diff --git a/Documentation/x86/kernel-stacks b/Documentation/x86/kernel-stacks
index 9a0aa4d3a866938170c1b652577c9ed9d69aab29..1b04596caea988f5a45637b1bc7d22e26528f70c 100644
--- a/Documentation/x86/kernel-stacks
+++ b/Documentation/x86/kernel-stacks
@@ -59,7 +59,7 @@ If that assumption is ever broken then the stacks will become corrupt.
The currently assigned IST stacks are :-
-* DOUBLEFAULT_STACK. EXCEPTION_STKSZ (PAGE_SIZE).
+* ESTACK_DF. EXCEPTION_STKSZ (PAGE_SIZE).
Used for interrupt 8 - Double Fault Exception (#DF).
@@ -68,7 +68,7 @@ The currently assigned IST stacks are :-
Using a separate stack allows the kernel to recover from it well enough
in many cases to still output an oops.
-* NMI_STACK. EXCEPTION_STKSZ (PAGE_SIZE).
+* ESTACK_NMI. EXCEPTION_STKSZ (PAGE_SIZE).
Used for non-maskable interrupts (NMI).
@@ -76,7 +76,7 @@ The currently assigned IST stacks are :-
middle of switching stacks. Using IST for NMI events avoids making
assumptions about the previous state of the kernel stack.
-* DEBUG_STACK. DEBUG_STKSZ
+* ESTACK_DB. DEBUG_STKSZ
Used for hardware debug interrupts (interrupt 1) and for software
debug interrupts (INT3).
@@ -86,7 +86,7 @@ The currently assigned IST stacks are :-
avoids making assumptions about the previous state of the kernel
stack.
-* MCE_STACK. EXCEPTION_STKSZ (PAGE_SIZE).
+* ESTACK_MCE. EXCEPTION_STKSZ (PAGE_SIZE).
Used for interrupt 18 - Machine Check Exception (#MC).
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 1f0efdb7b6294daba3e315be0b990ba8296b3fea..fd0a50452cb3564643036d5e15669ab8e121081d 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -841,7 +841,7 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt
/*
* Exception entry points.
*/
-#define CPU_TSS_IST(x) PER_CPU_VAR(cpu_tss_rw) + (TSS_ist + ((x) - 1) * 8)
+#define CPU_TSS_IST(x) PER_CPU_VAR(cpu_tss_rw) + (TSS_ist + (x) * 8)
/**
* idtentry - Generate an IDT entry stub
@@ -1129,7 +1129,7 @@ apicinterrupt3 HYPERV_STIMER0_VECTOR \
hv_stimer0_callback_vector hv_stimer0_vector_handler
#endif /* CONFIG_HYPERV */
-idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK
+idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=ESTACK_DB
idtentry int3 do_int3 has_error_code=0
idtentry stack_segment do_stack_segment has_error_code=1
diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h
index bcd8c05186049dd75db6b2c9f03a4fa9936a9692..6ab2c54c1bf9702442ea2478c360309aa47196c8 100644
--- a/arch/x86/include/asm/page_64_types.h
+++ b/arch/x86/include/asm/page_64_types.h
@@ -24,11 +24,14 @@
#define IRQ_STACK_ORDER (2 + KASAN_STACK_ORDER)
#define IRQ_STACK_SIZE (PAGE_SIZE << IRQ_STACK_ORDER)
-#define DOUBLEFAULT_STACK 1
-#define NMI_STACK 2
-#define DEBUG_STACK 3
-#define MCE_STACK 4
-#define N_EXCEPTION_STACKS 4 /* hw limit: 7 */
+/*
+ * The index for the tss.ist[] array. The hardware limit is 7 entries.
+ */
+#define ESTACK_DF 0
+#define ESTACK_NMI 1
+#define ESTACK_DB 2
+#define ESTACK_MCE 3
+#define N_EXCEPTION_STACKS 4
/*
* Set __PAGE_OFFSET to the most negative possible address +
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index cb28e98a0659abc5051b1e7fcb936b692a1a1264..0e4cb718fc4a471bd8cbb00cdae8b2c4fb50bd92 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -516,7 +516,7 @@ DEFINE_PER_CPU(struct cpu_entry_area *, cpu_entry_area);
*/
static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = {
[0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,
- [DEBUG_STACK - 1] = DEBUG_STKSZ
+ [ESTACK_DB] = DEBUG_STKSZ
};
#endif
@@ -1760,7 +1760,7 @@ void cpu_init(void)
estacks += exception_stack_sizes[v];
oist->ist[v] = t->x86_tss.ist[v] =
(unsigned long)estacks;
- if (v == DEBUG_STACK-1)
+ if (v == ESTACK_DB)
per_cpu(debug_stack_addr, cpu) = (unsigned long)estacks;
}
}
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 90f0fa88cbb39839f72f2cac5bdd8ec4da8acb11..455b47ef92509c6ee817e54aad57fa9b8fba040a 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -18,16 +18,16 @@
#include <asm/stacktrace.h>
-static char *exception_stack_names[N_EXCEPTION_STACKS] = {
- [ DOUBLEFAULT_STACK-1 ] = "#DF",
- [ NMI_STACK-1 ] = "NMI",
- [ DEBUG_STACK-1 ] = "#DB",
- [ MCE_STACK-1 ] = "#MC",
+static const char *exception_stack_names[N_EXCEPTION_STACKS] = {
+ [ ESTACK_DF ] = "#DF",
+ [ ESTACK_NMI ] = "NMI",
+ [ ESTACK_DB ] = "#DB",
+ [ ESTACK_MCE ] = "#MC",
};
-static unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = {
+static const unsigned long exception_stack_sizes[N_EXCEPTION_STACKS] = {
[0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ,
- [DEBUG_STACK - 1] = DEBUG_STKSZ
+ [ESTACK_DB] = DEBUG_STKSZ
};
const char *stack_type_name(enum stack_type type)
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 2877606e97de04b0e4c242e7b616583a2e82fd55..2188f734ec61341047ae31e31e6a94bfc1cb79c1 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -41,9 +41,12 @@ struct idt_data {
#define SYSG(_vector, _addr) \
G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL3, __KERNEL_CS)
-/* Interrupt gate with interrupt stack */
+/*
+ * Interrupt gate with interrupt stack. The _ist index is the index in
+ * the tss.ist[] array, but for the descriptor it needs to start at 1.
+ */
#define ISTG(_vector, _addr, _ist) \
- G(_vector, _addr, _ist, GATE_INTERRUPT, DPL0, __KERNEL_CS)
+ G(_vector, _addr, _ist + 1, GATE_INTERRUPT, DPL0, __KERNEL_CS)
/* Task gate */
#define TSKG(_vector, _gdt) \
@@ -180,11 +183,11 @@ gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss;
* cpu_init() when the TSS has been initialized.
*/
static const __initconst struct idt_data ist_idts[] = {
- ISTG(X86_TRAP_DB, debug, DEBUG_STACK),
- ISTG(X86_TRAP_NMI, nmi, NMI_STACK),
- ISTG(X86_TRAP_DF, double_fault, DOUBLEFAULT_STACK),
+ ISTG(X86_TRAP_DB, debug, ESTACK_DB),
+ ISTG(X86_TRAP_NMI, nmi, ESTACK_NMI),
+ ISTG(X86_TRAP_DF, double_fault, ESTACK_DF),
#ifdef CONFIG_X86_MCE
- ISTG(X86_TRAP_MC, &machine_check, MCE_STACK),
+ ISTG(X86_TRAP_MC, &machine_check, ESTACK_MCE),
#endif
};
diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index cf200466d5c8aeeb3ae30e513bbbf988d6395276..182e8b245e0630df2986fbbcc29c81f5124951c1 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -61,7 +61,7 @@ static inline void stack_overflow_check(struct pt_regs *regs)
return;
oist = this_cpu_ptr(&orig_ist);
- estack_top = (u64)oist->ist[DEBUG_STACK];
+ estack_top = (u64)oist->ist[ESTACK_DB];
estack_bottom = estack_top - DEBUG_STKSZ + STACK_MARGIN;
if (regs->sp >= estack_bottom && regs->sp <= estack_top)
return;
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 667f1da36208e93434178e07356abe764dd02dcc..0524e1d74f245338e1a4ee39b812a466690a9924 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -793,7 +793,7 @@ no_context(struct pt_regs *regs, unsigned long error_code,
if (is_vmalloc_addr((void *)address) &&
(((unsigned long)tsk->stack - 1 - address < PAGE_SIZE) ||
address - ((unsigned long)tsk->stack + THREAD_SIZE) < PAGE_SIZE)) {
- unsigned long stack = this_cpu_read(orig_ist.ist[DOUBLEFAULT_STACK]) - sizeof(void *);
+ unsigned long stack = this_cpu_read(orig_ist.ist[ESTACK_DF]) - sizeof(void *);
/*
* We're likely to be running with very little stack space
* left. It's plausible that we'd hit this condition but