Hi Jason,
Le 01/09/2024 à 15:22, Jason A. Donenfeld a écrit :
Hi Christophe,
Hmm, I'm not so sure I like this very much. I think it's important for these tests to fail when an arch tries to hook up the function to the vDSO, but it's still not exported for some reason. This also regresses the ARCH=x86_64 vs ARCH=x86 thing, which SRCARCH fixes.
What about, instead, something like below, replacing the other commit?
I need to look at it in more details and perfom a test, but after first look I can't figure out how it would work.
When I build selftests,
to build 32 bits selftests I do:
make ARCH=powerpc CROSS_COMPILE=ppc-linux-
to build a 64 bits BE selftests I do:
make ARCH=powerpc CROSS_COMPILE=powerpc64-linux-
to build a 64 bits LE selftests I do:
make ARCH=powerpc CROSS_COMPILE=powerpc64le-linux-
I addition, in case someone does the build on a native platform directly,
On 32 bits, uname -m returns 'ppc' On 64 bits, uname -m returns 'ppc64' On 64 bits little endian, uname -m returns 'ppc64le'
How would this fit in the logic where IIUC you just remove '_64' from 'x86_64' to get 'x86'
Christophe
Jason
From ccc53425c98f4f5c2a1edaf775089efb56bd106e Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Jason@zx2c4.com Date: Sun, 1 Sep 2024 15:05:01 +0200 Subject: [PATCH] selftests: vDSO: fix cross build for getrandom and chacha tests
Unlike the check for the standalone x86 test, the check for building the vDSO getrandom and chacaha tests looks at the architecture for the host rather than the architecture for the target when deciding if they should be built. Since the chacha test includes some assembler code this means that cross building with x86 as either the target or host is broken.
There's also some additional complications, where ARCH can legitimately be either x86_64 or x86, but the source code we need to compile lives in a directory path containing arch/x86. The standard SRCARCH variable handles that. And actually, all these variables and proper substitutions are already described in tools/scripts/Makefile.arch, so just include that to handle it.
Similarly, ARCH=x86 can actually describe ARCH=x86_64, just with CONFIG_64BIT, so we can't rely on ARCH for selecting non-32-bit tests. For that, check against $(ARCH)$(CONFIG_X86_32). This won't help for people manually running this inside the vDSO selftest directory (which isn't really supported anyway and has problems on various archs), but it should work for builds of the kselftests, where the CONFIG_* variables are defined. On x86_64 machines, $(ARCH)$(CONFIG_X86_32) will evaluate to x86. On arm64 machines, it will evaluate to arm64. On 32-bit x86 machines, it will evaluate to x86y, which won't match the filter list.
Reported-by: Mark Brown broonie@kernel.org Reported-by: Christophe Leroy christophe.leroy@csgroup.eu Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com
tools/testing/selftests/vDSO/Makefile | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile index e21e78aae24d..01a5805062b3 100644 --- a/tools/testing/selftests/vDSO/Makefile +++ b/tools/testing/selftests/vDSO/Makefile @@ -1,6 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -uname_M := $(shell uname -m 2>/dev/null || echo not) -ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/) +include ../../../scripts/Makefile.arch
TEST_GEN_PROGS := vdso_test_gettimeofday TEST_GEN_PROGS += vdso_test_getcpu @@ -10,7 +9,7 @@ ifeq ($(ARCH),$(filter $(ARCH),x86 x86_64)) TEST_GEN_PROGS += vdso_standalone_test_x86 endif TEST_GEN_PROGS += vdso_test_correctness -ifeq ($(uname_M),x86_64) +ifeq ($(ARCH)$(CONFIG_X86_32),$(filter $(ARCH)$(CONFIG_X86_32),x86)) TEST_GEN_PROGS += vdso_test_getrandom TEST_GEN_PROGS += vdso_test_chacha endif @@ -38,8 +37,8 @@ $(OUTPUT)/vdso_test_getrandom: CFLAGS += -isystem $(top_srcdir)/tools/include \ $(KHDR_INCLUDES) \ -isystem $(top_srcdir)/include/uapi
-$(OUTPUT)/vdso_test_chacha: $(top_srcdir)/tools/arch/$(ARCH)/vdso/vgetrandom-chacha.S +$(OUTPUT)/vdso_test_chacha: $(top_srcdir)/tools/arch/$(SRCARCH)/vdso/vgetrandom-chacha.S $(OUTPUT)/vdso_test_chacha: CFLAGS += -idirafter $(top_srcdir)/tools/include \
-idirafter $(top_srcdir)/arch/$(ARCH)/include \
-idirafter $(top_srcdir)/arch/$(SRCARCH)/include \ -idirafter $(top_srcdir)/include \ -D__ASSEMBLY__ -Wa,--noexecstack-- 2.46.0