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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>
hifive-unleashed-5.1
Laura Abbott 2018-07-20 14:41:53 -07:00 committed by Will Deacon
parent 2c870e6113
commit 8a1ccfbc9e
5 changed files with 111 additions and 26 deletions
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9
arch/arm64/include/asm/sdei.h
View File

@ -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;
}

73
arch/arm64/include/asm/stacktrace.h
View File

@ -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;

2
arch/arm64/kernel/ptrace.c
View File

@ -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);
}
/**

51
arch/arm64/kernel/sdei.c
View File

@ -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 (sp < low || sp >= high)
return false;
if (info) {
info->low = low;
info->high = high;
info->type = STACK_TYPE_SDEI_NORMAL;
}
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;
low = (unsigned long)raw_cpu_read(sdei_stack_critical_ptr);
high = low + SDEI_STACK_SIZE;
if (low <= sp && sp < high)
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)

2
arch/arm64/kernel/stacktrace.c
View File

@ -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));