From 5c8aaceab88ac787c0a4038b29143c954c2a45e0 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Tue, 16 Oct 2007 01:26:46 -0700 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 --git a/arch/um/include/kern_util.h b/arch/um/include/kern_util.h index 6c2be26..b84b5da 100644 --- a/arch/um/include/kern_util.h +++ b/arch/um/include/kern_util.h @@ -82,7 +82,9 @@ extern void check_stack_overflow(void *ptr); 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 --git a/arch/um/kernel/init_task.c b/arch/um/kernel/init_task.c index cba516e..fa90db9 100644 --- a/arch/um/kernel/init_task.c +++ b/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 --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c index 5ee7e85..8aeac4d 100644 --- a/arch/um/kernel/physmem.c +++ b/arch/um/kernel/physmem.c @@ -105,7 +105,7 @@ void __init setup_physmem(unsigned long start, unsigned long reserve_end, 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 --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index bfa52f2..f083787 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -82,9 +82,9 @@ unsigned long alloc_stack(int order, int atomic) 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 *task) void exit_thread(void) { - unprotect_stack((unsigned long) current_thread); } void *get_current(void) -- 2.7.4