user/sven/linux.git/arch/powerpc/lib/code-patching.c, branch v5.5.8

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/lib: Refactor __patch_instruction() to use __put_user_asm()

2019-04-21T13:06:02Z

__patch_instruction() is called in early boot, and uses __put_user_size(), which includes the allow/prevent calls to enforce KUAP, which could either be called too early, or in the Radix case, forced to use "early_" versions of functions just to safely handle this one case. __put_user_asm() does not do this, and thus is safe to use both in early boot, and later on since in this case it should only ever be touching kernel memory. __patch_instruction() was previously refactored to use __put_user_size() in order to be able to return -EFAULT, which would allow the kernel to patch instructions in userspace, which should never happen. This has the functional change of causing faults on userspace addresses if KUAP is turned on, which should never happen in practice. A future enhancement could be to double check the patch address is definitely allowed to be tampered with by the kernel. Signed-off-by: Russell Currey Signed-off-by: Michael Ellerman

powerpc: Remove duplicate headers

2019-04-20T12:02:44Z

Remove duplicate headers inclusions. Signed-off-by: Jagadeesh Pagadala Reviewed-by: Mukesh Ojha Signed-off-by: Michael Ellerman

powerpc: simplify patch_instruction_site() and patch_branch_site()

2018-12-19T07:56:32Z

Using patch_site_addr() helper, patch_instruction_site() and patch_branch_site() can be simplified and inlined. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: handover page flags with a pgprot_t parameter

2018-10-14T07:04:09Z

In order to avoid multiple conversions, handover directly a pgprot_t to map_kernel_page() as already done for radix. Do the same for __ioremap_caller() and __ioremap_at(). Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/lib: fix book3s/32 boot failure due to code patching

2018-10-02T13:34:14Z

Commit 51c3c62b58b3 ("powerpc: Avoid code patching freed init sections") accesses 'init_mem_is_free' flag too early, before the kernel is relocated. This provokes early boot failure (before the console is active). As it is not necessary to do this verification that early, this patch moves the test into patch_instruction() instead of __patch_instruction(). This modification also has the advantage of avoiding unnecessary remappings. Fixes: 51c3c62b58b3 ("powerpc: Avoid code patching freed init sections") Cc: stable@vger.kernel.org # 4.13+ Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: Avoid code patching freed init sections

2018-09-18T12:42:54Z

This stops us from doing code patching in init sections after they've been freed. In this chain: kvm_guest_init() -> kvm_use_magic_page() -> fault_in_pages_readable() -> __get_user() -> __get_user_nocheck() -> barrier_nospec(); We have a code patching location at barrier_nospec() and kvm_guest_init() is an init function. This whole chain gets inlined, so when we free the init section (hence kvm_guest_init()), this code goes away and hence should no longer be patched. We seen this as userspace memory corruption when using a memory checker while doing partition migration testing on powervm (this starts the code patching post migration via /sys/kernel/mobility/migration). In theory, it could also happen when using /sys/kernel/debug/powerpc/barrier_nospec. Cc: stable@vger.kernel.org # 4.13+ Signed-off-by: Michael Neuling Reviewed-by: Nicholas Piggin Reviewed-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/asm: Add a patch_site macro & helpers for patching instructions

2018-08-07T14:32:25Z

Add a macro and some helper C functions for patching single asm instructions. The gas macro means we can do something like: 1: nop patch_site 1b, patch__foo Which is less visually distracting than defining a GLOBAL symbol at 1, and also doesn't pollute the symbol table which can confuse eg. perf. These are obviously similar to our existing feature sections, but are not automatically patched based on CPU/MMU features, rather they are designed to be manually patched by C code at some arbitrary point. Signed-off-by: Michael Ellerman

powerpc/lib/feature-fixups: use raw_patch_instruction()

2018-01-21T04:06:25Z

feature fixups need to use patch_instruction() early in the boot, even before the code is relocated to its final address, requiring patch_instruction() to use PTRRELOC() in order to address data. But feature fixups applies on code before it is set to read only, even for modules. Therefore, feature fixups can use raw_patch_instruction() instead. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/lib/code-patching: refactor patch_instruction()

2018-01-21T04:06:25Z

patch_instruction() uses almost the same sequence as __patch_instruction() This patch refactor it so that patch_instruction() uses __patch_instruction() instead of duplicating code. Signed-off-by: Christophe Leroy Acked-by: Balbir Singh Signed-off-by: Michael Ellerman