diff options
| author | Sami Tolvanen <samitolvanen@google.com> | 2020-04-27 09:00:17 -0700 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-05-15 16:35:50 +0100 |
| commit | 439dc2a11727314cdc3ad0ad13c122d910dae411 (patch) | |
| tree | 834b05b4832d10d3b9f3e4c003e0bf882152096b | |
| parent | 5287569a790d2546a06db07e391bf84b8bd6cf51 (diff) | |
arm64: scs: Add shadow stacks for SDEI
This change adds per-CPU shadow call stacks for the SDEI handler.
Similarly to how the kernel stacks are handled, we add separate shadow
stacks for normal and critical events.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: James Morse <james.morse@arm.com>
Tested-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | arch/arm64/kernel/entry.S | 14 | ||||
| -rw-r--r-- | arch/arm64/kernel/scs.c | 5 |
2 files changed, 18 insertions, 1 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 244268d5ae47..cb0516e6f963 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -1049,13 +1049,16 @@ SYM_CODE_START(__sdei_asm_handler) mov x19, x1 +#if defined(CONFIG_VMAP_STACK) || defined(CONFIG_SHADOW_CALL_STACK) + ldrb w4, [x19, #SDEI_EVENT_PRIORITY] +#endif + #ifdef CONFIG_VMAP_STACK /* * entry.S may have been using sp as a scratch register, find whether * this is a normal or critical event and switch to the appropriate * stack for this CPU. */ - ldrb w4, [x19, #SDEI_EVENT_PRIORITY] cbnz w4, 1f ldr_this_cpu dst=x5, sym=sdei_stack_normal_ptr, tmp=x6 b 2f @@ -1065,6 +1068,15 @@ SYM_CODE_START(__sdei_asm_handler) mov sp, x5 #endif +#ifdef CONFIG_SHADOW_CALL_STACK + /* Use a separate shadow call stack for normal and critical events */ + cbnz w4, 3f + adr_this_cpu dst=x18, sym=sdei_shadow_call_stack_normal, tmp=x6 + b 4f +3: adr_this_cpu dst=x18, sym=sdei_shadow_call_stack_critical, tmp=x6 +4: +#endif + /* * We may have interrupted userspace, or a guest, or exit-from or * return-to either of these. We can't trust sp_el0, restore it. diff --git a/arch/arm64/kernel/scs.c b/arch/arm64/kernel/scs.c index acc6741d1a40..adc97f826fab 100644 --- a/arch/arm64/kernel/scs.c +++ b/arch/arm64/kernel/scs.c @@ -13,3 +13,8 @@ DEFINE_PER_CPU(unsigned long [SCS_SIZE/sizeof(long)], name) \ DEFINE_SCS(irq_shadow_call_stack); + +#ifdef CONFIG_ARM_SDE_INTERFACE +DEFINE_SCS(sdei_shadow_call_stack_normal); +DEFINE_SCS(sdei_shadow_call_stack_critical); +#endif |