diff options
Diffstat (limited to 'arch/mips/kernel/vdso.c')
-rw-r--r-- | arch/mips/kernel/vdso.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c new file mode 100644 index 0000000..e5cdfd6 --- /dev/null +++ b/arch/mips/kernel/vdso.c @@ -0,0 +1,110 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2009, 2010 Cavium Networks, Inc. + */ + + +#include <linux/kernel.h> +#include <linux/err.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/binfmts.h> +#include <linux/elf.h> +#include <linux/vmalloc.h> +#include <linux/unistd.h> + +#include <asm/vdso.h> +#include <asm/uasm.h> + +/* + * Including <asm/unistd.h> would give use the 64-bit syscall numbers ... + */ +#define __NR_O32_sigreturn 4119 +#define __NR_O32_rt_sigreturn 4193 +#define __NR_N32_rt_sigreturn 6211 + +static struct page *vdso_page; + +static void __init install_trampoline(u32 *tramp, unsigned int sigreturn) +{ + uasm_i_addiu(&tramp, 2, 0, sigreturn); /* li v0, sigreturn */ + uasm_i_syscall(&tramp, 0); +} + +static int __init init_vdso(void) +{ + struct mips_vdso *vdso; + + vdso_page = alloc_page(GFP_KERNEL); + if (!vdso_page) + panic("Cannot allocate vdso"); + + vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL); + if (!vdso) + panic("Cannot map vdso"); + clear_page(vdso); + + install_trampoline(vdso->rt_signal_trampoline, __NR_rt_sigreturn); +#ifdef CONFIG_32BIT + install_trampoline(vdso->signal_trampoline, __NR_sigreturn); +#else + install_trampoline(vdso->n32_rt_signal_trampoline, + __NR_N32_rt_sigreturn); + install_trampoline(vdso->o32_signal_trampoline, __NR_O32_sigreturn); + install_trampoline(vdso->o32_rt_signal_trampoline, + __NR_O32_rt_sigreturn); +#endif + + vunmap(vdso); + + return 0; +} +subsys_initcall(init_vdso); + +static unsigned long vdso_addr(unsigned long start) +{ + return STACK_TOP; +} + +int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) +{ + int ret; + unsigned long addr; + struct mm_struct *mm = current->mm; + + down_write(&mm->mmap_sem); + + addr = vdso_addr(mm->start_stack); + + addr = get_unmapped_area(NULL, addr, 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| + VM_ALWAYSDUMP, + &vdso_page); + + if (ret) + goto up_fail; + + mm->context.vdso = (void *)addr; + +up_fail: + up_write(&mm->mmap_sem); + return ret; +} + +const char *arch_vma_name(struct vm_area_struct *vma) +{ + if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) + return "[vdso]"; + return NULL; +} |