Files
linux-stable-mirror/arch/arm/include/asm/vmlinux.lds.h
Nathan Chancellor 59fc423183 ARM: 9443/1: Require linker to support KEEP within OVERLAY for DCE
commit e7607f7d6d upstream.

ld.lld prior to 21.0.0 does not support using the KEEP keyword within an
overlay description, which may be needed to avoid discarding necessary
sections within an overlay with '--gc-sections', which can be enabled
for the kernel via CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.

Disallow CONFIG_LD_DEAD_CODE_DATA_ELIMINATION without support for KEEP
within OVERLAY and introduce a macro, OVERLAY_KEEP, that can be used to
conditionally add KEEP when it is properly supported to avoid breaking
old versions of ld.lld.

Cc: stable@vger.kernel.org
Link: 381599f1fe
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
[nathan: Fix conflict in init/Kconfig due to lack of RUSTC symbols]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-10 14:39:40 +02:00

178 lines
4.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#include <asm-generic/vmlinux.lds.h>
#ifdef CONFIG_HOTPLUG_CPU
#define ARM_CPU_DISCARD(x)
#define ARM_CPU_KEEP(x) x
#else
#define ARM_CPU_DISCARD(x) x
#define ARM_CPU_KEEP(x)
#endif
#if (defined(CONFIG_SMP_ON_UP) && !defined(CONFIG_DEBUG_SPINLOCK)) || \
defined(CONFIG_GENERIC_BUG) || defined(CONFIG_JUMP_LABEL)
#define ARM_EXIT_KEEP(x) x
#define ARM_EXIT_DISCARD(x)
#else
#define ARM_EXIT_KEEP(x)
#define ARM_EXIT_DISCARD(x) x
#endif
#ifdef CONFIG_MMU
#define ARM_MMU_KEEP(x) x
#define ARM_MMU_DISCARD(x)
#else
#define ARM_MMU_KEEP(x)
#define ARM_MMU_DISCARD(x) x
#endif
/*
* ld.lld does not support NOCROSSREFS:
* https://github.com/ClangBuiltLinux/linux/issues/1609
*/
#ifdef CONFIG_LD_IS_LLD
#define NOCROSSREFS
#endif
#ifdef CONFIG_LD_CAN_USE_KEEP_IN_OVERLAY
#define OVERLAY_KEEP(x) KEEP(x)
#else
#define OVERLAY_KEEP(x) x
#endif
/* Set start/end symbol names to the LMA for the section */
#define ARM_LMA(sym, section) \
sym##_start = LOADADDR(section); \
sym##_end = LOADADDR(section) + SIZEOF(section)
#define PROC_INFO \
. = ALIGN(4); \
__proc_info_begin = .; \
KEEP(*(.proc.info.init)) \
__proc_info_end = .;
#define IDMAP_TEXT \
ALIGN_FUNCTION(); \
__idmap_text_start = .; \
*(.idmap.text) \
__idmap_text_end = .; \
#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) \
ARM_EXIT_DISCARD(EXIT_DATA) \
EXIT_CALL \
ARM_MMU_DISCARD(*(.text.fixup)) \
ARM_MMU_DISCARD(*(__ex_table)) \
COMMON_DISCARDS
/*
* Sections that should stay zero sized, which is safer to explicitly
* check instead of blindly discarding.
*/
#define ARM_ASSERTS \
.plt : { \
*(.iplt) *(.rel.iplt) *(.iplt) *(.igot.plt) \
} \
ASSERT(SIZEOF(.plt) == 0, \
"Unexpected run-time procedure linkages detected!")
#define ARM_DETAILS \
ELF_DETAILS \
.ARM.attributes 0 : { *(.ARM.attributes) }
#define ARM_STUBS_TEXT \
*(.gnu.warning) \
*(.glue_7) \
*(.glue_7t) \
*(.vfp11_veneer) \
*(.v4_bx)
#define ARM_TEXT \
IDMAP_TEXT \
__entry_text_start = .; \
*(.entry.text) \
__entry_text_end = .; \
IRQENTRY_TEXT \
SOFTIRQENTRY_TEXT \
TEXT_TEXT \
SCHED_TEXT \
LOCK_TEXT \
KPROBES_TEXT \
ARM_STUBS_TEXT \
. = ALIGN(4); \
*(.got) /* Global offset table */ \
ARM_CPU_KEEP(PROC_INFO)
/* Stack unwinding tables */
#define ARM_UNWIND_SECTIONS \
. = ALIGN(8); \
.ARM.unwind_idx : { \
__start_unwind_idx = .; \
*(.ARM.exidx*) \
__stop_unwind_idx = .; \
} \
.ARM.unwind_tab : { \
__start_unwind_tab = .; \
*(.ARM.extab*) \
__stop_unwind_tab = .; \
}
/*
* The vectors and stubs are relocatable code, and the
* only thing that matters is their relative offsets
*/
#define ARM_VECTORS \
__vectors_lma = .; \
OVERLAY 0xffff0000 : NOCROSSREFS AT(__vectors_lma) { \
.vectors { \
OVERLAY_KEEP(*(.vectors)) \
} \
.vectors.bhb.loop8 { \
OVERLAY_KEEP(*(.vectors.bhb.loop8)) \
} \
.vectors.bhb.bpiall { \
OVERLAY_KEEP(*(.vectors.bhb.bpiall)) \
} \
} \
ARM_LMA(__vectors, .vectors); \
ARM_LMA(__vectors_bhb_loop8, .vectors.bhb.loop8); \
ARM_LMA(__vectors_bhb_bpiall, .vectors.bhb.bpiall); \
. = __vectors_lma + SIZEOF(.vectors) + \
SIZEOF(.vectors.bhb.loop8) + \
SIZEOF(.vectors.bhb.bpiall); \
\
__stubs_lma = .; \
.stubs ADDR(.vectors) + 0x1000 : AT(__stubs_lma) { \
*(.stubs) \
} \
ARM_LMA(__stubs, .stubs); \
. = __stubs_lma + SIZEOF(.stubs); \
\
PROVIDE(vector_fiq_offset = vector_fiq - ADDR(.vectors));
#define ARM_TCM \
__itcm_start = ALIGN(4); \
.text_itcm ITCM_OFFSET : AT(__itcm_start - LOAD_OFFSET) { \
__sitcm_text = .; \
*(.tcm.text) \
*(.tcm.rodata) \
. = ALIGN(4); \
__eitcm_text = .; \
} \
. = __itcm_start + SIZEOF(.text_itcm); \
\
__dtcm_start = .; \
.data_dtcm DTCM_OFFSET : AT(__dtcm_start - LOAD_OFFSET) { \
__sdtcm_data = .; \
*(.tcm.data) \
. = ALIGN(4); \
__edtcm_data = .; \
} \
. = __dtcm_start + SIZEOF(.data_dtcm);