pm24.git/arch/powerpc/lib, branch rust-6.10

powerpc: xor_vmx: Add '-mhard-float' to CFLAGS

2024-03-06T13:13:28Z

arch/powerpc/lib/xor_vmx.o is built with '-msoft-float' (from the main powerpc Makefile) and '-maltivec' (from its CFLAGS), which causes an error when building with clang after a recent change in main: error: option '-msoft-float' cannot be specified with '-maltivec' make[6]: *** [scripts/Makefile.build:243: arch/powerpc/lib/xor_vmx.o] Error 1 Explicitly add '-mhard-float' before '-maltivec' in xor_vmx.o's CFLAGS to override the previous inclusion of '-msoft-float' (as the last option wins), which matches how other areas of the kernel use '-maltivec', such as AMDGPU. Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/1986 Link: https://github.com/llvm/llvm-project/commit/4792f912b232141ecba4cbae538873be3c28556c Signed-off-by: Nathan Chancellor Signed-off-by: Michael Ellerman Link: https://msgid.link/20240127-ppc-xor_vmx-drop-msoft-float-v1-1-f24140e81376@kernel.org

powerpc/64s: Move dcbt/dcbtst sequence into a macro

2024-03-03T12:05:21Z

There's an almost identical code sequence to specify load/store access hints in __copy_tofrom_user_power7(), copypage_power7() and memcpy_power7(). Move the sequence into a common macro, which is passed the registers to use as they differ slightly. There also needs to be a copy in the selftests, it could be shared in future if the headers are cleaned up / refactored. Signed-off-by: Michael Ellerman Link: https://msgid.link/20240229122521.762431-1-mpe@ellerman.id.au

powerpc: Use user_mode() macro when possible

2024-02-22T10:55:33Z

There is a nice macro to check user mode. Use it instead of open coding anding with MSR_PR to increase readability and avoid having to comment what that anding is for. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/fbf74887dcf1f1ba9e1680fc3247cbb581b00662.1708078228.git.christophe.leroy@csgroup.eu

powerpc/lib: Validate size for vector operations

2023-11-27T11:06:19Z

Some of the fp/vmx code in sstep.c assume a certain maximum size for the instructions being emulated. The size of those operations however is determined separately in analyse_instr(). Add a check to validate the assumption on the maximum size of the operations, so as to prevent any unintended kernel stack corruption. Signed-off-by: Naveen N Rao Reviewed-by: Gustavo A. R. Silva Build-tested-by: Gustavo A. R. Silva Signed-off-by: Michael Ellerman Link: https://msgid.link/20231123071705.397625-1-naveen@kernel.org

powerpc/lib: Avoid array bounds warnings in vec ops

2023-11-27T11:05:14Z

Building with GCC with -Warray-bounds enabled there are several warnings in sstep.c along the lines of: In function ‘do_byte_reverse’, inlined from ‘do_vec_load’ at arch/powerpc/lib/sstep.c:691:3, inlined from ‘emulate_loadstore’ at arch/powerpc/lib/sstep.c:3439:9: arch/powerpc/lib/sstep.c:289:23: error: array subscript 2 is outside array bounds of ‘u8[16]’ {aka ‘unsigned char[16]’} [-Werror=array-bounds=] 289 | up[2] = byterev_8(up[1]); | ~~~~~~^~~~~~~~~~~~~~~~~~ arch/powerpc/lib/sstep.c: In function ‘emulate_loadstore’: arch/powerpc/lib/sstep.c:681:11: note: at offset 16 into object ‘u’ of size 16 681 | } u = {}; | ^ do_byte_reverse() supports a size up to 32 bytes, but in these cases the caller is only passing a 16 byte buffer. In practice there is no bug, do_vec_load() is only called from the LOAD_VMX case in emulate_loadstore(). That in turn is only reached when analyse_instr() recognises VMX ops, and in all cases the size is no greater than 16: $ git grep -w LOAD_VMX arch/powerpc/lib/sstep.c arch/powerpc/lib/sstep.c: op->type = MKOP(LOAD_VMX, 0, 1); arch/powerpc/lib/sstep.c: op->type = MKOP(LOAD_VMX, 0, 2); arch/powerpc/lib/sstep.c: op->type = MKOP(LOAD_VMX, 0, 4); arch/powerpc/lib/sstep.c: op->type = MKOP(LOAD_VMX, 0, 16); Similarly for do_vec_store(). Although the warning is incorrect, the code would be safer if it clamped the size from the caller to the known size of the buffer. Do that using min_t(). Reported-by: Bagas Sanjaya Closes: https://lore.kernel.org/linuxppc-dev/YpbUcPrm61RLIiZF@debian.me/ Reported-by: Jan-Benedict Glaw Closes: https://lore.kernel.org/linuxppc-dev/20221212215117.aa7255t7qd6yefk4@lug-owl.de/ Reported-by: "Gustavo A. R. Silva" Closes: https://lore.kernel.org/linuxppc-dev/6a8bf78c-aedb-4d5a-b0aa-82a51a17b884@embeddedor.com/ Reviewed-by: "Gustavo A. R. Silva" Build-tested-by: "Gustavo A. R. Silva" Signed-off-by: Michael Ellerman Link: https://msgid.link/20231120235436.1569255-1-mpe@ellerman.id.au

powerpc: add crtsavres.o to always-y instead of extra-y

2023-11-27T11:01:15Z

crtsavres.o is linked to modules. However, as explained in commit d0e628cd817f ("kbuild: doc: clarify the difference between extra-y and always-y"), 'make modules' does not build extra-y. For example, the following command fails: $ make ARCH=powerpc LLVM=1 KBUILD_MODPOST_WARN=1 mrproper ps3_defconfig modules [snip] LD [M] arch/powerpc/platforms/cell/spufs/spufs.ko ld.lld: error: cannot open arch/powerpc/lib/crtsavres.o: No such file or directory make[3]: *** [scripts/Makefile.modfinal:56: arch/powerpc/platforms/cell/spufs/spufs.ko] Error 1 make[2]: *** [Makefile:1844: modules] Error 2 make[1]: *** [/home/masahiro/workspace/linux-kbuild/Makefile:350: __build_one_by_one] Error 2 make: *** [Makefile:234: __sub-make] Error 2 Signed-off-by: Masahiro Yamada Fixes: baa25b571a16 ("powerpc/64: Do not link crtsavres.o in vmlinux") Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://msgid.link/20231120232332.4100288-1-masahiroy@kernel.org

powerpc/code-patching: introduce patch_instructions()

2023-10-23T09:33:19Z

patch_instruction() entails setting up pte, patching the instruction, clearing the pte and flushing the tlb. If multiple instructions need to be patched, every instruction would have to go through the above drill unnecessarily. Instead, introduce patch_instructions() function that sets up the pte, clears the pte and flushes the tlb only once per page range of instructions to be patched. Duplicate most of the patch_instruction() code instead of merging with it, to avoid the performance degradation observed on ppc32, for patch_instruction(), with the code path merged. Also, setup poking_init() always as BPF expects poking_init() to be setup even when STRICT_KERNEL_RWX is off. Signed-off-by: Hari Bathini Acked-by: Song Liu Signed-off-by: Michael Ellerman Link: https://msgid.link/20231020141358.643575-2-hbathini@linux.ibm.com

powerpc/code-patching: Perform hwsync in __patch_instruction() in case of failure

2023-10-20T12:19:13Z

Commit c28c15b6d28a ("powerpc/code-patching: Use temporary mm for Radix MMU") added a hwsync for when __patch_instruction() fails, we results in a quite odd unbalanced logic. Instead of calling mb() when __patch_instruction() returns an error, call mb() in the __patch_instruction()'s error path directly. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/e88b154eaf2efd9ff177d472d3411dcdec8ff4f5.1696675567.git.christophe.leroy@csgroup.eu

powerpc/qspinlock: Rename yield_propagate_owner tunable

2023-10-20T11:43:34Z

Rename yield_propagate_owner to yield_sleepy_owner, which better describes what it does (what, not how). Signed-off-by: Nicholas Piggin Tested-by: Shrikanth Hegde Reviewed-by: "Nysal Jan K.A" Signed-off-by: Michael Ellerman Link: https://msgid.link/20231016124305.139923-7-npiggin@gmail.com

powerpc/qspinlock: Propagate sleepy if previous waiter is preempted

2023-10-20T11:43:34Z

The sleepy (aka lock-owner-is-preempted) condition is propagated down the queue by each waiter. If a waiter becomes preempted, it can no longer propagate sleepy. To allow subsequent waiters to yield to the lock owner, also check the lock owner in this case. Signed-off-by: Nicholas Piggin Tested-by: Shrikanth Hegde Reviewed-by: "Nysal Jan K.A" Signed-off-by: Michael Ellerman Link: https://msgid.link/20231016124305.139923-6-npiggin@gmail.com