x86/entry: Rename SYSENTER_stack to CPU_ENTRY_AREA_entry_stack

If the kernel oopses while on the trampoline stack, it will print
"<SYSENTER>" even if SYSENTER is not involved.  That is rather confusing.

The "SYSENTER" stack is used for a lot more than SYSENTER now.  Give it a
better string to display in stack dumps, and rename the kernel code to
match.

Also move the 32-bit code over to the new naming even though it still uses
the entry stack only for SYSENTER.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Dave Hansen 2017-12-04 17:25:07 -08:00 committed by Ingo Molnar
parent e8ffe96e59
commit 4fe2d8b11a
11 changed files with 44 additions and 38 deletions

View File

@ -942,9 +942,9 @@ ENTRY(debug)
/* Are we currently on the SYSENTER stack? */
movl PER_CPU_VAR(cpu_entry_area), %ecx
addl $CPU_ENTRY_AREA_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx
subl %eax, %ecx /* ecx = (end of SYSENTER_stack) - esp */
cmpl $SIZEOF_SYSENTER_stack, %ecx
addl $CPU_ENTRY_AREA_entry_stack + SIZEOF_entry_stack, %ecx
subl %eax, %ecx /* ecx = (end of entry_stack) - esp */
cmpl $SIZEOF_entry_stack, %ecx
jb .Ldebug_from_sysenter_stack
TRACE_IRQS_OFF
@ -986,9 +986,9 @@ ENTRY(nmi)
/* Are we currently on the SYSENTER stack? */
movl PER_CPU_VAR(cpu_entry_area), %ecx
addl $CPU_ENTRY_AREA_SYSENTER_stack + SIZEOF_SYSENTER_stack, %ecx
subl %eax, %ecx /* ecx = (end of SYSENTER_stack) - esp */
cmpl $SIZEOF_SYSENTER_stack, %ecx
addl $CPU_ENTRY_AREA_entry_stack + SIZEOF_entry_stack, %ecx
subl %eax, %ecx /* ecx = (end of entry_stack) - esp */
cmpl $SIZEOF_entry_stack, %ecx
jb .Lnmi_from_sysenter_stack
/* Not on SYSENTER stack. */

View File

@ -154,8 +154,8 @@ END(native_usergs_sysret64)
_entry_trampoline - CPU_ENTRY_AREA_entry_trampoline(%rip)
/* The top word of the SYSENTER stack is hot and is usable as scratch space. */
#define RSP_SCRATCH CPU_ENTRY_AREA_SYSENTER_stack + \
SIZEOF_SYSENTER_stack - 8 + CPU_ENTRY_AREA
#define RSP_SCRATCH CPU_ENTRY_AREA_entry_stack + \
SIZEOF_entry_stack - 8 + CPU_ENTRY_AREA
ENTRY(entry_SYSCALL_64_trampoline)
UNWIND_HINT_EMPTY

View File

@ -56,10 +56,10 @@ struct cpu_entry_area {
char gdt[PAGE_SIZE];
/*
* The GDT is just below SYSENTER_stack and thus serves (on x86_64) as
* The GDT is just below entry_stack and thus serves (on x86_64) as
* a a read-only guard page.
*/
struct SYSENTER_stack_page SYSENTER_stack_page;
struct entry_stack_page entry_stack_page;
/*
* On x86_64, the TSS is mapped RO. On x86_32, it's mapped RW because
@ -250,9 +250,9 @@ static inline struct cpu_entry_area *get_cpu_entry_area(int cpu)
return (struct cpu_entry_area *)__fix_to_virt(__get_cpu_entry_area_page_index(cpu, 0));
}
static inline struct SYSENTER_stack *cpu_SYSENTER_stack(int cpu)
static inline struct entry_stack *cpu_entry_stack(int cpu)
{
return &get_cpu_entry_area(cpu)->SYSENTER_stack_page.stack;
return &get_cpu_entry_area(cpu)->entry_stack_page.stack;
}
#endif /* !__ASSEMBLY__ */

View File

@ -336,12 +336,12 @@ struct x86_hw_tss {
#define IO_BITMAP_OFFSET (offsetof(struct tss_struct, io_bitmap) - offsetof(struct tss_struct, x86_tss))
#define INVALID_IO_BITMAP_OFFSET 0x8000
struct SYSENTER_stack {
struct entry_stack {
unsigned long words[64];
};
struct SYSENTER_stack_page {
struct SYSENTER_stack stack;
struct entry_stack_page {
struct entry_stack stack;
} __aligned(PAGE_SIZE);
struct tss_struct {

View File

@ -16,7 +16,7 @@ enum stack_type {
STACK_TYPE_TASK,
STACK_TYPE_IRQ,
STACK_TYPE_SOFTIRQ,
STACK_TYPE_SYSENTER,
STACK_TYPE_ENTRY,
STACK_TYPE_EXCEPTION,
STACK_TYPE_EXCEPTION_LAST = STACK_TYPE_EXCEPTION + N_EXCEPTION_STACKS-1,
};
@ -29,7 +29,7 @@ struct stack_info {
bool in_task_stack(unsigned long *stack, struct task_struct *task,
struct stack_info *info);
bool in_sysenter_stack(unsigned long *stack, struct stack_info *info);
bool in_entry_stack(unsigned long *stack, struct stack_info *info);
int get_stack_info(unsigned long *stack, struct task_struct *task,
struct stack_info *info, unsigned long *visit_mask);

View File

@ -97,6 +97,6 @@ void common(void) {
/* Layout info for cpu_entry_area */
OFFSET(CPU_ENTRY_AREA_tss, cpu_entry_area, tss);
OFFSET(CPU_ENTRY_AREA_entry_trampoline, cpu_entry_area, entry_trampoline);
OFFSET(CPU_ENTRY_AREA_SYSENTER_stack, cpu_entry_area, SYSENTER_stack_page);
DEFINE(SIZEOF_SYSENTER_stack, sizeof(struct SYSENTER_stack));
OFFSET(CPU_ENTRY_AREA_entry_stack, cpu_entry_area, entry_stack_page);
DEFINE(SIZEOF_entry_stack, sizeof(struct entry_stack));
}

View File

@ -48,7 +48,7 @@ void foo(void)
/* Offset from the sysenter stack to tss.sp0 */
DEFINE(TSS_sysenter_sp0, offsetof(struct cpu_entry_area, tss.x86_tss.sp0) -
offsetofend(struct cpu_entry_area, SYSENTER_stack_page.stack));
offsetofend(struct cpu_entry_area, entry_stack_page.stack));
#ifdef CONFIG_CC_STACKPROTECTOR
BLANK();

View File

@ -487,8 +487,8 @@ static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);
#endif
static DEFINE_PER_CPU_PAGE_ALIGNED(struct SYSENTER_stack_page,
SYSENTER_stack_storage);
static DEFINE_PER_CPU_PAGE_ALIGNED(struct entry_stack_page,
entry_stack_storage);
static void __init
set_percpu_fixmap_pages(int idx, void *ptr, int pages, pgprot_t prot)
@ -523,8 +523,8 @@ static void __init setup_cpu_entry_area(int cpu)
#endif
__set_fixmap(get_cpu_entry_area_index(cpu, gdt), get_cpu_gdt_paddr(cpu), gdt_prot);
set_percpu_fixmap_pages(get_cpu_entry_area_index(cpu, SYSENTER_stack_page),
per_cpu_ptr(&SYSENTER_stack_storage, cpu), 1,
set_percpu_fixmap_pages(get_cpu_entry_area_index(cpu, entry_stack_page),
per_cpu_ptr(&entry_stack_storage, cpu), 1,
PAGE_KERNEL);
/*
@ -1323,7 +1323,7 @@ void enable_sep_cpu(void)
tss->x86_tss.ss1 = __KERNEL_CS;
wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0);
wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_SYSENTER_stack(cpu) + 1), 0);
wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1), 0);
wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0);
put_cpu();
@ -1440,7 +1440,7 @@ void syscall_init(void)
* AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit).
*/
wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
wrmsrl_safe(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_SYSENTER_stack(cpu) + 1));
wrmsrl_safe(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1));
wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat);
#else
wrmsrl(MSR_CSTAR, (unsigned long)ignore_sysret);
@ -1655,7 +1655,7 @@ void cpu_init(void)
*/
set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
load_TR_desc();
load_sp0((unsigned long)(cpu_SYSENTER_stack(cpu) + 1));
load_sp0((unsigned long)(cpu_entry_stack(cpu) + 1));
load_mm_ldt(&init_mm);

View File

@ -43,9 +43,9 @@ bool in_task_stack(unsigned long *stack, struct task_struct *task,
return true;
}
bool in_sysenter_stack(unsigned long *stack, struct stack_info *info)
bool in_entry_stack(unsigned long *stack, struct stack_info *info)
{
struct SYSENTER_stack *ss = cpu_SYSENTER_stack(smp_processor_id());
struct entry_stack *ss = cpu_entry_stack(smp_processor_id());
void *begin = ss;
void *end = ss + 1;
@ -53,7 +53,7 @@ bool in_sysenter_stack(unsigned long *stack, struct stack_info *info)
if ((void *)stack < begin || (void *)stack >= end)
return false;
info->type = STACK_TYPE_SYSENTER;
info->type = STACK_TYPE_ENTRY;
info->begin = begin;
info->end = end;
info->next_sp = NULL;
@ -111,13 +111,13 @@ void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
* - task stack
* - interrupt stack
* - HW exception stacks (double fault, nmi, debug, mce)
* - SYSENTER stack
* - entry stack
*
* x86-32 can have up to four stacks:
* - task stack
* - softirq stack
* - hardirq stack
* - SYSENTER stack
* - entry stack
*/
for (regs = NULL; stack; stack = PTR_ALIGN(stack_info.next_sp, sizeof(long))) {
const char *stack_name;

View File

@ -26,8 +26,8 @@ const char *stack_type_name(enum stack_type type)
if (type == STACK_TYPE_SOFTIRQ)
return "SOFTIRQ";
if (type == STACK_TYPE_SYSENTER)
return "SYSENTER";
if (type == STACK_TYPE_ENTRY)
return "ENTRY_TRAMPOLINE";
return NULL;
}
@ -96,7 +96,7 @@ int get_stack_info(unsigned long *stack, struct task_struct *task,
if (task != current)
goto unknown;
if (in_sysenter_stack(stack, info))
if (in_entry_stack(stack, info))
goto recursion_check;
if (in_hardirq_stack(stack, info))

View File

@ -37,8 +37,14 @@ const char *stack_type_name(enum stack_type type)
if (type == STACK_TYPE_IRQ)
return "IRQ";
if (type == STACK_TYPE_SYSENTER)
return "SYSENTER";
if (type == STACK_TYPE_ENTRY) {
/*
* On 64-bit, we have a generic entry stack that we
* use for all the kernel entry points, including
* SYSENTER.
*/
return "ENTRY_TRAMPOLINE";
}
if (type >= STACK_TYPE_EXCEPTION && type <= STACK_TYPE_EXCEPTION_LAST)
return exception_stack_names[type - STACK_TYPE_EXCEPTION];
@ -118,7 +124,7 @@ int get_stack_info(unsigned long *stack, struct task_struct *task,
if (in_irq_stack(stack, info))
goto recursion_check;
if (in_sysenter_stack(stack, info))
if (in_entry_stack(stack, info))
goto recursion_check;
goto unknown;