Contributors: 20
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Thomas Gleixner |
183 |
33.39% |
8 |
20.00% |
| Ingo Molnar |
91 |
16.61% |
3 |
7.50% |
| Steven Rostedt |
80 |
14.60% |
2 |
5.00% |
| Jeremy Fitzhardinge |
53 |
9.67% |
1 |
2.50% |
| Lai Jiangshan |
39 |
7.12% |
1 |
2.50% |
| Linus Torvalds (pre-git) |
30 |
5.47% |
7 |
17.50% |
| Andi Kleen |
23 |
4.20% |
2 |
5.00% |
| Zwane Mwaikambo |
9 |
1.64% |
1 |
2.50% |
| Mitsuo Hayasaka |
9 |
1.64% |
1 |
2.50% |
| Eric Dumazet |
8 |
1.46% |
1 |
2.50% |
| Linus Torvalds |
8 |
1.46% |
4 |
10.00% |
| David Howells |
3 |
0.55% |
1 |
2.50% |
| Nicolai Stange |
3 |
0.55% |
1 |
2.50% |
| Tejun Heo |
2 |
0.36% |
1 |
2.50% |
| Jaswinder Singh Rajput |
2 |
0.36% |
1 |
2.50% |
| Andrew Lutomirski |
1 |
0.18% |
1 |
2.50% |
| Frédéric Weisbecker |
1 |
0.18% |
1 |
2.50% |
| Greg Kroah-Hartman |
1 |
0.18% |
1 |
2.50% |
| Dave Jones |
1 |
0.18% |
1 |
2.50% |
| Shaohua Li |
1 |
0.18% |
1 |
2.50% |
| Total |
548 |
|
40 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
*
* This file contains the lowest level x86-specific interrupt
* entry, irq-stacks and irq statistics code. All the remaining
* irq logic is done by the generic kernel/irq/ code and
* by the x86-specific irq controller code. (e.g. i8259.c and
* io_apic.c.)
*/
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel_stat.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <linux/percpu.h>
#include <linux/mm.h>
#include <asm/apic.h>
#include <asm/nospec-branch.h>
#ifdef CONFIG_DEBUG_STACKOVERFLOW
int sysctl_panic_on_stackoverflow __read_mostly;
/* Debugging check for stack overflow: is there less than 1KB free? */
static int check_stack_overflow(void)
{
long sp;
__asm__ __volatile__("andl %%esp,%0" :
"=r" (sp) : "0" (THREAD_SIZE - 1));
return sp < (sizeof(struct thread_info) + STACK_WARN);
}
static void print_stack_overflow(void)
{
printk(KERN_WARNING "low stack detected by irq handler\n");
dump_stack();
if (sysctl_panic_on_stackoverflow)
panic("low stack detected by irq handler - check messages\n");
}
#else
static inline int check_stack_overflow(void) { return 0; }
static inline void print_stack_overflow(void) { }
#endif
DEFINE_PER_CPU(struct irq_stack *, hardirq_stack_ptr);
DEFINE_PER_CPU(struct irq_stack *, softirq_stack_ptr);
static void call_on_stack(void *func, void *stack)
{
asm volatile("xchgl %%ebx,%%esp \n"
CALL_NOSPEC
"movl %%ebx,%%esp \n"
: "=b" (stack)
: "0" (stack),
[thunk_target] "D"(func)
: "memory", "cc", "edx", "ecx", "eax");
}
static inline void *current_stack(void)
{
return (void *)(current_stack_pointer & ~(THREAD_SIZE - 1));
}
static inline int execute_on_irq_stack(int overflow, struct irq_desc *desc)
{
struct irq_stack *curstk, *irqstk;
u32 *isp, *prev_esp, arg1;
curstk = (struct irq_stack *) current_stack();
irqstk = __this_cpu_read(hardirq_stack_ptr);
/*
* this is where we switch to the IRQ stack. However, if we are
* already using the IRQ stack (because we interrupted a hardirq
* handler) we can't do that and just have to keep using the
* current stack (which is the irq stack already after all)
*/
if (unlikely(curstk == irqstk))
return 0;
isp = (u32 *) ((char *)irqstk + sizeof(*irqstk));
/* Save the next esp at the bottom of the stack */
prev_esp = (u32 *)irqstk;
*prev_esp = current_stack_pointer;
if (unlikely(overflow))
call_on_stack(print_stack_overflow, isp);
asm volatile("xchgl %%ebx,%%esp \n"
CALL_NOSPEC
"movl %%ebx,%%esp \n"
: "=a" (arg1), "=b" (isp)
: "0" (desc), "1" (isp),
[thunk_target] "D" (desc->handle_irq)
: "memory", "cc", "ecx");
return 1;
}
/*
* Allocate per-cpu stacks for hardirq and softirq processing
*/
int irq_init_percpu_irqstack(unsigned int cpu)
{
int node = cpu_to_node(cpu);
struct page *ph, *ps;
if (per_cpu(hardirq_stack_ptr, cpu))
return 0;
ph = alloc_pages_node(node, THREADINFO_GFP, THREAD_SIZE_ORDER);
if (!ph)
return -ENOMEM;
ps = alloc_pages_node(node, THREADINFO_GFP, THREAD_SIZE_ORDER);
if (!ps) {
__free_pages(ph, THREAD_SIZE_ORDER);
return -ENOMEM;
}
per_cpu(hardirq_stack_ptr, cpu) = page_address(ph);
per_cpu(softirq_stack_ptr, cpu) = page_address(ps);
return 0;
}
void do_softirq_own_stack(void)
{
struct irq_stack *irqstk;
u32 *isp, *prev_esp;
irqstk = __this_cpu_read(softirq_stack_ptr);
/* build the stack frame on the softirq stack */
isp = (u32 *) ((char *)irqstk + sizeof(*irqstk));
/* Push the previous esp onto the stack */
prev_esp = (u32 *)irqstk;
*prev_esp = current_stack_pointer;
call_on_stack(__do_softirq, isp);
}
bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
{
int overflow = check_stack_overflow();
if (IS_ERR_OR_NULL(desc))
return false;
if (user_mode(regs) || !execute_on_irq_stack(overflow, desc)) {
if (unlikely(overflow))
print_stack_overflow();
generic_handle_irq_desc(desc);
}
return true;
}