wireguard-linux/arch/powerpc/kernel/paca.c, branch jd/unified-crypt-queue

powerpc/64: Prevent stack protection in early boot

2020-03-25T01:09:38Z

The previous commit reduced the amount of code that is run before we setup a paca. However there are still a few remaining functions that run with no paca, or worse, with an arbitrary value in r13 that will be used as a paca pointer. In particular the stack protector canary is stored in the paca, so if stack protector is activated for any of these functions we will read the stack canary from wherever r13 points. If r13 happens to point outside of memory we will get a machine check / checkstop. For example if we modify initialise_paca() to trigger stack protection, and then boot in the mambo simulator with r13 poisoned in skiboot before calling the kernel: DEBUG: 19952232: (19952232): INSTRUCTION: PC=0xC0000000191FC1E8: [0x3C4C006D]: addis r2,r12,0x6D [fetch] DEBUG: 19952236: (19952236): INSTRUCTION: PC=0xC00000001807EAD8: [0x7D8802A6]: mflr r12 [fetch] FATAL ERROR: 19952276: (19952276): Check Stop for 0:0: Machine Check with ME bit of MSR off DEBUG: 19952276: (19952276): INSTRUCTION: PC=0xC0000000191FCA7C: [0xE90D0CF8]: ld r8,0xCF8(r13) [Instruction Failed] INFO: 19952276: (19952277): ** Execution stopped: Mambo Error, Machine Check Stop, ** systemsim % bt pc: 0xC0000000191FCA7C initialise_paca+0x54 lr: 0xC0000000191FC22C early_setup+0x44 stack:0x00000000198CBED0 0x0 +0x0 stack:0x00000000198CBF00 0xC0000000191FC22C early_setup+0x44 stack:0x00000000198CBF90 0x1801C968 +0x1801C968 So annotate the relevant functions to ensure stack protection is never enabled for them. Fixes: 06ec27aea9fc ("powerpc/64: add stack protector support") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200320032116.1024773-2-mpe@ellerman.id.au

powerpc/64: Setup a paca before parsing device tree etc.

2020-03-25T01:09:37Z

Currently we set up the paca after parsing the device tree for CPU features. Prior to that, r13 contains random data, which means there is random data in r13 while we're running the generic dt parsing code. This random data varies depending on whether we boot through a vmlinux or a zImage: for the vmlinux case it's usually around zero, but for zImages we see random values like 912a72603d420015. This is poor practice, and can also lead to difficult-to-debug crashes. For example, when kcov is enabled, the kcov instrumentation attempts to read preempt_count out of the current task, which goes via the paca. This then crashes in the zImage case. Similarly stack protector can cause crashes if r13 is bogus, by reading from the stack canary in the paca. To resolve this: - move the paca setup to before the CPU feature parsing. - because we no longer have access to CPU feature flags in paca setup, change the HV feature test in the paca setup path to consider the actual value of the MSR rather than the CPU feature. Translations get switched on once we leave early_setup, so I think we'd already catch any other cases where the paca or task aren't set up. Boot tested on a P9 guest and host. Fixes: fb0b0a73b223 ("powerpc: Enable kcov") Fixes: 06ec27aea9fc ("powerpc/64: add stack protector support") Cc: stable@vger.kernel.org # v4.20+ Reviewed-by: Andrew Donnellan Suggested-by: Michael Ellerman Signed-off-by: Daniel Axtens [mpe: Reword comments & change log a bit to mention stack protector] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200320032116.1024773-1-mpe@ellerman.id.au

powerpc/pseries/svm: Use shared memory for LPPACA structures

2019-08-29T23:55:40Z

LPPACA structures need to be shared with the host. Hence they need to be in shared memory. Instead of allocating individual chunks of memory for a given structure from memblock, a contiguous chunk of memory is allocated and then converted into shared memory. Subsequent allocation requests will come from the contiguous chunk which will be always shared memory for all structures. While we are able to use a kmem_cache constructor for the Debug Trace Log, LPPACAs are allocated very early in the boot process (before SLUB is available) so we need to use a simpler scheme here. Introduce helper is_svm_platform() which uses the S bit of the MSR to tell whether we're running as a secure guest. Signed-off-by: Anshuman Khandual Signed-off-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190820021326.6884-9-bauerman@linux.ibm.com

powerpc/pseries: Add and use LPPACA_SIZE constant

2019-08-29T23:55:40Z

Helps document what the hard-coded number means. Also take the opportunity to fix an #endif comment. Suggested-by: Alexey Kardashevskiy Signed-off-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190820021326.6884-8-bauerman@linux.ibm.com

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman

powerpc/mm: Add helpers for accessing hash translation related variables

2019-04-21T13:12:38Z

We want to switch to allocating them runtime only when hash translation is enabled. Add helpers so that both book3s and nohash can be adapted to upcoming change easily. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman

powerpc: use memblock functions returning virtual address

2019-03-12T17:04:01Z

Since only the virtual address of allocated blocks is used, lets use functions returning directly virtual address. Those functions have the advantage of also zeroing the block. [rppt@linux.ibm.com: powerpc: remove duplicated alloc_stack() function] Link: http://lkml.kernel.org/r/20190226064032.GA5873@rapoport-lnx [rppt@linux.ibm.com: updated error message in alloc_stack() to be more verbose] [rppt@linux.ibm.com: convereted several additional call sites ] Link: http://lkml.kernel.org/r/1548057848-15136-3-git-send-email-rppt@linux.ibm.com Signed-off-by: Christophe Leroy Signed-off-by: Mike Rapoport Acked-by: Michael Ellerman Cc: Catalin Marinas Cc: Christoph Hellwig Cc: "David S. Miller" Cc: Dennis Zhou Cc: Geert Uytterhoeven Cc: Greentime Hu Cc: Greg Kroah-Hartman Cc: Guan Xuetao Cc: Guo Ren Cc: Guo Ren [c-sky] Cc: Heiko Carstens Cc: Juergen Gross [Xen] Cc: Mark Salter Cc: Matt Turner Cc: Max Filippov Cc: Michal Simek Cc: Paul Burton Cc: Petr Mladek Cc: Richard Weinberger Cc: Rich Felker Cc: Rob Herring Cc: Rob Herring Cc: Russell King Cc: Stafford Horne Cc: Tony Luck Cc: Vineet Gupta Cc: Yoshinori Sato Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

powerpc: prefer memblock APIs returning virtual address

2019-03-08T02:32:03Z

Patch series "memblock: simplify several early memory allocation", v4. These patches simplify some of the early memory allocations by replacing usage of older memblock APIs with newer and shinier ones. Quite a few places in the arch/ code allocated memory using a memblock API that returns a physical address of the allocated area, then converted this physical address to a virtual one and then used memset(0) to clear the allocated range. More recent memblock APIs do all the three steps in one call and their usage simplifies the code. It's important to note that regardless of API used, the core allocation is nearly identical for any set of memblock allocators: first it tries to find a free memory with all the constraints specified by the caller and then falls back to the allocation with some or all constraints disabled. The first three patches perform the conversion of call sites that have exact requirements for the node and the possible memory range. The fourth patch is a bit one-off as it simplifies openrisc's implementation of pte_alloc_one_kernel(), and not only the memblock usage. The fifth patch takes care of simpler cases when the allocation can be satisfied with a simple call to memblock_alloc(). The sixth patch removes one-liner wrappers for memblock_alloc on arm and unicore32, as suggested by Christoph. This patch (of 6): There are a several places that allocate memory using memblock APIs that return a physical address, convert the returned address to the virtual address and frequently also memset(0) the allocated range. Update these places to use memblock allocators already returning a virtual address. Use memblock functions that clear the allocated memory instead of calling memset(0) where appropriate. The calls to memblock_alloc_base() that were not followed by memset(0) are replaced with memblock_alloc_try_nid_raw(). Since the latter does not panic() when the allocation fails, the appropriate panic() calls are added to the call sites. Link: http://lkml.kernel.org/r/1546248566-14910-2-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: "David S. Miller" Cc: Guan Xuetao Cc: Greentime Hu Cc: Heiko Carstens Cc: Jonas Bonn Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: Michal Hocko Cc: Michal Simek Cc: Mark Salter Cc: Paul Mackerras Cc: Rich Felker Cc: Russell King Cc: Stefan Kristiansson Cc: Stafford Horne Cc: Vincent Chen Cc: Yoshinori Sato Cc: Christoph Hellwig Cc: Michal Simek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: replace all open encodings for NUMA_NO_NODE

2019-03-06T05:07:14Z

Patch series "Replace all open encodings for NUMA_NO_NODE", v3. All these places for replacement were found by running the following grep patterns on the entire kernel code. Please let me know if this might have missed some instances. This might also have replaced some false positives. I will appreciate suggestions, inputs and review. 1. git grep "nid == -1" 2. git grep "node == -1" 3. git grep "nid = -1" 4. git grep "node = -1" This patch (of 2): At present there are multiple places where invalid node number is encoded as -1. Even though implicitly understood it is always better to have macros in there. Replace these open encodings for an invalid node number with the global macro NUMA_NO_NODE. This helps remove NUMA related assumptions like 'invalid node' from various places redirecting them to a common definition. Link: http://lkml.kernel.org/r/1545127933-10711-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Reviewed-by: David Hildenbrand Acked-by: Jeff Kirsher [ixgbe] Acked-by: Jens Axboe [mtip32xx] Acked-by: Vinod Koul [dmaengine.c] Acked-by: Michael Ellerman [powerpc] Acked-by: Doug Ledford [drivers/infiniband] Cc: Joseph Qi Cc: Hans Verkuil Cc: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memblock: stop using implicit alignment to SMP_CACHE_BYTES

2018-10-31T15:54:16Z

When a memblock allocation APIs are called with align = 0, the alignment is implicitly set to SMP_CACHE_BYTES. Implicit alignment is done deep in the memblock allocator and it can come as a surprise. Not that such an alignment would be wrong even when used incorrectly but it is better to be explicit for the sake of clarity and the prinicple of the least surprise. Replace all such uses of memblock APIs with the 'align' parameter explicitly set to SMP_CACHE_BYTES and stop implicit alignment assignment in the memblock internal allocation functions. For the case when memblock APIs are used via helper functions, e.g. like iommu_arena_new_node() in Alpha, the helper functions were detected with Coccinelle's help and then manually examined and updated where appropriate. The direct memblock APIs users were updated using the semantic patch below: @@ expression size, min_addr, max_addr, nid; @@ ( | - memblock_alloc_try_nid_raw(size, 0, min_addr, max_addr, nid) + memblock_alloc_try_nid_raw(size, SMP_CACHE_BYTES, min_addr, max_addr, nid) | - memblock_alloc_try_nid_nopanic(size, 0, min_addr, max_addr, nid) + memblock_alloc_try_nid_nopanic(size, SMP_CACHE_BYTES, min_addr, max_addr, nid) | - memblock_alloc_try_nid(size, 0, min_addr, max_addr, nid) + memblock_alloc_try_nid(size, SMP_CACHE_BYTES, min_addr, max_addr, nid) | - memblock_alloc(size, 0) + memblock_alloc(size, SMP_CACHE_BYTES) | - memblock_alloc_raw(size, 0) + memblock_alloc_raw(size, SMP_CACHE_BYTES) | - memblock_alloc_from(size, 0, min_addr) + memblock_alloc_from(size, SMP_CACHE_BYTES, min_addr) | - memblock_alloc_nopanic(size, 0) + memblock_alloc_nopanic(size, SMP_CACHE_BYTES) | - memblock_alloc_low(size, 0) + memblock_alloc_low(size, SMP_CACHE_BYTES) | - memblock_alloc_low_nopanic(size, 0) + memblock_alloc_low_nopanic(size, SMP_CACHE_BYTES) | - memblock_alloc_from_nopanic(size, 0, min_addr) + memblock_alloc_from_nopanic(size, SMP_CACHE_BYTES, min_addr) | - memblock_alloc_node(size, 0, nid) + memblock_alloc_node(size, SMP_CACHE_BYTES, nid) ) [mhocko@suse.com: changelog update] [akpm@linux-foundation.org: coding-style fixes] [rppt@linux.ibm.com: fix missed uses of implicit alignment] Link: http://lkml.kernel.org/r/20181016133656.GA10925@rapoport-lnx Link: http://lkml.kernel.org/r/1538687224-17535-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport Suggested-by: Michal Hocko Acked-by: Paul Burton [MIPS] Acked-by: Michael Ellerman [powerpc] Acked-by: Michal Hocko Cc: Catalin Marinas Cc: Chris Zankel Cc: Geert Uytterhoeven Cc: Guan Xuetao Cc: Ingo Molnar Cc: Matt Turner Cc: Michal Simek Cc: Richard Weinberger Cc: Russell King Cc: Thomas Gleixner Cc: Tony Luck Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds