x86: kallsyms: disable absolute percpu symbols on !SMP

scripts/kallsyms.c has a special --absolute-percpu command line option which deals with the zero based per cpu offsets that are used when building for SMP on x86_64. This means that the option should only be passed in that case, so add a Kconfig symbol with the correct predicate, and use that instead. Signed-off-by: Ard Biesheuvel <[email protected]> Tested-by: Guenter Roeck <[email protected]> Reviewed-by: Kees Cook <[email protected]> Tested-by: Kees Cook <[email protected]> Acked-by: Rusty Russell <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Michael Ellerman <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Benjamin Herrenschmidt <[email protected]> Cc: Michal Marek <[email protected]> Cc: Arnd Bergmann <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
huntrar · Mar 15, 2016 · 4d5d566 · 4d5d566
1 parent 6b8c69e
commit 4d5d566
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diff --git a/init/Kconfig b/init/Kconfig
@@ -1420,6 +1420,10 @@ config KALLSYMS_ALL
 
 	   Say N unless you really need all symbols.
 
+config KALLSYMS_ABSOLUTE_PERCPU
+	bool
+	default X86_64 && SMP
+
 config PRINTK
 	default y
 	bool "Enable support for printk" if EXPERT

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
@@ -86,7 +86,7 @@ kallsyms()
 		kallsymopt="${kallsymopt} --page-offset=$CONFIG_PAGE_OFFSET"
 	fi
 
-	if [ -n "${CONFIG_X86_64}" ]; then
+	if [ -n "${CONFIG_KALLSYMS_ABSOLUTE_PERCPU}" ]; then
 		kallsymopt="${kallsymopt} --absolute-percpu"
 	fi