dd3ef10ea2
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>
87 lines
1.6 KiB
C
87 lines
1.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
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#include <linux/kernel.h>
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#include <linux/err.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/binfmts.h>
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#include <linux/elf.h>
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#include <linux/vmalloc.h>
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#include <linux/unistd.h>
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#include <linux/uaccess.h>
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#include <asm/vdso.h>
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#include <asm/cacheflush.h>
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static struct page *vdso_page;
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static int __init init_vdso(void)
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{
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struct csky_vdso *vdso;
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int err = 0;
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vdso_page = alloc_page(GFP_KERNEL);
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if (!vdso_page)
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panic("Cannot allocate vdso");
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vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL);
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if (!vdso)
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panic("Cannot map vdso");
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clear_page(vdso);
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err = setup_vdso_page(vdso->rt_signal_retcode);
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if (err)
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panic("Cannot set signal return code, err: %x.", err);
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dcache_wb_range((unsigned long)vdso, (unsigned long)vdso + 16);
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vunmap(vdso);
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return 0;
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}
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subsys_initcall(init_vdso);
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int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
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{
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int ret;
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unsigned long addr;
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struct mm_struct *mm = current->mm;
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down_write(&mm->mmap_sem);
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addr = get_unmapped_area(NULL, STACK_TOP, PAGE_SIZE, 0, 0);
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if (IS_ERR_VALUE(addr)) {
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ret = addr;
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goto up_fail;
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}
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ret = install_special_mapping(
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mm,
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addr,
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PAGE_SIZE,
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VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
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&vdso_page);
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if (ret)
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goto up_fail;
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mm->context.vdso = (void *)addr;
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up_fail:
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up_write(&mm->mmap_sem);
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return ret;
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}
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const char *arch_vma_name(struct vm_area_struct *vma)
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{
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if (vma->vm_mm == NULL)
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return NULL;
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if (vma->vm_start == (long)vma->vm_mm->context.vdso)
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return "[vdso]";
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else
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return NULL;
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}
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