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Commit 9a18c9c8 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Greg Kroah-Hartman
Browse files

exit: Add and use make_task_dead. 



commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream.

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: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 2f87e255

arch/alpha/kernel/traps.c

+3 −3
Original line number Diff line number Diff line
@@ -192,7 +192,7 @@ die_if_kernel(char * str, struct pt_regs *regs, long err, unsigned long *r9_15) 
		local_irq_enable();

		while (1);

	}

	do_exit(SIGSEGV);

	make_task_dead(SIGSEGV);

}



#ifndef CONFIG_MATHEMU
@@ -577,7 +577,7 @@ do_entUna(void * va, unsigned long opcode, unsigned long reg, 


	printk("Bad unaligned kernel access at %016lx: %p %lx %lu\n",

		pc, va, opcode, reg);

	do_exit(SIGSEGV);

	make_task_dead(SIGSEGV);



got_exception:

	/* Ok, we caught the exception, but we don't want it.  Is there
@@ -632,7 +632,7 @@ do_entUna(void * va, unsigned long opcode, unsigned long reg, 
		local_irq_enable();

		while (1);

	}

	do_exit(SIGSEGV);

	make_task_dead(SIGSEGV);

}



/*

arch/alpha/mm/fault.c

+1 −1
Original line number Diff line number Diff line
@@ -206,7 +206,7 @@ do_page_fault(unsigned long address, unsigned long mmcsr, 
	printk(KERN_ALERT "Unable to handle kernel paging request at "

	       "virtual address %016lx\n", address);

	die_if_kernel("Oops", regs, cause, (unsigned long*)regs - 16);

	do_exit(SIGKILL);

	make_task_dead(SIGKILL);



	/* We ran out of memory, or some other thing happened to us that

	   made us unable to handle the page fault gracefully.  */

arch/arm/kernel/traps.c

+1 −1
Original line number Diff line number Diff line
@@ -341,7 +341,7 @@ static void oops_end(unsigned long flags, struct pt_regs *regs, int signr) 
	if (panic_on_oops)

		panic("Fatal exception");

	if (signr)

		do_exit(signr);

		make_task_dead(signr);

}



/*

arch/arm/mm/fault.c

+1 −1
Original line number Diff line number Diff line
@@ -124,7 +124,7 @@ __do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, 
	show_pte(KERN_ALERT, mm, addr);

	die("Oops", regs, fsr);

	bust_spinlocks(0);

	do_exit(SIGKILL);

	make_task_dead(SIGKILL);

}



/*

arch/arm64/kernel/traps.c

+1 −1
Original line number Diff line number Diff line
@@ -202,7 +202,7 @@ void die(const char *str, struct pt_regs *regs, int err) 
	raw_spin_unlock_irqrestore(&die_lock, flags);



	if (ret != NOTIFY_STOP)

		do_exit(SIGSEGV);

		make_task_dead(SIGSEGV);

}



static void arm64_show_signal(int signo, const char *str)