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-rw-r--r--Documentation/nommu-mmap.txt31
-rw-r--r--Documentation/sysctl/vm.txt18
-rw-r--r--arch/arm/include/asm/mmu.h1
-rw-r--r--arch/arm/mm/dma-mapping.c28
-rw-r--r--arch/blackfin/include/asm/mmu.h1
-rw-r--r--arch/blackfin/kernel/ptrace.c6
-rw-r--r--arch/blackfin/kernel/traps.c11
-rw-r--r--arch/frv/kernel/ptrace.c11
-rw-r--r--arch/h8300/include/asm/mmu.h1
-rw-r--r--arch/m68knommu/include/asm/mmu.h1
-rw-r--r--arch/sh/include/asm/mmu.h1
-rw-r--r--fs/binfmt_elf_fdpic.c35
-rw-r--r--fs/binfmt_flat.c34
-rw-r--r--fs/proc/internal.h2
-rw-r--r--fs/proc/meminfo.c6
-rw-r--r--fs/proc/nommu.c71
-rw-r--r--fs/proc/task_nommu.c120
-rw-r--r--fs/ramfs/file-nommu.c21
-rw-r--r--include/asm-frv/mmu.h1
-rw-r--r--include/asm-m32r/mmu.h1
-rw-r--r--include/linux/mm.h18
-rw-r--r--include/linux/mm_types.h19
-rw-r--r--init/initramfs.c1
-rw-r--r--ipc/shm.c12
-rw-r--r--kernel/fork.c4
-rw-r--r--kernel/sysctl.c14
-rw-r--r--lib/Kconfig.debug7
-rw-r--r--mm/mmap.c10
-rw-r--r--mm/nommu.c1027
29 files changed, 992 insertions, 521 deletions
diff --git a/Documentation/nommu-mmap.txt b/Documentation/nommu-mmap.txt
index 7714f57..b565e82 100644
--- a/Documentation/nommu-mmap.txt
+++ b/Documentation/nommu-mmap.txt
@@ -109,12 +109,18 @@ and it's also much more restricted in the latter case:
FURTHER NOTES ON NO-MMU MMAP
============================
- (*) A request for a private mapping of less than a page in size may not return
- a page-aligned buffer. This is because the kernel calls kmalloc() to
- allocate the buffer, not get_free_page().
+ (*) A request for a private mapping of a file may return a buffer that is not
+ page-aligned. This is because XIP may take place, and the data may not be
+ paged aligned in the backing store.
- (*) A list of all the mappings on the system is visible through /proc/maps in
- no-MMU mode.
+ (*) A request for an anonymous mapping will always be page aligned. If
+ possible the size of the request should be a power of two otherwise some
+ of the space may be wasted as the kernel must allocate a power-of-2
+ granule but will only discard the excess if appropriately configured as
+ this has an effect on fragmentation.
+
+ (*) A list of all the private copy and anonymous mappings on the system is
+ visible through /proc/maps in no-MMU mode.
(*) A list of all the mappings in use by a process is visible through
/proc/<pid>/maps in no-MMU mode.
@@ -242,3 +248,18 @@ PROVIDING SHAREABLE BLOCK DEVICE SUPPORT
Provision of shared mappings on block device files is exactly the same as for
character devices. If there isn't a real device underneath, then the driver
should allocate sufficient contiguous memory to honour any supported mapping.
+
+
+=================================
+ADJUSTING PAGE TRIMMING BEHAVIOUR
+=================================
+
+NOMMU mmap automatically rounds up to the nearest power-of-2 number of pages
+when performing an allocation. This can have adverse effects on memory
+fragmentation, and as such, is left configurable. The default behaviour is to
+aggressively trim allocations and discard any excess pages back in to the page
+allocator. In order to retain finer-grained control over fragmentation, this
+behaviour can either be disabled completely, or bumped up to a higher page
+watermark where trimming begins.
+
+Page trimming behaviour is configurable via the sysctl `vm.nr_trim_pages'.
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index cd05994..a341507 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -38,6 +38,7 @@ Currently, these files are in /proc/sys/vm:
- numa_zonelist_order
- nr_hugepages
- nr_overcommit_hugepages
+- nr_trim_pages (only if CONFIG_MMU=n)
==============================================================
@@ -348,3 +349,20 @@ Change the maximum size of the hugepage pool. The maximum is
nr_hugepages + nr_overcommit_hugepages.
See Documentation/vm/hugetlbpage.txt
+
+==============================================================
+
+nr_trim_pages
+
+This is available only on NOMMU kernels.
+
+This value adjusts the excess page trimming behaviour of power-of-2 aligned
+NOMMU mmap allocations.
+
+A value of 0 disables trimming of allocations entirely, while a value of 1
+trims excess pages aggressively. Any value >= 1 acts as the watermark where
+trimming of allocations is initiated.
+
+The default value is 1.
+
+See Documentation/nommu-mmap.txt for more information.
diff --git a/arch/arm/include/asm/mmu.h b/arch/arm/include/asm/mmu.h
index 53099d4..b561584 100644
--- a/arch/arm/include/asm/mmu.h
+++ b/arch/arm/include/asm/mmu.h
@@ -24,7 +24,6 @@ typedef struct {
* modified for 2.6 by Hyok S. Choi <hyok.choi@samsung.com>
*/
typedef struct {
- struct vm_list_struct *vmlist;
unsigned long end_brk;
} mm_context_t;
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 6796001..310e479 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -71,7 +71,7 @@ static DEFINE_SPINLOCK(consistent_lock);
* the amount of RAM found at boot time.) I would imagine that get_vm_area()
* would have to initialise this each time prior to calling vm_region_alloc().
*/
-struct vm_region {
+struct arm_vm_region {
struct list_head vm_list;
unsigned long vm_start;
unsigned long vm_end;
@@ -79,20 +79,20 @@ struct vm_region {
int vm_active;
};
-static struct vm_region consistent_head = {
+static struct arm_vm_region consistent_head = {
.vm_list = LIST_HEAD_INIT(consistent_head.vm_list),
.vm_start = CONSISTENT_BASE,
.vm_end = CONSISTENT_END,
};
-static struct vm_region *
-vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp)
+static struct arm_vm_region *
+arm_vm_region_alloc(struct arm_vm_region *head, size_t size, gfp_t gfp)
{
unsigned long addr = head->vm_start, end = head->vm_end - size;
unsigned long flags;
- struct vm_region *c, *new;
+ struct arm_vm_region *c, *new;
- new = kmalloc(sizeof(struct vm_region), gfp);
+ new = kmalloc(sizeof(struct arm_vm_region), gfp);
if (!new)
goto out;
@@ -127,9 +127,9 @@ vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp)
return NULL;
}
-static struct vm_region *vm_region_find(struct vm_region *head, unsigned long addr)
+static struct arm_vm_region *arm_vm_region_find(struct arm_vm_region *head, unsigned long addr)
{
- struct vm_region *c;
+ struct arm_vm_region *c;
list_for_each_entry(c, &head->vm_list, vm_list) {
if (c->vm_active && c->vm_start == addr)
@@ -149,7 +149,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
pgprot_t prot)
{
struct page *page;
- struct vm_region *c;
+ struct arm_vm_region *c;
unsigned long order;
u64 mask = ISA_DMA_THRESHOLD, limit;
@@ -214,7 +214,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
/*
* Allocate a virtual address in the consistent mapping region.
*/
- c = vm_region_alloc(&consistent_head, size,
+ c = arm_vm_region_alloc(&consistent_head, size,
gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
if (c) {
pte_t *pte;
@@ -311,13 +311,13 @@ static int dma_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
unsigned long flags, user_size, kern_size;
- struct vm_region *c;
+ struct arm_vm_region *c;
int ret = -ENXIO;
user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
spin_lock_irqsave(&consistent_lock, flags);
- c = vm_region_find(&consistent_head, (unsigned long)cpu_addr);
+ c = arm_vm_region_find(&consistent_head, (unsigned long)cpu_addr);
spin_unlock_irqrestore(&consistent_lock, flags);
if (c) {
@@ -359,7 +359,7 @@ EXPORT_SYMBOL(dma_mmap_writecombine);
*/
void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle)
{
- struct vm_region *c;
+ struct arm_vm_region *c;
unsigned long flags, addr;
pte_t *ptep;
int idx;
@@ -378,7 +378,7 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
size = PAGE_ALIGN(size);
spin_lock_irqsave(&consistent_lock, flags);
- c = vm_region_find(&consistent_head, (unsigned long)cpu_addr);
+ c = arm_vm_region_find(&consistent_head, (unsigned long)cpu_addr);
if (!c)
goto no_area;
diff --git a/arch/blackfin/include/asm/mmu.h b/arch/blackfin/include/asm/mmu.h
index 757e439..dbfd686 100644
--- a/arch/blackfin/include/asm/mmu.h
+++ b/arch/blackfin/include/asm/mmu.h
@@ -10,7 +10,6 @@ struct sram_list_struct {
};
typedef struct {
- struct vm_list_struct *vmlist;
unsigned long end_brk;
unsigned long stack_start;
diff --git a/arch/blackfin/kernel/ptrace.c b/arch/blackfin/kernel/ptrace.c
index d2d3885..594e325 100644
--- a/arch/blackfin/kernel/ptrace.c
+++ b/arch/blackfin/kernel/ptrace.c
@@ -160,15 +160,15 @@ put_reg(struct task_struct *task, int regno, unsigned long data)
static inline int is_user_addr_valid(struct task_struct *child,
unsigned long start, unsigned long len)
{
- struct vm_list_struct *vml;
+ struct vm_area_struct *vma;
struct sram_list_struct *sraml;
/* overflow */
if (start + len < start)
return -EIO;
- for (vml = child->mm->context.vmlist; vml; vml = vml->next)
- if (start >= vml->vma->vm_start && start + len < vml->vma->vm_end)
+ vma = find_vma(child->mm, start);
+ if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
return 0;
for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
index 17d8e41..5b0667d 100644
--- a/arch/blackfin/kernel/traps.c
+++ b/arch/blackfin/kernel/traps.c
@@ -32,6 +32,7 @@
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/fs.h>
+#include <linux/rbtree.h>
#include <asm/traps.h>
#include <asm/cacheflush.h>
#include <asm/cplb.h>
@@ -83,6 +84,7 @@ static void decode_address(char *buf, unsigned long address)
struct mm_struct *mm;
unsigned long flags, offset;
unsigned char in_atomic = (bfin_read_IPEND() & 0x10) || in_atomic();
+ struct rb_node *n;
#ifdef CONFIG_KALLSYMS
unsigned long symsize;
@@ -128,9 +130,10 @@ static void decode_address(char *buf, unsigned long address)
if (!mm)
continue;
- vml = mm->context.vmlist;
- while (vml) {
- struct vm_area_struct *vma = vml->vma;
+ for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) {
+ struct vm_area_struct *vma;
+
+ vma = rb_entry(n, struct vm_area_struct, vm_rb);
if (address >= vma->vm_start && address < vma->vm_end) {
char _tmpbuf[256];
@@ -176,8 +179,6 @@ static void decode_address(char *buf, unsigned long address)
goto done;
}
-
- vml = vml->next;
}
if (!in_atomic)
mmput(mm);
diff --git a/arch/frv/kernel/ptrace.c b/arch/frv/kernel/ptrace.c
index 709e9bd..5e7d401 100644
--- a/arch/frv/kernel/ptrace.c
+++ b/arch/frv/kernel/ptrace.c
@@ -69,7 +69,8 @@ static inline int put_reg(struct task_struct *task, int regno,
}
/*
- * check that an address falls within the bounds of the target process's memory mappings
+ * check that an address falls within the bounds of the target process's memory
+ * mappings
*/
static inline int is_user_addr_valid(struct task_struct *child,
unsigned long start, unsigned long len)
@@ -79,11 +80,11 @@ static inline int is_user_addr_valid(struct task_struct *child,
return -EIO;
return 0;
#else
- struct vm_list_struct *vml;
+ struct vm_area_struct *vma;
- for (vml = child->mm->context.vmlist; vml; vml = vml->next)
- if (start >= vml->vma->vm_start && start + len <= vml->vma->vm_end)
- return 0;
+ vma = find_vma(child->mm, start);
+ if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
+ return 0;
return -EIO;
#endif
diff --git a/arch/h8300/include/asm/mmu.h b/arch/h8300/include/asm/mmu.h
index 2ce06ea..3130996 100644
--- a/arch/h8300/include/asm/mmu.h
+++ b/arch/h8300/include/asm/mmu.h
@@ -4,7 +4,6 @@
/* Copyright (C) 2002, David McCullough <davidm@snapgear.com> */
typedef struct {
- struct vm_list_struct *vmlist;
unsigned long end_brk;
} mm_context_t;
diff --git a/arch/m68knommu/include/asm/mmu.h b/arch/m68knommu/include/asm/mmu.h
index 5fa6b68..e2da1e6 100644
--- a/arch/m68knommu/include/asm/mmu.h
+++ b/arch/m68knommu/include/asm/mmu.h
@@ -4,7 +4,6 @@
/* Copyright (C) 2002, David McCullough <davidm@snapgear.com> */
typedef struct {
- struct vm_list_struct *vmlist;
unsigned long end_brk;
} mm_context_t;
diff --git a/arch/sh/include/asm/mmu.h b/arch/sh/include/asm/mmu.h
index fdcb93b..6c43625 100644
--- a/arch/sh/include/asm/mmu.h
+++ b/arch/sh/include/asm/mmu.h
@@ -9,7 +9,6 @@ typedef struct {
mm_context_id_t id;
void *vdso;
#else
- struct vm_list_struct *vmlist;
unsigned long end_brk;
#endif
#ifdef CONFIG_BINFMT_ELF_FDPIC
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index aa5b432..f3e72c5 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -168,9 +168,6 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm,
struct elf_fdpic_params exec_params, interp_params;
struct elf_phdr *phdr;
unsigned long stack_size, entryaddr;
-#ifndef CONFIG_MMU
- unsigned long fullsize;
-#endif
#ifdef ELF_FDPIC_PLAT_INIT
unsigned long dynaddr;
#endif
@@ -390,11 +387,6 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm,
goto error_kill;
}
- /* expand the stack mapping to use up the entire allocation granule */
- fullsize = kobjsize((char *) current->mm->start_brk);
- if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
- fullsize, 0, 0)))
- stack_size = fullsize;
up_write(&current->mm->mmap_sem);
current->mm->brk = current->mm->start_brk;
@@ -1567,11 +1559,9 @@ end_coredump:
static int elf_fdpic_dump_segments(struct file *file, size_t *size,
unsigned long *limit, unsigned long mm_flags)
{
- struct vm_list_struct *vml;
-
- for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
- struct vm_area_struct *vma = vml->vma;
+ struct vm_area_struct *vma;
+ for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
if (!maydump(vma, mm_flags))
continue;
@@ -1617,9 +1607,6 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
elf_fpxregset_t *xfpu = NULL;
#endif
int thread_status_size = 0;
-#ifndef CONFIG_MMU
- struct vm_list_struct *vml;
-#endif
elf_addr_t *auxv;
unsigned long mm_flags;
@@ -1685,13 +1672,7 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
fill_prstatus(prstatus, current, signr);
elf_core_copy_regs(&prstatus->pr_reg, regs);
-#ifdef CONFIG_MMU
segs = current->mm->map_count;
-#else
- segs = 0;
- for (vml = current->mm->context.vmlist; vml; vml = vml->next)
- segs++;
-#endif
#ifdef ELF_CORE_EXTRA_PHDRS
segs += ELF_CORE_EXTRA_PHDRS;
#endif
@@ -1766,20 +1747,10 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
mm_flags = current->mm->flags;
/* write program headers for segments dump */
- for (
-#ifdef CONFIG_MMU
- vma = current->mm->mmap; vma; vma = vma->vm_next
-#else
- vml = current->mm->context.vmlist; vml; vml = vml->next
-#endif
- ) {
+ for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
struct elf_phdr phdr;
size_t sz;
-#ifndef CONFIG_MMU
- vma = vml->vma;
-#endif
-
sz = vma->vm_end - vma->vm_start;
phdr.p_type = PT_LOAD;
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 7bbd5c6..5cebf0b 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -417,8 +417,8 @@ static int load_flat_file(struct linux_binprm * bprm,
unsigned long textpos = 0, datapos = 0, result;
unsigned long realdatastart = 0;
unsigned long text_len, data_len, bss_len, stack_len, flags;
- unsigned long len, reallen, memp = 0;
- unsigned long extra, rlim;
+ unsigned long len, memp = 0;
+ unsigned long memp_size, extra, rlim;
unsigned long *reloc = 0, *rp;
struct inode *inode;
int i, rev, relocs = 0;
@@ -543,17 +543,10 @@ static int load_flat_file(struct linux_binprm * bprm,
}
len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
+ len = PAGE_ALIGN(len);
down_write(&current->mm->mmap_sem);
realdatastart = do_mmap(0, 0, len,
PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
- /* Remap to use all availabe slack region space */
- if (realdatastart && (realdatastart < (unsigned long)-4096)) {
- reallen = kobjsize((void *)realdatastart);
- if (reallen > len) {
- realdatastart = do_mremap(realdatastart, len,
- reallen, MREMAP_FIXED, realdatastart);
- }
- }
up_write(&current->mm->mmap_sem);
if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) {
@@ -591,21 +584,14 @@ static int load_flat_file(struct linux_binprm * bprm,
reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
memp = realdatastart;
-
+ memp_size = len;
} else {
len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
+ len = PAGE_ALIGN(len);
down_write(&current->mm->mmap_sem);
textpos = do_mmap(0, 0, len,
PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
- /* Remap to use all availabe slack region space */
- if (textpos && (textpos < (unsigned long) -4096)) {
- reallen = kobjsize((void *)textpos);
- if (reallen > len) {
- textpos = do_mremap(textpos, len, reallen,
- MREMAP_FIXED, textpos);
- }
- }
up_write(&current->mm->mmap_sem);
if (!textpos || textpos >= (unsigned long) -4096) {
@@ -622,7 +608,7 @@ static int load_flat_file(struct linux_binprm * bprm,
reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) +
MAX_SHARED_LIBS * sizeof(unsigned long));
memp = textpos;
-
+ memp_size = len;
#ifdef CONFIG_BINFMT_ZFLAT
/*
* load it all in and treat it like a RAM load from now on
@@ -680,10 +666,12 @@ static int load_flat_file(struct linux_binprm * bprm,
* set up the brk stuff, uses any slack left in data/bss/stack
* allocation. We put the brk after the bss (between the bss
* and stack) like other platforms.
+ * Userspace code relies on the stack pointer starting out at
+ * an address right at the end of a page.
*/
current->mm->start_brk = datapos + data_len + bss_len;
current->mm->brk = (current->mm->start_brk + 3) & ~3;
- current->mm->context.end_brk = memp + kobjsize((void *) memp) - stack_len;
+ current->mm->context.end_brk = memp + memp_size - stack_len;
}
if (flags & FLAT_FLAG_KTRACE)
@@ -790,8 +778,8 @@ static int load_flat_file(struct linux_binprm * bprm,
/* zero the BSS, BRK and stack areas */
memset((void*)(datapos + data_len), 0, bss_len +
- (memp + kobjsize((void *) memp) - stack_len - /* end brk */
- libinfo->lib_list[id].start_brk) + /* start brk */
+ (memp + memp_size - stack_len - /* end brk */
+ libinfo->lib_list[id].start_brk) + /* start brk */
stack_len);
return 0;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 3e8aeb8..cd53ff8 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -41,8 +41,6 @@ do { \
(vmi)->used = 0; \
(vmi)->largest_chunk = 0; \
} while(0)
-
-extern int nommu_vma_show(struct seq_file *, struct vm_area_struct *);
#endif
extern int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index b1675c4..43d2394 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -74,6 +74,9 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
"LowTotal: %8lu kB\n"
"LowFree: %8lu kB\n"
#endif
+#ifndef CONFIG_MMU
+ "MmapCopy: %8lu kB\n"
+#endif
"SwapTotal: %8lu kB\n"
"SwapFree: %8lu kB\n"
"Dirty: %8lu kB\n"
@@ -116,6 +119,9 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
K(i.totalram-i.totalhigh),
K(i.freeram-i.freehigh),
#endif
+#ifndef CONFIG_MMU
+ K((unsigned long) atomic_read(&mmap_pages_allocated)),
+#endif
K(i.totalswap),
K(i.freeswap),
K(global_page_state(NR_FILE_DIRTY)),
diff --git a/fs/proc/nommu.c b/fs/proc/nommu.c
index 3f87d26..b446d7a 100644
--- a/fs/proc/nommu.c
+++ b/fs/proc/nommu.c
@@ -33,33 +33,33 @@
#include "internal.h"
/*
- * display a single VMA to a sequenced file
+ * display a single region to a sequenced file
*/
-int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
+static int nommu_region_show(struct seq_file *m, struct vm_region *region)
{
unsigned long ino = 0;
struct file *file;
dev_t dev = 0;
int flags, len;
- flags = vma->vm_flags;
- file = vma->vm_file;
+ flags = region->vm_flags;
+ file = region->vm_file;
if (file) {
- struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
+ struct inode *inode = region->vm_file->f_path.dentry->d_inode;
dev = inode->i_sb->s_dev;
ino = inode->i_ino;
}
seq_printf(m,
"%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
- vma->vm_start,
- vma->vm_end,
+ region->vm_start,
+ region->vm_end,
flags & VM_READ ? 'r' : '-',
flags & VM_WRITE ? 'w' : '-',
flags & VM_EXEC ? 'x' : '-',
flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
- ((loff_t)vma->vm_pgoff) << PAGE_SHIFT,
+ ((loff_t)region->vm_pgoff) << PAGE_SHIFT,
MAJOR(dev), MINOR(dev), ino, &len);
if (file) {
@@ -75,61 +75,54 @@ int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
}
/*
- * display a list of all the VMAs the kernel knows about
+ * display a list of all the REGIONs the kernel knows about
* - nommu kernals have a single flat list
*/
-static int nommu_vma_list_show(struct seq_file *m, void *v)
+static int nommu_region_list_show(struct seq_file *m, void *_p)
{
- struct vm_area_struct *vma;
+ struct rb_node *p = _p;
- vma = rb_entry((struct rb_node *) v, struct vm_area_struct, vm_rb);
- return nommu_vma_show(m, vma);
+ return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb));
}
-static void *nommu_vma_list_start(struct seq_file *m, loff_t *_pos)
+static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos)
{
- struct rb_node *_rb;
+ struct rb_node *p;
loff_t pos = *_pos;
- void *next = NULL;
- down_read(&nommu_vma_sem);
+ down_read(&nommu_region_sem);
- for (_rb = rb_first(&nommu_vma_tree); _rb; _rb = rb_next(_rb)) {
- if (pos == 0) {
- next = _rb;
- break;
- }
- pos--;
- }
-
- return next;
+ for (p = rb_first(&nommu_region_tree); p; p = rb_next(p))
+ if (pos-- == 0)
+ return p;
+ return NULL;
}
-static void nommu_vma_list_stop(struct seq_file *m, void *v)
+static void nommu_region_list_stop(struct seq_file *m, void *v)
{
- up_read(&nommu_vma_sem);
+ up_read(&nommu_region_sem);
}
-static void *nommu_vma_list_next(struct seq_file *m, void *v, loff_t *pos)
+static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos)
{
(*pos)++;
return rb_next((struct rb_node *) v);
}
-static const struct seq_operations proc_nommu_vma_list_seqop = {
- .start = nommu_vma_list_start,
- .next = nommu_vma_list_next,
- .stop = nommu_vma_list_stop,
- .show = nommu_vma_list_show
+static struct seq_operations proc_nommu_region_list_seqop = {
+ .start = nommu_region_list_start,
+ .next = nommu_region_list_next,
+ .stop = nommu_region_list_stop,
+ .show = nommu_region_list_show
};
-static int proc_nommu_vma_list_open(struct inode *inode, struct file *file)
+static int proc_nommu_region_list_open(struct inode *inode, struct file *file)
{
- return seq_open(file, &proc_nommu_vma_list_seqop);
+ return seq_open(file, &proc_nommu_region_list_seqop);
}
-static const struct file_operations proc_nommu_vma_list_operations = {
- .open = proc_nommu_vma_list_open,
+static const struct file_operations proc_nommu_region_list_operations = {
+ .open = proc_nommu_region_list_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
@@ -137,7 +130,7 @@ static const struct file_operations proc_nommu_vma_list_operations = {
static int __init proc_nommu_init(void)
{
- proc_create("maps", S_IRUGO, NULL, &proc_nommu_vma_list_operations);
+ proc_create("maps", S_IRUGO, NULL, &proc_nommu_region_list_operations);
return 0;
}
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index d4a8be3..343ea12 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -15,25 +15,32 @@
*/
void task_mem(struct seq_file *m, struct mm_struct *mm)
{
- struct vm_list_struct *vml;
- unsigned long bytes = 0, sbytes = 0, slack = 0;
+ struct vm_area_struct *vma;
+ struct vm_region *region;
+ struct rb_node *p;
+ unsigned long bytes = 0, sbytes = 0, slack = 0, size;
down_read(&mm->mmap_sem);
- for (vml = mm->context.vmlist; vml; vml = vml->next) {
- if (!vml->vma)
- continue;
+ for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
+ vma = rb_entry(p, struct vm_area_struct, vm_rb);
+
+ bytes += kobjsize(vma);
+
+ region = vma->vm_region;
+ if (region) {
+ size = kobjsize(region);
+ size += region->vm_end - region->vm_start;
+ } else {
+ size = vma->vm_end - vma->vm_start;
+ }
- bytes += kobjsize(vml);
if (atomic_read(&mm->mm_count) > 1 ||
- atomic_read(&vml->vma->vm_usage) > 1
- ) {
- sbytes += kobjsize((void *) vml->vma->vm_start);
- sbytes += kobjsize(vml->vma);
+ vma->vm_flags & VM_MAYSHARE) {
+ sbytes += size;
} else {
- bytes += kobjsize((void *) vml->vma->vm_start);
- bytes += kobjsize(vml->vma);
- slack += kobjsize((void *) vml->vma->vm_start) -
- (vml->vma->vm_end - vml->vma->vm_start);
+ bytes += size;
+ if (region)
+ slack = region->vm_end - vma->vm_end;
}
}
@@ -70,13 +77,14 @@ void task_mem(struct seq_file *m, struct mm_struct *mm)
unsigned long task_vsize(struct mm_struct *mm)
{
- struct vm_list_struct *tbp;
+ struct vm_area_struct *vma;
+ struct rb_node *p;
unsigned long vsize = 0;
down_read(&mm->mmap_sem);
- for (tbp = mm->context.vmlist; tbp; tbp = tbp->next) {
- if (tbp->vma)
- vsize += kobjsize((void *) tbp->vma->vm_start);
+ for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
+ vma = rb_entry(p, struct vm_area_struct, vm_rb);
+ vsize += vma->vm_end - vma->vm_start;
}
up_read(&mm->mmap_sem);
return vsize;
@@ -85,15 +93,19 @@ unsigned long task_vsize(struct mm_struct *mm)
int task_statm(struct mm_struct *mm, int *shared, int *text,
int *data, int *resident)
{
- struct vm_list_struct *tbp;
+ struct vm_area_struct *vma;
+ struct vm_region *region;
+ struct rb_node *p;
int size = kobjsize(mm);
down_read(&mm->mmap_sem);
- for (tbp = mm->context.vmlist; tbp; tbp = tbp->next) {
- size += kobjsize(tbp);
- if (tbp->vma) {
- size += kobjsize(tbp->vma);
- size += kobjsize((void *) tbp->vma->vm_start);
+ for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
+ vma = rb_entry(p, struct vm_area_struct, vm_rb);
+ size += kobjsize(vma);
+ region = vma->vm_region;
+ if (region) {
+ size += kobjsize(region);
+ size += region->vm_end - region->vm_start;
}
}
@@ -105,20 +117,62 @@ int task_statm(struct mm_struct *mm, int *shared, int *text,
}
/*
+ * display a single VMA to a sequenced file
+ */
+static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
+{
+ unsigned long ino = 0;
+ struct file *file;
+ dev_t dev = 0;
+ int flags, len;
+
+ flags = vma->vm_flags;
+ file = vma->vm_file;
+
+ if (file) {
+ struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
+ dev = inode->i_sb->s_dev;
+ ino = inode->i_ino;
+ }
+
+ seq_printf(m,
+ "%08lx-%08lx %c%c%c%c %08lx %02x:%02x %lu %n",
+ vma->vm_start,
+ vma->vm_end,
+ flags & VM_READ ? 'r' : '-',
+ flags & VM_WRITE ? 'w' : '-',
+ flags & VM_EXEC ? 'x' : '-',
+ flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
+ vma->vm_pgoff << PAGE_SHIFT,
+ MAJOR(dev), MINOR(dev), ino, &len);
+
+ if (file) {
+ len = 25 + sizeof(void *) * 6 - len;
+ if (len < 1)
+ len = 1;
+ seq_printf(m, "%*c", len, ' ');
+ seq_path(m, &file->f_path, "");
+ }
+
+ seq_putc(m, '\n');
+ return 0;
+}
+
+/*
* display mapping lines for a particular process's /proc/pid/maps
*/
-static int show_map(struct seq_file *m, void *_vml)
+static int show_map(struct seq_file *m, void *_p)
{
- struct vm_list_struct *vml = _vml;
+ struct rb_node *p = _p;
- return nommu_vma_show(m, vml->vma);
+ return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb));
}
static void *m_start(struct seq_file *m, loff_t *pos)
{
struct proc_maps_private *priv = m->private;
- struct vm_list_struct *vml;
struct mm_struct *mm;
+ struct rb_node *p;
loff_t n = *pos;
/* pin the task and mm whilst we play with them */
@@ -134,9 +188,9 @@ static void *m_start(struct seq_file *m, loff_t *pos)
}
/* start from the Nth VMA */
- for (vml = mm->context.vmlist; vml; vml = vml->next)
+ for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
if (n-- == 0)
- return vml;
+ return p;
return NULL;
}
@@ -152,12 +206,12 @@ static void m_stop(struct seq_file *m, void *_vml)
}
}
-static void *m_next(struct seq_file *m, void *_vml, loff_t *pos)
+static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
{
- struct vm_list_struct *vml = _vml;
+ struct rb_node *p = _p;
(*pos)++;
- return vml ? vml->next : NULL;
+ return p ? rb_next(p) : NULL;
}
static const struct seq_operations proc_pid_maps_ops = {
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index 76acdbc..b9b567a 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -262,11 +262,11 @@ unsigned long ramfs_nommu_get_unmapped_area(struct file *file,
ret = -ENOMEM;
pages = kzalloc(lpages * sizeof(struct page *), GFP_KERNEL);
if (!pages)
- goto out;
+ goto out_free;
nr = find_get_pages(inode->i_mapping, pgoff, lpages, pages);
if (nr != lpages)
- goto out; /* leave if some pages were missing */
+ goto out_free_pages; /* leave if some pages were missing */
/* check the pages for physical adjacency */
ptr = pages;
@@ -274,19 +274,18 @@ unsigned long ramfs_nommu_get_unmapped_area(struct file *file,
page++;
for (loop = lpages; loop > 1; loop--)
if (*ptr++ != page++)
- goto out;
+ goto out_free_pages;
/* okay - all conditions fulfilled */
ret = (unsigned long) page_address(pages[0]);
- out:
- if (pages) {
- ptr = pages;
- for (loop = lpages; loop > 0; loop--)
- put_page(*ptr++);
- kfree(pages);
- }
-
+out_free_pages:
+ ptr = pages;
+ for (loop = nr; loop > 0; loop--)
+ put_page(*ptr++);
+out_free:
+ kfree(pages);
+out:
return ret;
}
diff --git a/include/asm-frv/mmu.h b/include/asm-frv/mmu.h
index 22c0371..86ca0e8 100644
--- a/include/asm-frv/mmu.h
+++ b/include/asm-frv/mmu.h
@@ -22,7 +22,6 @@ typedef struct {
unsigned long dtlb_ptd_mapping; /* [DAMR5] PTD mapping for dtlb cached PGE */
#else
- struct vm_list_struct *vmlist;
unsigned long end_brk;
#endif
diff --git a/include/asm-m32r/mmu.h b/include/asm-m32r/mmu.h
index d9bd724..150cb92 100644
--- a/include/asm-m32r/mmu.h
+++ b/include/asm-m32r/mmu.h
@@ -4,7 +4,6 @@
#if !defined(CONFIG_MMU)
typedef struct {
- struct vm_list_struct *vmlist;
unsigned long end_brk;
} mm_context_t;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 4a3d28c..b91a73f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -56,19 +56,9 @@ extern unsigned long mmap_min_addr;
extern struct kmem_cache *vm_area_cachep;
-/*
- * This struct defines the per-mm list of VMAs for uClinux. If CONFIG_MMU is
- * disabled, then there's a single shared list of VMAs maintained by the
- * system, and mm's subscribe to these individually
- */
-struct vm_list_struct {
- struct vm_list_struct *next;
- struct vm_area_struct *vma;
-};
-
#ifndef CONFIG_MMU
-extern struct rb_root nommu_vma_tree;
-extern struct rw_semaphore nommu_vma_sem;
+extern struct rb_root nommu_region_tree;
+extern struct rw_semaphore nommu_region_sem;
extern unsigned int kobjsize(const void *objp);
#endif
@@ -1061,6 +1051,7 @@ extern void memmap_init_zone(unsigned long, int, unsigned long,
unsigned long, enum memmap_context);
extern void setup_per_zone_pages_min(void);
extern void mem_init(void);
+extern void __init mmap_init(void);
extern void show_mem(void);
extern void si_meminfo(struct sysinfo * val);
extern void si_meminfo_node(struct sysinfo *val, int nid);
@@ -1072,6 +1063,9 @@ extern void setup_per_cpu_pageset(void);
static inline void setup_per_cpu_pageset(void) {}
#endif
+/* nommu.c */
+extern atomic_t mmap_pages_allocated;
+
/* prio_tree.c */
void vma_prio_tree_add(struct vm_area_struct *, struct vm_area_struct *old);
void vma_prio_tree_insert(struct vm_area_struct *, struct prio_tree_root *);
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 9cfc9b6..92915e8 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -97,6 +97,23 @@ struct page {
};
/*
+ * A region containing a mapping of a non-memory backed file under NOMMU
+ * conditions. These are held in a global tree and are pinned by the VMAs that
+ * map parts of them.
+ */
+struct vm_region {
+ struct rb_node vm_rb; /* link in global region tree */
+ unsigned long vm_flags; /* VMA vm_flags */
+ unsigned long vm_start; /* start address of region */
+ unsigned long vm_end; /* region initialised to here */
+ unsigned long vm_top; /* region allocated to here */
+ unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */
+ struct file *vm_file; /* the backing file or NULL */
+
+ atomic_t vm_usage; /* region usage count */
+};
+
+/*
* This struct defines a memory VMM memory area. There is one of these
* per VM-area/task. A VM area is any part of the process virtual memory
* space that has a special rule for the page-fault handlers (ie a shared
@@ -152,7 +169,7 @@ struct vm_area_struct {
unsigned long vm_truncate_count;/* truncate_count or restart_addr */
#ifndef CONFIG_MMU
- atomic_t vm_usage; /* refcount (VMAs shared if !MMU) */
+ struct vm_region *vm_region; /* NOMMU mapping region */
#endif
#ifdef CONFIG_NUMA
struct mempolicy *vm_policy; /* NUMA policy for the VMA */
diff --git a/init/initramfs.c b/init/initramfs.c
index 4f5ba75..d9c941c 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -317,6 +317,7 @@ static int __init do_name(void)
if (wfd >= 0) {
sys_fchown(wfd, uid, gid);
sys_fchmod(wfd, mode);
+ sys_ftruncate(wfd, body_len);
vcollected = kstrdup(collected, GFP_KERNEL);
state = CopyFile;
}
diff --git a/ipc/shm.c b/ipc/shm.c
index b125b56..d0ab552 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -990,6 +990,7 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
*/
vma = find_vma(mm, addr);
+#ifdef CONFIG_MMU
while (vma) {
next = vma->vm_next;
@@ -1034,6 +1035,17 @@ asmlinkage long sys_shmdt(char __user *shmaddr)
vma = next;
}
+#else /* CONFIG_MMU */
+ /* under NOMMU conditions, the exact address to be destroyed must be
+ * given */
+ retval = -EINVAL;
+ if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
+ do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
+ retval = 0;
+ }
+
+#endif
+
up_write(&mm->mmap_sem);
return retval;
}
diff --git a/kernel/fork.c b/kernel/fork.c
index 4018308..1d68f12 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1481,12 +1481,10 @@ void __init proc_caches_init(void)
fs_cachep = kmem_cache_create("fs_cache",
sizeof(struct fs_struct), 0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
- vm_area_cachep = kmem_cache_create("vm_area_struct",
- sizeof(struct vm_area_struct), 0,
- SLAB_PANIC, NULL);
mm_cachep = kmem_cache_create("mm_struct",
sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
+ mmap_init();
}
/*
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 92f6e5b..89d7443 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -82,6 +82,9 @@ extern int percpu_pagelist_fraction;
extern int compat_log;
extern int latencytop_enabled;
extern int sysctl_nr_open_min, sysctl_nr_open_max;
+#ifndef CONFIG_MMU
+extern int sysctl_nr_trim_pages;
+#endif
#ifdef CONFIG_RCU_TORTURE_TEST
extern int rcutorture_runnable;
#endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
@@ -1102,6 +1105,17 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = &proc_dointvec
},
+#else
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "nr_trim_pages",
+ .data = &sysctl_nr_trim_pages,
+ .maxlen = sizeof(sysctl_nr_trim_pages),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec_minmax,
+ .strategy = &sysctl_intvec,
+ .extra1 = &zero,
+ },
#endif
{
.ctl_name = VM_LAPTOP_MODE,
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2e75478..d0a32aa 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -512,6 +512,13 @@ config DEBUG_VIRTUAL
If unsure, say N.
+config DEBUG_NOMMU_REGIONS
+ bool "Debug the global anon/private NOMMU mapping region tree"
+ depends on DEBUG_KERNEL && !MMU
+ help
+ This option causes the global tree of anonymous and private mapping
+ regions to be regularly checked for invalid topology.
+
config DEBUG_WRITECOUNT
bool "Debug filesystem writers count"
depends on DEBUG_KERNEL
diff --git a/mm/mmap.c b/mm/mmap.c
index a910c045..7496231 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2472,3 +2472,13 @@ void mm_drop_all_locks(struct mm_struct *mm)
mutex_unlock(&mm_all_locks_mutex);
}
+
+/*
+ * initialise the VMA slab
+ */
+void __init mmap_init(void)
+{
+ vm_area_cachep = kmem_cache_create("vm_area_struct",
+ sizeof(struct vm_area_struct), 0,
+ SLAB_PANIC, NULL);
+}
diff --git a/mm/nommu.c b/mm/nommu.c
index 1c28ea3..60ed837 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -6,11 +6,11 @@
*
* See Documentation/nommu-mmap.txt
*
- * Copyright (c) 2004-2005 David Howells <dhowells@redhat.com>
+ * Copyright (c) 2004-2008 David Howells <dhowells@redhat.com>
* Copyright (c) 2000-2003 David McCullough <davidm@snapgear.com>
* Copyright (c) 2000-2001 D Jeff Dionne <jeff@uClinux.org>
* Copyright (c) 2002 Greg Ungerer <gerg@snapgear.com>
- * Copyright (c) 2007 Paul Mundt <lethal@linux-sh.org>
+ * Copyright (c) 2007-2008 Paul Mundt <lethal@linux-sh.org>
*/
#include <linux/module.h>
@@ -33,6 +33,28 @@
#include <asm/uaccess.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
+#include "internal.h"
+
+static inline __attribute__((format(printf, 1, 2)))
+void no_printk(const char *fmt, ...)
+{
+}
+
+#if 0
+#define kenter(FMT, ...) \
+ printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+ printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
+#define kdebug(FMT, ...) \
+ printk(KERN_DEBUG "xxx" FMT"yyy\n", ##__VA_ARGS__)
+#else
+#define kenter(FMT, ...) \
+ no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
+#define kleave(FMT, ...) \
+ no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
+#define kdebug(FMT, ...) \
+ no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
+#endif
#include "internal.h"
@@ -40,19 +62,22 @@ void *high_memory;
struct page *mem_map;
unsigned long max_mapnr;
unsigned long num_physpages;
-unsigned long askedalloc, realalloc;
atomic_long_t vm_committed_space = ATOMIC_LONG_INIT(0);
int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
int sysctl_overcommit_ratio = 50; /* default is 50% */
int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT;
+int sysctl_nr_trim_pages = 1; /* page trimming behaviour */
int heap_stack_gap = 0;
+atomic_t mmap_pages_allocated;
+
EXPORT_SYMBOL(mem_map);
EXPORT_SYMBOL(num_physpages);
-/* list of shareable VMAs */
-struct rb_root nommu_vma_tree = RB_ROOT;
-DECLARE_RWSEM(nommu_vma_sem);
+/* list of mapped, potentially shareable regions */
+static struct kmem_cache *vm_region_jar;
+struct rb_root nommu_region_tree = RB_ROOT;
+DECLARE_RWSEM(nommu_region_sem);
struct vm_operations_struct generic_file_vm_ops = {
};
@@ -124,6 +149,20 @@ unsigned int kobjsize(const void *objp)
return ksize(objp);
/*
+ * If it's not a compound page, see if we have a matching VMA
+ * region. This test is intentionally done in reverse order,
+ * so if there's no VMA, we still fall through and hand back
+ * PAGE_SIZE for 0-order pages.
+ */
+ if (!PageCompound(page)) {
+ struct vm_area_struct *vma;
+
+ vma = find_vma(current->mm, (unsigned long)objp);
+ if (vma)
+ return vma->vm_end - vma->vm_start;
+ }
+
+ /*
* The ksize() function is only guaranteed to work for pointers
* returned by kmalloc(). So handle arbitrary pointers here.
*/
@@ -401,129 +440,178 @@ asmlinkage unsigned long sys_brk(unsigned long brk)
return mm->brk = brk;
}
-#ifdef DEBUG
-static void show_process_blocks(void)
+/*
+ * initialise the VMA and region record slabs
+ */
+void __init mmap_init(void)
{
- struct vm_list_struct *vml;
-
- printk("Process blocks %d:", current->pid);
-
- for (vml = &current->mm->context.vmlist; vml; vml = vml->next) {
- printk(" %p: %p", vml, vml->vma);
- if (vml->vma)
- printk(" (%d @%lx #%d)",
- kobjsize((void *) vml->vma->vm_start),
- vml->vma->vm_start,
- atomic_read(&vml->vma->vm_usage));
- printk(vml->next ? " ->" : ".\n");
- }
+ vm_region_jar = kmem_cache_create("vm_region_jar",
+ sizeof(struct vm_region), 0,
+ SLAB_PANIC, NULL);
+ vm_area_cachep = kmem_cache_create("vm_area_struct",
+ sizeof(struct vm_area_struct), 0,
+ SLAB_PANIC, NULL);
}
-#endif /* DEBUG */
/*
- * add a VMA into a process's mm_struct in the appropriate place in the list
- * - should be called with mm->mmap_sem held writelocked
+ * validate the region tree
+ * - the caller must hold the region lock
*/
-static void add_vma_to_mm(struct mm_struct *mm, struct vm_list_struct *vml)
+#ifdef CONFIG_DEBUG_NOMMU_REGIONS
+static noinline void validate_nommu_regions(void)
{
- struct vm_list_struct **ppv;
-
- for (ppv = &current->mm->context.vmlist; *ppv; ppv = &(*ppv)->next)
- if ((*ppv)->vma->vm_start > vml->vma->vm_start)
- break;
-
- vml->next = *ppv;
- *ppv = vml;
+ struct vm_region *region, *last;
+ struct rb_node *p, *lastp;
+
+ lastp = rb_first(&nommu_region_tree);
+ if (!lastp)
+ return;
+
+ last = rb_entry(lastp, struct vm_region, vm_rb);
+ if (unlikely(last->vm_end <= last->vm_start))
+ BUG();
+ if (unlikely(last->vm_top < last->vm_end))
+ BUG();
+
+ while ((p = rb_next(lastp))) {
+ region = rb_entry(p, struct vm_region, vm_rb);
+ last = rb_entry(lastp, struct vm_region, vm_rb);
+
+ if (unlikely(region->vm_end <= region->vm_start))
+ BUG();
+ if (unlikely(region->vm_top < region->vm_end))
+ BUG();
+ if (unlikely(region->vm_start < last->vm_top))
+ BUG();
+
+ lastp = p;
+ }
}
+#else
+#define validate_nommu_regions() do {} while(0)
+#endif
/*
- * look up the first VMA in which addr resides, NULL if none
- * - should be called with mm->mmap_sem at least held readlocked
+ * add a region into the global tree
*/
-struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
+static void add_nommu_region(struct vm_region *region)
{
- struct vm_list_struct *loop, *vml;
+ struct vm_region *pregion;
+ struct rb_node **p, *parent;
- /* search the vm_start ordered list */
- vml = NULL;
- for (loop = mm->context.vmlist; loop; loop = loop->next) {
- if (loop->vma->vm_start > addr)
- break;
- vml = loop;
+ validate_nommu_regions();
+
+ BUG_ON(region->vm_start & ~PAGE_MASK);
+
+ parent = NULL;
+ p = &nommu_region_tree.rb_node;
+ while (*p) {
+ parent = *p;
+ pregion = rb_entry(parent, struct vm_region, vm_rb);
+ if (region->vm_start < pregion->vm_start)
+ p = &(*p)->rb_left;
+ else if (region->vm_start > pregion->vm_start)
+ p = &(*p)->rb_right;
+ else if (pregion == region)
+ return;
+ else
+ BUG();
}
- if (vml && vml->vma->vm_end > addr)
- return vml->vma;
+ rb_link_node(&region->vm_rb, parent, p);
+ rb_insert_color(&region->vm_rb, &nommu_region_tree);
- return NULL;
+ validate_nommu_regions();
}
-EXPORT_SYMBOL(find_vma);
/*
- * find a VMA
- * - we don't extend stack VMAs under NOMMU conditions
+ * delete a region from the global tree
*/
-struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
+static void delete_nommu_region(struct vm_region *region)
{
- return find_vma(mm, addr);
-}
+ BUG_ON(!nommu_region_tree.rb_node);
-int expand_stack(struct vm_area_struct *vma, unsigned long address)
-{
- return -ENOMEM;
+ validate_nommu_regions();
+ rb_erase(&region->vm_rb, &nommu_region_tree);
+ validate_nommu_regions();
}
/*
- * look up the first VMA exactly that exactly matches addr
- * - should be called with mm->mmap_sem at least held readlocked
+ * free a contiguous series of pages
*/
-static inline struct vm_area_struct *find_vma_exact(struct mm_struct *mm,
- unsigned long addr)
+static void free_page_series(unsigned long from, unsigned long to)
{
- struct vm_list_struct *vml;
-
- /* search the vm_start ordered list */
- for (vml = mm->context.vmlist; vml; vml = vml->next) {
- if (vml->vma->vm_start == addr)
- return vml->vma;
- if (vml->vma->vm_start > addr)
- break;
+ for (; from < to; from += PAGE_SIZE) {
+ struct page *page = virt_to_page(from);
+
+ kdebug("- free %lx", from);
+ atomic_dec(&mmap_pages_allocated);
+ if (page_count(page) != 1)
+ kdebug("free page %p [%d]", page, page_count(page));
+ put_page(page);
}
-
- return NULL;
}
/*
- * find a VMA in the global tree
+ * release a reference to a region
+ * - the caller must hold the region semaphore, which this releases
+ * - the region may not have been added to the tree yet, in which case vm_top
+ * will equal vm_start
*/
-static inline struct vm_area_struct *find_nommu_vma(unsigned long start)
+static void __put_nommu_region(struct vm_region *region)
+ __releases(nommu_region_sem)
{
- struct vm_area_struct *vma;
- struct rb_node *n = nommu_vma_tree.rb_node;
+ kenter("%p{%d}", region, atomic_read(&region->vm_usage));
- while (n) {
- vma = rb_entry(n, struct vm_area_struct, vm_rb);
+ BUG_ON(!nommu_region_tree.rb_node);
- if (start < vma->vm_start)
- n = n->rb_left;
- else if (start > vma->vm_start)
- n = n->rb_right;
- else
- return vma;
+ if (atomic_dec_and_test(&region->vm_usage)) {
+ if (region->vm_top > region->vm_start)
+ delete_nommu_region(region);
+ up_write(&nommu_region_sem);
+
+ if (region->vm_file)
+ fput(region->vm_file);
+
+ /* IO memory and memory shared directly out of the pagecache
+ * from ramfs/tmpfs mustn't be released here */
+ if (region->vm_flags & VM_MAPPED_COPY) {
+ kdebug("free series");
+ free_page_series(region->vm_start, region->vm_top);
+ }
+ kmem_cache_free(vm_region_jar, region);
+ } else {
+ up_write(&nommu_region_sem);
}
+}
- return NULL;
+/*
+ * release a reference to a region
+ */
+static void put_nommu_region(struct vm_region *region)
+{
+ down_write(&nommu_region_sem);
+ __put_nommu_region(region);
}
/*
- * add a VMA in the global tree
+ * add a VMA into a process's mm_struct in the appropriate place in the list
+ * and tree and add to the address space's page tree also if not an anonymous
+ * page
+ * - should be called with mm->mmap_sem held writelocked
*/
-static void add_nommu_vma(struct vm_area_struct *vma)
+static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
{
- struct vm_area_struct *pvma;
+ struct vm_area_struct *pvma, **pp;
struct address_space *mapping;
- struct rb_node **p = &nommu_vma_tree.rb_node;
- struct rb_node *parent = NULL;
+ struct rb_node **p, *parent;
+
+ kenter(",%p", vma);
+
+ BUG_ON(!vma->vm_region);
+
+ mm->map_count++;
+ vma->vm_mm = mm;
/* add the VMA to the mapping */
if (vma->vm_file) {
@@ -534,42 +622,62 @@ static void add_nommu_vma(struct vm_area_struct *vma)
flush_dcache_mmap_unlock(mapping);
}
- /* add the VMA to the master list */
+ /* add the VMA to the tree */
+ parent = NULL;
+ p = &mm->mm_rb.rb_node;
while (*p) {
parent = *p;
pvma = rb_entry(parent, struct vm_area_struct, vm_rb);
- if (vma->vm_start < pvma->vm_start) {
+ /* sort by: start addr, end addr, VMA struct addr in that order
+ * (the latter is necessary as we may get identical VMAs) */
+ if (vma->vm_start < pvma->vm_start)
p = &(*p)->rb_left;
- }
- else if (vma->vm_start > pvma->vm_start) {
+ else if (vma->vm_start > pvma->vm_start)
p = &(*p)->rb_right;
- }
- else {
- /* mappings are at the same address - this can only
- * happen for shared-mem chardevs and shared file
- * mappings backed by ramfs/tmpfs */
- BUG_ON(!(pvma->vm_flags & VM_SHARED));
-
- if (vma < pvma)
- p = &(*p)->rb_left;
- else if (vma > pvma)
- p = &(*p)->rb_right;
- else
- BUG();
- }
+ else if (vma->vm_end < pvma->vm_end)
+ p = &(*p)->rb_left;
+ else if (vma->vm_end > pvma->vm_end)
+ p = &(*p)->rb_right;
+ else if (vma < pvma)
+ p = &(*p)->rb_left;
+ else if (vma > pvma)
+ p = &(*p)->rb_right;
+ else
+ BUG();
}
rb_link_node(&vma->vm_rb, parent, p);
- rb_insert_color(&vma->vm_rb, &nommu_vma_tree);
+ rb_insert_color(&vma->vm_rb, &mm->mm_rb);
+
+ /* add VMA to the VMA list also */
+ for (pp = &mm->mmap; (pvma = *pp); pp = &(*pp)->vm_next) {
+ if (pvma->vm_start > vma->vm_start)
+ break;
+ if (pvma->vm_start < vma->vm_start)
+ continue;
+ if (pvma->vm_end < vma->vm_end)
+ break;
+ }
+
+ vma->vm_next = *pp;
+ *pp = vma;
}
/*
- * delete a VMA from the global list
+ * delete a VMA from its owning mm_struct and address space
*/
-static void delete_nommu_vma(struct vm_area_struct *vma)
+static void delete_vma_from_mm(struct vm_area_struct *vma)
{
+ struct vm_area_struct **pp;
struct address_space *mapping;
+ struct mm_struct *mm = vma->vm_mm;
+
+ kenter("%p", vma);
+
+ mm->map_count--;
+ if (mm->mmap_cache == vma)
+ mm->mmap_cache = NULL;
/* remove the VMA from the mapping */
if (vma->vm_file) {
@@ -580,8 +688,115 @@ static void delete_nommu_vma(struct vm_area_struct *vma)
flush_dcache_mmap_unlock(mapping);
}
- /* remove from the master list */
- rb_erase(&vma->vm_rb, &nommu_vma_tree);
+ /* remove from the MM's tree and list */
+ rb_erase(&vma->vm_rb, &mm->mm_rb);
+ for (pp = &mm->mmap; *pp; pp = &(*pp)->vm_next) {
+ if (*pp == vma) {
+ *pp = vma->vm_next;
+ break;
+ }
+ }
+
+ vma->vm_mm = NULL;
+}
+
+/*
+ * destroy a VMA record
+ */
+static void delete_vma(struct mm_struct *mm, struct vm_area_struct *vma)
+{
+ kenter("%p", vma);
+ if (vma->vm_ops && vma->vm_ops->close)
+ vma->vm_ops->close(vma);
+ if (vma->vm_file) {
+ fput(vma->vm_file);
+ if (vma->vm_flags & VM_EXECUTABLE)
+ removed_exe_file_vma(mm);
+ }
+ put_nommu_region(vma->vm_region);
+ kmem_cache_free(vm_area_cachep, vma);
+}
+
+/*
+ * look up the first VMA in which addr resides, NULL if none
+ * - should be called with mm->mmap_sem at least held readlocked
+ */
+struct vm_area_struct *find_vma(struct mm_struct *mm, unsigned long addr)
+{
+ struct vm_area_struct *vma;
+ struct rb_node *n = mm->mm_rb.rb_node;
+
+ /* check the cache first */
+ vma = mm->mmap_cache;
+ if (vma && vma->vm_start <= addr && vma->vm_end > addr)
+ return vma;
+
+ /* trawl the tree (there may be multiple mappings in which addr
+ * resides) */
+ for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) {
+ vma = rb_entry(n, struct vm_area_struct, vm_rb);
+ if (vma->vm_start > addr)
+ return NULL;
+ if (vma->vm_end > addr) {
+ mm->mmap_cache = vma;
+ return vma;
+ }
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL(find_vma);
+
+/*
+ * find a VMA
+ * - we don't extend stack VMAs under NOMMU conditions
+ */
+struct vm_area_struct *find_extend_vma(struct mm_struct *mm, unsigned long addr)
+{
+ return find_vma(mm, addr);
+}
+
+/*
+ * expand a stack to a given address
+ * - not supported under NOMMU conditions
+ */
+int expand_stack(struct vm_area_struct *vma, unsigned long address)
+{
+ return -ENOMEM;
+}
+
+/*
+ * look up the first VMA exactly that exactly matches addr
+ * - should be called with mm->mmap_sem at least held readlocked
+ */
+static struct vm_area_struct *find_vma_exact(struct mm_struct *mm,
+ unsigned long addr,
+ unsigned long len)
+{
+ struct vm_area_struct *vma;
+ struct rb_node *n = mm->mm_rb.rb_node;
+ unsigned long end = addr + len;
+
+ /* check the cache first */
+ vma = mm->mmap_cache;
+ if (vma && vma->vm_start == addr && vma->vm_end == end)
+ return vma;
+
+ /* trawl the tree (there may be multiple mappings in which addr
+ * resides) */
+ for (n = rb_first(&mm->mm_rb); n; n = rb_next(n)) {
+ vma = rb_entry(n, struct vm_area_struct, vm_rb);
+ if (vma->vm_start < addr)
+ continue;
+ if (vma->vm_start > addr)
+ return NULL;
+ if (vma->vm_end == end) {
+ mm->mmap_cache = vma;
+ return vma;
+ }
+ }
+
+ return NULL;
}
/*
@@ -596,7 +811,7 @@ static int validate_mmap_request(struct file *file,
unsigned long pgoff,
unsigned long *_capabilities)
{
- unsigned long capabilities;
+ unsigned long capabilities, rlen;
unsigned long reqprot = prot;
int ret;
@@ -616,12 +831,12 @@ static int validate_mmap_request(struct file *file,
return -EINVAL;
/* Careful about overflows.. */
- len = PAGE_ALIGN(len);
- if (!len || len > TASK_SIZE)
+ rlen = PAGE_ALIGN(len);
+ if (!rlen || rlen > TASK_SIZE)
return -ENOMEM;
/* offset overflow? */
- if ((pgoff + (len >> PAGE_SHIFT)) < pgoff)
+ if ((pgoff + (rlen >> PAGE_SHIFT)) < pgoff)
return -EOVERFLOW;
if (file) {
@@ -795,13 +1010,18 @@ static unsigned long determine_vm_flags(struct file *file,
}
/*
- * set up a shared mapping on a file
+ * set up a shared mapping on a file (the driver or filesystem provides and
+ * pins the storage)
*/
-static int do_mmap_shared_file(struct vm_area_struct *vma, unsigned long len)
+static int do_mmap_shared_file(struct vm_area_struct *vma)
{
int ret;
ret = vma->vm_file->f_op->mmap(vma->vm_file, vma);
+ if (ret == 0) {
+ vma->vm_region->vm_top = vma->vm_region->vm_end;
+ return ret;
+ }
if (ret != -ENOSYS)
return ret;
@@ -815,10 +1035,14 @@ static int do_mmap_shared_file(struct vm_area_struct *vma, unsigned long len)
/*
* set up a private mapping or an anonymous shared mapping
*/
-static int do_mmap_private(struct vm_area_struct *vma, unsigned long len)
+static int do_mmap_private(struct vm_area_struct *vma,
+ struct vm_region *region,
+ unsigned long len)
{
+ struct page *pages;
+ unsigned long total, point, n, rlen;
void *base;
- int ret;
+ int ret, order;
/* invoke the file's mapping function so that it can keep track of
* shared mappings on devices or memory
@@ -826,34 +1050,63 @@ static int do_mmap_private(struct vm_area_struct *vma, unsigned long len)
*/
if (vma->vm_file) {
ret = vma->vm_file->f_op->mmap(vma->vm_file, vma);
- if (ret != -ENOSYS) {
+ if (ret == 0) {
/* shouldn't return success if we're not sharing */
- BUG_ON(ret == 0 && !(vma->vm_flags & VM_MAYSHARE));
- return ret; /* success or a real error */
+ BUG_ON(!(vma->vm_flags & VM_MAYSHARE));
+ vma->vm_region->vm_top = vma->vm_region->vm_end;
+ return ret;
}
+ if (ret != -ENOSYS)
+ return ret;
/* getting an ENOSYS error indicates that direct mmap isn't
* possible (as opposed to tried but failed) so we'll try to
* make a private copy of the data and map that instead */
}
+ rlen = PAGE_ALIGN(len);
+
/* allocate some memory to hold the mapping
* - note that this may not return a page-aligned address if the object
* we're allocating is smaller than a page
*/
- base = kmalloc(len, GFP_KERNEL|__GFP_COMP);
- if (!base)
+ order = get_order(rlen);
+ kdebug("alloc order %d for %lx", order, len);
+
+ pages = alloc_pages(GFP_KERNEL, order);
+ if (!pages)
goto enomem;
- vma->vm_start = (unsigned long) base;
- vma->vm_end = vma->vm_start + len;
- vma->vm_flags |= VM_MAPPED_COPY;
+ total = 1 << order;
+ atomic_add(total, &mmap_pages_allocated);
+
+ point = rlen >> PAGE_SHIFT;
+
+ /* we allocated a power-of-2 sized page set, so we may want to trim off
+ * the excess */
+ if (sysctl_nr_trim_pages && total - point >= sysctl_nr_trim_pages) {
+ while (total > point) {
+ order = ilog2(total - point);
+ n = 1 << order;
+ kdebug("shave %lu/%lu @%lu", n, total - point, total);
+ atomic_sub(n, &mmap_pages_allocated);
+ total -= n;
+ set_page_refcounted(pages + total);
+ __free_pages(pages + total, order);
+ }
+ }
+
+ for (point = 1; point < total; point++)
+ set_page_refcounted(&pages[point]);
-#ifdef WARN_ON_SLACK
- if (len + WARN_ON_SLACK <= kobjsize(result))
- printk("Allocation of %lu bytes from process %d has %lu bytes of slack\n",
- len, current->pid, kobjsize(result) - len);
-#endif
+ base = page_address(pages);
+ region->vm_flags = vma->vm_flags |= VM_MAPPED_COPY;
+ region->vm_start = (unsigned long) base;
+ region->vm_end = region->vm_start + rlen;
+ region->vm_top = region->vm_start + (total << PAGE_SHIFT);
+
+ vma->vm_start = region->vm_start;
+ vma->vm_end = region->vm_start + len;
if (vma->vm_file) {
/* read the contents of a file into the copy */
@@ -865,26 +1118,28 @@ static int do_mmap_private(struct vm_area_struct *vma, unsigned long len)
old_fs = get_fs();
set_fs(KERNEL_DS);
- ret = vma->vm_file->f_op->read(vma->vm_file, base, len, &fpos);
+ ret = vma->vm_file->f_op->read(vma->vm_file, base, rlen, &fpos);
set_fs(old_fs);
if (ret < 0)
goto error_free;
/* clear the last little bit */
- if (ret < len)
- memset(base + ret, 0, len - ret);
+ if (ret < rlen)
+ memset(base + ret, 0, rlen - ret);
} else {
/* if it's an anonymous mapping, then just clear it */
- memset(base, 0, len);
+ memset(base, 0, rlen);
}
return 0;
error_free:
- kfree(base);
- vma->vm_start = 0;
+ free_page_series(region->vm_start, region->vm_end);
+ region->vm_start = vma->vm_start = 0;
+ region->vm_end = vma->vm_end = 0;
+ region->vm_top = 0;
return ret;
enomem:
@@ -904,13 +1159,14 @@ unsigned long do_mmap_pgoff(struct file *file,
unsigned long flags,
unsigned long pgoff)
{
- struct vm_list_struct *vml = NULL;
- struct vm_area_struct *vma = NULL;
+ struct vm_area_struct *vma;
+ struct vm_region *region;
struct rb_node *rb;
- unsigned long capabilities, vm_flags;
- void *result;
+ unsigned long capabilities, vm_flags, result;
int ret;
+ kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff);
+
if (!(flags & MAP_FIXED))
addr = round_hint_to_min(addr);
@@ -918,73 +1174,120 @@ unsigned long do_mmap_pgoff(struct file *file,
* mapping */
ret = validate_mmap_request(file, addr, len, prot, flags, pgoff,
&capabilities);
- if (ret < 0)
+ if (ret < 0) {
+ kleave(" = %d [val]", ret);
return ret;
+ }
/* we've determined that we can make the mapping, now translate what we
* now know into VMA flags */
vm_flags = determine_vm_flags(file, prot, flags, capabilities);
- /* we're going to need to record the mapping if it works */
- vml = kzalloc(sizeof(struct vm_list_struct), GFP_KERNEL);
- if (!vml)
- goto error_getting_vml;
+ /* we're going to need to record the mapping */
+ region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL);
+ if (!region)
+ goto error_getting_region;
+
+ vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
+ if (!vma)
+ goto error_getting_vma;
+
+ atomic_set(&region->vm_usage, 1);
+ region->vm_flags = vm_flags;
+ region->vm_pgoff = pgoff;
+
+ INIT_LIST_HEAD(&vma->anon_vma_node);
+ vma->vm_flags = vm_flags;
+ vma->vm_pgoff = pgoff;
- down_write(&nommu_vma_sem);
+ if (file) {
+ region->vm_file = file;
+ get_file(file);
+ vma->vm_file = file;
+ get_file(file);
+ if (vm_flags & VM_EXECUTABLE) {
+ added_exe_file_vma(current->mm);
+ vma->vm_mm = current->mm;
+ }
+ }
- /* if we want to share, we need to check for VMAs created by other
+ down_write(&nommu_region_sem);
+
+ /* if we want to share, we need to check for regions created by other
* mmap() calls that overlap with our proposed mapping
- * - we can only share with an exact match on most regular files
+ * - we can only share with a superset match on most regular files
* - shared mappings on character devices and memory backed files are
* permitted to overlap inexactly as far as we are concerned for in
* these cases, sharing is handled in the driver or filesystem rather
* than here
*/
if (vm_flags & VM_MAYSHARE) {
- unsigned long pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
- unsigned long vmpglen;
+ struct vm_region *pregion;
+ unsigned long pglen, rpglen, pgend, rpgend, start;
- /* suppress VMA sharing for shared regions */
- if (vm_flags & VM_SHARED &&
- capabilities & BDI_CAP_MAP_DIRECT)
- goto dont_share_VMAs;
+ pglen = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ pgend = pgoff + pglen;
- for (rb = rb_first(&nommu_vma_tree); rb; rb = rb_next(rb)) {
- vma = rb_entry(rb, struct vm_area_struct, vm_rb);
+ for (rb = rb_first(&nommu_region_tree); rb; rb = rb_next(rb)) {
+ pregion = rb_entry(rb, struct vm_region, vm_rb);
- if (!(vma->vm_flags & VM_MAYSHARE))
+ if (!(pregion->vm_flags & VM_MAYSHARE))
continue;
/* search for overlapping mappings on the same file */
- if (vma->vm_file->f_path.dentry->d_inode != file->f_path.dentry->d_inode)
+ if (pregion->vm_file->f_path.dentry->d_inode !=
+ file->f_path.dentry->d_inode)
continue;
- if (vma->vm_pgoff >= pgoff + pglen)
+ if (pregion->vm_pgoff >= pgend)
continue;
- vmpglen = vma->vm_end - vma->vm_start + PAGE_SIZE - 1;
- vmpglen >>= PAGE_SHIFT;
- if (pgoff >= vma->vm_pgoff + vmpglen)
+ rpglen = pregion->vm_end - pregion->vm_start;
+ rpglen = (rpglen + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ rpgend = pregion->vm_pgoff + rpglen;
+ if (pgoff >= rpgend)
continue;
- /* handle inexactly overlapping matches between mappings */
- if (vma->vm_pgoff != pgoff || vmpglen != pglen) {
+ /* handle inexactly overlapping matches between
+ * mappings */
+ if ((pregion->vm_pgoff != pgoff || rpglen != pglen) &&
+ !(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) {
+ /* new mapping is not a subset of the region */
if (!(capabilities & BDI_CAP_MAP_DIRECT))
goto sharing_violation;
continue;
}
- /* we've found a VMA we can share */
- atomic_inc(&vma->vm_usage);
-
- vml->vma = vma;
- result = (void *) vma->vm_start;
- goto shared;
+ /* we've found a region we can share */
+ atomic_inc(&pregion->vm_usage);
+ vma->vm_region = pregion;
+ start = pregion->vm_start;
+ start += (pgoff - pregion->vm_pgoff) << PAGE_SHIFT;
+ vma->vm_start = start;
+ vma->vm_end = start + len;
+
+ if (pregion->vm_flags & VM_MAPPED_COPY) {
+ kdebug("share copy");
+ vma->vm_flags |= VM_MAPPED_COPY;
+ } else {
+ kdebug("share mmap");
+ ret = do_mmap_shared_file(vma);
+ if (ret < 0) {
+ vma->vm_region = NULL;
+ vma->vm_start = 0;
+ vma->vm_end = 0;
+ atomic_dec(&pregion->vm_usage);
+ pregion = NULL;
+ goto error_just_free;
+ }
+ }
+ fput(region->vm_file);
+ kmem_cache_free(vm_region_jar, region);
+ region = pregion;
+ result = start;
+ goto share;
}
- dont_share_VMAs:
- vma = NULL;
-
/* obtain the address at which to make a shared mapping
* - this is the hook for quasi-memory character devices to
* tell us the location of a shared mapping
@@ -995,113 +1298,93 @@ unsigned long do_mmap_pgoff(struct file *file,
if (IS_ERR((void *) addr)) {
ret = addr;
if (ret != (unsigned long) -ENOSYS)
- goto error;
+ goto error_just_free;
/* the driver refused to tell us where to site
* the mapping so we'll have to attempt to copy
* it */
ret = (unsigned long) -ENODEV;
if (!(capabilities & BDI_CAP_MAP_COPY))
- goto error;
+ goto error_just_free;
capabilities &= ~BDI_CAP_MAP_DIRECT;
+ } else {
+ vma->vm_start = region->vm_start = addr;
+ vma->vm_end = region->vm_end = addr + len;
}
}
}
- /* we're going to need a VMA struct as well */
- vma = kzalloc(sizeof(struct vm_area_struct), GFP_KERNEL);
- if (!vma)
- goto error_getting_vma;
-
- INIT_LIST_HEAD(&vma->anon_vma_node);
- atomic_set(&vma->vm_usage, 1);
- if (file) {
- get_file(file);
- if (vm_flags & VM_EXECUTABLE) {
- added_exe_file_vma(current->mm);
- vma->vm_mm = current->mm;
- }
- }
- vma->vm_file = file;
- vma->vm_flags = vm_flags;
- vma->vm_start = addr;
- vma->vm_end = addr + len;
- vma->vm_pgoff = pgoff;
-
- vml->vma = vma;
+ vma->vm_region = region;
/* set up the mapping */
if (file && vma->vm_flags & VM_SHARED)
- ret = do_mmap_shared_file(vma, len);
+ ret = do_mmap_shared_file(vma);
else
- ret = do_mmap_private(vma, len);
+ ret = do_mmap_private(vma, region, len);
if (ret < 0)
- goto error;
-
- /* okay... we have a mapping; now we have to register it */
- result = (void *) vma->vm_start;
+ goto error_put_region;
- if (vma->vm_flags & VM_MAPPED_COPY) {
- realalloc += kobjsize(result);
- askedalloc += len;
- }
+ add_nommu_region(region);
- realalloc += kobjsize(vma);
- askedalloc += sizeof(*vma);
+ /* okay... we have a mapping; now we have to register it */
+ result = vma->vm_start;
current->mm->total_vm += len >> PAGE_SHIFT;
- add_nommu_vma(vma);
-
- shared:
- realalloc += kobjsize(vml);
- askedalloc += sizeof(*vml);
-
- add_vma_to_mm(current->mm, vml);
+share:
+ add_vma_to_mm(current->mm, vma);
- up_write(&nommu_vma_sem);
+ up_write(&nommu_region_sem);
if (prot & PROT_EXEC)
- flush_icache_range((unsigned long) result,
- (unsigned long) result + len);
+ flush_icache_range(result, result + len);
-#ifdef DEBUG
- printk("do_mmap:\n");
- show_process_blocks();
-#endif
-
- return (unsigned long) result;
+ kleave(" = %lx", result);
+ return result;
- error:
- up_write(&nommu_vma_sem);
- kfree(vml);
+error_put_region:
+ __put_nommu_region(region);
if (vma) {
if (vma->vm_file) {
fput(vma->vm_file);
if (vma->vm_flags & VM_EXECUTABLE)
removed_exe_file_vma(vma->vm_mm);
}
- kfree(vma);
+ kmem_cache_free(vm_area_cachep, vma);
}
+ kleave(" = %d [pr]", ret);
return ret;
- sharing_violation:
- up_write(&nommu_vma_sem);
- printk("Attempt to share mismatched mappings\n");
- kfree(vml);
- return -EINVAL;
+error_just_free:
+ up_write(&nommu_region_sem);
+error:
+ fput(region->vm_file);
+ kmem_cache_free(vm_region_jar, region);
+ fput(vma->vm_file);
+ if (vma->vm_flags & VM_EXECUTABLE)
+ removed_exe_file_vma(vma->vm_mm);
+ kmem_cache_free(vm_area_cachep, vma);
+ kleave(" = %d", ret);
+ return ret;
- error_getting_vma:
- up_write(&nommu_vma_sem);
- kfree(vml);
- printk("Allocation of vma for %lu byte allocation from process %d failed\n",
+sharing_violation:
+ up_write(&nommu_region_sem);
+ printk(KERN_WARNING "Attempt to share mismatched mappings\n");
+ ret = -EINVAL;
+ goto error;
+
+error_getting_vma:
+ kmem_cache_free(vm_region_jar, region);
+ printk(KERN_WARNING "Allocation of vma for %lu byte allocation"
+ " from process %d failed\n",
len, current->pid);
show_free_areas();
return -ENOMEM;
- error_getting_vml:
- printk("Allocation of vml for %lu byte allocation from process %d failed\n",
+error_getting_region:
+ printk(KERN_WARNING "Allocation of vm region for %lu byte allocation"
+ " from process %d failed\n",
len, current->pid);
show_free_areas();
return -ENOMEM;
@@ -1109,85 +1392,183 @@ unsigned long do_mmap_pgoff(struct file *file,
EXPORT_SYMBOL(do_mmap_pgoff);
/*
- * handle mapping disposal for uClinux
+ * split a vma into two pieces at address 'addr', a new vma is allocated either
+ * for the first part or the tail.
*/
-static void put_vma(struct mm_struct *mm, struct vm_area_struct *vma)
+int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long addr, int new_below)
{
- if (vma) {
- down_write(&nommu_vma_sem);
+ struct vm_area_struct *new;
+ struct vm_region *region;
+ unsigned long npages;
- if (atomic_dec_and_test(&vma->vm_usage)) {
- delete_nommu_vma(vma);
+ kenter("");
- if (vma->vm_ops && vma->vm_ops->close)
- vma->vm_ops->close(vma);
+ /* we're only permitted to split anonymous regions that have a single
+ * owner */
+ if (vma->vm_file ||
+ atomic_read(&vma->vm_region->vm_usage) != 1)
+ return -ENOMEM;
- /* IO memory and memory shared directly out of the pagecache from
- * ramfs/tmpfs mustn't be released here */
- if (vma->vm_flags & VM_MAPPED_COPY) {
- realalloc -= kobjsize((void *) vma->vm_start);
- askedalloc -= vma->vm_end - vma->vm_start;
- kfree((void *) vma->vm_start);
- }
+ if (mm->map_count >= sysctl_max_map_count)
+ return -ENOMEM;
- realalloc -= kobjsize(vma);
- askedalloc -= sizeof(*vma);
+ region = kmem_cache_alloc(vm_region_jar, GFP_KERNEL);
+ if (!region)
+ return -ENOMEM;
- if (vma->vm_file) {
- fput(vma->vm_file);
- if (vma->vm_flags & VM_EXECUTABLE)
- removed_exe_file_vma(mm);
- }
- kfree(vma);
- }
+ new = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
+ if (!new) {
+ kmem_cache_free(vm_region_jar, region);
+ return -ENOMEM;
+ }
+
+ /* most fields are the same, copy all, and then fixup */
+ *new = *vma;
+ *region = *vma->vm_region;
+ new->vm_region = region;
+
+ npages = (addr - vma->vm_start) >> PAGE_SHIFT;
- up_write(&nommu_vma_sem);
+ if (new_below) {
+ region->vm_top = region->vm_end = new->vm_end = addr;
+ } else {
+ region->vm_start = new->vm_start = addr;
+ region->vm_pgoff = new->vm_pgoff += npages;
+ }
+
+ if (new->vm_ops && new->vm_ops->open)
+ new->vm_ops->open(new);
+
+ delete_vma_from_mm(vma);
+ down_write(&nommu_region_sem);
+ delete_nommu_region(vma->vm_region);
+ if (new_below) {
+ vma->vm_region->vm_start = vma->vm_start = addr;
+ vma->vm_region->vm_pgoff = vma->vm_pgoff += npages;
+ } else {
+ vma->vm_region->vm_end = vma->vm_end = addr;
+ vma->vm_region->vm_top = addr;
}
+ add_nommu_region(vma->vm_region);
+ add_nommu_region(new->vm_region);
+ up_write(&nommu_region_sem);
+ add_vma_to_mm(mm, vma);
+ add_vma_to_mm(mm, new);
+ return 0;
}
/*
- * release a mapping
- * - under NOMMU conditions the parameters must match exactly to the mapping to
- * be removed
+ * shrink a VMA by removing the specified chunk from either the beginning or
+ * the end
*/
-int do_munmap(struct mm_struct *mm, unsigned long addr, size_t len)
+static int shrink_vma(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long from, unsigned long to)
{
- struct vm_list_struct *vml, **parent;
- unsigned long end = addr + len;
+ struct vm_region *region;
-#ifdef DEBUG
- printk("do_munmap:\n");
-#endif
+ kenter("");
- for (parent = &mm->context.vmlist; *parent; parent = &(*parent)->next) {
- if ((*parent)->vma->vm_start > addr)
- break;
- if ((*parent)->vma->vm_start == addr &&
- ((len == 0) || ((*parent)->vma->vm_end == end)))
- goto found;
+ /* adjust the VMA's pointers, which may reposition it in the MM's tree
+ * and list */
+ delete_vma_from_mm(vma);
+ if (from > vma->vm_start)
+ vma->vm_end = from;
+ else
+ vma->vm_start = to;
+ add_vma_to_mm(mm, vma);
+
+ /* cut the backing region down to size */
+ region = vma->vm_region;
+ BUG_ON(atomic_read(&region->vm_usage) != 1);
+
+ down_write(&nommu_region_sem);
+ delete_nommu_region(region);
+ if (from > region->vm_start) {
+ to = region->vm_top;
+ region->vm_top = region->vm_end = from;
+ } else {
+ region->vm_start = to;
}
+ add_nommu_region(region);
+ up_write(&nommu_region_sem);
- printk("munmap of non-mmaped memory by process %d (%s): %p\n",
- current->pid, current->comm, (void *) addr);
- return -EINVAL;
+ free_page_series(from, to);
+ return 0;
+}
- found:
- vml = *parent;
+/*
+ * release a mapping
+ * - under NOMMU conditions the chunk to be unmapped must be backed by a single
+ * VMA, though it need not cover the whole VMA
+ */
+int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
+{
+ struct vm_area_struct *vma;
+ struct rb_node *rb;
+ unsigned long end = start + len;
+ int ret;
- put_vma(mm, vml->vma);
+ kenter(",%lx,%zx", start, len);
- *parent = vml->next;
- realalloc -= kobjsize(vml);
- askedalloc -= sizeof(*vml);
- kfree(vml);
+ if (len == 0)
+ return -EINVAL;
- update_hiwater_vm(mm);
- mm->total_vm -= len >> PAGE_SHIFT;
+ /* find the first potentially overlapping VMA */
+ vma = find_vma(mm, start);
+ if (!vma) {
+ printk(KERN_WARNING
+ "munmap of memory not mmapped by process %d (%s):"
+ " 0x%lx-0x%lx\n",
+ current->pid, current->comm, start, start + len - 1);
+ return -EINVAL;
+ }
-#ifdef DEBUG
- show_process_blocks();
-#endif
+ /* we're allowed to split an anonymous VMA but not a file-backed one */
+ if (vma->vm_file) {
+ do {
+ if (start > vma->vm_start) {
+ kleave(" = -EINVAL [miss]");
+ return -EINVAL;
+ }
+ if (end == vma->vm_end)
+ goto erase_whole_vma;
+ rb = rb_next(&vma->vm_rb);
+ vma = rb_entry(rb, struct vm_area_struct, vm_rb);
+ } while (rb);
+ kleave(" = -EINVAL [split file]");
+ return -EINVAL;
+ } else {
+ /* the chunk must be a subset of the VMA found */
+ if (start == vma->vm_start && end == vma->vm_end)
+ goto erase_whole_vma;
+ if (start < vma->vm_start || end > vma->vm_end) {
+ kleave(" = -EINVAL [superset]");
+ return -EINVAL;
+ }
+ if (start & ~PAGE_MASK) {
+ kleave(" = -EINVAL [unaligned start]");
+ return -EINVAL;
+ }
+ if (end != vma->vm_end && end & ~PAGE_MASK) {
+ kleave(" = -EINVAL [unaligned split]");
+ return -EINVAL;
+ }
+ if (start != vma->vm_start && end != vma->vm_end) {
+ ret = split_vma(mm, vma, start, 1);
+ if (ret < 0) {
+ kleave(" = %d [split]", ret);
+ return ret;
+ }
+ }
+ return shrink_vma(mm, vma, start, end);
+ }
+erase_whole_vma:
+ delete_vma_from_mm(vma);
+ delete_vma(mm, vma);
+ kleave(" = 0");
return 0;
}
EXPORT_SYMBOL(do_munmap);
@@ -1204,32 +1585,26 @@ asmlinkage long sys_munmap(unsigned long addr, size_t len)
}
/*
- * Release all mappings
+ * release all the mappings made in a process's VM space
*/
-void exit_mmap(struct mm_struct * mm)
+void exit_mmap(struct mm_struct *mm)
{
- struct vm_list_struct *tmp;
-
- if (mm) {
-#ifdef DEBUG
- printk("Exit_mmap:\n");
-#endif
+ struct vm_area_struct *vma;
- mm->total_vm = 0;
+ if (!mm)
+ return;
- while ((tmp = mm->context.vmlist)) {
- mm->context.vmlist = tmp->next;
- put_vma(mm, tmp->vma);
+ kenter("");
- realalloc -= kobjsize(tmp);
- askedalloc -= sizeof(*tmp);
- kfree(tmp);
- }
+ mm->total_vm = 0;
-#ifdef DEBUG
- show_process_blocks();
-#endif
+ while ((vma = mm->mmap)) {
+ mm->mmap = vma->vm_next;
+ delete_vma_from_mm(vma);
+ delete_vma(mm, vma);
}
+
+ kleave("");
}
unsigned long do_brk(unsigned long addr, unsigned long len)
@@ -1242,8 +1617,8 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
* time (controlled by the MREMAP_MAYMOVE flag and available VM space)
*
* under NOMMU conditions, we only permit changing a mapping's size, and only
- * as long as it stays within the hole allocated by the kmalloc() call in
- * do_mmap_pgoff() and the block is not shareable
+ * as long as it stays within the region allocated by do_mmap_private() and the
+ * block is not shareable
*
* MREMAP_FIXED is not supported under NOMMU conditions
*/
@@ -1254,13 +1629,16 @@ unsigned long do_mremap(unsigned long addr,
struct vm_area_struct *vma;
/* insanity checks first */
- if (new_len == 0)
+ if (old_len == 0 || new_len == 0)
return (unsigned long) -EINVAL;
+ if (addr & ~PAGE_MASK)
+ return -EINVAL;
+
if (flags & MREMAP_FIXED && new_addr != addr)
return (unsigned long) -EINVAL;
- vma = find_vma_exact(current->mm, addr);
+ vma = find_vma_exact(current->mm, addr, old_len);
if (!vma)
return (unsigned long) -EINVAL;
@@ -1270,22 +1648,19 @@ unsigned long do_mremap(unsigned long addr,
if (vma->vm_flags & VM_MAYSHARE)
return (unsigned long) -EPERM;
- if (new_len > kobjsize((void *) addr))
+ if (new_len > vma->vm_region->vm_end - vma->vm_region->vm_start)
return (unsigned long) -ENOMEM;
/* all checks complete - do it */
vma->vm_end = vma->vm_start + new_len;
-
- askedalloc -= old_len;
- askedalloc += new_len;
-
return vma->vm_start;
}
EXPORT_SYMBOL(do_mremap);
-asmlinkage unsigned long sys_mremap(unsigned long addr,
- unsigned long old_len, unsigned long new_len,
- unsigned long flags, unsigned long new_addr)
+asmlinkage
+unsigned long sys_mremap(unsigned long addr,
+ unsigned long old_len, unsigned long new_len,
+ unsigned long flags, unsigned long new_addr)
{
unsigned long ret;
generated by cgit v1.1 at 2024-12-26 19:33:25 +0000