On Wed, Aug 14, 2024 at 12:56 PM Xi Ruoyao <xry111@xxxxxxxxxxx> wrote: > > On Thu, 2024-07-18 at 10:34 -0700, Fangrui Song wrote: > > glibc added support for .gnu.hash in 2006 and .hash has been obsoleted > > for more than one decade in many Linux distributions. Using > > --hash-style=sysv might imply unaddressed issues and confuse readers. > > > > Just drop the option and rely on the linker default, which is likely > > "both", or "gnu" when the distribution really wants to eliminate sysv > > hash overhead. > > > > Similar to commit 6b7e26547fad ("x86/vdso: Emit a GNU hash"). > > > > Signed-off-by: Fangrui Song <maskray@xxxxxxxxxx> > > Hi Fangrui, > > If I read tools/testing/selftests/vDSO/parse_vdso.c correctly, it does > know DT_GNU_HASH as at now. Thus after this change the vDSO selftests > are skipped with "Couldn't find __vdso_gettimeofday" etc if the distro > enables --hash-style=gnu by default. > > So it seems we need to add DT_GNU_HASH support for parse_vdso.c to keep > test coverage. Hi Xi, Perhaps the selftests file needs DT_GNU_HASH support like https://github.com/abseil/abseil-cpp/commit/1278ee9bd9bd4916181521fac96d6fa1100e38e6 > > --- > > arch/arm64/kernel/vdso/Makefile | 2 +- > > arch/arm64/kernel/vdso32/Makefile | 2 +- > > 2 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile > > index d63930c82839..d11da6461278 100644 > > --- a/arch/arm64/kernel/vdso/Makefile > > +++ b/arch/arm64/kernel/vdso/Makefile > > @@ -21,7 +21,7 @@ btildflags-$(CONFIG_ARM64_BTI_KERNEL) += -z force-bti > > # potential future proofing if we end up with internal calls to the exported > > # routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so > > # preparation in build-time C")). > > -ldflags-y := -shared -soname=linux-vdso.so.1 --hash-style=sysv \ > > +ldflags-y := -shared -soname=linux-vdso.so.1 \ > > -Bsymbolic --build-id=sha1 -n $(btildflags-y) > > > > ifdef CONFIG_LD_ORPHAN_WARN > > diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile > > index cc4508c604b2..25a2cb6317f3 100644 > > --- a/arch/arm64/kernel/vdso32/Makefile > > +++ b/arch/arm64/kernel/vdso32/Makefile > > @@ -98,7 +98,7 @@ VDSO_AFLAGS += -D__ASSEMBLY__ > > # From arm vDSO Makefile > > VDSO_LDFLAGS += -Bsymbolic --no-undefined -soname=linux-vdso.so.1 > > VDSO_LDFLAGS += -z max-page-size=4096 -z common-page-size=4096 > > -VDSO_LDFLAGS += -shared --hash-style=sysv --build-id=sha1 > > +VDSO_LDFLAGS += -shared --build-id=sha1 > > VDSO_LDFLAGS += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL) > > > > > > -- > Xi Ruoyao <xry111@xxxxxxxxxxx> > School of Aerospace Science and Technology, Xidian University -- 宋方睿