pm24.git/arch/powerpc/kernel/vdso/Makefile, branch cpufreq-rust

powerpc/Makefile: Allow overriding CPP

2024-11-15T00:59:55Z

Unlike all other arches, powerpc doesn't allow the user to override CPP, because it sets it unconditionally in the arch Makefile. This can lead to strange build failures. Instead add the required flags to KBUILD_CPPFLAGS, which are passed to CPP, CC and AS invocations by the generic Makefile logic. Reported-by: Arnd Bergmann Tested-by: Nathan Chancellor Reviewed-by: Nathan Chancellor Closes: https://lore.kernel.org/all/20240607061629.530301-1-arnd@kernel.org Signed-off-by: Arnd Bergmann [mpe: Rebase, write change log, add Arnd's SoB as communicated privately] Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241107112646.32401-1-mpe@ellerman.id.au

powerpc/vdso: Drop -mstack-protector-guard flags in 32-bit files with clang

2024-11-04T06:03:10Z

Under certain conditions, the 64-bit '-mstack-protector-guard' flags may end up in the 32-bit vDSO flags, resulting in build failures due to the structure of clang's argument parsing of the stack protector options, which validates the arguments of the stack protector guard flags unconditionally in the frontend, choking on the 64-bit values when targeting 32-bit: clang: error: invalid value 'r13' in 'mstack-protector-guard-reg=', expected one of: r2 clang: error: invalid value 'r13' in 'mstack-protector-guard-reg=', expected one of: r2 make[3]: *** [arch/powerpc/kernel/vdso/Makefile:85: arch/powerpc/kernel/vdso/vgettimeofday-32.o] Error 1 make[3]: *** [arch/powerpc/kernel/vdso/Makefile:87: arch/powerpc/kernel/vdso/vgetrandom-32.o] Error 1 Remove these flags by adding them to the CC32FLAGSREMOVE variable, which already handles situations similar to this. Additionally, reformat and align a comment better for the expanding CONFIG_CC_IS_CLANG block. Cc: stable@vger.kernel.org # v6.1+ Signed-off-by: Nathan Chancellor Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241030-powerpc-vdso-drop-stackp-flags-clang-v1-1-d95e7376d29c@kernel.org

powerpc/vdso: allow r30 in vDSO code generation of getrandom

2024-09-30T09:19:43Z

For gettimeofday, -ffixed-r30 was passed to work around a bug in Go code, where the vDSO trampoline forgot to save and restore this register across function calls. But Go requires a different trampoline for every call, and there's no reason that new Go code needs to be broken and add more bugs. So remove -ffixed-r30 for getrandom. Fixes: 8072b39c3a75 ("powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64") Signed-off-by: Jason A. Donenfeld Signed-off-by: Michael Ellerman Link: https://msgid.link/20240925175021.1526936-2-Jason@zx2c4.com

powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64

2024-09-13T15:28:36Z

Extend getrandom() vDSO implementation to VDSO64. Tested on QEMU on both ppc64_defconfig and ppc64le_defconfig. Results from a Power9 (PowerNV): ~ # ./vdso_test_getrandom bench-single vdso: 25000000 times in 0.787943615 seconds libc: 25000000 times in 14.101887252 seconds syscall: 25000000 times in 14.047475082 seconds Signed-off-by: Christophe Leroy Tested-by: Madhavan Srinivasan Acked-by: Michael Ellerman Signed-off-by: Jason A. Donenfeld

powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO32

2024-09-13T15:28:36Z

To be consistent with other VDSO functions, the function is called __kernel_getrandom() __arch_chacha20_blocks_nostack() fonction is implemented basically with 32 bits operations. It performs 4 QUARTERROUND operations in parallele. There are enough registers to avoid using the stack: On input: r3: output bytes r4: 32-byte key input r5: 8-byte counter input/output r6: number of 64-byte blocks to write to output During operation: stack: pointer to counter (r5) and non-volatile registers (r14-131) r0: counter of blocks (initialised with r6) r4: Value '4' after key has been read, used for indexing r5-r12: key r14-r15: block counter r16-r31: chacha state At the end: r0, r6-r12: Zeroised r5, r14-r31: Restored Performance on powerpc 885 (using kernel selftest): ~# ./vdso_test_getrandom bench-single vdso: 25000000 times in 62.938002291 seconds libc: 25000000 times in 535.581916866 seconds syscall: 25000000 times in 531.525042806 seconds Performance on powerpc 8321 (using kernel selftest): ~# ./vdso_test_getrandom bench-single vdso: 25000000 times in 16.899318858 seconds libc: 25000000 times in 131.050596522 seconds syscall: 25000000 times in 129.794790389 seconds This first patch adds support for VDSO32. As selftests cannot easily be generated only for VDSO32, and because the following patch brings support for VDSO64 anyway, this patch opts out all code in __arch_chacha20_blocks_nostack() so that vdso_test_chacha will not fail to compile and will not crash on PPC64/PPC64LE, allthough the selftest itself will fail. Signed-off-by: Christophe Leroy Acked-by: Michael Ellerman Signed-off-by: Jason A. Donenfeld

powerpc/vdso: Refactor CFLAGS for CVDSO build

2024-09-13T15:28:36Z

In order to avoid two much duplication when we add new VDSO functionnalities in C like getrandom, refactor common CFLAGS. Signed-off-by: Christophe Leroy Acked-by: Michael Ellerman Signed-off-by: Jason A. Donenfeld

powerpc/vdso32: Add crtsavres

2024-09-13T15:28:36Z

Commit 08c18b63d965 ("powerpc/vdso32: Add missing _restgpr_31_x to fix build failure") added _restgpr_31_x to the vdso for gettimeofday, but the work on getrandom shows that we will need more of those functions. Remove _restgpr_31_x and link in crtsavres.o so that we get all save/restore functions when optimising the kernel for size. Signed-off-by: Christophe Leroy Acked-by: Ard Biesheuvel Acked-by: Michael Ellerman Signed-off-by: Jason A. Donenfeld

Makefile: remove redundant tool coverage variables

2024-05-14T14:35:48Z

Now Kbuild provides reasonable defaults for objtool, sanitizers, and profilers. Remove redundant variables. Note: This commit changes the coverage for some objects: - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV - include arch/sparc/vdso/vdso-image-*.o into UBSAN - include arch/sparc/vdso/vma.o into UBSAN - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV - include arch/x86/entry/vdso/vma.o into GCOV, KCOV - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV I believe these are positive effects because all of them are kernel space objects. Signed-off-by: Masahiro Yamada Reviewed-by: Kees Cook Tested-by: Roberto Sassu

kbuild: use $(src) instead of $(srctree)/$(src) for source directory

2024-05-09T19:34:52Z

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier

arch: use $(obj)/ instead of $(src)/ for preprocessed linker scripts

2024-05-02T11:14:16Z

These are generated files. Prefix them with $(obj)/ instead of $(src)/. Signed-off-by: Masahiro Yamada Acked-by: Helge Deller Reviewed-by: Nicolas Schier