kernel.git/arch/powerpc/lib/Makefile, branch linux-5.8.y

x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()

2020-11-01T11:45:37Z

commit ec6347bb43395cb92126788a1a5b25302543f815 upstream. In reaction to a proposal to introduce a memcpy_mcsafe_fast() implementation Linus points out that memcpy_mcsafe() is poorly named relative to communicating the scope of the interface. Specifically what addresses are valid to pass as source, destination, and what faults / exceptions are handled. Of particular concern is that even though x86 might be able to handle the semantics of copy_mc_to_user() with its common copy_user_generic() implementation other archs likely need / want an explicit path for this case: On Fri, May 1, 2020 at 11:28 AM Linus Torvalds wrote: > > On Thu, Apr 30, 2020 at 6:21 PM Dan Williams wrote: > > > > However now I see that copy_user_generic() works for the wrong reason. > > It works because the exception on the source address due to poison > > looks no different than a write fault on the user address to the > > caller, it's still just a short copy. So it makes copy_to_user() work > > for the wrong reason relative to the name. > > Right. > > And it won't work that way on other architectures. On x86, we have a > generic function that can take faults on either side, and we use it > for both cases (and for the "in_user" case too), but that's an > artifact of the architecture oddity. > > In fact, it's probably wrong even on x86 - because it can hide bugs - > but writing those things is painful enough that everybody prefers > having just one function. Replace a single top-level memcpy_mcsafe() with either copy_mc_to_user(), or copy_mc_to_kernel(). Introduce an x86 copy_mc_fragile() name as the rename for the low-level x86 implementation formerly named memcpy_mcsafe(). It is used as the slow / careful backend that is supplanted by a fast copy_mc_generic() in a follow-on patch. One side-effect of this reorganization is that separating copy_mc_64.S to its own file means that perf no longer needs to track dependencies for its memcpy_64.S benchmarks. [ bp: Massage a bit. ] Signed-off-by: Dan Williams Signed-off-by: Borislav Petkov Reviewed-by: Tony Luck Acked-by: Michael Ellerman Cc: Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqbg@mail.gmail.com Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Greg Kroah-Hartman

powerpc: Test prefixed code patching

2020-05-18T14:11:02Z

Expand the code-patching self-tests to includes tests for patching prefixed instructions. Signed-off-by: Jordan Niethe [mpe: Use CONFIG_PPC64 not __powerpc64__] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200506034050.24806-25-jniethe5@gmail.com

powerpc: Add a probe_user_read_inst() function

2020-05-18T14:10:37Z

Introduce a probe_user_read_inst() function to use in cases where probe_user_read() is used for getting an instruction. This will be more useful for prefixed instructions. Signed-off-by: Jordan Niethe Reviewed-by: Alistair Popple [mpe: Don't write to *inst on error, fold in __user annotations] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200506034050.24806-14-jniethe5@gmail.com

powerpc/memcpy: Add memcpy_mcsafe for pmem

2019-08-21T12:23:48Z

The pmem infrastructure uses memcpy_mcsafe in the pmem layer so as to convert machine check exceptions into a return value on failure in case a machine check exception is encountered during the memcpy. The return value is the number of bytes remaining to be copied. This patch largely borrows from the copyuser_power7 logic and does not add the VMX optimizations, largely to keep the patch simple. If needed those optimizations can be folded in. Signed-off-by: Balbir Singh [arbab@linux.ibm.com: Added symbol export] Co-developed-by: Santosh Sivaraj Signed-off-by: Santosh Sivaraj Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190820081352.8641-7-santosh@fossix.org

powerpc/32: activate ARCH_HAS_PMEM_API and ARCH_HAS_UACCESS_FLUSHCACHE

2019-08-05T08:53:04Z

PPC32 also have flush_dcache_range() so it can also support ARCH_HAS_PMEM_API and ARCH_HAS_UACCESS_FLUSHCACHE without changes. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/a682a2f9db308c5cfe77e45aa3352e41bc9f4e33.1564554634.git.christophe.leroy@c-s.fr

powerpc/lib: only build ldstfp.o when CONFIG_PPC_FPU is set

2019-05-28T02:08:11Z

The entire code in ldstfp.o is enclosed into #ifdef CONFIG_PPC_FPU, so there is no point in building it when this config is not selected. Fixes: cd64d1697cf0 ("powerpc: mtmsrd not defined") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc/lib: fix redundant inclusion of quad.o

2019-05-28T02:08:11Z

quad.o is only for PPC64, and already included in obj64-y, so it doesn't have to be in obj-y Fixes: 31bfdb036f12 ("powerpc: Use instruction emulation infrastructure to handle alignment faults") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: disable KASAN instrumentation on early/critical files.

2019-05-02T15:20:26Z

All files containing functions run before kasan_early_init() is called must have KASAN instrumentation disabled. For those file, branch profiling also have to be disabled otherwise each if () generates a call to ftrace_likely_update(). Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman

powerpc: prepare string/mem functions for KASAN

2019-05-02T15:20:25Z

CONFIG_KASAN implements wrappers for memcpy() memmove() and memset() Those wrappers are doing the verification then call respectively __memcpy() __memmove() and __memset(). The arches are therefore expected to rename their optimised functions that way. For files on which KASAN is inhibited, #defines are used to allow them to directly call optimised versions of the functions without going through the KASAN wrappers. See commit 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions") for details. Other string / mem functions do not (yet) have kasan wrappers, we therefore have to fallback to the generic versions when KASAN is active, otherwise KASAN checks will be skipped. Signed-off-by: Christophe Leroy [mpe: Fixups to keep selftests working] Signed-off-by: Michael Ellerman

powerpc: sstep: Add tests for compute type instructions

2019-02-23T10:04:31Z

This enhances the current selftest framework for validating the in-kernel instruction emulation infrastructure by adding support for compute type instructions i.e. integer ALU-based instructions. Originally, this framework was limited to only testing load and store instructions. While most of the GPRs can be validated, support for SPRs is limited to LR, CR and XER for now. When writing the test cases, one must ensure that the Stack Pointer (GPR1) or the Thread Pointer (GPR13) are not touched by any means as these are vital non-volatile registers. Signed-off-by: Sandipan Das [mpe: Use patch_site for the code patching] Signed-off-by: Michael Ellerman