| Message ID | 5825E8BF.3020501@arm.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Nov 11, 2016 at 4:50 PM, Szabolcs Nagy <szabolcs.nagy@arm.com> wrote: > The __cpu_indicator_init and __cpu_model symbols are not safe to use > from shared libgcc_s.so from ifunc resolvers, so since gcc-6, only > the definitions from static libgcc.a are used, however the symbols > are kept in libgcc_s as well for backward compatibility (with > appropriate symbol version). On targets without such backward > compatibility concern add cpuinfo to the static library only (this > avoids running the ctor, reduces libgcc_s size and elf abi concerns > because of gnu symbol versions). > > build tested on x86_64-linux-gnu and x86_64-linux-musl. > > ok to commit? > > i'd like to back port this to gcc-6 because musl dynamic linker > cannot load the libgcc_s.so.1 with the versioned symbols > (not an abi break: those symbols were never used on musl and > the current code does not work). > > libgcc/ChangeLog: > > 2016-11-11 Szabolcs Nagy <szabolcs.nagy@arm.com> > > * config.host (i[3456]86-*-musl*, x86_64-*-musl*): Use > i386/t-cpuinfo-static instead of i386/t-cpuinfo. > * config/i386/t-cpuinfo-static: New. LGTM, it is musl specific, but you know the musl part best ;) Rubber-stamped OK for mainline and backports. Thanks, Uros.
On Fri, Nov 11, 2016 at 05:40:04PM +0100, Uros Bizjak wrote: > On Fri, Nov 11, 2016 at 4:50 PM, Szabolcs Nagy <szabolcs.nagy@arm.com> wrote: > > The __cpu_indicator_init and __cpu_model symbols are not safe to use > > from shared libgcc_s.so from ifunc resolvers, so since gcc-6, only > > the definitions from static libgcc.a are used, however the symbols > > are kept in libgcc_s as well for backward compatibility (with > > appropriate symbol version). On targets without such backward > > compatibility concern add cpuinfo to the static library only (this > > avoids running the ctor, reduces libgcc_s size and elf abi concerns > > because of gnu symbol versions). > > > > build tested on x86_64-linux-gnu and x86_64-linux-musl. > > > > ok to commit? > > > > i'd like to back port this to gcc-6 because musl dynamic linker > > cannot load the libgcc_s.so.1 with the versioned symbols > > (not an abi break: those symbols were never used on musl and > > the current code does not work). > > > > libgcc/ChangeLog: > > > > 2016-11-11 Szabolcs Nagy <szabolcs.nagy@arm.com> > > > > * config.host (i[3456]86-*-musl*, x86_64-*-musl*): Use > > i386/t-cpuinfo-static instead of i386/t-cpuinfo. > > * config/i386/t-cpuinfo-static: New. > > LGTM, it is musl specific, but you know the musl part best ;) > > Rubber-stamped OK for mainline and backports. I would have preferred the previously-rejected fix getting rid of the gratuitous dependency on binding to a non-default symver, that works the same on all targets, but I'm fine with whatever fixes the problem without introducing new ABI mess. Rich
diff --git a/libgcc/config.host b/libgcc/config.host index 4291cfe..64beb21 100644 --- a/libgcc/config.host +++ b/libgcc/config.host @@ -1320,7 +1320,14 @@ esac case ${host} in i[34567]86-*-* | x86_64-*-*) - tmake_file="${tmake_file} i386/t-cpuinfo" + case ${host} in + *-musl*) + tmake_file="${tmake_file} i386/t-cpuinfo-static" + ;; + *) + tmake_file="${tmake_file} i386/t-cpuinfo" + ;; + esac ;; esac diff --git a/libgcc/config/i386/t-cpuinfo-static b/libgcc/config/i386/t-cpuinfo-static new file mode 100644 index 0000000..504307d --- /dev/null +++ b/libgcc/config/i386/t-cpuinfo-static @@ -0,0 +1,4 @@ +# If the compatibility cpuinfo symbols in shared libgcc_s are not needed +# then they can be added to the static library only. + +LIB2ADD_ST += $(srcdir)/config/i386/cpuinfo.c