diff options
Diffstat (limited to 'arch/arm/kernel/process.c')
-rw-r--r-- | arch/arm/kernel/process.c | 53 |
1 files changed, 48 insertions, 5 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 6e8931ccf13e..ac4c2e5e17e4 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -408,6 +408,7 @@ EXPORT_SYMBOL(dump_fpu); unsigned long get_wchan(struct task_struct *p) { struct stackframe frame; + unsigned long stack_page; int count = 0; if (!p || p == current || p->state == TASK_RUNNING) return 0; @@ -416,9 +417,11 @@ unsigned long get_wchan(struct task_struct *p) frame.sp = thread_saved_sp(p); frame.lr = 0; /* recovered from the stack */ frame.pc = thread_saved_pc(p); + stack_page = (unsigned long)task_stack_page(p); do { - int ret = unwind_frame(&frame); - if (ret < 0) + if (frame.sp < stack_page || + frame.sp >= stack_page + THREAD_SIZE || + unwind_frame(&frame) < 0) return 0; if (!in_sched_functions(frame.pc)) return frame.pc; @@ -433,10 +436,11 @@ unsigned long arch_randomize_brk(struct mm_struct *mm) } #ifdef CONFIG_MMU +#ifdef CONFIG_KUSER_HELPERS /* * The vectors page is always readable from user space for the - * atomic helpers and the signal restart code. Insert it into the - * gate_vma so that it is visible through ptrace and /proc/<pid>/mem. + * atomic helpers. Insert it into the gate_vma so that it is visible + * through ptrace and /proc/<pid>/mem. */ static struct vm_area_struct gate_vma = { .vm_start = 0xffff0000, @@ -465,9 +469,48 @@ int in_gate_area_no_mm(unsigned long addr) { return in_gate_area(NULL, addr); } +#define is_gate_vma(vma) ((vma) == &gate_vma) +#else +#define is_gate_vma(vma) 0 +#endif const char *arch_vma_name(struct vm_area_struct *vma) { - return (vma == &gate_vma) ? "[vectors]" : NULL; + return is_gate_vma(vma) ? "[vectors]" : + (vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ? + "[sigpage]" : NULL; +} + +static struct page *signal_page; +extern struct page *get_signal_page(void); + +int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +{ + struct mm_struct *mm = current->mm; + unsigned long addr; + int ret; + + if (!signal_page) + signal_page = get_signal_page(); + if (!signal_page) + return -ENOMEM; + + down_write(&mm->mmap_sem); + addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0); + if (IS_ERR_VALUE(addr)) { + ret = addr; + goto up_fail; + } + + ret = install_special_mapping(mm, addr, PAGE_SIZE, + VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC, + &signal_page); + + if (ret == 0) + mm->context.sigpage = addr; + + up_fail: + up_write(&mm->mmap_sem); + return ret; } #endif |