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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2024-09-03 12:09:17 +0000
committerJason A. Donenfeld <Jason@zx2c4.com>2024-09-13 17:28:36 +0200
commit712676ea2bb3882a852bcf49862c4247317fc9b2 (patch)
tree17d406ce2b8c3ee29444e36f3ff9ba9abaabc22d /tools
parent2c2ca3416b4090aef8c646adccfc3be4b712db8a (diff)
arm64: vDSO: Wire up getrandom() vDSO implementation
Hook up the generic vDSO implementation to the aarch64 vDSO data page. The _vdso_rng_data required data is placed within the _vdso_data vvar page, by using a offset larger than the vdso_data. The vDSO function requires a ChaCha20 implementation that does not write to the stack, and that can do an entire ChaCha20 permutation. The one provided uses NEON on the permute operation, with a fallback to the syscall for chips that do not support AdvSIMD. This also passes the vdso_test_chacha test along with vdso_test_getrandom. The vdso_test_getrandom bench-single result on Neoverse-N1 shows: vdso: 25000000 times in 0.783884250 seconds libc: 25000000 times in 8.780275399 seconds syscall: 25000000 times in 8.786581518 seconds A small fixup to arch/arm64/include/asm/mman.h was required to avoid pulling kernel code into the vDSO, similar to what's already done in arch/arm64/include/asm/rwonce.h. Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'tools')
l---------tools/arch/arm64/vdso1
-rw-r--r--tools/include/linux/compiler.h4
-rw-r--r--tools/testing/selftests/vDSO/Makefile3
3 files changed, 7 insertions, 1 deletions
diff --git a/tools/arch/arm64/vdso b/tools/arch/arm64/vdso
new file mode 120000
index 000000000000..233c7a26f6e5
--- /dev/null
+++ b/tools/arch/arm64/vdso
@@ -0,0 +1 @@
+../../../arch/arm64/kernel/vdso \ No newline at end of file
diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h
index 6f7f22ac9da5..4366da278033 100644
--- a/tools/include/linux/compiler.h
+++ b/tools/include/linux/compiler.h
@@ -2,6 +2,8 @@
#ifndef _TOOLS_LINUX_COMPILER_H_
#define _TOOLS_LINUX_COMPILER_H_
+#ifndef __ASSEMBLY__
+
#include <linux/compiler_types.h>
#ifndef __compiletime_error
@@ -224,4 +226,6 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
__asm__ ("" : "=r" (var) : "0" (var))
#endif
+#endif /* __ASSEMBLY__ */
+
#endif /* _TOOLS_LINUX_COMPILER_H */
diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile
index 04930125035e..3c6fafbd83a6 100644
--- a/tools/testing/selftests/vDSO/Makefile
+++ b/tools/testing/selftests/vDSO/Makefile
@@ -9,7 +9,7 @@ ifeq ($(ARCH),$(filter $(ARCH),x86 x86_64))
TEST_GEN_PROGS += vdso_standalone_test_x86
endif
TEST_GEN_PROGS += vdso_test_correctness
-ifeq ($(ARCH)$(CONFIG_X86_32),$(filter $(ARCH)$(CONFIG_X86_32),x86 x86_64 loongarch))
+ifeq ($(ARCH)$(CONFIG_X86_32),$(filter $(ARCH)$(CONFIG_X86_32),x86 x86_64 loongarch arm64))
TEST_GEN_PROGS += vdso_test_getrandom
TEST_GEN_PROGS += vdso_test_chacha
endif
@@ -40,5 +40,6 @@ $(OUTPUT)/vdso_test_getrandom: CFLAGS += -isystem $(top_srcdir)/tools/include \
$(OUTPUT)/vdso_test_chacha: $(top_srcdir)/tools/arch/$(SRCARCH)/vdso/vgetrandom-chacha.S
$(OUTPUT)/vdso_test_chacha: CFLAGS += -idirafter $(top_srcdir)/tools/include \
-idirafter $(top_srcdir)/arch/$(SRCARCH)/include \
+ -idirafter $(top_srcdir)/arch/$(SRCARCH)/include/generated \
-idirafter $(top_srcdir)/include \
-D__ASSEMBLY__ -Wa,--noexecstack