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| author | Will Deacon <will@kernel.org> | 2020-05-28 18:03:40 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-05-28 18:03:40 +0100 |
| commit | 082af5ec5080b028f7d0846a6c27cbb87f288205 (patch) | |
| tree | 9b34b36586c9453628849fc5acee655012cb7b1e /arch/arm64/kernel/efi-rt-wrapper.S | |
| parent | c350717ec7de67daad26d996efe7f3d97d95aa9c (diff) | |
| parent | 258c3d628fe9e7512d98a0000709773457c66ef1 (diff) | |
| download | linux-082af5ec5080b028f7d0846a6c27cbb87f288205.tar.gz | |
Merge branch 'for-next/scs' into for-next/core
Support for Clang's Shadow Call Stack in the kernel
(Sami Tolvanen and Will Deacon)
* for-next/scs:
arm64: entry-ftrace.S: Update comment to indicate that x18 is live
scs: Move DEFINE_SCS macro into core code
scs: Remove references to asm/scs.h from core code
scs: Move scs_overflow_check() out of architecture code
arm64: scs: Use 'scs_sp' register alias for x18
scs: Move accounting into alloc/free functions
arm64: scs: Store absolute SCS stack pointer value in thread_info
efi/libstub: Disable Shadow Call Stack
arm64: scs: Add shadow stacks for SDEI
arm64: Implement Shadow Call Stack
arm64: Disable SCS for hypervisor code
arm64: vdso: Disable Shadow Call Stack
arm64: efi: Restore register x18 if it was corrupted
arm64: Preserve register x18 when CPU is suspended
arm64: Reserve register x18 from general allocation with SCS
scs: Disable when function graph tracing is enabled
scs: Add support for stack usage debugging
scs: Add page accounting for shadow call stack allocations
scs: Add support for Clang's Shadow Call Stack (SCS)
Diffstat (limited to 'arch/arm64/kernel/efi-rt-wrapper.S')
| -rw-r--r-- | arch/arm64/kernel/efi-rt-wrapper.S | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/arm64/kernel/efi-rt-wrapper.S b/arch/arm64/kernel/efi-rt-wrapper.S index 1192c4bb48df..75691a2641c1 100644 --- a/arch/arm64/kernel/efi-rt-wrapper.S +++ b/arch/arm64/kernel/efi-rt-wrapper.S @@ -34,5 +34,14 @@ SYM_FUNC_START(__efi_rt_asm_wrapper) ldp x29, x30, [sp], #32 b.ne 0f ret -0: b efi_handle_corrupted_x18 // tail call +0: + /* + * With CONFIG_SHADOW_CALL_STACK, the kernel uses x18 to store a + * shadow stack pointer, which we need to restore before returning to + * potentially instrumented code. This is safe because the wrapper is + * called with preemption disabled and a separate shadow stack is used + * for interrupts. + */ + mov x18, x2 + b efi_handle_corrupted_x18 // tail call SYM_FUNC_END(__efi_rt_asm_wrapper) |