mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-26 06:20:54 +07:00
Merge branch 'tip/x86/core-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core
This commit is contained in:
Ingo Molnar
commit
03f70388c3
@ -101,6 +101,28 @@ extern void aout_dump_debugregs(struct user *dump);
|
||||
|
||||
extern void hw_breakpoint_restore(void);
|
||||
|
||||
#ifdef CONFIG_X86_64
|
||||
DECLARE_PER_CPU(int, debug_stack_usage);
|
||||
static inline void debug_stack_usage_inc(void)
|
||||
{
|
||||
__get_cpu_var(debug_stack_usage)++;
|
||||
}
|
||||
static inline void debug_stack_usage_dec(void)
|
||||
{
|
||||
__get_cpu_var(debug_stack_usage)--;
|
||||
}
|
||||
int is_debug_stack(unsigned long addr);
|
||||
void debug_stack_set_zero(void);
|
||||
void debug_stack_reset(void);
|
||||
#else /* !X86_64 */
|
||||
static inline int is_debug_stack(unsigned long addr) { return 0; }
|
||||
static inline void debug_stack_set_zero(void) { }
|
||||
static inline void debug_stack_reset(void) { }
|
||||
static inline void debug_stack_usage_inc(void) { }
|
||||
static inline void debug_stack_usage_dec(void) { }
|
||||
#endif /* X86_64 */
|
||||
|
||||
|
||||
#endif /* __KERNEL__ */
|
||||
|
||||
#endif /* _ASM_X86_DEBUGREG_H */
|
||||
|
||||
@ -35,6 +35,8 @@ static inline void fill_ldt(struct desc_struct *desc, const struct user_desc *in
|
||||
|
||||
extern struct desc_ptr idt_descr;
|
||||
extern gate_desc idt_table[];
|
||||
extern struct desc_ptr nmi_idt_descr;
|
||||
extern gate_desc nmi_idt_table[];
|
||||
|
||||
struct gdt_page {
|
||||
struct desc_struct gdt[GDT_ENTRIES];
|
||||
@ -307,6 +309,16 @@ static inline void set_desc_limit(struct desc_struct *desc, unsigned long limit)
|
||||
desc->limit = (limit >> 16) & 0xf;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_X86_64
|
||||
static inline void set_nmi_gate(int gate, void *addr)
|
||||
{
|
||||
gate_desc s;
|
||||
|
||||
pack_gate(&s, GATE_INTERRUPT, (unsigned long)addr, 0, 0, __KERNEL_CS);
|
||||
write_idt_entry(nmi_idt_table, gate, &s);
|
||||
}
|
||||
#endif
|
||||
|
||||
static inline void _set_gate(int gate, unsigned type, void *addr,
|
||||
unsigned dpl, unsigned ist, unsigned seg)
|
||||
{
|
||||
|
||||
@ -1026,6 +1026,8 @@ __setup("clearcpuid=", setup_disablecpuid);
|
||||
|
||||
#ifdef CONFIG_X86_64
|
||||
struct desc_ptr idt_descr = { NR_VECTORS * 16 - 1, (unsigned long) idt_table };
|
||||
struct desc_ptr nmi_idt_descr = { NR_VECTORS * 16 - 1,
|
||||
(unsigned long) nmi_idt_table };
|
||||
|
||||
DEFINE_PER_CPU_FIRST(union irq_stack_union,
|
||||
irq_stack_union) __aligned(PAGE_SIZE);
|
||||
@ -1090,6 +1092,26 @@ unsigned long kernel_eflags;
|
||||
*/
|
||||
DEFINE_PER_CPU(struct orig_ist, orig_ist);
|
||||
|
||||
static DEFINE_PER_CPU(unsigned long, debug_stack_addr);
|
||||
DEFINE_PER_CPU(int, debug_stack_usage);
|
||||
|
||||
int is_debug_stack(unsigned long addr)
|
||||
{
|
||||
return __get_cpu_var(debug_stack_usage) ||
|
||||
(addr <= __get_cpu_var(debug_stack_addr) &&
|
||||
addr > (__get_cpu_var(debug_stack_addr) - DEBUG_STKSZ));
|
||||
}
|
||||
|
||||
void debug_stack_set_zero(void)
|
||||
{
|
||||
load_idt((const struct desc_ptr *)&nmi_idt_descr);
|
||||
}
|
||||
|
||||
void debug_stack_reset(void)
|
||||
{
|
||||
load_idt((const struct desc_ptr *)&idt_descr);
|
||||
}
|
||||
|
||||
#else /* CONFIG_X86_64 */
|
||||
|
||||
DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
|
||||
@ -1208,6 +1230,8 @@ void __cpuinit cpu_init(void)
|
||||
estacks += exception_stack_sizes[v];
|
||||
oist->ist[v] = t->x86_tss.ist[v] =
|
||||
(unsigned long)estacks;
|
||||
if (v == DEBUG_STACK-1)
|
||||
per_cpu(debug_stack_addr, cpu) = (unsigned long)estacks;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
@ -1475,62 +1475,214 @@ ENTRY(error_exit)
|
||||
CFI_ENDPROC
|
||||
END(error_exit)
|
||||
|
||||
/*
|
||||
* Test if a given stack is an NMI stack or not.
|
||||
*/
|
||||
.macro test_in_nmi reg stack nmi_ret normal_ret
|
||||
cmpq %\reg, \stack
|
||||
ja \normal_ret
|
||||
subq $EXCEPTION_STKSZ, %\reg
|
||||
cmpq %\reg, \stack
|
||||
jb \normal_ret
|
||||
jmp \nmi_ret
|
||||
.endm
|
||||
|
||||
/* runs on exception stack */
|
||||
ENTRY(nmi)
|
||||
INTR_FRAME
|
||||
PARAVIRT_ADJUST_EXCEPTION_FRAME
|
||||
pushq_cfi $-1
|
||||
/*
|
||||
* We allow breakpoints in NMIs. If a breakpoint occurs, then
|
||||
* the iretq it performs will take us out of NMI context.
|
||||
* This means that we can have nested NMIs where the next
|
||||
* NMI is using the top of the stack of the previous NMI. We
|
||||
* can't let it execute because the nested NMI will corrupt the
|
||||
* stack of the previous NMI. NMI handlers are not re-entrant
|
||||
* anyway.
|
||||
*
|
||||
* To handle this case we do the following:
|
||||
* Check the a special location on the stack that contains
|
||||
* a variable that is set when NMIs are executing.
|
||||
* The interrupted task's stack is also checked to see if it
|
||||
* is an NMI stack.
|
||||
* If the variable is not set and the stack is not the NMI
|
||||
* stack then:
|
||||
* o Set the special variable on the stack
|
||||
* o Copy the interrupt frame into a "saved" location on the stack
|
||||
* o Copy the interrupt frame into a "copy" location on the stack
|
||||
* o Continue processing the NMI
|
||||
* If the variable is set or the previous stack is the NMI stack:
|
||||
* o Modify the "copy" location to jump to the repeate_nmi
|
||||
* o return back to the first NMI
|
||||
*
|
||||
* Now on exit of the first NMI, we first clear the stack variable
|
||||
* The NMI stack will tell any nested NMIs at that point that it is
|
||||
* nested. Then we pop the stack normally with iret, and if there was
|
||||
* a nested NMI that updated the copy interrupt stack frame, a
|
||||
* jump will be made to the repeat_nmi code that will handle the second
|
||||
* NMI.
|
||||
*/
|
||||
|
||||
/* Use %rdx as out temp variable throughout */
|
||||
pushq_cfi %rdx
|
||||
|
||||
/*
|
||||
* Check the special variable on the stack to see if NMIs are
|
||||
* executing.
|
||||
*/
|
||||
cmp $1, -8(%rsp)
|
||||
je nested_nmi
|
||||
|
||||
/*
|
||||
* Now test if the previous stack was an NMI stack.
|
||||
* We need the double check. We check the NMI stack to satisfy the
|
||||
* race when the first NMI clears the variable before returning.
|
||||
* We check the variable because the first NMI could be in a
|
||||
* breakpoint routine using a breakpoint stack.
|
||||
*/
|
||||
lea 6*8(%rsp), %rdx
|
||||
test_in_nmi rdx, 4*8(%rsp), nested_nmi, first_nmi
|
||||
|
||||
nested_nmi:
|
||||
/*
|
||||
* Do nothing if we interrupted the fixup in repeat_nmi.
|
||||
* It's about to repeat the NMI handler, so we are fine
|
||||
* with ignoring this one.
|
||||
*/
|
||||
movq $repeat_nmi, %rdx
|
||||
cmpq 8(%rsp), %rdx
|
||||
ja 1f
|
||||
movq $end_repeat_nmi, %rdx
|
||||
cmpq 8(%rsp), %rdx
|
||||
ja nested_nmi_out
|
||||
|
||||
1:
|
||||
/* Set up the interrupted NMIs stack to jump to repeat_nmi */
|
||||
leaq -6*8(%rsp), %rdx
|
||||
movq %rdx, %rsp
|
||||
CFI_ADJUST_CFA_OFFSET 6*8
|
||||
pushq_cfi $__KERNEL_DS
|
||||
pushq_cfi %rdx
|
||||
pushfq_cfi
|
||||
pushq_cfi $__KERNEL_CS
|
||||
pushq_cfi $repeat_nmi
|
||||
|
||||
/* Put stack back */
|
||||
addq $(11*8), %rsp
|
||||
CFI_ADJUST_CFA_OFFSET -11*8
|
||||
|
||||
nested_nmi_out:
|
||||
popq_cfi %rdx
|
||||
|
||||
/* No need to check faults here */
|
||||
INTERRUPT_RETURN
|
||||
|
||||
first_nmi:
|
||||
/*
|
||||
* Because nested NMIs will use the pushed location that we
|
||||
* stored in rdx, we must keep that space available.
|
||||
* Here's what our stack frame will look like:
|
||||
* +-------------------------+
|
||||
* | original SS |
|
||||
* | original Return RSP |
|
||||
* | original RFLAGS |
|
||||
* | original CS |
|
||||
* | original RIP |
|
||||
* +-------------------------+
|
||||
* | temp storage for rdx |
|
||||
* +-------------------------+
|
||||
* | NMI executing variable |
|
||||
* +-------------------------+
|
||||
* | Saved SS |
|
||||
* | Saved Return RSP |
|
||||
* | Saved RFLAGS |
|
||||
* | Saved CS |
|
||||
* | Saved RIP |
|
||||
* +-------------------------+
|
||||
* | copied SS |
|
||||
* | copied Return RSP |
|
||||
* | copied RFLAGS |
|
||||
* | copied CS |
|
||||
* | copied RIP |
|
||||
* +-------------------------+
|
||||
* | pt_regs |
|
||||
* +-------------------------+
|
||||
*
|
||||
* The saved RIP is used to fix up the copied RIP that a nested
|
||||
* NMI may zero out. The original stack frame and the temp storage
|
||||
* is also used by nested NMIs and can not be trusted on exit.
|
||||
*/
|
||||
/* Set the NMI executing variable on the stack. */
|
||||
pushq_cfi $1
|
||||
|
||||
/* Copy the stack frame to the Saved frame */
|
||||
.rept 5
|
||||
pushq_cfi 6*8(%rsp)
|
||||
.endr
|
||||
|
||||
/* Make another copy, this one may be modified by nested NMIs */
|
||||
.rept 5
|
||||
pushq_cfi 4*8(%rsp)
|
||||
.endr
|
||||
|
||||
/* Do not pop rdx, nested NMIs will corrupt it */
|
||||
movq 11*8(%rsp), %rdx
|
||||
|
||||
/*
|
||||
* Everything below this point can be preempted by a nested
|
||||
* NMI if the first NMI took an exception. Repeated NMIs
|
||||
* caused by an exception and nested NMI will start here, and
|
||||
* can still be preempted by another NMI.
|
||||
*/
|
||||
restart_nmi:
|
||||
pushq_cfi $-1 /* ORIG_RAX: no syscall to restart */
|
||||
subq $ORIG_RAX-R15, %rsp
|
||||
CFI_ADJUST_CFA_OFFSET ORIG_RAX-R15
|
||||
/*
|
||||
* Use save_paranoid to handle SWAPGS, but no need to use paranoid_exit
|
||||
* as we should not be calling schedule in NMI context.
|
||||
* Even with normal interrupts enabled. An NMI should not be
|
||||
* setting NEED_RESCHED or anything that normal interrupts and
|
||||
* exceptions might do.
|
||||
*/
|
||||
call save_paranoid
|
||||
DEFAULT_FRAME 0
|
||||
/* paranoidentry do_nmi, 0; without TRACE_IRQS_OFF */
|
||||
movq %rsp,%rdi
|
||||
movq $-1,%rsi
|
||||
call do_nmi
|
||||
#ifdef CONFIG_TRACE_IRQFLAGS
|
||||
/* paranoidexit; without TRACE_IRQS_OFF */
|
||||
/* ebx: no swapgs flag */
|
||||
DISABLE_INTERRUPTS(CLBR_NONE)
|
||||
testl %ebx,%ebx /* swapgs needed? */
|
||||
jnz nmi_restore
|
||||
testl $3,CS(%rsp)
|
||||
jnz nmi_userspace
|
||||
nmi_swapgs:
|
||||
SWAPGS_UNSAFE_STACK
|
||||
nmi_restore:
|
||||
RESTORE_ALL 8
|
||||
/* Clear the NMI executing stack variable */
|
||||
movq $0, 10*8(%rsp)
|
||||
jmp irq_return
|
||||
nmi_userspace:
|
||||
GET_THREAD_INFO(%rcx)
|
||||
movl TI_flags(%rcx),%ebx
|
||||
andl $_TIF_WORK_MASK,%ebx
|
||||
jz nmi_swapgs
|
||||
movq %rsp,%rdi /* &pt_regs */
|
||||
call sync_regs
|
||||
movq %rax,%rsp /* switch stack for scheduling */
|
||||
testl $_TIF_NEED_RESCHED,%ebx
|
||||
jnz nmi_schedule
|
||||
movl %ebx,%edx /* arg3: thread flags */
|
||||
ENABLE_INTERRUPTS(CLBR_NONE)
|
||||
xorl %esi,%esi /* arg2: oldset */
|
||||
movq %rsp,%rdi /* arg1: &pt_regs */
|
||||
call do_notify_resume
|
||||
DISABLE_INTERRUPTS(CLBR_NONE)
|
||||
jmp nmi_userspace
|
||||
nmi_schedule:
|
||||
ENABLE_INTERRUPTS(CLBR_ANY)
|
||||
call schedule
|
||||
DISABLE_INTERRUPTS(CLBR_ANY)
|
||||
jmp nmi_userspace
|
||||
CFI_ENDPROC
|
||||
#else
|
||||
jmp paranoid_exit
|
||||
CFI_ENDPROC
|
||||
#endif
|
||||
END(nmi)
|
||||
|
||||
/*
|
||||
* If an NMI hit an iret because of an exception or breakpoint,
|
||||
* it can lose its NMI context, and a nested NMI may come in.
|
||||
* In that case, the nested NMI will change the preempted NMI's
|
||||
* stack to jump to here when it does the final iret.
|
||||
*/
|
||||
repeat_nmi:
|
||||
INTR_FRAME
|
||||
/* Update the stack variable to say we are still in NMI */
|
||||
movq $1, 5*8(%rsp)
|
||||
|
||||
/* copy the saved stack back to copy stack */
|
||||
.rept 5
|
||||
pushq_cfi 4*8(%rsp)
|
||||
.endr
|
||||
|
||||
jmp restart_nmi
|
||||
CFI_ENDPROC
|
||||
end_repeat_nmi:
|
||||
|
||||
ENTRY(ignore_sysret)
|
||||
CFI_STARTPROC
|
||||
mov $-ENOSYS,%eax
|
||||
|
||||
@ -417,6 +417,10 @@ ENTRY(phys_base)
|
||||
ENTRY(idt_table)
|
||||
.skip IDT_ENTRIES * 16
|
||||
|
||||
.align L1_CACHE_BYTES
|
||||
ENTRY(nmi_idt_table)
|
||||
.skip IDT_ENTRIES * 16
|
||||
|
||||
__PAGE_ALIGNED_BSS
|
||||
.align PAGE_SIZE
|
||||
ENTRY(empty_zero_page)
|
||||
|
||||
@ -405,9 +405,108 @@ static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
|
||||
unknown_nmi_error(reason, regs);
|
||||
}
|
||||
|
||||
/*
|
||||
* NMIs can hit breakpoints which will cause it to lose its
|
||||
* NMI context with the CPU when the breakpoint does an iret.
|
||||
*/
|
||||
#ifdef CONFIG_X86_32
|
||||
/*
|
||||
* For i386, NMIs use the same stack as the kernel, and we can
|
||||
* add a workaround to the iret problem in C. Simply have 3 states
|
||||
* the NMI can be in.
|
||||
*
|
||||
* 1) not running
|
||||
* 2) executing
|
||||
* 3) latched
|
||||
*
|
||||
* When no NMI is in progress, it is in the "not running" state.
|
||||
* When an NMI comes in, it goes into the "executing" state.
|
||||
* Normally, if another NMI is triggered, it does not interrupt
|
||||
* the running NMI and the HW will simply latch it so that when
|
||||
* the first NMI finishes, it will restart the second NMI.
|
||||
* (Note, the latch is binary, thus multiple NMIs triggering,
|
||||
* when one is running, are ignored. Only one NMI is restarted.)
|
||||
*
|
||||
* If an NMI hits a breakpoint that executes an iret, another
|
||||
* NMI can preempt it. We do not want to allow this new NMI
|
||||
* to run, but we want to execute it when the first one finishes.
|
||||
* We set the state to "latched", and the first NMI will perform
|
||||
* an cmpxchg on the state, and if it doesn't successfully
|
||||
* reset the state to "not running" it will restart the next
|
||||
* NMI.
|
||||
*/
|
||||
enum nmi_states {
|
||||
NMI_NOT_RUNNING,
|
||||
NMI_EXECUTING,
|
||||
NMI_LATCHED,
|
||||
};
|
||||
static DEFINE_PER_CPU(enum nmi_states, nmi_state);
|
||||
|
||||
#define nmi_nesting_preprocess(regs) \
|
||||
do { \
|
||||
if (__get_cpu_var(nmi_state) != NMI_NOT_RUNNING) { \
|
||||
__get_cpu_var(nmi_state) = NMI_LATCHED; \
|
||||
return; \
|
||||
} \
|
||||
nmi_restart: \
|
||||
__get_cpu_var(nmi_state) = NMI_EXECUTING; \
|
||||
} while (0)
|
||||
|
||||
#define nmi_nesting_postprocess() \
|
||||
do { \
|
||||
if (cmpxchg(&__get_cpu_var(nmi_state), \
|
||||
NMI_EXECUTING, NMI_NOT_RUNNING) != NMI_EXECUTING) \
|
||||
goto nmi_restart; \
|
||||
} while (0)
|
||||
#else /* x86_64 */
|
||||
/*
|
||||
* In x86_64 things are a bit more difficult. This has the same problem
|
||||
* where an NMI hitting a breakpoint that calls iret will remove the
|
||||
* NMI context, allowing a nested NMI to enter. What makes this more
|
||||
* difficult is that both NMIs and breakpoints have their own stack.
|
||||
* When a new NMI or breakpoint is executed, the stack is set to a fixed
|
||||
* point. If an NMI is nested, it will have its stack set at that same
|
||||
* fixed address that the first NMI had, and will start corrupting the
|
||||
* stack. This is handled in entry_64.S, but the same problem exists with
|
||||
* the breakpoint stack.
|
||||
*
|
||||
* If a breakpoint is being processed, and the debug stack is being used,
|
||||
* if an NMI comes in and also hits a breakpoint, the stack pointer
|
||||
* will be set to the same fixed address as the breakpoint that was
|
||||
* interrupted, causing that stack to be corrupted. To handle this case,
|
||||
* check if the stack that was interrupted is the debug stack, and if
|
||||
* so, change the IDT so that new breakpoints will use the current stack
|
||||
* and not switch to the fixed address. On return of the NMI, switch back
|
||||
* to the original IDT.
|
||||
*/
|
||||
static DEFINE_PER_CPU(int, update_debug_stack);
|
||||
|
||||
static inline void nmi_nesting_preprocess(struct pt_regs *regs)
|
||||
{
|
||||
/*
|
||||
* If we interrupted a breakpoint, it is possible that
|
||||
* the nmi handler will have breakpoints too. We need to
|
||||
* change the IDT such that breakpoints that happen here
|
||||
* continue to use the NMI stack.
|
||||
*/
|
||||
if (unlikely(is_debug_stack(regs->sp))) {
|
||||
debug_stack_set_zero();
|
||||
__get_cpu_var(update_debug_stack) = 1;
|
||||
}
|
||||
}
|
||||
|
||||
static inline void nmi_nesting_postprocess(void)
|
||||
{
|
||||
if (unlikely(__get_cpu_var(update_debug_stack)))
|
||||
debug_stack_reset();
|
||||
}
|
||||
#endif
|
||||
|
||||
dotraplinkage notrace __kprobes void
|
||||
do_nmi(struct pt_regs *regs, long error_code)
|
||||
{
|
||||
nmi_nesting_preprocess(regs);
|
||||
|
||||
nmi_enter();
|
||||
|
||||
inc_irq_stat(__nmi_count);
|
||||
@ -416,6 +515,9 @@ do_nmi(struct pt_regs *regs, long error_code)
|
||||
default_do_nmi(regs);
|
||||
|
||||
nmi_exit();
|
||||
|
||||
/* On i386, may loop back to preprocess */
|
||||
nmi_nesting_postprocess();
|
||||
}
|
||||
|
||||
void stop_nmi(void)
|
||||
|
||||
@ -316,9 +316,15 @@ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
|
||||
return;
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Let others (NMI) know that the debug stack is in use
|
||||
* as we may switch to the interrupt stack.
|
||||
*/
|
||||
debug_stack_usage_inc();
|
||||
preempt_conditional_sti(regs);
|
||||
do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
|
||||
preempt_conditional_cli(regs);
|
||||
debug_stack_usage_dec();
|
||||
}
|
||||
|
||||
#ifdef CONFIG_X86_64
|
||||
@ -411,6 +417,12 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
|
||||
SIGTRAP) == NOTIFY_STOP)
|
||||
return;
|
||||
|
||||
/*
|
||||
* Let others (NMI) know that the debug stack is in use
|
||||
* as we may switch to the interrupt stack.
|
||||
*/
|
||||
debug_stack_usage_inc();
|
||||
|
||||
/* It's safe to allow irq's after DR6 has been saved */
|
||||
preempt_conditional_sti(regs);
|
||||
|
||||
@ -418,6 +430,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
|
||||
handle_vm86_trap((struct kernel_vm86_regs *) regs,
|
||||
error_code, 1);
|
||||
preempt_conditional_cli(regs);
|
||||
debug_stack_usage_dec();
|
||||
return;
|
||||
}
|
||||
|
||||
@ -437,6 +450,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
|
||||
if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
|
||||
send_sigtrap(tsk, regs, error_code, si_code);
|
||||
preempt_conditional_cli(regs);
|
||||
debug_stack_usage_dec();
|
||||
|
||||
return;
|
||||
}
|
||||
@ -723,4 +737,10 @@ void __init trap_init(void)
|
||||
cpu_init();
|
||||
|
||||
x86_init.irqs.trap_init();
|
||||
|
||||
#ifdef CONFIG_X86_64
|
||||
memcpy(&nmi_idt_table, &idt_table, IDT_ENTRIES * 16);
|
||||
set_nmi_gate(1, &debug);
|
||||
set_nmi_gate(3, &int3);
|
||||
#endif
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user