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Commit 5c8aacea authored Oct 16, 2007 by Jeff Dike Committed by Linus Torvalds Oct 16, 2007

uml: stop specially protecting kernel stacks



Map all of physical memory as executable to avoid having to change stack
protections during fork and exit.

unprotect_stack is now called only from MODE_TT code, so it is marked as such.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 8d820760

arch/um/include/kern_util.h

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -82,7 +82,9 @@ extern void check_stack_overflow(void *ptr);
	extern void relay_signal(int sig, union uml_pt_regs *regs);		extern void relay_signal(int sig, union uml_pt_regs *regs);
	extern int user_context(unsigned long sp);		extern int user_context(unsigned long sp);
	extern void timer_irq(union uml_pt_regs *regs);		extern void timer_irq(union uml_pt_regs *regs);
			#ifdef CONFIG_MODE_TT
	extern void unprotect_stack(unsigned long stack);		extern void unprotect_stack(unsigned long stack);
			#endif
	extern void do_uml_exitcalls(void);		extern void do_uml_exitcalls(void);
	extern int attach_debugger(int idle_pid, int pid, int stop);		extern int attach_debugger(int idle_pid, int pid, int stop);
	extern int config_gdb(char *str);		extern int config_gdb(char *str);

arch/um/kernel/init_task.c

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -47,7 +47,9 @@ union thread_union cpu0_irqstack
	__attribute__((__section__(".data.init_irqstack"))) =		__attribute__((__section__(".data.init_irqstack"))) =
	{ INIT_THREAD_INFO(init_task) };		{ INIT_THREAD_INFO(init_task) };

			#ifdef CONFIG_MODE_TT
	void unprotect_stack(unsigned long stack)		void unprotect_stack(unsigned long stack)
	{		{
	os_protect_memory((void *) stack, THREAD_SIZE, 1, 1, 0);		os_protect_memory((void *) stack, THREAD_SIZE, 1, 1, 0);
	}		}
			#endif

arch/um/kernel/physmem.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -105,7 +105,7 @@ void __init setup_physmem(unsigned long start, unsigned long reserve_end,

	offset = uml_reserved - uml_physmem;		offset = uml_reserved - uml_physmem;
	err = os_map_memory((void *) uml_reserved, physmem_fd, offset,		err = os_map_memory((void *) uml_reserved, physmem_fd, offset,
	len - offset, 1, 1, 0);		len - offset, 1, 1, 1);
	if(err < 0){		if(err < 0){
	os_print_error(err, "Mapping memory");		os_print_error(err, "Mapping memory");
	exit(1);		exit(1);

arch/um/kernel/process.c

+2 −3

Original line number	Original line	Diff line number	Diff line
	@@ -84,7 +84,7 @@ unsigned long alloc_stack(int order, int atomic)
	page = __get_free_pages(flags, order);		page = __get_free_pages(flags, order);
	if (page == 0)		if (page == 0)
	return 0;		return 0;
	stack_protections(page);
	return page;		return page;
	}		}

	@@ -141,7 +141,6 @@ void release_thread(struct task_struct *task)

	void exit_thread(void)		void exit_thread(void)
	{		{
	unprotect_stack((unsigned long) current_thread);
	}		}

	void *get_current(void)		void *get_current(void)