arm64: Add stack information to on_accessible_stack

In preparation for enabling the stackleak plugin on arm64,
we need a way to get the bounds of the current stack. Extend
on_accessible_stack to get this information.

Acked-by: Alexander Popov <alex.popov@linux.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
[will: folded in fix for allmodconfig build breakage w/ sdei]
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm64/include/asm/sdei.h b/arch/arm64/include/asm/sdei.h
index e073e688668562a83fdde315262a3d5685f90d88..ffe47d766c2593601573f748a18c84645bec79ad 100644 (file)
--- a/arch/arm64/include/asm/sdei.h
+++ b/arch/arm64/include/asm/sdei.h
@@ -40,15 +40,18 @@ asmlinkage unsigned long __sdei_handler(struct pt_regs *regs,
 unsigned long sdei_arch_get_entry_point(int conduit);
 #define sdei_arch_get_entry_point(x)   sdei_arch_get_entry_point(x)
 
-bool _on_sdei_stack(unsigned long sp);
-static inline bool on_sdei_stack(unsigned long sp)
+struct stack_info;
+
+bool _on_sdei_stack(unsigned long sp, struct stack_info *info);
+static inline bool on_sdei_stack(unsigned long sp,
+                               struct stack_info *info)
 {
        if (!IS_ENABLED(CONFIG_VMAP_STACK))
                return false;
        if (!IS_ENABLED(CONFIG_ARM_SDE_INTERFACE))
                return false;
        if (in_nmi())
-               return _on_sdei_stack(sp);
+               return _on_sdei_stack(sp, info);
 
        return false;
 }

diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 902f9edacbea94b96a85321ff79d45e8ac59fd73..e86737b7c924118ecc3de12f80163e68312ba522 100644 (file)
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -32,6 +32,21 @@ struct stackframe {
 #endif
 };
 
+enum stack_type {
+       STACK_TYPE_UNKNOWN,
+       STACK_TYPE_TASK,
+       STACK_TYPE_IRQ,
+       STACK_TYPE_OVERFLOW,
+       STACK_TYPE_SDEI_NORMAL,
+       STACK_TYPE_SDEI_CRITICAL,
+};
+
+struct stack_info {
+       unsigned long low;
+       unsigned long high;
+       enum stack_type type;
+};
+
 extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
 extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
                            int (*fn)(struct stackframe *, void *), void *data);
@@ -39,7 +54,8 @@ extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk);
 
 DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
 
-static inline bool on_irq_stack(unsigned long sp)
+static inline bool on_irq_stack(unsigned long sp,
+                               struct stack_info *info)
 {
        unsigned long low = (unsigned long)raw_cpu_read(irq_stack_ptr);
        unsigned long high = low + IRQ_STACK_SIZE;
@@ -47,46 +63,79 @@ static inline bool on_irq_stack(unsigned long sp)
        if (!low)
                return false;
 
-       return (low <= sp && sp < high);
+       if (sp < low || sp >= high)
+               return false;
+
+       if (info) {
+               info->low = low;
+               info->high = high;
+               info->type = STACK_TYPE_IRQ;
+       }
+
+       return true;
 }
 
-static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp)
+static inline bool on_task_stack(struct task_struct *tsk, unsigned long sp,
+                               struct stack_info *info)
 {
        unsigned long low = (unsigned long)task_stack_page(tsk);
        unsigned long high = low + THREAD_SIZE;
 
-       return (low <= sp && sp < high);
+       if (sp < low || sp >= high)
+               return false;
+
+       if (info) {
+               info->low = low;
+               info->high = high;
+               info->type = STACK_TYPE_TASK;
+       }
+
+       return true;
 }
 
 #ifdef CONFIG_VMAP_STACK
 DECLARE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
 
-static inline bool on_overflow_stack(unsigned long sp)
+static inline bool on_overflow_stack(unsigned long sp,
+                               struct stack_info *info)
 {
        unsigned long low = (unsigned long)raw_cpu_ptr(overflow_stack);
        unsigned long high = low + OVERFLOW_STACK_SIZE;
 
-       return (low <= sp && sp < high);
+       if (sp < low || sp >= high)
+               return false;
+
+       if (info) {
+               info->low = low;
+               info->high = high;
+               info->type = STACK_TYPE_OVERFLOW;
+       }
+
+       return true;
 }
 #else
-static inline bool on_overflow_stack(unsigned long sp) { return false; }
+static inline bool on_overflow_stack(unsigned long sp,
+                       struct stack_info *info) { return false; }
 #endif
 
+
 /*
  * We can only safely access per-cpu stacks from current in a non-preemptible
  * context.
  */
-static inline bool on_accessible_stack(struct task_struct *tsk, unsigned long sp)
+static inline bool on_accessible_stack(struct task_struct *tsk,
+                                       unsigned long sp,
+                                       struct stack_info *info)
 {
-       if (on_task_stack(tsk, sp))
+       if (on_task_stack(tsk, sp, info))
                return true;
        if (tsk != current || preemptible())
                return false;
-       if (on_irq_stack(sp))
+       if (on_irq_stack(sp, info))
                return true;
-       if (on_overflow_stack(sp))
+       if (on_overflow_stack(sp, info))
                return true;
-       if (on_sdei_stack(sp))
+       if (on_sdei_stack(sp, info))
                return true;
 
        return false;

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 299758f9b9c46d15f27789f76b52be6858f2d6e7..6219486fa25fa4490d4397f6aee15e18fc208559 100644 (file)
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -132,7 +132,7 @@ static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 {
        return ((addr & ~(THREAD_SIZE - 1))  ==
                (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))) ||
-               on_irq_stack(addr);
+               on_irq_stack(addr, NULL);
 }
 
 /**

diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c
index 6b8d90d5ceaece66e937e1f57651fd1719cf536c..a94a868f0532e0f15d675e24bf9659c4a20201e0 100644 (file)
--- a/arch/arm64/kernel/sdei.c
+++ b/arch/arm64/kernel/sdei.c
@@ -13,6 +13,7 @@
 #include <asm/mmu.h>
 #include <asm/ptrace.h>
 #include <asm/sections.h>
+#include <asm/stacktrace.h>
 #include <asm/sysreg.h>
 #include <asm/vmap_stack.h>
 
@@ -88,23 +89,55 @@ static int init_sdei_stacks(void)
        return err;
 }
 
-bool _on_sdei_stack(unsigned long sp)
+bool on_sdei_normal_stack(unsigned long sp,
+                       struct stack_info *info)
 {
-       unsigned long low, high;
+       unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_normal_ptr);
+       unsigned long high = low + SDEI_STACK_SIZE;
 
-       if (!IS_ENABLED(CONFIG_VMAP_STACK))
+       if (sp < low || sp >= high)
                return false;
 
-       low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr);
-       high = low + SDEI_STACK_SIZE;
+       if (info) {
+               info->low = low;
+               info->high = high;
+               info->type = STACK_TYPE_SDEI_NORMAL;
+       }
 
-       if (low <= sp && sp < high)
+       return true;
+}
+
+bool on_sdei_critical_stack(unsigned long sp,
+                       struct stack_info *info)
+{
+       unsigned long low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr);
+       unsigned long high = low + SDEI_STACK_SIZE;
+
+       if (sp < low || sp >= high)
+               return false;
+
+       if (info) {
+               info->low = low;
+               info->high = high;
+               info->type = STACK_TYPE_SDEI_CRITICAL;
+       }
+
+       return true;
+}
+
+bool _on_sdei_stack(unsigned long sp,
+               struct stack_info *info)
+{
+       if (!IS_ENABLED(CONFIG_VMAP_STACK))
+               return false;
+
+       if (on_sdei_critical_stack(sp, info))
                return true;
 
-       low = (unsigned long)raw_cpu_read(sdei_stack_normal_ptr);
-       high = low + SDEI_STACK_SIZE;
+       if (on_sdei_normal_stack(sp, info))
+               return true;
 
-       return (low <= sp && sp < high);
+       return false;
 }
 
 unsigned long sdei_arch_get_entry_point(int conduit)

diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index d5718a060672e1696618904c8844447daa042007..4989f7ea1e59925ff9eda5ac68c7ac3cedb3d4fe 100644 (file)
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -50,7 +50,7 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame)
        if (!tsk)
                tsk = current;
 
-       if (!on_accessible_stack(tsk, fp))
+       if (!on_accessible_stack(tsk, fp, NULL))
                return -EINVAL;
 
        frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));