Commit 5155cf7b authored by Palmer Dabbelt's avatar Palmer Dabbelt

Merge remote-tracking branch 'palmer/riscv-vdso-cleanup' into fixes

This contains a VDSO cleanup, along with a handful of VDSO fixes.

* palmer/riscv-vdso-cleanup:
  riscv/vdso: make arch_setup_additional_pages wait for mmap_sem for write killable
  riscv/vdso: Move vdso data page up front
  riscv/vdso: Refactor asm/vdso.h
parents 6880fa6c 8bb0ab3a
......@@ -82,4 +82,5 @@ static inline int syscall_get_arch(struct task_struct *task)
#endif
}
asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
#endif /* _ASM_RISCV_SYSCALL_H */
......@@ -16,18 +16,24 @@
#ifdef CONFIG_MMU
#include <linux/types.h>
#include <generated/vdso-offsets.h>
/*
* All systems with an MMU have a VDSO, but systems without an MMU don't
* support shared libraries and therefor don't have one.
*/
#ifdef CONFIG_MMU
#define __VVAR_PAGES 1
#ifndef CONFIG_GENERIC_TIME_VSYSCALL
struct vdso_data {
};
#endif
#ifndef __ASSEMBLY__
#include <generated/vdso-offsets.h>
#define VDSO_SYMBOL(base, name) \
(void __user *)((unsigned long)(base) + __vdso_##name##_offset)
#endif /* CONFIG_MMU */
asmlinkage long sys_riscv_flush_icache(uintptr_t, uintptr_t, uintptr_t);
#endif /* !__ASSEMBLY__ */
#endif /* CONFIG_MMU */
#endif /* _ASM_RISCV_VDSO_H */
......@@ -7,7 +7,6 @@
#include <linux/linkage.h>
#include <linux/syscalls.h>
#include <asm-generic/syscalls.h>
#include <asm/vdso.h>
#include <asm/syscall.h>
#undef __SYSCALL
......
......@@ -12,14 +12,24 @@
#include <linux/binfmts.h>
#include <linux/err.h>
#include <asm/page.h>
#include <asm/vdso.h>
#ifdef CONFIG_GENERIC_TIME_VSYSCALL
#include <vdso/datapage.h>
#else
#include <asm/vdso.h>
struct vdso_data {
};
#endif
extern char vdso_start[], vdso_end[];
enum vvar_pages {
VVAR_DATA_PAGE_OFFSET,
VVAR_NR_PAGES,
};
#define VVAR_SIZE (VVAR_NR_PAGES << PAGE_SHIFT)
static unsigned int vdso_pages __ro_after_init;
static struct page **vdso_pagelist __ro_after_init;
......@@ -38,7 +48,7 @@ static int __init vdso_init(void)
vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;
vdso_pagelist =
kcalloc(vdso_pages + 1, sizeof(struct page *), GFP_KERNEL);
kcalloc(vdso_pages + VVAR_NR_PAGES, sizeof(struct page *), GFP_KERNEL);
if (unlikely(vdso_pagelist == NULL)) {
pr_err("vdso: pagelist allocation failed\n");
return -ENOMEM;
......@@ -63,38 +73,41 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
unsigned long vdso_base, vdso_len;
int ret;
vdso_len = (vdso_pages + 1) << PAGE_SHIFT;
BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
vdso_len = (vdso_pages + VVAR_NR_PAGES) << PAGE_SHIFT;
if (mmap_write_lock_killable(mm))
return -EINTR;
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;
}
/*
* 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;
mm->context.vdso = NULL;
ret = install_special_mapping(mm, vdso_base, VVAR_SIZE,
(VM_READ | VM_MAYREAD), &vdso_pagelist[vdso_pages]);
if (unlikely(ret))
goto end;
ret =
install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
install_special_mapping(mm, vdso_base + VVAR_SIZE,
vdso_pages << PAGE_SHIFT,
(VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
vdso_pagelist);
if (unlikely(ret)) {
mm->context.vdso = NULL;
if (unlikely(ret))
goto end;
}
vdso_base += (vdso_pages << PAGE_SHIFT);
ret = install_special_mapping(mm, vdso_base, PAGE_SIZE,
(VM_READ | VM_MAYREAD), &vdso_pagelist[vdso_pages]);
/*
* 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 + VVAR_SIZE;
if (unlikely(ret))
mm->context.vdso = NULL;
end:
mmap_write_unlock(mm);
return ret;
......@@ -105,7 +118,7 @@ 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]";
if (vma->vm_mm && (vma->vm_start ==
(long)vma->vm_mm->context.vdso + PAGE_SIZE))
(long)vma->vm_mm->context.vdso - VVAR_SIZE))
return "[vdso_data]";
return NULL;
}
......@@ -3,12 +3,13 @@
* Copyright (C) 2012 Regents of the University of California
*/
#include <asm/page.h>
#include <asm/vdso.h>
OUTPUT_ARCH(riscv)
SECTIONS
{
PROVIDE(_vdso_data = . + PAGE_SIZE);
PROVIDE(_vdso_data = . - __VVAR_PAGES * PAGE_SIZE);
. = SIZEOF_HEADERS;
.hash : { *(.hash) } :text
......
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