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Diffstat (limited to 'arch/csky/kernel/vdso.c')
-rw-r--r--arch/csky/kernel/vdso.c123
1 files changed, 70 insertions, 53 deletions
diff --git a/arch/csky/kernel/vdso.c b/arch/csky/kernel/vdso.c
index abc3dbc658d4..839523920843 100644
--- a/arch/csky/kernel/vdso.c
+++ b/arch/csky/kernel/vdso.c
@@ -1,86 +1,103 @@
// 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 <linux/err.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <asm/page.h>
#include <asm/vdso.h>
-#include <asm/cacheflush.h>
-static struct page *vdso_page;
+extern char vdso_start[], vdso_end[];
-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");
+static unsigned int vdso_pages;
+static struct page **vdso_pagelist;
- vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL);
- if (!vdso)
- panic("Cannot map vdso");
+/*
+ * The vDSO data page.
+ */
+static union {
+ struct vdso_data data;
+ u8 page[PAGE_SIZE];
+} vdso_data_store __page_aligned_data;
+struct vdso_data *vdso_data = &vdso_data_store.data;
- clear_page(vdso);
-
- err = setup_vdso_page(vdso->rt_signal_retcode);
- if (err)
- panic("Cannot set signal return code, err: %x.", err);
+static int __init vdso_init(void)
+{
+ unsigned int i;
+
+ vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;
+ vdso_pagelist =
+ kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL);
+ if (unlikely(vdso_pagelist == NULL)) {
+ pr_err("vdso: pagelist allocation failed\n");
+ return -ENOMEM;
+ }
- dcache_wb_range((unsigned long)vdso, (unsigned long)vdso + 16);
+ for (i = 0; i < vdso_pages; i++) {
+ struct page *pg;
- vunmap(vdso);
+ pg = virt_to_page(vdso_start + (i << PAGE_SHIFT));
+ vdso_pagelist[i] = pg;
+ }
+ vdso_pagelist[i] = virt_to_page(vdso_data);
return 0;
}
-subsys_initcall(init_vdso);
+arch_initcall(vdso_init);
-int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
+int arch_setup_additional_pages(struct linux_binprm *bprm,
+ int uses_interp)
{
- int ret;
- unsigned long addr;
struct mm_struct *mm = current->mm;
+ unsigned long vdso_base, vdso_len;
+ int ret;
- mmap_write_lock(mm);
+ vdso_len = (vdso_pages + 1) << PAGE_SHIFT;
- addr = get_unmapped_area(NULL, STACK_TOP, PAGE_SIZE, 0, 0);
- if (IS_ERR_VALUE(addr)) {
- ret = addr;
- goto up_fail;
+ mmap_write_lock(mm);
+ vdso_base = get_unmapped_area(NULL, 0, vdso_len, 0, 0);
+ if (IS_ERR_VALUE(vdso_base)) {
+ ret = vdso_base;
+ goto end;
}
- 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;
+ /*
+ * Put vDSO base into mm struct. We need to do this before calling
+ * install_special_mapping or the perf counter mmap tracking code
+ * will fail to recognise it as a vDSO (since arch_vma_name fails).
+ */
+ mm->context.vdso = (void *)vdso_base;
+
+ ret =
+ install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
+ (VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
+ vdso_pagelist);
+
+ if (unlikely(ret)) {
+ mm->context.vdso = NULL;
+ goto end;
+ }
- mm->context.vdso = (void *)addr;
+ vdso_base += (vdso_pages << PAGE_SHIFT);
+ ret = install_special_mapping(mm, vdso_base, PAGE_SIZE,
+ (VM_READ | VM_MAYREAD), &vdso_pagelist[vdso_pages]);
-up_fail:
+ if (unlikely(ret))
+ mm->context.vdso = NULL;
+end:
mmap_write_unlock(mm);
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)
+ if (vma->vm_mm && (vma->vm_start == (long)vma->vm_mm->context.vdso))
return "[vdso]";
- else
- return NULL;
+ if (vma->vm_mm && (vma->vm_start ==
+ (long)vma->vm_mm->context.vdso + PAGE_SIZE))
+ return "[vdso_data]";
+ return NULL;
}