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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2022-04-18 09:50:39 -0700 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-04-22 12:32:04 +0200 |
| commit | 4ab7674f5951ac6a8ac4fa8828090edb64a4771f (patch) | |
| tree | acd05dfd8faea515ddc411501bd25627da4cd148 /arch | |
| parent | 26e176896a5bb9222ae3433da902edd2566a61a4 (diff) | |
| download | linux-4ab7674f5951ac6a8ac4fa8828090edb64a4771f.tar.bz2 | |
objtool: Make jump label hack optional
Objtool secretly does a jump label hack to overcome the limitations of
the toolchain. Make the hack explicit (and optional for other arches)
by turning it into a cmdline option and kernel config option.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/3bdcbfdd27ecb01ddec13c04bdf756a583b13d24.1650300597.git.jpoimboe@redhat.com
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/Kconfig | 4 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/jump_label.h | 6 |
3 files changed, 8 insertions, 3 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 04cdef16db24..9dce6d6e3bc3 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -46,6 +46,7 @@ config JUMP_LABEL bool "Optimize very unlikely/likely branches" depends on HAVE_ARCH_JUMP_LABEL depends on CC_HAS_ASM_GOTO + select OBJTOOL if HAVE_JUMP_LABEL_HACK help This option enables a transparent branch optimization that makes certain almost-always-true or almost-always-false branch @@ -1031,6 +1032,9 @@ config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT config HAVE_OBJTOOL bool +config HAVE_JUMP_LABEL_HACK + bool + config HAVE_STACK_VALIDATION bool help diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 43e26ee1611e..26d012f1eeb8 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -212,6 +212,7 @@ config X86 select HAVE_IOREMAP_PROT select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 select HAVE_IRQ_TIME_ACCOUNTING + select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL select HAVE_KERNEL_BZIP2 select HAVE_KERNEL_GZIP select HAVE_KERNEL_LZ4 diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index 3ce0e67c579c..071572e23d3a 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -20,7 +20,7 @@ _ASM_PTR "%c0 + %c1 - .\n\t" \ ".popsection \n\t" -#ifdef CONFIG_OBJTOOL +#ifdef CONFIG_HAVE_JUMP_LABEL_HACK static __always_inline bool arch_static_branch(struct static_key *key, bool branch) { @@ -34,7 +34,7 @@ l_yes: return true; } -#else /* !CONFIG_OBJTOOL */ +#else /* !CONFIG_HAVE_JUMP_LABEL_HACK */ static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch) { @@ -48,7 +48,7 @@ l_yes: return true; } -#endif /* CONFIG_OBJTOOL */ +#endif /* CONFIG_HAVE_JUMP_LABEL_HACK */ static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch) { |