Messages in this thread | | | Subject | Re: [PATCH] x86/retpoline: change RETPOLINE into CONFIG_RETPOLINE | From | Zhenzhong Duan <> | Date | Wed, 2 Jan 2019 09:17:01 +0800 |
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On 2019/1/1 7:42, Nadav Amit wrote: > A recent enhancement intentionally fails the kernel build if the > compiler does not support retpolines and CONFIG_RETPOLINE is set. > > However, the patch that introduced it did not change RETPOLINE macro > references into CONFIG_RETPOLINE ones. As a result, indirect branches > that are used by init functions are not kept (i.e., they use > retpolines), and modules that do not use retpolines are marked as > retpoline-safe. > > Fix it be changing RETPOLINE into CONFIG_RETPOLINE. > > Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support") > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: David Woodhouse <dwmw@amazon.co.uk> > Cc: Andy Lutomirski <luto@kernel.org> > Cc: Masahiro Yamada <yamada.masahiro@socionext.com> > Cc: stable@vger.kernel.org > Signed-off-by: Nadav Amit <namit@vmware.com> > --- > arch/x86/kernel/cpu/bugs.c | 2 +- > include/linux/compiler-gcc.h | 2 +- > include/linux/module.h | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c > index 8654b8b0c848..1de0f4170178 100644 > --- a/arch/x86/kernel/cpu/bugs.c > +++ b/arch/x86/kernel/cpu/bugs.c > @@ -215,7 +215,7 @@ static enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init = > static enum spectre_v2_user_mitigation spectre_v2_user __ro_after_init = > SPECTRE_V2_USER_NONE; > > -#ifdef RETPOLINE > +#ifdef CONFIG_RETPOLINE > static bool spectre_v2_bad_module; > > bool retpoline_module_ok(bool has_retpoline) > diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h > index 2010493e1040..977ddf2774f9 100644 > --- a/include/linux/compiler-gcc.h > +++ b/include/linux/compiler-gcc.h > @@ -68,7 +68,7 @@ > */ > #define uninitialized_var(x) x = x > > -#ifdef RETPOLINE > +#ifdef CONFIG_RETPOLINE > #define __noretpoline __attribute__((__indirect_branch__("keep"))) > #endif > > diff --git a/include/linux/module.h b/include/linux/module.h > index fce6b4335e36..0c575f51fe57 100644 > --- a/include/linux/module.h > +++ b/include/linux/module.h > @@ -817,7 +817,7 @@ static inline void module_bug_finalize(const Elf_Ehdr *hdr, > static inline void module_bug_cleanup(struct module *mod) {} > #endif /* CONFIG_GENERIC_BUG */ > > -#ifdef RETPOLINE > +#ifdef CONFIG_RETPOLINE > extern bool retpoline_module_ok(bool has_retpoline); > #else > static inline bool retpoline_module_ok(bool has_retpoline)
Someone sent a similar patch last month, see below link, you missed the change in scripts/mod/modpost.c
https://lkml.org/lkml/2018/12/10/540
But you patch description is more clear.
-- Thanks Zhenzhong
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