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// SPDX-License-Identifier: GPL-2.0
/*
* Stack dumping functions
*
* Copyright IBM Corp. 1999, 2013
*/
#include <linux/kallsyms.h>
#include <linux/hardirq.h>
#include <linux/kprobes.h>
#include <linux/utsname.h>
#include <linux/export.h>
#include <linux/kdebug.h>
#include <linux/ptrace.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <asm/processor.h>
#include <asm/debug.h>
#include <asm/dis.h>
#include <asm/ipl.h>
/*
* For dump_trace we have tree different stack to consider:
* - the panic stack which is used if the kernel stack has overflown
* - the asynchronous interrupt stack (cpu related)
* - the synchronous kernel stack (process related)
* The stack trace can start at any of the three stacks and can potentially
* touch all of them. The order is: panic stack, async stack, sync stack.
*/
static unsigned long
__dump_trace(dump_trace_func_t func, void *data, unsigned long sp,
unsigned long low, unsigned long high)
{
struct stack_frame *sf;
struct pt_regs *regs;
while (1) {
if (sp < low || sp > high - sizeof(*sf))
return sp;
sf = (struct stack_frame *) sp;
if (func(data, sf->gprs[8], 0))
return sp;
/* Follow the backchain. */
while (1) {
low = sp;
sp = sf->back_chain;
if (!sp)
break;
if (sp <= low || sp > high - sizeof(*sf))
return sp;
sf = (struct stack_frame *) sp;
if (func(data, sf->gprs[8], 1))
return sp;
}
/* Zero backchain detected, check for interrupt frame. */
sp = (unsigned long) (sf + 1);
if (sp <= low || sp > high - sizeof(*regs))
return sp;
regs = (struct pt_regs *) sp;
if (!user_mode(regs)) {
if (func(data, regs->psw.addr, 1))
return sp;
}
low = sp;
sp = regs->gprs[15];
}
}
void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,
unsigned long sp)
{
unsigned long frame_size;
frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
#ifdef CONFIG_CHECK_STACK
sp = __dump_trace(func, data, sp,
S390_lowcore.panic_stack + frame_size - PAGE_SIZE,
S390_lowcore.panic_stack + frame_size);
#endif
sp = __dump_trace(func, data, sp,
S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
S390_lowcore.async_stack + frame_size);
task = task ?: current;
__dump_trace(func, data, sp,
(unsigned long)task_stack_page(task),
(unsigned long)task_stack_page(task) + THREAD_SIZE);
}
EXPORT_SYMBOL_GPL(dump_trace);
static int show_address(void *data, unsigned long address, int reliable)
{
if (reliable)
printk(" [<%016lx>] %pSR \n", address, (void *)address);
else
printk("([<%016lx>] %pSR)\n", address, (void *)address);
return 0;
}
void show_stack(struct task_struct *task, unsigned long *stack)
{
unsigned long sp = (unsigned long) stack;
if (!sp)
sp = task ? task->thread.ksp : current_stack_pointer();
printk("Call Trace:\n");
dump_trace(show_address, NULL, task, sp);
if (!task)
task = current;
debug_show_held_locks(task);
}
static void show_last_breaking_event(struct pt_regs *regs)
{
printk("Last Breaking-Event-Address:\n");
printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
}
void show_registers(struct pt_regs *regs)
{
struct psw_bits *psw = &psw_bits(regs->psw);
char *mode;
mode = user_mode(regs) ? "User" : "Krnl";
printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
if (!user_mode(regs))
pr_cont(" (%pSR)", (void *)regs->psw.addr);
pr_cont("\n");
printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
"P:%x AS:%x CC:%x PM:%x", psw->per, psw->dat, psw->io, psw->ext,
psw->key, psw->mcheck, psw->wait, psw->pstate, psw->as, psw->cc, psw->pm);
pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
printk(" %016lx %016lx %016lx %016lx\n",
regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
printk(" %016lx %016lx %016lx %016lx\n",
regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
printk(" %016lx %016lx %016lx %016lx\n",
regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
show_code(regs);
}
void show_regs(struct pt_regs *regs)
{
show_regs_print_info(KERN_DEFAULT);
show_registers(regs);
/* Show stack backtrace if pt_regs is from kernel mode */
if (!user_mode(regs))
show_stack(NULL, (unsigned long *) regs->gprs[15]);
show_last_breaking_event(regs);
}
static DEFINE_SPINLOCK(die_lock);
void die(struct pt_regs *regs, const char *str)
{
static int die_counter;
oops_enter();
lgr_info_log();
debug_stop_all();
console_verbose();
spin_lock_irq(&die_lock);
bust_spinlocks(1);
printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
regs->int_code >> 17, ++die_counter);
#ifdef CONFIG_PREEMPT
pr_cont("PREEMPT ");
#endif
#ifdef CONFIG_SMP
pr_cont("SMP ");
#endif
if (debug_pagealloc_enabled())
pr_cont("DEBUG_PAGEALLOC");
pr_cont("\n");
notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
print_modules();
show_regs(regs);
bust_spinlocks(0);
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irq(&die_lock);
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception: panic_on_oops");
oops_exit();
make_task_dead(SIGSEGV);
}
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