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>
This commit is contained in:
Ard Biesheuvel
2022-10-27 17:59:06 +02:00
committed by Will Deacon
parent f0c4d9fc9c
commit 68c76ad4a9
9 changed files with 45 additions and 2 deletions

View File

@@ -3,6 +3,12 @@
* 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)