kernel.git/arch/s390/lib/Makefile, branch linux-6.15.y

s390/crc32: expose CRC32 functions through lib

2024-12-02T01:23:01Z

Move the s390 CRC32 assembly code into the lib directory and wire it up to the library interface. This allows it to be used without going through the crypto API. It remains usable via the crypto API too via the shash algorithms that use the library interface. Thus all the arch-specific "shash" code becomes unnecessary and is removed. Note: to see the diff from arch/s390/crypto/crc32-vx.c to arch/s390/lib/crc32-glue.c, view this commit with 'git show -M10'. Reviewed-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20241202010844.144356-10-ebiggers@kernel.org Signed-off-by: Eric Biggers

s390/expoline: Make modules use kernel expolines

2024-04-17T11:38:03Z

Currently, kernel modules contain their own set of expoline thunks. In the case of EXPOLINE_EXTERN, this involves postlinking of precompiled expoline.o. expoline.o is also necessary for out-of-source tree module builds. Now that the kernel modules area is less than 4 GB away from kernel expoline thunks, make modules use kernel expolines. Also make EXPOLINE_EXTERN the default if the compiler supports it. This simplifies build and aligns with the approach adopted by other architectures. Signed-off-by: Vasily Gorbik Signed-off-by: Alexander Gordeev

s390/checksum: provide vector register variant of csum_partial()

2024-02-16T13:30:17Z

Provide a faster variant of csum_partial() which uses vector registers instead of the cksm instruction. Signed-off-by: Heiko Carstens

s390: select ARCH_SUPPORTS_INT128

2023-05-15T12:12:14Z

s390 has instructions to support 128 bit arithmetics, e.g. a 64 bit multiply instruction with a 128 bit result. Also 128 bit integer artithmetics are already used in s390 specific architecture code (see e.g. read_persistent_clock64()). Therefore select ARCH_SUPPORTS_INT128. However limit this to clang for now, since gcc generates inefficient code, which may lead to stack overflows, when compiling lib/crypto/curve25519-hacl64.c which depends on ARCH_SUPPORTS_INT128. The gcc generated functions have 6kb stack frames, compared to only 1kb of the code generated with clang. If the kernel is compiled with -Os library calls for __ashlti3(), __ashrti3(), and __lshrti3() may be generated. Similar to arm64 and riscv provide assembler implementations for these functions. Acked-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/nospec: build expoline.o for modules_prepare target

2022-07-13T13:21:55Z

When CONFIG_EXPOLINE_EXTERN is used expoline thunks are generated from arch/s390/lib/expoline.S and postlinked into every module. This is also true for external modules. Add expoline.o build to the modules_prepare target. Fixes: 1d2ad084800e ("s390/nospec: add an option to use thunk-extern") Reported-by: Joe Lawrence Tested-by: Sumanth Korikkar Acked-by: Sumanth Korikkar Tested-by: C. Erastus Toe Tested-by: Joe Lawrence Link: https://lore.kernel.org/r/patch-1.thread-d13b6c.git-a2387a74dc49.your-ad-here.call-01656331067-ext-4899@work.hours Signed-off-by: Vasily Gorbik Signed-off-by: Alexander Gordeev

s390/nospec: add an option to use thunk-extern

2022-03-10T14:58:17Z

Currently with -mindirect-branch=thunk and -mfunction-return=thunk compiler options expoline thunks are put into individual COMDAT group sections. s390 is the only architecture which has group sections and it has implications for kpatch and objtool tools support. Using -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern is an alternative, which comes with a need to generate all required expoline thunks manually. Unfortunately modules area is too far away from the kernel image, and expolines from the kernel image cannon be used. But since all new distributions (except Debian) build kernels for machine generations newer than z10, where "exrl" instruction is available, that leaves only 16 expolines thunks possible. Provide an option to build the kernel with -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern for z10 or newer. This also requires to postlink expoline thunks into all modules explicitly. Currently modules already contain most expolines anyhow. Unfortunately -mindirect-branch=thunk-extern and -mfunction-return=thunk-extern options support is broken in gcc <= 11.2. Additional compile test is required to verify proper gcc support. Acked-by: Ilya Leoshkevich Co-developed-by: Sumanth Korikkar Signed-off-by: Sumanth Korikkar Signed-off-by: Vasily Gorbik

s390/module: test loading modules with a lot of relocations

2022-01-24T08:10:59Z

Add a test in order to prevent regressions. Signed-off-by: Ilya Leoshkevich Reviewed-by: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Signed-off-by: Heiko Carstens

kprobes: add testcases for s390

2021-10-04T07:49:37Z

Add a few testcases to make sure that it's not possible to place a kprobe in the mid of an instruction on s390. Signed-off-by: Sven Schnelle Acked-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: enable HAVE_FUNCTION_ERROR_INJECTION

2020-07-27T08:33:28Z

This kernel feature is required for enabling BPF_KPROBE_OVERRIDE. Define override_function_with_return() and regs_set_return_value() functions, and fix compile errors in syscall_wrapper.h. Signed-off-by: Ilya Leoshkevich Signed-off-by: Heiko Carstens

s390/unwind: add a test for the internal API

2019-11-30T09:52:46Z

unwind_for_each_frame can take at least 8 different sets of parameters. Add a test to make sure they all are handled in a sane way. Reviewed-by: Heiko Carstens Signed-off-by: Ilya Leoshkevich Co-developed-by: Vasily Gorbik Signed-off-by: Vasily Gorbik