[PATCH AUTOSEL 4.18 24/27] vmlinux.lds.h: Fix incomplete .text.exit discards

Sasha Levin
2018-10-22T10:20:17Z

From: Peter Oberparleiter <oberpar@linux.ibm.com>

[ Upstream commit 8dcf86caa1e3daf4a6ccf38e97f4f752b411f829 ]

Enabling CONFIG_GCOV_PROFILE_ALL=y causes linker errors on ARM:

`.text.exit' referenced in section `.ARM.exidx.text.exit':
defined in discarded section `.text.exit'

`.text.exit' referenced in section `.fini_array.00100':
defined in discarded section `.text.exit'

And related errors on NDS32:

`.text.exit' referenced in section `.dtors.65435':
defined in discarded section `.text.exit'

The gcov compiler flags cause certain compiler versions to generate
additional destructor-related sections that are not yet handled by the
linker script, resulting in references between discarded and
non-discarded sections.

Since destructors are not used in the Linux kernel, fix this by
discarding these additional sections.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Greentime Hu <green.hu@gmail.com>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm/kernel/vmlinux.lds.h | 2 ++
include/asm-generic/vmlinux.lds.h | 4 ++--
2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kernel/vmlinux.lds.h b/arch/arm/kernel/vmlinux.lds.h
index ae5fdff18406..8247bc15addc 100644
--- a/arch/arm/kernel/vmlinux.lds.h
+++ b/arch/arm/kernel/vmlinux.lds.h
@@ -49,6 +49,8 @@
#define ARM_DISCARD \
*(.ARM.exidx.exit.text) \
*(.ARM.extab.exit.text) \
+ *(.ARM.exidx.text.exit) \
+ *(.ARM.extab.text.exit) \
ARM_CPU_DISCARD(*(.ARM.exidx.cpuexit.text)) \
ARM_CPU_DISCARD(*(.ARM.extab.cpuexit.text)) \
ARM_EXIT_DISCARD(EXIT_TEXT) \
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index e373e2e10f6a..a11f86014352 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -617,8 +617,8 @@

#define EXIT_DATA \
*(.exit.data .exit.data.*) \
- *(.fini_array) \
- *(.dtors) \
+ *(.fini_array .fini_array.*) \
+ *(.dtors .dtors.*) \
MEM_DISCARD(exit.data*) \
MEM_DISCARD(exit.rodata*)

--
2.17.1