diff options
| author | Sami Tolvanen <samitolvanen@google.com> | 2023-09-27 22:48:02 +0000 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2023-10-27 14:43:08 -0700 |
| commit | d1584d791a297aa8ed93503382a682a6ecfc4218 (patch) | |
| tree | 371b56adbd1d77f436e143555ab9fb47b4ad50c0 /arch/riscv/purgatory | |
| parent | e609b4f4252a2ad2454736078693571b9fbff019 (diff) | |
riscv: Implement Shadow Call Stack
Implement CONFIG_SHADOW_CALL_STACK for RISC-V. When enabled, the
compiler injects instructions to all non-leaf C functions to
store the return address to the shadow stack and unconditionally
load it again before returning, which makes it harder to corrupt
the return address through a stack overflow, for example.
The active shadow call stack pointer is stored in the gp
register, which makes SCS incompatible with gp relaxation. Use
--no-relax-gp to ensure gp relaxation is disabled and disable
global pointer loading. Add SCS pointers to struct thread_info,
implement SCS initialization, and task switching
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230927224757.1154247-12-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/purgatory')
| -rw-r--r-- | arch/riscv/purgatory/Makefile | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/riscv/purgatory/Makefile b/arch/riscv/purgatory/Makefile index 9e6476719abb..6a3c16bd5ca3 100644 --- a/arch/riscv/purgatory/Makefile +++ b/arch/riscv/purgatory/Makefile @@ -81,6 +81,10 @@ ifdef CONFIG_CFI_CLANG PURGATORY_CFLAGS_REMOVE += $(CC_FLAGS_CFI) endif +ifdef CONFIG_SHADOW_CALL_STACK +PURGATORY_CFLAGS_REMOVE += $(CC_FLAGS_SCS) +endif + CFLAGS_REMOVE_purgatory.o += $(PURGATORY_CFLAGS_REMOVE) CFLAGS_purgatory.o += $(PURGATORY_CFLAGS) |