There is nothing architecture-specific about scs_overflow_check() as it's just a trivial wrapper around scs_corrupted().
For parity with task_stack_end_corrupted(), rename scs_corrupted() to task_scs_end_corrupted() and call it from schedule_debug() when CONFIG_SCHED_STACK_END_CHECK_is enabled. Finally, remove the unused scs_overflow_check() function entirely. This has absolutely no impact on architectures that do not support SCS (currently arm64 only). Signed-off-by: Will Deacon <[email protected]> --- arch/arm64/include/asm/scs.h | 18 ------------------ arch/arm64/kernel/process.c | 2 -- arch/arm64/kernel/scs.c | 2 +- include/linux/scs.h | 4 ++-- kernel/sched/core.c | 3 +++ kernel/scs.c | 3 ++- 6 files changed, 8 insertions(+), 24 deletions(-) diff --git a/arch/arm64/include/asm/scs.h b/arch/arm64/include/asm/scs.h index d46efdd2060a..eaa2cd92e4c1 100644 --- a/arch/arm64/include/asm/scs.h +++ b/arch/arm64/include/asm/scs.h @@ -24,24 +24,6 @@ .endm #endif /* CONFIG_SHADOW_CALL_STACK */ -#else /* __ASSEMBLY__ */ - -#include <linux/scs.h> - -#ifdef CONFIG_SHADOW_CALL_STACK - -static inline void scs_overflow_check(struct task_struct *tsk) -{ - if (unlikely(scs_corrupted(tsk))) - panic("corrupted shadow stack detected inside scheduler\n"); -} - -#else /* CONFIG_SHADOW_CALL_STACK */ - -static inline void scs_overflow_check(struct task_struct *tsk) {} - -#endif /* CONFIG_SHADOW_CALL_STACK */ - #endif /* __ASSEMBLY __ */ #endif /* _ASM_SCS_H */ diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index a35d3318492c..56be4cbf771f 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -52,7 +52,6 @@ #include <asm/mmu_context.h> #include <asm/processor.h> #include <asm/pointer_auth.h> -#include <asm/scs.h> #include <asm/stacktrace.h> #if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_STACKPROTECTOR_PER_TASK) @@ -516,7 +515,6 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, entry_task_switch(next); uao_thread_switch(next); ssbs_thread_switch(next); - scs_overflow_check(next); /* * Complete any pending TLB or cache maintenance on this CPU in case diff --git a/arch/arm64/kernel/scs.c b/arch/arm64/kernel/scs.c index adc97f826fab..955875dff9e1 100644 --- a/arch/arm64/kernel/scs.c +++ b/arch/arm64/kernel/scs.c @@ -6,7 +6,7 @@ */ #include <linux/percpu.h> -#include <asm/scs.h> +#include <linux/scs.h> /* Allocate a static per-CPU shadow stack */ #define DEFINE_SCS(name) \ diff --git a/include/linux/scs.h b/include/linux/scs.h index 0eb2485ef832..2fd3df50e93e 100644 --- a/include/linux/scs.h +++ b/include/linux/scs.h @@ -47,7 +47,7 @@ static inline unsigned long *__scs_magic(void *s) return (unsigned long *)(s + SCS_SIZE) - 1; } -static inline bool scs_corrupted(struct task_struct *tsk) +static inline bool task_scs_end_corrupted(struct task_struct *tsk) { unsigned long *magic = __scs_magic(task_scs(tsk)); unsigned long sz = task_scs_sp(tsk) - task_scs(tsk); @@ -60,8 +60,8 @@ static inline bool scs_corrupted(struct task_struct *tsk) static inline void scs_init(void) {} static inline void scs_task_reset(struct task_struct *tsk) {} static inline int scs_prepare(struct task_struct *tsk, int node) { return 0; } -static inline bool scs_corrupted(struct task_struct *tsk) { return false; } static inline void scs_release(struct task_struct *tsk) {} +static inline bool task_scs_end_corrupted(struct task_struct *tsk) { return false; } #endif /* CONFIG_SHADOW_CALL_STACK */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 934e03cfaec7..a1d815a11b90 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3878,6 +3878,9 @@ static inline void schedule_debug(struct task_struct *prev, bool preempt) #ifdef CONFIG_SCHED_STACK_END_CHECK if (task_stack_end_corrupted(prev)) panic("corrupted stack end detected inside scheduler\n"); + + if (task_scs_end_corrupted(prev)) + panic("corrupted shadow stack detected inside scheduler\n"); #endif #ifdef CONFIG_DEBUG_ATOMIC_SLEEP diff --git a/kernel/scs.c b/kernel/scs.c index aea841cd7586..faf0ecd7b893 100644 --- a/kernel/scs.c +++ b/kernel/scs.c @@ -98,7 +98,8 @@ void scs_release(struct task_struct *tsk) if (!s) return; - WARN(scs_corrupted(tsk), "corrupted shadow stack detected when freeing task\n"); + WARN(task_scs_end_corrupted(tsk), + "corrupted shadow stack detected when freeing task\n"); scs_check_usage(tsk); scs_free(s); } -- 2.26.2.761.g0e0b3e54be-goog
