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8bb0ab3ae7
riscv architectures relying on mmap_sem for write in their
arch_setup_additional_pages. If the waiting task gets killed by the oom
killer it would block oom_reaper from asynchronous address space reclaim
and reduce the chances of timely OOM resolving. Wait for the lock in
the killable mode and return with EINTR if the task got killed while
waiting.
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Fixes: 76d2a0493a ("RISC-V: Init and Halt Code")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
124 lines
2.8 KiB
C
124 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2004 Benjamin Herrenschmidt, IBM Corp.
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* <benh@kernel.crashing.org>
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* Copyright (C) 2012 ARM Limited
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* Copyright (C) 2015 Regents of the University of California
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*/
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#include <linux/elf.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/binfmts.h>
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#include <linux/err.h>
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#include <asm/page.h>
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#include <asm/vdso.h>
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#ifdef CONFIG_GENERIC_TIME_VSYSCALL
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#include <vdso/datapage.h>
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#else
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struct vdso_data {
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};
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#endif
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extern char vdso_start[], vdso_end[];
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enum vvar_pages {
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VVAR_DATA_PAGE_OFFSET,
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VVAR_NR_PAGES,
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};
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#define VVAR_SIZE (VVAR_NR_PAGES << PAGE_SHIFT)
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static unsigned int vdso_pages __ro_after_init;
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static struct page **vdso_pagelist __ro_after_init;
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/*
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* The vDSO data page.
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*/
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static union {
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struct vdso_data data;
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u8 page[PAGE_SIZE];
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} vdso_data_store __page_aligned_data;
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struct vdso_data *vdso_data = &vdso_data_store.data;
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static int __init vdso_init(void)
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{
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unsigned int i;
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vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;
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vdso_pagelist =
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kcalloc(vdso_pages + VVAR_NR_PAGES, sizeof(struct page *), GFP_KERNEL);
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if (unlikely(vdso_pagelist == NULL)) {
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pr_err("vdso: pagelist allocation failed\n");
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return -ENOMEM;
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}
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for (i = 0; i < vdso_pages; i++) {
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struct page *pg;
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pg = virt_to_page(vdso_start + (i << PAGE_SHIFT));
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vdso_pagelist[i] = pg;
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}
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vdso_pagelist[i] = virt_to_page(vdso_data);
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return 0;
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}
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arch_initcall(vdso_init);
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int arch_setup_additional_pages(struct linux_binprm *bprm,
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int uses_interp)
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{
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struct mm_struct *mm = current->mm;
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unsigned long vdso_base, vdso_len;
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int ret;
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BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
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vdso_len = (vdso_pages + VVAR_NR_PAGES) << PAGE_SHIFT;
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if (mmap_write_lock_killable(mm))
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return -EINTR;
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vdso_base = get_unmapped_area(NULL, 0, vdso_len, 0, 0);
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if (IS_ERR_VALUE(vdso_base)) {
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ret = vdso_base;
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goto end;
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}
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mm->context.vdso = NULL;
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ret = install_special_mapping(mm, vdso_base, VVAR_SIZE,
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(VM_READ | VM_MAYREAD), &vdso_pagelist[vdso_pages]);
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if (unlikely(ret))
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goto end;
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ret =
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install_special_mapping(mm, vdso_base + VVAR_SIZE,
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vdso_pages << PAGE_SHIFT,
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(VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
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vdso_pagelist);
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if (unlikely(ret))
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goto end;
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/*
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* Put vDSO base into mm struct. We need to do this before calling
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* install_special_mapping or the perf counter mmap tracking code
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* will fail to recognise it as a vDSO (since arch_vma_name fails).
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*/
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mm->context.vdso = (void *)vdso_base + VVAR_SIZE;
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end:
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mmap_write_unlock(mm);
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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 && (vma->vm_start == (long)vma->vm_mm->context.vdso))
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return "[vdso]";
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if (vma->vm_mm && (vma->vm_start ==
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(long)vma->vm_mm->context.vdso - VVAR_SIZE))
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return "[vdso_data]";
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return NULL;
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}
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