- 10 Nov, 2020 10 commits
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With the intoduction of hardware tag-based KASAN some kernel checks of this kind: ifdef CONFIG_KASAN will be updated to: if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) x86 and s390 use a trick to #undef CONFIG_KASAN for some of the code that isn't linked with KASAN runtime and shouldn't have any KASAN annotations. Also #undef CONFIG_KASAN_GENERIC with CONFIG_KASAN. Signed-off-by:
Andrey Konovalov <andreyknvl@google.com> Signed-off-by:
Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by:
Marco Elver <elver@google.com> Acked-by:
Vasily Gorbik <gor@linux.ibm.com> --- Change-Id: I2a622db0cb86a8feb60c30d8cb09190075be2a90
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Hardware tag-based KASAN has granules of MTE_GRANULE_SIZE. Define KASAN_GRANULE_SIZE to MTE_GRANULE_SIZE for CONFIG_KASAN_HW_TAGS. Signed-off-by:
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This patch add a set of arch_*() memory tagging helpers currently only defined for arm64 when hardware tag-based KASAN is enabled. These helpers will be used by KASAN runtime to implement the hardware tag-based mode. The arch-level indirection level is introduced to simplify adding hardware tag-based KASAN support for other architectures in the future by defining the appropriate arch_*() macros. Signed-off-by:
Catalin Marinas <catalin.marinas@arm.com> --- Change-Id: I42b0795a28067872f8308e00c6f0195bca435c2a
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Hardware tag-based KASAN uses the memory tagging approach, which requires all allocations to be aligned to the memory granule size. Align the allocations to MTE_GRANULE_SIZE via ARCH_SLAB_MINALIGN when CONFIG_KASAN_HW_TAGS is enabled. Signed-off-by:
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Vincenzo Frascino authored
free_reserved_area() memsets the pages belonging to a given memory area. To do that retrieves the page address via page_address(). For the architectures that support KASAN the pointer to the page can be tagged as a result of page_address() but the underlying memory untouched by any allocator. This scenario causes a tag fault during the memset() operation. Untag the address to avoid spurious faults. Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: -
Vincenzo Frascino authored
When MTE is present, the GCR_EL1 register contains the tags mask that allows to exclude tags from the random generation via the IRG instruction. With the introduction of the new Tag-Based KASAN API that provides a mechanism to reserve tags for special reasons, the MTE implementation has to make sure that the GCR_EL1 setting for the kernel does not affect the userspace processes and viceversa. Save and restore the kernel/user mask in GCR_EL1 in kernel entry and exit. Signed-off-by:
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Vincenzo Frascino authored
The gcr_user mask is a per thread mask that represents the tags that are excluded from random generation when the Memory Tagging Extension is present and an 'irg' instruction is invoked. gcr_user affects the behavior on EL0 only. Currently that mask is an include mask and it is controlled by the user via prctl() while GCR_EL1 accepts an exclude mask. Convert the include mask into an exclude one to make it easier the register setting. Note: This change will affect gcr_kernel (for EL1) introduced with a future patch. Signed-off-by:
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Vincenzo Frascino authored
Hardware tag-based KASAN relies on Memory Tagging Extension (MTE) feature and requires it to be enabled. MTE supports This patch adds a new mte_init_tags() helper, that enables MTE in Synchronous mode in EL1 and is intended to be called from KASAN runtime during initialization. The Tag Checking operation causes a synchronous data abort as a consequence of a tag check fault when MTE is configured in synchronous mode. As part of this change enable match-all tag for EL1 to allow the kernel to access user pages without faulting. This is required because the kernel does not have knowledge of the tags set by the user in a page. Note: For MTE, the TCF bit field in SCTLR_EL1 affects only EL1 in a similar way as TCF0 affects EL0. MTE that is built on top of the Top Byte Ignore (TBI) feature hence we enable it as part of this patch as well. Signed-off-by:
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Vincenzo Frascino authored
Add the implementation of the in-kernel fault handler. When a tag fault happens on a kernel address: * MTE is disabled on the current CPU, * the execution continues. When a tag fault happens on a user address: * the kernel executes do_bad_area() and panics. The tag fault handler for kernel addresses is currently empty and will be filled in by a future commit. Signed-off-by:
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Vincenzo Frascino authored
The hardware tag-based KASAN for compatibility with the other modes stores the tag associated to a page in page->flags. Due to this the kernel faults on access when it allocates a page with an initial tag and the user changes the tags. Reset the tag associated by the kernel to a page in all the meaningful places to prevent kernel faults on access. Note: An alternative to this approach could be to modify page_to_virt(). This though could end up being racy, in fact if a CPU checks the PG_mte_tagged bit and decides that the page is not tagged but another CPU maps the same with PROT_MTE and becomes tagged the subsequent kernel access would fail. Signed-off-by:
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- 09 Nov, 2020 27 commits
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Vincenzo Frascino authored
Provide helper functions to manipulate allocation and pointer tags for kernel addresses. Low-level helper functions (mte_assign_*, written in assembly) operate tag values from the [0x0, 0xF] range. High-level helper functions (mte_get/set_*) use the [0xF0, 0xFF] range to preserve compatibility with normal kernel pointers that have 0xFF in their top byte. MTE_GRANULE_SIZE and related definitions are moved to mte-def.h header that doesn't have any dependencies and is safe to include into any low-level header. Signed-off-by:
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Vincenzo Frascino authored
Hardware tag-based KASAN relies on Memory Tagging Extension (MTE) which is an armv8.5-a architecture extension. Enable the correct asm option when the compiler supports it in order to allow the usage of ALTERNATIVE()s with MTE instructions. Signed-off-by:
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Andrey Konovalov authored
This patch adds a configuration option for a new KASAN mode called hardware tag-based KASAN. This mode uses the memory tagging approach like the software tag-based mode, but relies on arm64 Memory Tagging Extension feature for tag management and access checking. Signed-off-by:
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Andrey Konovalov authored
Software tag-based KASAN provides its own tag checking machinery that can conflict with MTE. Don't allow enabling software tag-based KASAN when MTE is enabled. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Rework print_memory_metadata() to make it agnostic with regard to the way metadata is stored. Allow providing a separate metadata_fetch_row() implementation for each KASAN mode. Hardware tag-based KASAN will provide its own implementation that doesn't use shadow memory. No functional changes for software modes. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Hardware tag-based KASAN won't be using shadow memory, but will reuse these macros. Rename "SHADOW" to implementation-neutral "META". No functional changes. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. kasan_non_canonical_hook() is only applicable to KASAN modes that use shadow memory, and won't be needed for hardware tag-based KASAN. No functional changes for software modes. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Hardware tag-based KASAN won't be using shadow memory, but will reuse this function. Rename "shadow" to implementation-neutral "metadata". No functional changes. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Hardware tag-based KASAN won't be using shadow memory, but will reuse this function. Rename "shadow" to implementation-neutral "metadata". No functional changes. Signed-off-by:
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Andrey Konovalov authored
Rename kasan_init_tags() to kasan_init_sw_tags() as the upcoming hardware tag-based KASAN mode will have its own initialization routine. Also similarly to kasan_init() mark kasan_init_tags() as __init. Signed-off-by:
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Andrey Konovalov authored
Software tag-based KASAN mode is fully initialized with kasan_init_tags(), while the generic mode only requires kasan_init(). Move the initialization message for tag-based mode into kasan_init_tags(). Also fix pr_fmt() usage for KASAN code: generic.c doesn't need it as it doesn't use any printing functions; tag-based mode should use "kasan:" instead of KBUILD_MODNAME (which stands for file name). Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Hardware tag-based KASAN won't use kasan_depth. Only define and use it when one of the software KASAN modes are enabled. No functional changes for software modes. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Hardware tag-based KASAN won't be using shadow memory. Only initialize it when one of the software KASAN modes are enabled. No functional changes for software modes. Signed-off-by:
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Andrey Konovalov authored
Decoding routines aren't needed when CONFIG_KASAN_STACK_ENABLE is not enabled. Currently only generic KASAN mode implements stack error reporting. No functional changes for software modes. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. For software KASAN modes the check is based on the value in the shadow memory. Hardware tag-based KASAN won't be using shadow, so hide the implementation of the check in check_invalid_free(). Also simplify the code for software tag-based mode. No functional changes for software modes. Signed-off-by:
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Andrey Konovalov authored
Both KASAN_GENERIC and KASAN_SW_TAGS have common dependencies, move those to KASAN. Signed-off-by:
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Andrey Konovalov authored
Rename generic_report.c to report_generic.c and tags_report.c to report_sw_tags.c, as their content is more relevant to report.c file. Also rename tags.c to sw_tags.c to better reflect that this file contains code for software tag-based mode. No functional changes. Signed-off-by:
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Andrey Konovalov authored
Define KASAN_GRANULE_PAGE as (KASAN_GRANULE_SIZE << PAGE_SHIFT), which is the same as (KASAN_GRANULE_SIZE * PAGE_SIZE), and use it across KASAN code to simplify it. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. The new mode won't be using shadow memory. Move all shadow-related code to shadow.c, which is only enabled for software KASAN modes that use shadow memory. No functional changes for software modes. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. The new mode won't be using shadow memory, so only build init.c that contains shadow initialization code for software modes. No functional changes for software modes. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. The new mode won't be using shadow memory, but will still use the concept of memory granules. Each memory granule maps to a single metadata entry: 8 bytes per one shadow byte for generic mode, 16 bytes per one shadow byte for software tag-based mode, and 16 bytes per one allocation tag for hardware tag-based mode. Rename KASAN_SHADOW_SCALE_SIZE to KASAN_GRANULE_SIZE, and KASAN_SHADOW_MASK to KASAN_GRANULE_MASK. Also use MASK when used as a mask, otherwise use SIZE. No functional changes. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. The new mode won't be using shadow memory, but will reuse the same functions. Rename kasan_unpoison_shadow to kasan_unpoison_memory, and kasan_poison_shadow to kasan_poison_memory. No functional changes. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Group shadow-related KASAN function declarations and only define them for the two existing software modes. No functional changes for software modes. Signed-off-by:
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Andrey Konovalov authored
asm/kasan.h relies on pgd_t and _REGION1_SHIFT definitions and therefore requires asm/pgtable.h include. Include asm/pgtable.h from asm/kasan.h. Signed-off-by:
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Andrey Konovalov authored
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Group all vmalloc-related function declarations in include/linux/kasan.h, and their implementations in mm/kasan/common.c. No functional changes. Signed-off-by:
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Andrey Konovalov authored
Currently only generic KASAN mode supports vmalloc, reflect that in the config. Signed-off-by:
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Andrey Konovalov authored
Don't mention "GNU General Public License version 2" text explicitly, as it's already covered by the SPDX-License-Identifier. Signed-off-by:
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- 05 Nov, 2020 3 commits
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Linus Torvalds authored
Merge tag 'linux-kselftest-kunit-fixes-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pull Kunit fixes from Shuah Khan: "Several kunit_tool and documentation fixes" * tag 'linux-kselftest-kunit-fixes-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: kunit: tools: fix kunit_tool tests for parsing test plans Documentation: kunit: Update Kconfig parts for KUNIT's module support kunit: test: fix remaining kernel-doc warnings kunit: Don't fail test suites if one of them is empty kunit: Fix kunit.py --raw_output option
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-traceLinus Torvalds authored
Pull tracing fixes from Steven Rostedt: - Fix off-by-one error in retrieving the context buffer for trace_printk() - Fix off-by-one error in stack nesting limit - Fix recursion to not make all NMI code false positive as recursing - Stop losing events in function tracing when transitioning between irq context - Stop losing events in ring buffer when transitioning between irq context - Fix return code of error pointer in parse_synth_field() to prevent NULL pointer dereference. - Fix false positive of NMI recursion in kprobe event handling * tag 'trace-v5.10-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: kprobes: Tell lockdep about kprobe nesting tracing: Make -ENOMEM the default error for parse_synth_field() ring-buffer: Fix recursion protection transitions between interrupt context tracing: Fix the checking of stackidx in __ftrace_trace_stack ftrace: Handle tracing when switching between context ftrace: Fix recursion check for NMI test tracing: Fix out of bounds write in get_trace_buf
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git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linuxLinus Torvalds authored
Pull hyperv fixes from Wei Liu: - clarify a comment (Michael Kelley) - change a pr_warn() to pr_info() (Olaf Hering) * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Clarify comment on x2apic mode hv_balloon: disable warning when floor reached
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