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* arm64: dump: Add checking for writable and exectuable pagesLaura Abbott2016-11-071-0/+54
| | | | | | | | | | | | | | | Page mappings with full RWX permissions are a security risk. x86 has an option to walk the page tables and dump any bad pages. (See e1a58320a38d ("x86/mm: Warn on W^X mappings")). Add a similar implementation for arm64. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [catalin.marinas@arm.com: folded fix for KASan out of bounds from Mark Rutland] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: dump: Make the page table dumping seq_file optionalLaura Abbott2016-11-071-7/+19
| | | | | | | | | | | | | | The page table dumping code always assumes it will be dumping to a seq_file to userspace. Future code will be taking advantage of the page table dumping code but will not need the seq_file. Make the seq_file optional for these cases. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: dump: Make ptdump debugfs a separate optionLaura Abbott2016-11-071-21/+5
| | | | | | | | | | | | | ptdump_register currently initializes a set of page table information and registers debugfs. There are uses for the ptdump option without wanting the debugfs options. Split this out to make it a separate option. Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Kees Cook <keescook@chromium.org> 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: Catalin Marinas <catalin.marinas@arm.com>
* arm64: Fix shift warning in arch/arm64/mm/dump.cCatalin Marinas2016-08-181-3/+3
| | | | | | | | | | | | | | | | | | When building with 48-bit VAs and 16K page configuration, it's possible to get the following warning when building the arm64 page table dumping code: arch/arm64/mm/dump.c: In function ‘walk_pud’: arch/arm64/mm/dump.c:274:102: warning: right shift count >= width of type [-Wshift-count-overflow] This is because pud_offset(pgd, 0) performs a shift to the right by 36 while the value 0 has the type 'int' by default, therefore 32-bit. This patch modifies all the p*_offset() uses in arch/arm64/mm/dump.c to use 0UL for the address argument. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: mm: dump: make page table dumping reusableMark Rutland2016-06-211-12/+20
| | | | | | | | | | | | | For debugging purposes, it would be nice if we could export page tables other than the swapper_pg_dir to userspace. To enable this, this patch refactors the arm64 page table dumping code such that multiple tables may be registered with the framework, and exported under debugfs. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: mm: dump: log span levelMark Rutland2016-06-031-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The page table dump code logs spans of entries at the same level (pgd/pud/pmd/pte) which have the same attributes. While we log the (decoded) attributes, we don't log the level, which leaves the output ambiguous and/or confusing in some cases. For example: 0xffff800800000000-0xffff800980000000 6G RW NX SHD AF BLK UXN MEM/NORMAL If using 4K pages, this may describe a span of 6 1G block entries at the PGD/PUD level, or 3072 2M block entries at the PMD level. This patch adds the page table level to each output line, removing this ambiguity. For the example above, this will produce: 0xffffffc800000000-0xffffffc980000000 6G PUD RW NX SHD AF BLK UXN MEM/NORMAL When 3 level tables are in use, and we use the asm-generic/nopud.h definitions, the dump code treats each entry in the PGD as a 1 element table at the PUD level, and logs spans as being PUDs, which can be confusing. To counteract this, the "PUD" mnemonic is replaced with "PGD" when CONFIG_PGTABLE_LEVELS <= 3. Likewise for "PMD" when CONFIG_PGTABLE_LEVELS <= 2. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Huang Shijie <shijie.huang@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Steve Capper <steve.capper@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: ptdump: add region marker for kasan shadow regionArd Biesheuvel2016-04-251-0/+5
| | | | | | | | | Annotate the KASAN shadow region with boundary markers, so that its mappings stand out in the page table dumper output. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: ptdump: use static initializers for vmemmap region boundariesArd Biesheuvel2016-04-251-36/+13
| | | | | | | | | | There is no need to initialize the vmemmap region boundaries dynamically, since they are compile time constants. So just add these constants to the global struct initializer, and drop the dynamic assignment and related code. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: mm: move vmemmap region right below the linear regionArd Biesheuvel2016-04-141-8/+8
| | | | | | | | | | | | This moves the vmemmap region right below PAGE_OFFSET, aka the start of the linear region, and redefines its size to be a power of two. Due to the placement of PAGE_OFFSET in the middle of the address space, whose size is a power of two as well, this guarantees that virt to page conversions and vice versa can be implemented efficiently, by masking and shifting rather than ordinary arithmetic. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: mm: dump: Use VA_START directly instead of private LOWEST_ADDRKefeng Wang2016-02-261-3/+1
| | | | | | | | | Use VA_START macro in asm/memory.h instead of private LOWEST_ADDR definition in dump.c. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: move kernel image to base of vmalloc areaArd Biesheuvel2016-02-181-6/+6
| | | | | | | | | | | | | | | | This moves the module area to right before the vmalloc area, and moves the kernel image to the base of the vmalloc area. This is an intermediate step towards implementing KASLR, which allows the kernel image to be located anywhere in the vmalloc area. Since other subsystems such as hibernate may still need to refer to the kernel text or data segments via their linears addresses, both are mapped in the linear region as well. The linear alias of the text region is mapped read-only/non-executable to prevent inadvertent modification or execution. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: ptdump: Indicate whether memory should be faultingLaura Abbott2016-02-161-0/+5
| | | | | | | | | | | | | With CONFIG_DEBUG_PAGEALLOC, pages do not have the valid bit set when free in the buddy allocator. Add an indiciation to the page table dumping code that the valid bit is not set, 'F' for fault, to make this easier to understand. Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: Fix an enum typo in mm/dump.cMasanari Iida2016-01-251-1/+1
| | | | | | | | This patch fixes a typo in mm/dump.c: "MODUELS_END_NR" should be "MODULES_END_NR". Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: Make the kernel page dump utility aware of the CONT bitJeremy Linton2015-10-081-1/+17
| | | | | | | | The kernel page dump utility needs to be aware of the CONT bit before it will break up pages ranges for display. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* arm64: mm: Fix build error with CONFIG_SPARSEMEM_VMEMMAP disabledJungseung Lee2015-05-051-0/+2
| | | | | | | | | | | | | | | | | This fix the below build error: arch/arm64/mm/dump.c: In function ‘ptdump_init’: arch/arm64/mm/dump.c:331:18: error: ‘VMEMMAP_START_NR’ undeclared (first use in this function) address_markers[VMEMMAP_START_NR].start_address = ^ arch/arm64/mm/dump.c:331:18: note: each undeclared identifier is reported only once for each function it appears in arch/arm64/mm/dump.c:333:18: error: ‘VMEMMAP_END_NR’ undeclared (first use in this function) address_markers[VMEMMAP_END_NR].start_address = ^ Acked-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Jungseung Lee <js07.lee@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* Merge tag 'arm64-upstream' of ↵Linus Torvalds2015-02-111-10/+20
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "arm64 updates for 3.20: - reimplementation of the virtual remapping of UEFI Runtime Services in a way that is stable across kexec - emulation of the "setend" instruction for 32-bit tasks (user endianness switching trapped in the kernel, SCTLR_EL1.E0E bit set accordingly) - compat_sys_call_table implemented in C (from asm) and made it a constant array together with sys_call_table - export CPU cache information via /sys (like other architectures) - DMA API implementation clean-up in preparation for IOMMU support - macros clean-up for KVM - dropped some unnecessary cache+tlb maintenance - CONFIG_ARM64_CPU_SUSPEND clean-up - defconfig update (CPU_IDLE) The EFI changes going via the arm64 tree have been acked by Matt Fleming. There is also a patch adding sys_*stat64 prototypes to include/linux/syscalls.h, acked by Andrew Morton" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (47 commits) arm64: compat: Remove incorrect comment in compat_siginfo arm64: Fix section mismatch on alloc_init_p[mu]d() arm64: Avoid breakage caused by .altmacro in fpsimd save/restore macros arm64: mm: use *_sect to check for section maps arm64: drop unnecessary cache+tlb maintenance arm64:mm: free the useless initial page table arm64: Enable CPU_IDLE in defconfig arm64: kernel: remove ARM64_CPU_SUSPEND config option arm64: make sys_call_table const arm64: Remove asm/syscalls.h arm64: Implement the compat_sys_call_table in C syscalls: Declare sys_*stat64 prototypes if __ARCH_WANT_(COMPAT_)STAT64 compat: Declare compat_sys_sigpending and compat_sys_sigprocmask prototypes arm64: uapi: expose our struct ucontext to the uapi headers smp, ARM64: Kill SMP single function call interrupt arm64: Emulate SETEND for AArch32 tasks arm64: Consolidate hotplug notifier for instruction emulation arm64: Track system support for mixed endian EL0 arm64: implement generic IOMMU configuration arm64: Combine coherent and non-coherent swiotlb dma_ops ...
| * arm64: mm: use *_sect to check for section mapsMark Rutland2015-01-281-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The {pgd,pud,pmd}_bad family of macros have slightly fuzzy cross-architecture semantics, and seem to imply a populated entry that is not a next-level table, rather than a particular type of entry (e.g. a section map). In arm64 code, for those cases where we care about whether an entry is a section mapping, we can instead use the {pud,pmd}_sect macros to explicitly check for this case. This helps to document precisely what we care about, making the code easier to read, and allows for future relaxation of the *_bad macros to check for other "bad" entries. To that end this patch updates the table dumping and initial table setup to check for section mappings with {pud,pmd}_sect, and adds/restores BUG_ON(*_bad((*p)) checks after we've handled the *_sect and *_none cases so as to catch remaining "bad" cases. In the fault handling code, show_pte is left with *_bad checks as it only cares about whether it can walk the next level table, and this path is used for both kernel and userspace fault handling. The former case will be followed by a die() where we'll report the address that triggered the fault, which can be useful context for debugging. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Steve Capper <steve.capper@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Kees Cook <keescook@chromium.org> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| * arm64: mm: dump: add missing includesMark Rutland2015-01-231-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The arm64 dump code is currently relying on some definitions which are pulled in via transitive dependencies. It seems we have implicit dependencies on the following definitions: * MODULES_VADDR (asm/memory.h) * MODULES_END (asm/memory.h) * PAGE_OFFSET (asm/memory.h) * PTE_* (asm/pgtable-hwdef.h) * ENOMEM (linux/errno.h) * device_initcall (linux/init.h) This patch ensures we explicitly include the relevant headers for the above items, fixing the observed build issue and hopefully preventing future issues as headers are refactored. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Mark Brown <broonie@kernel.org> Acked-by: Steve Capper <steve.capper@linaro.org> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| * arm64: Fix overlapping VA allocationsMark Rutland2015-01-231-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PCI IO space was intended to be 16MiB, at 32MiB below MODULES_VADDR, but commit d1e6dc91b532d3d3 ("arm64: Add architectural support for PCI") extended this to cover the full 32MiB. The final 8KiB of this 32MiB is also allocated for the fixmap, allowing for potential clashes between the two. This change was masked by assumptions in mem_init and the page table dumping code, which assumed the I/O space to be 16MiB long through seaparte hard-coded definitions. This patch changes the definition of the PCI I/O space allocation to live in asm/memory.h, along with the other VA space allocations. As the fixmap allocation depends on the number of fixmap entries, this is moved below the PCI I/O space allocation. Both the fixmap and PCI I/O space are guarded with 2MB of padding. Sites assuming the I/O space was 16MiB are moved over use new PCI_IO_{START,END} definitions, which will keep in sync with the size of the IO space (now restored to 16MiB). As a useful side effect, the use of the new PCI_IO_{START,END} definitions prevents a build issue in the dumping code due to a (now redundant) missing include of io.h for PCI_IOBASE. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Kees Cook <keescook@chromium.org> Cc: Laura Abbott <lauraa@codeaurora.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Will Deacon <will.deacon@arm.com> [catalin.marinas@arm.com: reorder FIXADDR and PCI_IO address_markers_idx enum] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* | arm64: dump: Fix implicit inclusion of definition for PCI_IOBASEMark Brown2015-01-231-0/+1
|/ | | | | | | | | | | | | Since c9465b4ec37a68425 (arm64: add support to dump the kernel page tables) allmodconfig has failed to build on arm64 as a result of: ../arch/arm64/mm/dump.c:55:20: error: 'PCI_IOBASE' undeclared here (not in a function) Fix this by explicitly including io.h to ensure that a definition is present. Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: mm: dump: don't skip final regionMark Rutland2014-12-111-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the final page table entry we walk is a valid mapping, the page table dumping code will not log the region this entry is part of, as the final note_page call in ptdump_show will trigger an early return. Luckily this isn't seen on contemporary systems as they typically don't have enough RAM to extend the linear mapping right to the end of the address space. In note_page, we log a region when we reach its end (i.e. we hit an entry immediately afterwards which has different prot bits or is invalid). The final entry has no subsequent entry, so we will not log this immediately. We try to cater for this with a subsequent call to note_page in ptdump_show, but this returns early as 0 < LOWEST_ADDR, and hence we will skip a valid mapping if it spans to the final entry we note. Unlike 32-bit ARM, the pgd with the kernel mapping is never shared with user mappings, so we do not need the check to ensure we don't log user page tables. Due to the way addr is constructed in the walk_* functions, it can never be less than LOWEST_ADDR when walking the page tables, so it is not necessary to avoid dereferencing invalid table addresses. The existing checks for st->current_prot and st->marker[1].start_address are sufficient to ensure we will not print and/or dereference garbage when trying to log information. This patch removes the unnecessary check against LOWEST_ADDR, ensuring we log all regions in the kernel page table, including those which span right to the end of the address space. Cc: Kees Cook <keescook@chromium.org> Acked-by: Laura Abbott <lauraa@codeaurora.org> Acked-by: Steve Capper <steve.capper@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: mm: dump: fix shift warningMark Rutland2014-12-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | When building with 48-bit VAs, it's possible to get the following warning when building the arm64 page table dumping code: arch/arm64/mm/dump.c: In function ‘walk_pgd’: arch/arm64/mm/dump.c:266:2: warning: right shift count >= width of type pgd_t *pgd = pgd_offset(mm, 0); ^ As pgd_offset is a macro and the second argument is not cast to any particular type, the zero will be given integer type by the compiler. As pgd_offset passes the pargument to pgd_index, we then try to shift the 32-bit integer by at least 39 bits (for 4k pages). Elsewhere the pgd_offset is passed a second argument of unsigned long type, so let's do the same here by passing '0UL' rather than '0'. Cc: Kees Cook <keescook@chromium.org> Acked-by: Laura Abbott <lauraa@codeaurora.org> Acked-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
* arm64: add support to dump the kernel page tablesLaura Abbott2014-11-261-0/+332
In a similar manner to arm, it's useful to be able to dump the page tables to verify permissions and memory types. Add a debugfs file to check the page tables. Acked-by: Steve Capper <steve.capper@linaro.org> Tested-by: Steve Capper <steve.capper@linaro.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Laura Abbott <lauraa@codeaurora.org> [will: s/BUFFERABLE/NORMAL-NC/] Signed-off-by: Will Deacon <will.deacon@arm.com>
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