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* Merge tag 'random-6.12-rc1-for-linus' of ↵Linus Torvalds2024-09-181-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/crng/random Pull random number generator updates from Jason Donenfeld: "Originally I'd planned on sending each of the vDSO getrandom() architecture ports to their respective arch trees. But as we started to work on this, we found lots of interesting issues in the shared code and infrastructure, the fixes for which the various archs needed to base their work. So in the end, this turned into a nice collaborative effort fixing up issues and porting to 5 new architectures -- arm64, powerpc64, powerpc32, s390x, and loongarch64 -- with everybody pitching in and commenting on each other's code. It was a fun development cycle. This contains: - Numerous fixups to the vDSO selftest infrastructure, getting it running successfully on more platforms, and fixing bugs in it. - Additions to the vDSO getrandom & chacha selftests. Basically every time manual review unearthed a bug in a revision of an arch patch, or an ambiguity, the tests were augmented. By the time the last arch was submitted for review, s390x, v1 of the series was essentially fine right out of the gate. - Fixes to the the generic C implementation of vDSO getrandom, to build and run successfully on all archs, decoupling it from assumptions we had (unintentionally) made on x86_64 that didn't carry through to the other architectures. - Port of vDSO getrandom to LoongArch64, from Xi Ruoyao and acked by Huacai Chen. - Port of vDSO getrandom to ARM64, from Adhemerval Zanella and acked by Will Deacon. - Port of vDSO getrandom to PowerPC, in both 32-bit and 64-bit varieties, from Christophe Leroy and acked by Michael Ellerman. - Port of vDSO getrandom to S390X from Heiko Carstens, the arch maintainer. While it'd be natural for there to be things to fix up over the course of the development cycle, these patches got a decent amount of review from a fairly diverse crew of folks on the mailing lists, and, for the most part, they've been cooking in linux-next, which has been helpful for ironing out build issues. In terms of architectures, I think that mostly takes care of the important 64-bit archs with hardware still being produced and running production loads in settings where vDSO getrandom is likely to help. Arguably there's still RISC-V left, and we'll see for 6.13 whether they find it useful and submit a port" * tag 'random-6.12-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (47 commits) selftests: vDSO: check cpu caps before running chacha test s390/vdso: Wire up getrandom() vdso implementation s390/vdso: Move vdso symbol handling to separate header file s390/vdso: Allow alternatives in vdso code s390/module: Provide find_section() helper s390/facility: Let test_facility() generate static branch if possible s390/alternatives: Remove ALT_FACILITY_EARLY s390/facility: Disable compile time optimization for decompressor code selftests: vDSO: fix vdso_config for s390 selftests: vDSO: fix ELF hash table entry size for s390x powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO64 powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO32 powerpc/vdso: Refactor CFLAGS for CVDSO build powerpc/vdso32: Add crtsavres mm: Define VM_DROPPABLE for powerpc/32 powerpc/vdso: Fix VDSO data access when running in a non-root time namespace selftests: vDSO: don't include generated headers for chacha test arm64: vDSO: Wire up getrandom() vDSO implementation arm64: alternative: make alternative_has_cap_likely() VDSO compatible selftests: vDSO: also test counter in vdso_test_chacha ...
| * powerpc/vdso: Wire up getrandom() vDSO implementation on VDSO32Christophe Leroy2024-09-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | powerpc/vdso: Don't discard rela sectionsChristophe Leroy2024-08-221-1/+3
|/ | | | | | | | | | | | | | | After building the VDSO, there is a verification that it contains no dynamic relocation, see commit aff69273af61 ("vdso: Improve cmd_vdso_check to check all dynamic relocations"). This verification uses readelf -r and doesn't work if rela sections are discarded. Fixes: 8ad57add77d3 ("powerpc/build: vdso linker warning for orphan sections") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/45c3e6fc76cad05ad2cac0f5b5dfb4fae86dc9d6.1724153239.git.christophe.leroy@csgroup.eu
* powerpc/build: vdso linker warning for orphan sectionsNicholas Piggin2023-06-151-1/+3
| | | | | | | | | | Add --orphan-handlin for vdsos, and adjust vdso linker scripts to deal with orphan sections. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20230609051002.3342-1-npiggin@gmail.com
* powerpc: Drops STABS_DEBUG from linker scriptsMichael Ellerman2022-09-301-1/+0
| | | | | | | | | | | | No toolchain we support should be generating stabs debug information anymore. Drop the sections entirely from our linker scripts. We removed all the manual stabs annotations in commit 12318163737c ("powerpc/32: Remove remaining .stabs annotations"). Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220928130951.1732983-1-mpe@ellerman.id.au
* powerpc/vdso: Remove unused ENTRY in linker scriptsNathan Chancellor2022-05-191-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When linking vdso{32,64}.so.dbg with ld.lld, there is a warning about not finding _start for the starting address: ld.lld: warning: cannot find entry symbol _start; not setting start address ld.lld: warning: cannot find entry symbol _start; not setting start address Looking at GCC + GNU ld, the entry point address is 0x0: $ llvm-readelf -h vdso{32,64}.so.dbg &| rg "(File|Entry point address):" File: vdso32.so.dbg Entry point address: 0x0 File: vdso64.so.dbg Entry point address: 0x0 This matches what ld.lld emits: $ powerpc64le-linux-gnu-readelf -p .comment vdso{32,64}.so.dbg File: vdso32.so.dbg String dump of section '.comment': [ 0] Linker: LLD 14.0.0 [ 14] clang version 14.0.0 (Fedora 14.0.0-1.fc37) File: vdso64.so.dbg String dump of section '.comment': [ 0] Linker: LLD 14.0.0 [ 14] clang version 14.0.0 (Fedora 14.0.0-1.fc37) $ llvm-readelf -h vdso{32,64}.so.dbg &| rg "(File|Entry point address):" File: vdso32.so.dbg Entry point address: 0x0 File: vdso64.so.dbg Entry point address: 0x0 Remove ENTRY to remove the warning, as it is unnecessary for the vDSO to function correctly. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220511185001.3269404-2-nathan@kernel.org
* powerpc/vdso: Merge vdso64 and vdso32 into a single directoryChristophe Leroy2022-02-121-0/+140
merge vdso64 into vdso32 and rename it vdso. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4dbe05cc130f6a0858d09ac72e436c373cb08b70.1642782130.git.christophe.leroy@csgroup.eu