1 files changed, 51 insertions, 31 deletions
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index fca97bd3d8ae..f356d3ea0c70 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -50,52 +50,72 @@ const char *stack_type_name(enum stack_type type)
        return NULL;
 }
-struct estack_layout {
+/**
-        unsigned int    begin;
+ * struct estack_pages - Page descriptor for exception stacks
-        unsigned int    end;
+ * @offs:       Offset from the start of the exception stack area
+ * @size:       Size of the exception stack
+ * @type:       Type to store in the stack_info struct
+ */
+struct estack_pages {
+        u32     offs;
+        u16     size;
+        u16     type;
 };
-#define ESTACK_ENTRY(x) {                                                 \
+#define EPAGERANGE(st)                                                  \
-        .begin  = offsetof(struct cea_exception_stacks, x## _stack),      \
+        [PFN_DOWN(CEA_ESTACK_OFFS(st)) ...                              \
-        .end    = offsetof(struct cea_exception_stacks, x## _stack_guard) \
+         PFN_DOWN(CEA_ESTACK_OFFS(st) + CEA_ESTACK_SIZE(st) - 1)] = {   \
-        }
+                .offs   = CEA_ESTACK_OFFS(st),                          \
+                .size   = CEA_ESTACK_SIZE(st),                          \
+                .type   = STACK_TYPE_EXCEPTION + ESTACK_ ##st, }
-static const struct estack_layout layout[] = {
+/*
-        [ ESTACK_DF     ]       = ESTACK_ENTRY(DF),
+ * Array of exception stack page descriptors. If the stack is larger than
-        [ ESTACK_NMI    ]       = ESTACK_ENTRY(NMI),
+ * PAGE_SIZE, all pages covering a particular stack will have the same
-        [ ESTACK_DB2    ]       = { .begin = 0, .end = 0},
+ * info. The guard pages including the not mapped DB2 stack are zeroed
-        [ ESTACK_DB1    ]       = ESTACK_ENTRY(DB1),
+ * out.
-        [ ESTACK_DB     ]       = ESTACK_ENTRY(DB),
+ */
-        [ ESTACK_MCE    ]       = ESTACK_ENTRY(MCE),
+static const
+struct estack_pages estack_pages[CEA_ESTACK_PAGES] ____cacheline_aligned = {
+        EPAGERANGE(DF),
+        EPAGERANGE(NMI),
+        EPAGERANGE(DB1),
+        EPAGERANGE(DB),
+        EPAGERANGE(MCE),
 };
 static bool in_exception_stack(unsigned long *stack, struct stack_info *info)
 {
-        unsigned long estacks, begin, end, stk = (unsigned long)stack;
+        unsigned long begin, end, stk = (unsigned long)stack;
+        const struct estack_pages *ep;
        struct pt_regs *regs;
        unsigned int k;
        BUILD_BUG_ON(N_EXCEPTION_STACKS != 6);
-        estacks = (unsigned long)__this_cpu_read(cea_exception_stacks);
+        begin = (unsigned long)__this_cpu_read(cea_exception_stacks);
+        end = begin + sizeof(struct cea_exception_stacks);
-        for (k = 0; k < N_EXCEPTION_STACKS; k++) {
+        /* Bail if @stack is outside the exception stack area. */
-                begin = estacks + layout[k].begin;
+        if (stk < begin || stk >= end)
-                end   = estacks + layout[k].end;
+                return false;
-                regs  = (struct pt_regs *)end - 1;
-                if (stk < begin || stk >= end)
+        /* Calc page offset from start of exception stacks */
-                        continue;
+        k = (stk - begin) >> PAGE_SHIFT;
+        /* Lookup the page descriptor */
+        ep = &estack_pages[k];
+        /* Guard page? */
+        if (!ep->size)
+                return false;
-                info->type      = STACK_TYPE_EXCEPTION + k;
+        begin += (unsigned long)ep->offs;
-                info->begin     = (unsigned long *)begin;
+        end = begin + (unsigned long)ep->size;
-                info->end       = (unsigned long *)end;
+        regs = (struct pt_regs *)end - 1;
-                info->next_sp   = (unsigned long *)regs->sp;
-                return true;
+        info->type      = ep->type;
-        }
+        info->begin     = (unsigned long *)begin;
+        info->end       = (unsigned long *)end;
-        return false;
+        info->next_sp   = (unsigned long *)regs->sp;
+        return true;
 }
 static bool in_irq_stack(unsigned long *stack, struct stack_info *info)

diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index fca97bd3d8ae..f356d3ea0c70 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c
@@ -50,52 +50,72 @@ const char *stack_type_name(enum stack_type type)
50	return NULL;	50	return NULL;
51	}	51	}
52		52
53	struct estack_layout {	53	/**
54	unsigned int begin;	54	* struct estack_pages - Page descriptor for exception stacks
55	unsigned int end;	55	* @offs: Offset from the start of the exception stack area
		56	* @size: Size of the exception stack
		57	* @type: Type to store in the stack_info struct
		58	*/
		59	struct estack_pages {
		60	u32 offs;
		61	u16 size;
		62	u16 type;
56	};	63	};
57		64
58	#define ESTACK_ENTRY(x) { \	65	#define EPAGERANGE(st) \
59	.begin = offsetof(struct cea_exception_stacks, x## _stack), \	66	[PFN_DOWN(CEA_ESTACK_OFFS(st)) ... \
60	.end = offsetof(struct cea_exception_stacks, x## _stack_guard) \	67	PFN_DOWN(CEA_ESTACK_OFFS(st) + CEA_ESTACK_SIZE(st) - 1)] = { \
61	}	68	.offs = CEA_ESTACK_OFFS(st), \
		69	.size = CEA_ESTACK_SIZE(st), \
		70	.type = STACK_TYPE_EXCEPTION + ESTACK_ ##st, }
62		71
63	static const struct estack_layout layout[] = {	72	/*
64	[ ESTACK_DF ] = ESTACK_ENTRY(DF),	73	* Array of exception stack page descriptors. If the stack is larger than
65	[ ESTACK_NMI ] = ESTACK_ENTRY(NMI),	74	* PAGE_SIZE, all pages covering a particular stack will have the same
66	[ ESTACK_DB2 ] = { .begin = 0, .end = 0},	75	* info. The guard pages including the not mapped DB2 stack are zeroed
67	[ ESTACK_DB1 ] = ESTACK_ENTRY(DB1),	76	* out.
68	[ ESTACK_DB ] = ESTACK_ENTRY(DB),	77	*/
69	[ ESTACK_MCE ] = ESTACK_ENTRY(MCE),	78	static const
		79	struct estack_pages estack_pages[CEA_ESTACK_PAGES] ____cacheline_aligned = {
		80	EPAGERANGE(DF),
		81	EPAGERANGE(NMI),
		82	EPAGERANGE(DB1),
		83	EPAGERANGE(DB),
		84	EPAGERANGE(MCE),
70	};	85	};
71		86
72	static bool in_exception_stack(unsigned long stack, struct stack_info info)	87	static bool in_exception_stack(unsigned long stack, struct stack_info info)
73	{	88	{
74	unsigned long estacks, begin, end, stk = (unsigned long)stack;	89	unsigned long begin, end, stk = (unsigned long)stack;
		90	const struct estack_pages *ep;
75	struct pt_regs *regs;	91	struct pt_regs *regs;
76	unsigned int k;	92	unsigned int k;
77		93
78	BUILD_BUG_ON(N_EXCEPTION_STACKS != 6);	94	BUILD_BUG_ON(N_EXCEPTION_STACKS != 6);
79		95
80	estacks = (unsigned long)__this_cpu_read(cea_exception_stacks);	96	begin = (unsigned long)__this_cpu_read(cea_exception_stacks);
81		97	end = begin + sizeof(struct cea_exception_stacks);
82	for (k = 0; k < N_EXCEPTION_STACKS; k++) {	98	/* Bail if @stack is outside the exception stack area. */
83	begin = estacks + layout[k].begin;	99	if (stk < begin \|\| stk >= end)
84	end = estacks + layout[k].end;	100	return false;
85	regs = (struct pt_regs *)end - 1;
86		101
87	if (stk < begin \|\| stk >= end)	102	/* Calc page offset from start of exception stacks */
88	continue;	103	k = (stk - begin) >> PAGE_SHIFT;
		104	/* Lookup the page descriptor */
		105	ep = &estack_pages[k];
		106	/* Guard page? */
		107	if (!ep->size)
		108	return false;
89		109
90	info->type = STACK_TYPE_EXCEPTION + k;	110	begin += (unsigned long)ep->offs;
91	info->begin = (unsigned long *)begin;	111	end = begin + (unsigned long)ep->size;
92	info->end = (unsigned long *)end;	112	regs = (struct pt_regs *)end - 1;
93	info->next_sp = (unsigned long *)regs->sp;
94		113
95	return true;	114	info->type = ep->type;
96	}	115	info->begin = (unsigned long *)begin;
97		116	info->end = (unsigned long *)end;
98	return false;	117	info->next_sp = (unsigned long *)regs->sp;
		118	return true;
99	}	119	}
100		120
101	static bool in_irq_stack(unsigned long stack, struct stack_info info)	121	static bool in_irq_stack(unsigned long stack, struct stack_info info)