Le 16/02/2023 à 06:09, Rohan McLure a écrit : > KCSAN instruments calls to atomic builtins, and will in turn call these > builtins itself. As such, architectures supporting KCSAN must have > compiler support for these atomic primitives. > > Since 32-bit systems are unlikely to have 64-bit compiler builtins, > provide a stub for each missing builtin, and use BUG() to assert > unreachability. > > In commit 725aea873261 ("xtensa: enable KCSAN"), xtensa implements these > locally. Move these definitions to be accessible to all 32-bit > architectures that do not provide the necessary builtins, with opt in > for PowerPC and xtensa. > > Signed-off-by: Rohan McLure <rmcl...@linux.ibm.com> > Reviewed-by: Max Filippov <jcmvb...@gmail.com>
This series should also be addressed to KCSAN Maintainers, shouldn't it ? KCSAN M: Marco Elver <el...@google.com> R: Dmitry Vyukov <dvyu...@google.com> L: kasan-...@googlegroups.com S: Maintained F: Documentation/dev-tools/kcsan.rst F: include/linux/kcsan*.h F: kernel/kcsan/ F: lib/Kconfig.kcsan F: scripts/Makefile.kcsan > --- > Previously issued as a part of a patch series adding KCSAN support to > 64-bit. > Link: > https://lore.kernel.org/linuxppc-dev/167646486000.1421441.10070059569986228558.b4...@ellerman.id.au/T/#t > v1: Remove __has_builtin check, as gcc is not obligated to inline > builtins detected using this check, but instead is permitted to supply > them in libatomic: > Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108734 > Instead, opt-in PPC32 and xtensa. > --- > arch/xtensa/lib/Makefile | 1 - > kernel/kcsan/Makefile | 2 ++ > arch/xtensa/lib/kcsan-stubs.c => kernel/kcsan/stubs.c | 0 > 3 files changed, 2 insertions(+), 1 deletion(-) > rename arch/xtensa/lib/kcsan-stubs.c => kernel/kcsan/stubs.c (100%) > > diff --git a/arch/xtensa/lib/Makefile b/arch/xtensa/lib/Makefile > index 7ecef0519a27..d69356dc97df 100644 > --- a/arch/xtensa/lib/Makefile > +++ b/arch/xtensa/lib/Makefile > @@ -8,5 +8,4 @@ lib-y += memcopy.o memset.o checksum.o \ > divsi3.o udivsi3.o modsi3.o umodsi3.o mulsi3.o umulsidi3.o \ > usercopy.o strncpy_user.o strnlen_user.o > lib-$(CONFIG_PCI) += pci-auto.o > -lib-$(CONFIG_KCSAN) += kcsan-stubs.o > KCSAN_SANITIZE_kcsan-stubs.o := n > diff --git a/kernel/kcsan/Makefile b/kernel/kcsan/Makefile > index 8cf70f068d92..86dd713d8855 100644 > --- a/kernel/kcsan/Makefile > +++ b/kernel/kcsan/Makefile > @@ -12,6 +12,8 @@ CFLAGS_core.o := $(call cc-option,-fno-conserve-stack) \ > -fno-stack-protector -DDISABLE_BRANCH_PROFILING > > obj-y := core.o debugfs.o report.o > +obj-$(CONFIG_PPC32) += stubs.o > +obj-$(CONFIG_XTENSA) += stubs.o Not sure it is acceptable to do it that way. There should likely be something like a CONFIG_ARCH_WANTS_KCSAN_STUBS in KCSAN's Kconfig then PPC32 and XTENSA should select it. > > KCSAN_INSTRUMENT_BARRIERS_selftest.o := y > obj-$(CONFIG_KCSAN_SELFTEST) += selftest.o > diff --git a/arch/xtensa/lib/kcsan-stubs.c b/kernel/kcsan/stubs.c > similarity index 100% > rename from arch/xtensa/lib/kcsan-stubs.c > rename to kernel/kcsan/stubs.c