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pagemap: pass mm into pagewalkers
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We need this at least for huge page detection for now, because powerpc
needs the vm_area_struct to be able to determine whether a virtual address
is referring to a huge page (its pmd_huge() doesn't work).

It might also come in handy for some of the other users.

Signed-off-by: Dave Hansen <[email protected]>
Acked-by: Matt Mackall <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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@torvalds
Dave Hansen authored and torvalds committed Jun 13, 2008
1 parent cfc53f6 commit 2165009
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Showing 3 changed files with 56 additions and 47 deletions.
44 changes: 25 additions & 19 deletions fs/proc/task_mmu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -315,9 +315,9 @@ struct mem_size_stats {
};

static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
void *private)
struct mm_walk *walk)
{
struct mem_size_stats *mss = private;
struct mem_size_stats *mss = walk->private;
struct vm_area_struct *vma = mss->vma;
pte_t *pte, ptent;
spinlock_t *ptl;
Expand Down Expand Up @@ -365,19 +365,21 @@ static int smaps_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
return 0;
}

static struct mm_walk smaps_walk = { .pmd_entry = smaps_pte_range };

static int show_smap(struct seq_file *m, void *v)
{
struct vm_area_struct *vma = v;
struct mem_size_stats mss;
int ret;
struct mm_walk smaps_walk = {
.pmd_entry = smaps_pte_range,
.mm = vma->vm_mm,
.private = &mss,
};

memset(&mss, 0, sizeof mss);
mss.vma = vma;
if (vma->vm_mm && !is_vm_hugetlb_page(vma))
walk_page_range(vma->vm_mm, vma->vm_start, vma->vm_end,
&smaps_walk, &mss);
walk_page_range(vma->vm_start, vma->vm_end, &smaps_walk);

ret = show_map(m, v);
if (ret)
Expand Down Expand Up @@ -426,9 +428,9 @@ const struct file_operations proc_smaps_operations = {
};

static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
unsigned long end, void *private)
unsigned long end, struct mm_walk *walk)
{
struct vm_area_struct *vma = private;
struct vm_area_struct *vma = walk->private;
pte_t *pte, ptent;
spinlock_t *ptl;
struct page *page;
Expand All @@ -452,8 +454,6 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
return 0;
}

static struct mm_walk clear_refs_walk = { .pmd_entry = clear_refs_pte_range };

static ssize_t clear_refs_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
Expand All @@ -476,11 +476,17 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
return -ESRCH;
mm = get_task_mm(task);
if (mm) {
static struct mm_walk clear_refs_walk;
memset(&clear_refs_walk, 0, sizeof(clear_refs_walk));
clear_refs_walk.pmd_entry = clear_refs_pte_range;
clear_refs_walk.mm = mm;
down_read(&mm->mmap_sem);
for (vma = mm->mmap; vma; vma = vma->vm_next)
for (vma = mm->mmap; vma; vma = vma->vm_next) {
clear_refs_walk.private = vma;
if (!is_vm_hugetlb_page(vma))
walk_page_range(mm, vma->vm_start, vma->vm_end,
&clear_refs_walk, vma);
walk_page_range(vma->vm_start, vma->vm_end,
&clear_refs_walk);
}
flush_tlb_mm(mm);
up_read(&mm->mmap_sem);
mmput(mm);
Expand Down Expand Up @@ -528,9 +534,9 @@ static int add_to_pagemap(unsigned long addr, u64 pfn,
}

static int pagemap_pte_hole(unsigned long start, unsigned long end,
void *private)
struct mm_walk *walk)
{
struct pagemapread *pm = private;
struct pagemapread *pm = walk->private;
unsigned long addr;
int err = 0;
for (addr = start; addr < end; addr += PAGE_SIZE) {
Expand All @@ -548,9 +554,9 @@ static u64 swap_pte_to_pagemap_entry(pte_t pte)
}

static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
void *private)
struct mm_walk *walk)
{
struct pagemapread *pm = private;
struct pagemapread *pm = walk->private;
pte_t *pte;
int err = 0;

Expand Down Expand Up @@ -675,8 +681,8 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
* user buffer is tracked in "pm", and the walk
* will stop when we hit the end of the buffer.
*/
ret = walk_page_range(mm, start_vaddr, end_vaddr,
&pagemap_walk, &pm);
ret = walk_page_range(start_vaddr, end_vaddr,
&pagemap_walk);
if (ret == PM_END_OF_BUFFER)
ret = 0;
/* don't need mmap_sem for these, but this looks cleaner */
Expand Down
17 changes: 9 additions & 8 deletions include/linux/mm.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -760,16 +760,17 @@ unsigned long unmap_vmas(struct mmu_gather **tlb,
* (see walk_page_range for more details)
*/
struct mm_walk {
int (*pgd_entry)(pgd_t *, unsigned long, unsigned long, void *);
int (*pud_entry)(pud_t *, unsigned long, unsigned long, void *);
int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, void *);
int (*pte_entry)(pte_t *, unsigned long, unsigned long, void *);
int (*pte_hole)(unsigned long, unsigned long, void *);
int (*pgd_entry)(pgd_t *, unsigned long, unsigned long, struct mm_walk *);
int (*pud_entry)(pud_t *, unsigned long, unsigned long, struct mm_walk *);
int (*pmd_entry)(pmd_t *, unsigned long, unsigned long, struct mm_walk *);
int (*pte_entry)(pte_t *, unsigned long, unsigned long, struct mm_walk *);
int (*pte_hole)(unsigned long, unsigned long, struct mm_walk *);
struct mm_struct *mm;
void *private;
};

int walk_page_range(const struct mm_struct *, unsigned long addr,
unsigned long end, const struct mm_walk *walk,
void *private);
int walk_page_range(unsigned long addr, unsigned long end,
struct mm_walk *walk);
void free_pgd_range(struct mmu_gather **tlb, unsigned long addr,
unsigned long end, unsigned long floor, unsigned long ceiling);
void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *start_vma,
Expand Down
42 changes: 22 additions & 20 deletions mm/pagewalk.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,14 +3,14 @@
#include <linux/sched.h>

static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
const struct mm_walk *walk, void *private)
struct mm_walk *walk)
{
pte_t *pte;
int err = 0;

pte = pte_offset_map(pmd, addr);
for (;;) {
err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, private);
err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, walk);
if (err)
break;
addr += PAGE_SIZE;
Expand All @@ -24,7 +24,7 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
}

static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
const struct mm_walk *walk, void *private)
struct mm_walk *walk)
{
pmd_t *pmd;
unsigned long next;
Expand All @@ -35,15 +35,15 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
next = pmd_addr_end(addr, end);
if (pmd_none_or_clear_bad(pmd)) {
if (walk->pte_hole)
err = walk->pte_hole(addr, next, private);
err = walk->pte_hole(addr, next, walk);
if (err)
break;
continue;
}
if (walk->pmd_entry)
err = walk->pmd_entry(pmd, addr, next, private);
err = walk->pmd_entry(pmd, addr, next, walk);
if (!err && walk->pte_entry)
err = walk_pte_range(pmd, addr, next, walk, private);
err = walk_pte_range(pmd, addr, next, walk);
if (err)
break;
} while (pmd++, addr = next, addr != end);
Expand All @@ -52,7 +52,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
}

static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
const struct mm_walk *walk, void *private)
struct mm_walk *walk)
{
pud_t *pud;
unsigned long next;
Expand All @@ -63,15 +63,15 @@ static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
next = pud_addr_end(addr, end);
if (pud_none_or_clear_bad(pud)) {
if (walk->pte_hole)
err = walk->pte_hole(addr, next, private);
err = walk->pte_hole(addr, next, walk);
if (err)
break;
continue;
}
if (walk->pud_entry)
err = walk->pud_entry(pud, addr, next, private);
err = walk->pud_entry(pud, addr, next, walk);
if (!err && (walk->pmd_entry || walk->pte_entry))
err = walk_pmd_range(pud, addr, next, walk, private);
err = walk_pmd_range(pud, addr, next, walk);
if (err)
break;
} while (pud++, addr = next, addr != end);
Expand All @@ -85,25 +85,24 @@ static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
* @addr: starting address
* @end: ending address
* @walk: set of callbacks to invoke for each level of the tree
* @private: private data passed to the callback function
*
* Recursively walk the page table for the memory area in a VMA,
* calling supplied callbacks. Callbacks are called in-order (first
* PGD, first PUD, first PMD, first PTE, second PTE... second PMD,
* etc.). If lower-level callbacks are omitted, walking depth is reduced.
*
* Each callback receives an entry pointer, the start and end of the
* associated range, and a caller-supplied private data pointer.
* Each callback receives an entry pointer and the start and end of the
* associated range, and a copy of the original mm_walk for access to
* the ->private or ->mm fields.
*
* No locks are taken, but the bottom level iterator will map PTE
* directories from highmem if necessary.
*
* If any callback returns a non-zero value, the walk is aborted and
* the return value is propagated back to the caller. Otherwise 0 is returned.
*/
int walk_page_range(const struct mm_struct *mm,
unsigned long addr, unsigned long end,
const struct mm_walk *walk, void *private)
int walk_page_range(unsigned long addr, unsigned long end,
struct mm_walk *walk)
{
pgd_t *pgd;
unsigned long next;
Expand All @@ -112,21 +111,24 @@ int walk_page_range(const struct mm_struct *mm,
if (addr >= end)
return err;

pgd = pgd_offset(mm, addr);
if (!walk->mm)
return -EINVAL;

pgd = pgd_offset(walk->mm, addr);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd)) {
if (walk->pte_hole)
err = walk->pte_hole(addr, next, private);
err = walk->pte_hole(addr, next, walk);
if (err)
break;
continue;
}
if (walk->pgd_entry)
err = walk->pgd_entry(pgd, addr, next, private);
err = walk->pgd_entry(pgd, addr, next, walk);
if (!err &&
(walk->pud_entry || walk->pmd_entry || walk->pte_entry))
err = walk_pud_range(pgd, addr, next, walk, private);
err = walk_pud_range(pgd, addr, next, walk);
if (err)
break;
} while (pgd++, addr = next, addr != end);
Expand Down

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