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linux/arch/s390/kernel/dumpstack.c
Eric W. Biederman 0e25498f8c exit: Add and use make_task_dead. 
There are two big uses of do_exit.  The first is it's design use to be
the guts of the exit(2) system call.  The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.

Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure.  In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.

Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.

As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00

229 lines
6.2 KiB
C
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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>
#include <asm/unwind.h>
const char *stack_type_name(enum stack_type type)
{
switch (type) {
case STACK_TYPE_TASK:
return "task";
case STACK_TYPE_IRQ:
return "irq";
case STACK_TYPE_NODAT:
return "nodat";
case STACK_TYPE_RESTART:
return "restart";
default:
return "unknown";
}
}
EXPORT_SYMBOL_GPL(stack_type_name);
static inline bool in_stack(unsigned long sp, struct stack_info *info,
enum stack_type type, unsigned long low,
unsigned long high)
{
if (sp < low || sp >= high)
return false;
info->type = type;
info->begin = low;
info->end = high;
return true;
}
static bool in_task_stack(unsigned long sp, struct task_struct *task,
struct stack_info *info)
{
unsigned long stack;
stack = (unsigned long) task_stack_page(task);
return in_stack(sp, info, STACK_TYPE_TASK, stack, stack + THREAD_SIZE);
}
static bool in_irq_stack(unsigned long sp, struct stack_info *info)
{
unsigned long frame_size, top;
frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
top = S390_lowcore.async_stack + frame_size;
return in_stack(sp, info, STACK_TYPE_IRQ, top - THREAD_SIZE, top);
}
static bool in_nodat_stack(unsigned long sp, struct stack_info *info)
{
unsigned long frame_size, top;
frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
top = S390_lowcore.nodat_stack + frame_size;
return in_stack(sp, info, STACK_TYPE_NODAT, top - THREAD_SIZE, top);
}
static bool in_mcck_stack(unsigned long sp, struct stack_info *info)
{
unsigned long frame_size, top;
frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
top = S390_lowcore.mcck_stack + frame_size;
return in_stack(sp, info, STACK_TYPE_MCCK, top - THREAD_SIZE, top);
}
static bool in_restart_stack(unsigned long sp, struct stack_info *info)
{
unsigned long frame_size, top;
frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
top = S390_lowcore.restart_stack + frame_size;
return in_stack(sp, info, STACK_TYPE_RESTART, top - THREAD_SIZE, top);
}
int get_stack_info(unsigned long sp, struct task_struct *task,
struct stack_info *info, unsigned long *visit_mask)
{
if (!sp)
goto unknown;
/* Sanity check: ABI requires SP to be aligned 8 bytes. */
if (sp & 0x7)
goto unknown;
/* Check per-task stack */
if (in_task_stack(sp, task, info))
goto recursion_check;
if (task != current)
goto unknown;
/* Check per-cpu stacks */
if (!in_irq_stack(sp, info) &&
!in_nodat_stack(sp, info) &&
!in_restart_stack(sp, info) &&
!in_mcck_stack(sp, info))
goto unknown;
recursion_check:
/*
* Make sure we don't iterate through any given stack more than once.
* If it comes up a second time then there's something wrong going on:
* just break out and report an unknown stack type.
*/
if (*visit_mask & (1UL << info->type))
goto unknown;
*visit_mask |= 1UL << info->type;
return 0;
unknown:
info->type = STACK_TYPE_UNKNOWN;
return -EINVAL;
}
void show_stack(struct task_struct *task, unsigned long *stack,
const char *loglvl)
{
struct unwind_state state;
printk("%sCall Trace:\n", loglvl);
unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
printk(state.reliable ? "%s [<%016lx>] %pSR \n" :
"%s([<%016lx>] %pSR)\n",
loglvl, state.ip, (void *) state.ip);
debug_show_held_locks(task ? : current);
}
static void show_last_breaking_event(struct pt_regs *regs)
{
printk("Last Breaking-Event-Address:\n");
printk(" [<%016lx>] %pSR\n", regs->last_break, (void *)regs->last_break);
}
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 : %px %px", 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], KERN_DEFAULT);
show_last_breaking_event(regs);
}
static DEFINE_SPINLOCK(die_lock);
void __noreturn 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 ");
#elif defined(CONFIG_PREEMPT_RT)
pr_cont("PREEMPT_RT ");
#endif
pr_cont("SMP ");
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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