Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'x86-urgent-2020-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"Two fixes for the x86 interrupt code:
- Unbreak the magic 'search the timer interrupt' logic in IO/APIC
code which got wreckaged when the core interrupt code made the
state tracking logic stricter.
That caused the interrupt line to stay masked after switching from
IO/APIC to PIC delivery mode, which obviously prevents interrupts
from being delivered.
- Make run_on_irqstack_code() typesafe. The function argument is a
void pointer which is then cast to 'void (*fun)(void *).
This breaks Control Flow Integrity checking in clang. Use proper
helper functions for the three variants reuqired"
* tag 'x86-urgent-2020-09-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ioapic: Unbreak check_timer()
x86/irq: Make run_on_irqstack_cond() typesafe
+69
-13
+1
-1
arch/x86/entry/common.c
+1
-1
arch/x86/entry/common.c
+2
arch/x86/entry/entry_64.S
+2
arch/x86/entry/entry_64.S
···
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682
* rdx: Function argument (can be NULL if none)
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*/
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SYM_FUNC_START(asm_call_on_stack)
685
+
SYM_INNER_LABEL(asm_call_sysvec_on_stack, SYM_L_GLOBAL)
686
+
SYM_INNER_LABEL(asm_call_irq_on_stack, SYM_L_GLOBAL)
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/*
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* Save the frame pointer unconditionally. This allows the ORC
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* unwinder to handle the stack switch.
+1
-1
arch/x86/include/asm/idtentry.h
+1
-1
arch/x86/include/asm/idtentry.h
···
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instrumentation_begin(); \
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irq_enter_rcu(); \
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kvm_set_cpu_l1tf_flush_l1d(); \
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-
run_on_irqstack_cond(__##func, regs, regs); \
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+
run_sysvec_on_irqstack_cond(__##func, regs); \
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irq_exit_rcu(); \
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instrumentation_end(); \
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irqentry_exit(regs, state); \
+62
-9
arch/x86/include/asm/irq_stack.h
+62
-9
arch/x86/include/asm/irq_stack.h
···
12
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return __this_cpu_read(irq_count) != -1;
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}
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-
void asm_call_on_stack(void *sp, void *func, void *arg);
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+
void asm_call_on_stack(void *sp, void (*func)(void), void *arg);
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+
void asm_call_sysvec_on_stack(void *sp, void (*func)(struct pt_regs *regs),
17
+
struct pt_regs *regs);
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+
void asm_call_irq_on_stack(void *sp, void (*func)(struct irq_desc *desc),
19
+
struct irq_desc *desc);
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-
static __always_inline void __run_on_irqstack(void *func, void *arg)
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+
static __always_inline void __run_on_irqstack(void (*func)(void))
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{
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void *tos = __this_cpu_read(hardirq_stack_ptr);
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__this_cpu_add(irq_count, 1);
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-
asm_call_on_stack(tos - 8, func, arg);
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+
asm_call_on_stack(tos - 8, func, NULL);
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+
__this_cpu_sub(irq_count, 1);
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+
}
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+
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+
static __always_inline void
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+
__run_sysvec_on_irqstack(void (*func)(struct pt_regs *regs),
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+
struct pt_regs *regs)
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+
{
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+
void *tos = __this_cpu_read(hardirq_stack_ptr);
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+
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+
__this_cpu_add(irq_count, 1);
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+
asm_call_sysvec_on_stack(tos - 8, func, regs);
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__this_cpu_sub(irq_count, 1);
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+
}
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+
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+
static __always_inline void
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__run_irq_on_irqstack(void (*func)(struct irq_desc *desc),
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+
struct irq_desc *desc)
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+
{
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+
void *tos = __this_cpu_read(hardirq_stack_ptr);
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+
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+
__this_cpu_add(irq_count, 1);
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+
asm_call_irq_on_stack(tos - 8, func, desc);
23
49
__this_cpu_sub(irq_count, 1);
24
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}
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26
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#else /* CONFIG_X86_64 */
27
53
static inline bool irqstack_active(void) { return false; }
28
-
static inline void __run_on_irqstack(void *func, void *arg) { }
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+
static inline void __run_on_irqstack(void (*func)(void)) { }
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+
static inline void __run_sysvec_on_irqstack(void (*func)(struct pt_regs *regs),
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+
struct pt_regs *regs) { }
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+
static inline void __run_irq_on_irqstack(void (*func)(struct irq_desc *desc),
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struct irq_desc *desc) { }
29
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#endif /* !CONFIG_X86_64 */
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static __always_inline bool irq_needs_irq_stack(struct pt_regs *regs)
···
67
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return !user_mode(regs) && !irqstack_active();
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}
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-
static __always_inline void run_on_irqstack_cond(void *func, void *arg,
40
+
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+
static __always_inline void run_on_irqstack_cond(void (*func)(void),
71
42
struct pt_regs *regs)
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{
73
-
void (*__func)(void *arg) = func;
74
-
75
44
lockdep_assert_irqs_disabled();
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45
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if (irq_needs_irq_stack(regs))
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-
__run_on_irqstack(__func, arg);
47
+
__run_on_irqstack(func);
79
48
else
80
-
__func(arg);
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+
func();
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+
}
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+
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+
static __always_inline void
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+
run_sysvec_on_irqstack_cond(void (*func)(struct pt_regs *regs),
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+
struct pt_regs *regs)
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+
{
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+
lockdep_assert_irqs_disabled();
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+
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+
if (irq_needs_irq_stack(regs))
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+
__run_sysvec_on_irqstack(func, regs);
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+
else
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+
func(regs);
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+
}
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+
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+
static __always_inline void
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+
run_irq_on_irqstack_cond(void (*func)(struct irq_desc *desc), struct irq_desc *desc,
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+
struct pt_regs *regs)
67
+
{
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+
lockdep_assert_irqs_disabled();
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+
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+
if (irq_needs_irq_stack(regs))
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+
__run_irq_on_irqstack(func, desc);
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+
else
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func(desc);
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74
}
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#endif
+1
arch/x86/kernel/apic/io_apic.c
+1
arch/x86/kernel/apic/io_apic.c
+1
-1
arch/x86/kernel/irq.c
+1
-1
arch/x86/kernel/irq.c