From: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
Other than the name, the vmf_ version takes a pfn_t parameter, and
returns a VM_FAULT_ code suitable for returning from a fault handler.
This patch also prevents vm_insert_pfn() from returning -EBUSY.
This is a good thing as several callers handled it incorrectly (and
none intentionally treat -EBUSY as a different case from 0).
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
---
arch/x86/entry/vdso/vma.c | 6 +++---
include/linux/mm.h | 4 ++--
mm/memory.c | 31 ++++++++++++++++++-------------
3 files changed, 23 insertions(+), 18 deletions(-)
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 7c912fe..660bb69 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -9,6 +9,7 @@
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/init.h>
+#include <linux/pfn_t.h>
#include <linux/random.h>
#include <linux/elf.h>
#include <linux/cpu.h>
@@ -131,10 +132,9 @@ static int vvar_fault(const struct vm_special_mapping *sm,
} else if (sym_offset == image->sym_hpet_page) {
#ifdef CONFIG_HPET_TIMER
if (hpet_address && vclock_was_used(VCLOCK_HPET)) {
- ret = vm_insert_pfn_prot(
- vma,
+ return vmf_insert_pfn_prot(vma,
(unsigned long)vmf->virtual_address,
- hpet_address >> PAGE_SHIFT,
+ phys_to_pfn_t(hpet_address, PFN_DEV),
pgprot_noncached(PAGE_READONLY));
}
#endif
diff --git a/include/linux/mm.h b/include/linux/mm.h
index fa6da9a..19f8741 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2138,8 +2138,8 @@ int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn);
-int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
- unsigned long pfn, pgprot_t pgprot);
+int vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
+ pfn_t pfn, pgprot_t pgprot);
int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn);
int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
diff --git a/mm/memory.c b/mm/memory.c
index a2eaeef..9b57318 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1554,7 +1554,11 @@ out:
int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn)
{
- return vm_insert_pfn_prot(vma, addr, pfn, vma->vm_page_prot);
+ int result = vmf_insert_pfn_prot(vma, addr,
+ __pfn_to_pfn_t(pfn, PFN_DEV), vma->vm_page_prot);
+ if (result & VM_FAULT_ERROR)
+ return -EFAULT;
+ return 0;
}
EXPORT_SYMBOL(vm_insert_pfn);
@@ -1570,13 +1574,13 @@ EXPORT_SYMBOL(vm_insert_pfn);
*
* This only makes sense for IO mappings, and it makes no sense for
* cow mappings. In general, using multiple vmas is preferable;
- * vm_insert_pfn_prot should only be used if using multiple VMAs is
+ * vmf_insert_pfn_prot should only be used if using multiple VMAs is
* impractical.
*/
-int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
- unsigned long pfn, pgprot_t pgprot)
+int vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
+ pfn_t pfn, pgprot_t pgprot)
{
- int ret;
+ int error;
/*
* Technically, architectures with pte_special can avoid all these
* restrictions (same for remap_pfn_range). However we would like
@@ -1587,18 +1591,19 @@ int vm_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
(VM_PFNMAP|VM_MIXEDMAP));
BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
- BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn));
+ BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_t_valid(pfn));
if (addr < vma->vm_start || addr >= vma->vm_end)
- return -EFAULT;
- if (track_pfn_insert(vma, &pgprot, __pfn_to_pfn_t(pfn, PFN_DEV)))
- return -EINVAL;
-
- ret = insert_pfn(vma, addr, __pfn_to_pfn_t(pfn, PFN_DEV), pgprot);
+ return VM_FAULT_SIGBUS;
+ if (track_pfn_insert(vma, &pgprot, pfn))
+ return VM_FAULT_SIGBUS;
- return ret;
+ error = insert_pfn(vma, addr, pfn, pgprot);
+ if (error == -EBUSY || !error)
+ return VM_FAULT_NOPAGE;
+ return VM_FAULT_SIGBUS;
}
-EXPORT_SYMBOL(vm_insert_pfn_prot);
+EXPORT_SYMBOL(vmf_insert_pfn_prot);
int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
pfn_t pfn)
--
2.7.0.rc3
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