are going to be the basis for new shared code that handles page tables for cases which are between kernels: kexec, and hibernate. Note: Eventually, get_safe_page() will be moved into a function pointer passed via argument, but for now keep it as is. Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: James Morse <james.morse@arm.com> [will: Keep these functions static until kexec needs them] Signed-off-by: Will Deacon <will@kernel.org>
2020-01-08arm64: hibernate: add PUD_SECT_RDONLYPavel Tatashin1-1/+1
There is PMD_SECT_RDONLY that is used in pud_* function which is confusing. Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-01-08arm64: hibernate: rename dst to page in create_safe_exec_pagePavel Tatashin1-6/+6
create_safe_exec_page() allocates a safe page and maps it at a specific location, also this function returns the physical address of newly allocated page. The destination VA, and PA are specified in arguments: dst_addr, phys_dst_addr However, within the function it uses "dst" which has unsigned long type, but is actually a pointers in the current virtual space. This is confusing to read. Rename dst to more appropriate page (page that is created), and also change its time to "void *" Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-01-08arm64: hibernate: remove gotos as they are not neededPavel Tatashin1-32/+17
Usually, gotos are used to handle cleanup after exception, but in case of create_safe_exec_page and swsusp_arch_resume there are no clean-ups. So, simply return the errors directly. Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-01-08arm64: hibernate: use get_safe_page directlyPavel Tatashin1-10/+7
create_safe_exec_page() uses hibernate's allocator to create a set of page table to map a single page that will contain the relocation code. Remove the allocator related arguments, and use get_safe_page directly, as it is done in other local functions in this file to simplify function prototype. Removing this function pointer makes it easier to refactor the code later. Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Matthias Brugger <mbrugger@suse.com> Signed-off-by: Will Deacon <will@kernel.org>
2020-01-08arm64: hibernate: pass the allocated pgdp to ttbr0Pavel Tatashin1-1/+1
ttbr0 should be set to the beginning of pgdp, however, currently in create_safe_exec_page it is set to pgdp after pgd_offset_raw(), which works by accident. Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-10-14arm64: hibernate: check pgd table allocationPavel Tatashin1-1/+8
There is a bug in create_safe_exec_page(), when page table is allocated it is not checked that table is allocated successfully: But it is dereferenced in: pgd_none(READ_ONCE(*pgdp)). Check that allocation was successful. Fixes: 82869ac57b5d ("arm64: kernel: Add support for hibernate/suspend-to-disk") Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-14arm64: memory: rename VA_START to PAGE_ENDMark Rutland1-1/+1
Prior to commit: 14c127c957c1c607 ("arm64: mm: Flip kernel VA space") ... VA_START described the start of the TTBR1 address space for a given VA size described by VA_BITS, where all kernel mappings began. Since that commit, VA_START described a portion midway through the address space, where the linear map ends and other kernel mappings begin. To avoid confusion, let's rename VA_START to PAGE_END, making it clear that it's not the start of the TTBR1 address space and implying that it's related to PAGE_OFFSET. Comments and other mnemonics are updated accordingly, along with a typo fix in the decription of VMEMMAP_SIZE. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Steve Capper <steve.capper@arm.com> Reviewed-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09arm64: mm: Flip kernel VA spaceSteve Capper1-1/+1
In order to allow for a KASAN shadow that changes size at boot time, one must fix the KASAN_SHADOW_END for both 48 & 52-bit VAs and "grow" the start address. Also, it is highly desirable to maintain the same function addresses in the kernel .text between VA sizes. Both of these requirements necessitate us to flip the kernel address space halves s.t. the direct linear map occupies the lower addresses. This patch puts the direct linear map in the lower addresses of the kernel VA range and everything else in the higher ranges. We need to adjust: *) KASAN shadow region placement logic, *) KASAN_SHADOW_OFFSET computation logic, *) virt_to_phys, phys_to_virt checks, *) page table dumper. These are all small changes, that need to take place atomically, so they are bundled into this commit. As part of the re-arrangement, a guard region of 2MB (to preserve alignment for fixed map) is added after the vmemmap. Otherwise the vmemmap could intersect with IS_ERR pointers. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194Thomas Gleixner1-2/+1
Based on 1 normalized pattern(s): license terms gnu general public license gpl version 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 161 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528170027.447718015@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-01arm64: hibernate: Clean the __hyp_text to PoC after resumeJames Morse1-1/+3
During resume hibernate restores all physical memory. Any memory that is accessed with the MMU disabled needs to be cleaned to the PoC. KVMs __hyp_text was previously ommitted as it runs with the MMU enabled, but now that the hyp-stub is located in this section, we must clean __hyp_text too. This ensures secondary CPUs that come online after hibernate has finished resuming, and load KVM via the freshly written hyp-stub see the correct instructions. Signed-off-by: James Morse <james.morse@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-07arm64: hibernate: Avoid sending cross-calling with interrupts disabledWill Deacon1-1/+1
Since commit 3b8c9f1cdfc50 ("arm64: IPI each CPU after invalidating the I-cache for kernel mappings"), a call to flush_icache_range() will use an IPI to cross-call other online CPUs so that any stale instructions are flushed from their pipelines. This triggers a WARN during the hibernation resume path, where flush_icache_range() is called with interrupts disabled and is therefore prone to deadlock: | Disabling non-boot CPUs ... | CPU1: shutdown | psci: CPU1 killed. | CPU2: shutdown | psci: CPU2 killed. | CPU3: shutdown | psci: CPU3 killed. | WARNING: CPU: 0 PID: 1 at ../kernel/smp.c:416 smp_call_function_many+0xd4/0x350 | Modules linked in: | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.20.0-rc4 #1 Since all secondary CPUs have been taken offline prior to invalidating the I-cache, there's actually no need for an IPI and we can simply call __flush_icache_range() instead. Cc: <stable@vger.kernel.org> Fixes: 3b8c9f1cdfc50 ("arm64: IPI each CPU after invalidating the I-cache for kernel mappings") Reported-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> Tested-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> Tested-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-31arm64: ssbd: Restore mitigation status on CPU resumeMarc Zyngier1-0/+11
On a system where firmware can dynamically change the state of the mitigation, the CPU will always come up with the mitigation enabled, including when coming back from suspend. If the user has requested "no mitigation" via a command line option, let's enforce it by calling into the firmware again to disable it. Similarily, for a resume from hibernate, the mitigation could have been disabled by the boot kernel. Let's ensure that it is set back on in that case. Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-16arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tablesWill Deacon1-72/+76
In many cases, page tables can be accessed concurrently by either another CPU (due to things like fast gup) or by the hardware page table walker itself, which may set access/dirty bits. In such cases, it is important to use READ_ONCE/WRITE_ONCE when accessing page table entries so that entries cannot be torn, merged or subject to apparent loss of coherence due to compiler transformations. Whilst there are some scenarios where this cannot happen (e.g. pinned kernel mappings for the linear region), the overhead of using READ_ONCE /WRITE_ONCE everywhere is minimal and makes the code an awful lot easier to reason about. This patch consistently uses these macros in the arch code, as well as explicitly namespacing pointers to page table entries from the entries themselves by using adopting a 'p' suffix for the former (as is sometimes used elsewhere in the kernel source). Tested-by: Yury Norov <ynorov@caviumnetworks.com> Tested-by: Richard Ruigrok <rruigrok@codeaurora.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-22arm64: don't open code page table entry creationKristina Martsenko1-2/+1
Instead of open coding the generation of page table entries, use the macros/functions that exist for this - pfn_p*d and p*d_populate. Most code in the kernel already uses these macros, this patch tries to fix up the few places that don't. This is useful for the next patch in this series, which needs to change the page table entry logic, and it's better to have that logic in one place. The KVM extended ID map is special, since we're creating a level above CONFIG_PGTABLE_LEVELS and the required function isn't available. Leave it as is and add a comment to explain it. (The normal kernel ID map code doesn't need this change because its page tables are created in assembly (__create_page_tables)). Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-22arm64: handle 52-bit addresses in TTBRKristina Martsenko1-1/+1
The top 4 bits of a 52-bit physical address are positioned at bits 2..5 in the TTBR registers. Introduce a couple of macros to move the bits there, and change all TTBR writers to use them. Leave TTBR0 PAN code unchanged, to avoid complicating it. A system with 52-bit PA will have PAN anyway (because it's ARMv8.1 or later), and a system without 52-bit PA can only use up to 48-bit PAs. A later patch in this series will add a kconfig dependency to ensure PAN is configured. In addition, when using 52-bit PA there is a special alignment requirement on the top-level table. We don't currently have any VA_BITS configuration that would violate the requirement, but one could be added in the future, so add a compile-time BUG_ON to check for it. Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Bob Picco <bob.picco@oracle.com> Reviewed-by: Bob Picco <bob.picco@oracle.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> [catalin.marinas@arm.com: added TTBR_BADD_MASK_52 comment] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-11-02arm64: explicitly mask all exceptionsJames Morse1-2/+3
There are a few places where we want to mask all exceptions. Today we do this in a piecemeal fashion, typically we expect the caller to have masked irqs and the arch code masks debug exceptions, ignoring serror which is probably masked. Make it clear that 'mask all exceptions' is the intention by adding helpers to do exactly that. This will let us unmask SError without having to add 'oh and SError' to these paths. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-08-21arm64: Move PTE_RDONLY bit handling out of set_pte_at()Catalin Marinas1-2/+2
Currently PTE_RDONLY is treated as a hardware only bit and not handled by the pte_mkwrite(), pte_wrprotect() or the user PAGE_* definitions. The set_pte_at() function is responsible for setting this bit based on the write permission or dirty state. This patch moves the PTE_RDONLY handling out of set_pte_at into the pte_mkwrite()/pte_wrprotect() functions. The PAGE_* definitions to need to be updated to explicitly include PTE_RDONLY when !PTE_WRITE. The patch also removes the redundant PAGE_COPY(_EXEC) definitions as they are identical to the corresponding PAGE_READONLY(_EXEC). Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-04-05arm64: hibernate: preserve kdump image around hibernationAKASHI Takahiro1-1/+9
Since arch_kexec_protect_crashkres() removes a mapping for crash dump kernel image, the loaded data won't be preserved around hibernation. In this patch, helper functions, crash_prepare_suspend()/ crash_post_resume(), are additionally called before/after hibernation so that the relevant memory segments will be mapped again and preserved just as the others are. In addition, to minimize the size of hibernation image, crash_is_nosave() is added to pfn_is_nosave() in order to recognize only the pages that hold loaded crash dump kernel image as saveable. Hibernation excludes any pages that are marked as Reserved and yet "nosave." Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-01-12arm64: Use __pa_symbol for kernel symbolsLaura Abbott1-15/+5
__pa_symbol is technically the marcro that should be used for kernel symbols. Switch to this as a pre-requisite for DEBUG_VIRTUAL which will do bounds checking. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-10arm64: add missing printk newlinesMark Rutland1-3/+3
A few printk calls in arm64 omit a trailing newline, even though there is no subsequent KERN_CONT printk associated with them, and we actually want a newline. This can result in unrelated lines being appended, rather than appearing on a new line. Additionally, timestamp prefixes may appear in-line. This makes the logs harder to read than necessary. Avoid this by adding a trailing newline. These were found with a shortlist generated by: $ git grep 'pr\(intk\|_.*\)(.*)' -- arch/arm64 | grep -v pr_fmt | grep -v '\\n"' Signed-off-by: Mark Rutland <mark.rutland@arm.com> CC: James Morse <james.morse@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-12-14treewide: Fix printk() message errorsMasanari Iida1-2/+2
This patch fix spelling typos in printk and kconfig. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-08-26Revert "arm64: hibernate: Refuse to hibernate if the boot cpu is offline"James Morse1-26/+0
Now that we use the MPIDR to resume on the same CPU that we hibernated on, we no longer need to refuse to hibernate if the boot cpu is offline. (Which we can't possibly know if kexec causes logical CPUs to be renumbered). This reverts commit 1fe492ce6482b77807b25d29690a48c46456beee. Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-26arm64: hibernate: Resume when hibernate image created on non-boot CPUJames Morse1-0/+51
disable_nonboot_cpus() assumes that the lowest numbered online CPU is the boot CPU, and that this is the correct CPU to run any power management code on. On arm64 CPU0 can be taken offline. For hibernate/resume this means we may hibernate on a CPU other than CPU0. If the system is rebooted with kexec 'CPU0' will be assigned to a different CPU. This complicates hibernate/resume as now we can't trust the CPU numbers. We currently forbid hibernate if CPU0 has been hotplugged out to avoid this situation without kexec. Save the MPIDR of the CPU we hibernated on in the hibernate arch-header, use hibernate_resume_nonboot_cpu_disable() to direct which CPU we should resume on based on the MPIDR of the CPU we hibernated on. This allows us to hibernate/resume on any CPU, even if the logical numbers have been shuffled by kexec. Signed-off-by: James Morse <james.morse@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-25arm64: hibernate: Support DEBUG_PAGEALLOCJames Morse1-9/+36
DEBUG_PAGEALLOC removes the valid bit of page table entries to prevent any access to unallocated memory. Hibernate uses this as a hint that those pages don't need to be saved/restored. This patch adds the kernel_page_present() function it uses. hibernate.c copies the resume kernel's linear map for use during restore. Add _copy_pte() to fill-in the holes made by DEBUG_PAGEALLOC in the resume kernel, so we can restore data the original kernel had at these addresses. Finally, DEBUG_PAGEALLOC means the linear-map alias of KERNEL_START to KERNEL_END may have holes in it, so we can't lazily clean this whole area to the PoC. Only clean the new mmuoff region, and the kernel/kvm idmaps. This reverts commit da24eb1f3f9e2c7b75c5f8c40d8e48e2c4789596. Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-25arm64: Create sections.hJames Morse1-6/+0
Each time new section markers are added, kernel/vmlinux.ld.S is updated, and new extern char __start_foo[] definitions are scattered through the tree. Create asm/include/sections.h to collect these definitions (and include the existing asm-generic version). Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-12arm64: hibernate: handle allocation failuresMark Rutland1-27/+32
In create_safe_exec_page(), we create a copy of the hibernate exit text, along with some page tables to map this via TTBR0. We then install the new tables in TTBR0. In swsusp_arch_resume() we call create_safe_exec_page() before trying a number of operations which may fail (e.g. copying the linear map page tables). If these fail, we bail out of swsusp_arch_resume() and return an error code, but leave TTBR0 as-is. Subsequently, the core hibernate code will call free_basic_memory_bitmaps(), which will free all of the memory allocations we made, including the page tables installed in TTBR0. Thus, we may have TTBR0 pointing at dangling freed memory for some period of time. If the hibernate attempt was triggered by a user requesting a hibernate test via the reboot syscall, we may return to userspace with the clobbered TTBR0 value. Avoid these issues by reorganising swsusp_arch_resume() such that we have no failure paths after create_safe_exec_page(). We also add a check that the zero page allocation succeeded, matching what we have for other allocations. Fixes: 82869ac57b5d ("arm64: kernel: Add support for hibernate/suspend-to-disk") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: James Morse <james.morse@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> # 4.7+ Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-08-12arm64: hibernate: avoid potential TLB conflictMark Rutland1-6/+17
In create_safe_exec_page we install a set of global mappings in TTBR0, then subsequently invalidate TLBs. While TTBR0 points at the zero page, and the TLBs should be free of stale global entries, we may have stale ASID-tagged entries (e.g. from the EFI runtime services mappings) for the same VAs. Per the ARM ARM these ASID-tagged entries may conflict with newly-allocated global entries, and we must follow a Break-Before-Make approach to avoid issues resulting from this. This patch reworks create_safe_exec_page to invalidate TLBs while the zero page is still in place, ensuring that there are no potential conflicts when the new TTBR0 value is installed. As a single CPU is online while this code executes, we do not need to perform broadcast TLB maintenance, and can call local_flush_tlb_all(), which also subsumes some barriers. The remaining assembly is converted to use write_sysreg() and isb(). Other than this, we safely manipulate TTBRs in the hibernate dance. The code we install as part of the new TTBR0 mapping (the hibernated kernel's swsusp_arch_suspend_exit) installs a zero page into TTBR1, invalidates TLBs, then installs its preferred value. Upon being restored to the middle of swsusp_arch_suspend, the new image will call __cpu_suspend_exit, which will call cpu_uninstall_idmap, installing the zero page in TTBR0 and invalidating all TLB entries. Fixes: 82869ac57b5d ("arm64: kernel: Add support for hibernate/suspend-to-disk") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: James Morse <james.morse@arm.com> Tested-by: James Morse <james.morse@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> # 4.7+ Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-06-22arm64: hibernate: Don't hibernate on systems with stuck CPUsJames Morse1-0/+6
Hibernate relies on cpu hotplug to prevent secondary cores executing the kernel text while it is being restored. Add a call to cpus_are_stuck_in_kernel() to determine if there are CPUs not counted by 'num_online_cpus()', and prevent hibernate in this case. Fixes: 82869ac57b5 ("arm64: kernel: Add support for hibernate/suspend-to-disk") Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-28arm64: hibernate: Refuse to hibernate if the boot cpu is offlineJames Morse1-0/+26
Hibernation represents a system state save/restore through a system reboot; this implies that the logical cpus carrying out hibernation/thawing must be the same, so that the context saved in the snapshot image on hibernation is consistent with the state of the system on resume. If resume from hibernation is driven through kernel command line parameter, the cpu responsible for thawing the system will be whatever CPU firmware boots the system on upon cold-boot (ie logical cpu 0); this means that in order to keep system context consistent between the hibernate snapshot image and system state on kernel resume from hibernate, logical cpu 0 must be online on hibernation and must be the logical cpu that creates the snapshot image. This patch adds a PM notifier that enforces logical cpu 0 is online when the hibernation is started (and prevents hibernation if it is not), which is sufficient to guarantee it will be the one creating the snapshot image therefore providing the resume cpu a consistent snapshot of the system to resume to. Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-28arm64: kernel: Add support for hibernate/suspend-to-diskJames Morse1-0/+461
Add support for hibernate/suspend-to-disk. Suspend borrows code from cpu_suspend() to write cpu state onto the stack, before calling swsusp_save() to save the memory image. Restore creates a set of temporary page tables, covering only the linear map, copies the restore code to a 'safe' page, then uses the copy to restore the memory image. The copied code executes in the lower half of the address space, and once complete, restores the original kernel's page tables. It then calls into cpu_resume(), and follows the normal cpu_suspend() path back into the suspend code. To restore a kernel using KASLR, the address of the page tables, and cpu_resume() are stored in the hibernate arch-header and the el2 vectors are pivotted via the 'safe' page in low memory. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Kevin Hilman <khilman@baylibre.com> # Tested on Juno R2 Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>