| 4e3fa1ae | 02-Oct-2024 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/vdso: Implement __arch_get_vdso_rng_data()
VDSO time functions do not call any other function, so they don't need to save/restore LR. However, retrieving the address of VDSO data page requir
powerpc/vdso: Implement __arch_get_vdso_rng_data()
VDSO time functions do not call any other function, so they don't need to save/restore LR. However, retrieving the address of VDSO data page requires using LR hence saving then restoring it, which can be heavy on some CPUs. On the other hand, VDSO functions on powerpc are not standard functions and require a wrapper function to call C VDSO functions. And that wrapper has to save and restore LR in order to call the C VDSO function, so retrieving VDSO data page address in that wrapper doesn't require additional save/restore of LR.
For random VDSO functions it is a bit different. Because the function calls __arch_chacha20_blocks_nostack(), it saves and restores LR. Retrieving VDSO data page address can then be done there without additional save/restore of LR.
So lets implement __arch_get_vdso_rng_data() and simplify the wrapper.
It starts paving the way for the day powerpc will implement a more standard ABI for VDSO functions.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/a1a9bd0df508f1b5c04684b7366940577dfc6262.1727858295.git.christophe.leroy@csgroup.eu
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| 3a7101e9 | 19-Sep-2024 |
Linus Torvalds <torvalds@linux-foundation.org> |
Merge tag 'powerpc-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- Reduce alignment constraints on STRICT_KERNEL_RWX and speed-
Merge tag 'powerpc-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- Reduce alignment constraints on STRICT_KERNEL_RWX and speed-up TLB misses on 8xx and 603
- Replace kretprobe code with rethook and enable fprobe
- Remove the "fast endian switch" syscall
- Handle DLPAR device tree updates in kernel, allowing the deprecation of the binary /proc/powerpc/ofdt interface
Thanks to Abhishek Dubey, Alex Shi, Benjamin Gray, Christophe Leroy, Gaosheng Cui, Gautam Menghani, Geert Uytterhoeven, Haren Myneni, Hari Bathini, Huang Xiaojia, Jinjie Ruan, Madhavan Srinivasan, Miguel Ojeda, Mina Almasry, Narayana Murty N, Naveen Rao, Rob Herring (Arm), Scott Cheloha, Segher Boessenkool, Stephen Rothwell, Thomas Zimmermann, Uwe Kleine-König, Vaibhav Jain, and Zhang Zekun.
* tag 'powerpc-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (59 commits) powerpc/atomic: Use YZ constraints for DS-form instructions MAINTAINERS: powerpc: Add Maddy powerpc: Switch back to struct platform_driver::remove() powerpc/pseries/eeh: Fix pseries_eeh_err_inject selftests/powerpc: Allow building without static libc macintosh/via-pmu: register_pmu_pm_ops() can be __init powerpc: Stop using no_llseek powerpc/64s: Remove the "fast endian switch" syscall powerpc/mm/64s: Restrict THP to Radix or HPT w/64K pages powerpc/mm/64s: Move THP reqs into a separate symbol powerpc/64s: Make mmu_hash_ops __ro_after_init powerpc: Replace kretprobe code with rethook on powerpc powerpc: pseries: Constify struct kobj_type powerpc: powernv: Constify struct kobj_type powerpc: Constify struct kobj_type powerpc/pseries/dlpar: Add device tree nodes for DLPAR IO add powerpc/pseries/dlpar: Remove device tree node for DLPAR IO remove powerpc/pseries: Use correct data types from pseries_hp_errorlog struct powerpc/vdso: Inconditionally use CFUNC macro powerpc/32: Implement validation of emergency stack ...
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| 8072b39c | 02-Sep-2024 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64
Extend getrandom() vDSO implementation to VDSO64.
Tested on QEMU on both ppc64_defconfig and ppc64le_defconfig.
Results from a Power
powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64
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 <christophe.leroy@csgroup.eu> Tested-by: Madhavan Srinivasan <maddy@linux.ibm.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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| 53cee505 | 02-Sep-2024 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO32
To be consistent with other VDSO functions, the function is called __kernel_getrandom()
__arch_chacha20_blocks_nostack() fonction is
powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO32
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 <christophe.leroy@csgroup.eu> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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| a6b67eb0 | 02-Sep-2024 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/vdso: Refactor CFLAGS for CVDSO build
In order to avoid two much duplication when we add new VDSO functionnalities in C like getrandom, refactor common CFLAGS.
Signed-off-by: Christophe Ler
powerpc/vdso: Refactor CFLAGS for CVDSO build
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 <christophe.leroy@csgroup.eu> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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| b163596a | 02-Sep-2024 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
powerpc/vdso32: Add crtsavres
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
powerpc/vdso32: Add crtsavres
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 <christophe.leroy@csgroup.eu> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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| 7f7f6f7a | 06-May-2024 |
Masahiro Yamada <masahiroy@kernel.org> |
Makefile: remove redundant tool coverage variables
Now Kbuild provides reasonable defaults for objtool, sanitizers, and profilers.
Remove redundant variables.
Note:
This commit changes the covera
Makefile: remove redundant tool coverage variables
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 <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Roberto Sassu <roberto.sassu@huawei.com>
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