From: Jeff Dike 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 Signed-off-by: Andrew Morton --- arch/um/include/kern_util.h | 2 ++ arch/um/kernel/init_task.c | 2 ++ arch/um/kernel/physmem.c | 2 +- arch/um/kernel/process.c | 5 ++--- 4 files changed, 7 insertions(+), 4 deletions(-) diff -puN arch/um/include/kern_util.h~uml-stop-specially-protecting-kernel-stacks arch/um/include/kern_util.h --- a/arch/um/include/kern_util.h~uml-stop-specially-protecting-kernel-stacks +++ a/arch/um/include/kern_util.h @@ -82,7 +82,9 @@ extern void check_stack_overflow(void *p extern void relay_signal(int sig, union uml_pt_regs *regs); extern int user_context(unsigned long sp); extern void timer_irq(union uml_pt_regs *regs); +#ifdef CONFIG_MODE_TT extern void unprotect_stack(unsigned long stack); +#endif extern void do_uml_exitcalls(void); extern int attach_debugger(int idle_pid, int pid, int stop); extern int config_gdb(char *str); diff -puN arch/um/kernel/init_task.c~uml-stop-specially-protecting-kernel-stacks arch/um/kernel/init_task.c --- a/arch/um/kernel/init_task.c~uml-stop-specially-protecting-kernel-stacks +++ a/arch/um/kernel/init_task.c @@ -47,7 +47,9 @@ union thread_union cpu0_irqstack __attribute__((__section__(".data.init_irqstack"))) = { INIT_THREAD_INFO(init_task) }; +#ifdef CONFIG_MODE_TT void unprotect_stack(unsigned long stack) { os_protect_memory((void *) stack, THREAD_SIZE, 1, 1, 0); } +#endif diff -puN arch/um/kernel/physmem.c~uml-stop-specially-protecting-kernel-stacks arch/um/kernel/physmem.c --- a/arch/um/kernel/physmem.c~uml-stop-specially-protecting-kernel-stacks +++ a/arch/um/kernel/physmem.c @@ -105,7 +105,7 @@ void __init setup_physmem(unsigned long offset = uml_reserved - uml_physmem; err = os_map_memory((void *) uml_reserved, physmem_fd, offset, - len - offset, 1, 1, 0); + len - offset, 1, 1, 1); if(err < 0){ os_print_error(err, "Mapping memory"); exit(1); diff -puN arch/um/kernel/process.c~uml-stop-specially-protecting-kernel-stacks arch/um/kernel/process.c --- a/arch/um/kernel/process.c~uml-stop-specially-protecting-kernel-stacks +++ a/arch/um/kernel/process.c @@ -82,9 +82,9 @@ unsigned long alloc_stack(int order, int if (atomic) flags = GFP_ATOMIC; page = __get_free_pages(flags, order); - if(page == 0) + if (page == 0) return 0; - stack_protections(page); + return page; } @@ -141,7 +141,6 @@ void release_thread(struct task_struct * void exit_thread(void) { - unprotect_stack((unsigned long) current_thread); } void *get_current(void) _