kernel_optimize_test/arch/csky/kernel/vdso.c
Guo Ren dd3ef10ea2 csky: VDSO and rt_sigreturn
This patch adds files related to VDSO and our VDSO only support
rt_sigreturn.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2018-10-26 00:54:22 +08:00

87 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#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 <linux/uaccess.h>
#include <asm/vdso.h>
#include <asm/cacheflush.h>
static struct page *vdso_page;
static int __init init_vdso(void)
{
struct csky_vdso *vdso;
int err = 0;
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);
err = setup_vdso_page(vdso->rt_signal_retcode);
if (err)
panic("Cannot set signal return code, err: %x.", err);
dcache_wb_range((unsigned long)vdso, (unsigned long)vdso + 16);
vunmap(vdso);
return 0;
}
subsys_initcall(init_vdso);
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 = get_unmapped_area(NULL, STACK_TOP, 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,
&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 == NULL)
return NULL;
if (vma->vm_start == (long)vma->vm_mm->context.vdso)
return "[vdso]";
else
return NULL;
}