efi/libstub/arm64: Use hidden attribute for struct screen_info reference
commit 760b61d76da6d6a99eb245ab61abf71ca5415cea upstream.
To prevent the compiler from emitting absolute references to screen_info
when building position independent code, redeclare the symbol with hidden
visibility.
Tested-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818194947.19347-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index a9e54aa..6561582 100644
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -54,6 +54,9 @@
#define alloc_screen_info(x...) &screen_info
#define free_screen_info(x...)
+/* redeclare as 'hidden' so the compiler will generate relative references */
+extern struct screen_info screen_info __attribute__((__visibility__("hidden")));
+
static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
{
}