From: Martin Schwidefsky Date: Fri, 27 Apr 2018 05:36:43 +0000 (+0200) Subject: s390: correct module section names for expoline code revert X-Git-Tag: v4.14.38~21 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=5787b55b50196ad1e462789acc49d5bcefff57fb;p=users%2Fdwmw2%2Flinux.git s390: correct module section names for expoline code revert [ Upstream commit 6cf09958f32b9667bb3ebadf74367c791112771b ] The main linker script vmlinux.lds.S for the kernel image merges the expoline code patch tables into two section ".nospec_call_table" and ".nospec_return_table". This is *not* done for the modules, there the sections retain their original names as generated by gcc: ".s390_indirect_call", ".s390_return_mem" and ".s390_return_reg". The module_finalize code has to check for the compiler generated section names, otherwise no code patching is done. This slows down the module code in case of "spectre_v2=off". Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c index 7b337f85ca2f9..b441e069e674f 100644 --- a/arch/s390/kernel/module.c +++ b/arch/s390/kernel/module.c @@ -478,11 +478,11 @@ int module_finalize(const Elf_Ehdr *hdr, apply_alternatives(aseg, aseg + s->sh_size); if (IS_ENABLED(CONFIG_EXPOLINE) && - (!strcmp(".nospec_call_table", secname))) + (!strncmp(".s390_indirect", secname, 14))) nospec_revert(aseg, aseg + s->sh_size); if (IS_ENABLED(CONFIG_EXPOLINE) && - (!strcmp(".nospec_return_table", secname))) + (!strncmp(".s390_return", secname, 12))) nospec_revert(aseg, aseg + s->sh_size); }