linux/scripts/module.lds.S
Ard Biesheuvel 68c76ad4a9 arm64: unwind: add asynchronous unwind tables to kernel and modules
Enable asynchronous unwind table generation for both the core kernel as
well as modules, and emit the resulting .eh_frame sections as init code
so we can use the unwind directives for code patching at boot or module
load time.

This will be used by dynamic shadow call stack support, which will rely
on code patching rather than compiler codegen to emit the shadow call
stack push and pop instructions.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20221027155908.1940624-2-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2022-11-09 18:06:35 +00:00

61 lines
1.4 KiB
ArmAsm

/*
* Common module linker script, always used when linking a module.
* Archs are free to supply their own linker scripts. ld will
* combine them automatically.
*/
#ifdef CONFIG_UNWIND_TABLES
#define DISCARD_EH_FRAME
#else
#define DISCARD_EH_FRAME *(.eh_frame)
#endif
SECTIONS {
/DISCARD/ : {
*(.discard)
*(.discard.*)
}
__ksymtab 0 : { *(SORT(___ksymtab+*)) }
__ksymtab_gpl 0 : { *(SORT(___ksymtab_gpl+*)) }
__kcrctab 0 : { *(SORT(___kcrctab+*)) }
__kcrctab_gpl 0 : { *(SORT(___kcrctab_gpl+*)) }
.ctors 0 : ALIGN(8) { *(SORT(.ctors.*)) *(.ctors) }
.init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
.altinstructions 0 : ALIGN(8) { KEEP(*(.altinstructions)) }
__bug_table 0 : ALIGN(8) { KEEP(*(__bug_table)) }
__jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) }
__patchable_function_entries : { *(__patchable_function_entries) }
#ifdef CONFIG_ARCH_USES_CFI_TRAPS
__kcfi_traps : { KEEP(*(.kcfi_traps)) }
#endif
#ifdef CONFIG_LTO_CLANG
/*
* With CONFIG_LTO_CLANG, LLD always enables -fdata-sections and
* -ffunction-sections, which increases the size of the final module.
* Merge the split sections in the final binary.
*/
.bss : {
*(.bss .bss.[0-9a-zA-Z_]*)
*(.bss..L*)
}
.data : {
*(.data .data.[0-9a-zA-Z_]*)
*(.data..L*)
}
.rodata : {
*(.rodata .rodata.[0-9a-zA-Z_]*)
*(.rodata..L*)
}
#endif
}
/* bring in arch-specific sections */
#include <asm/module.lds.h>