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-rw-r--r--mm/nommu.c130
1 files changed, 49 insertions, 81 deletions
diff --git a/mm/nommu.c b/mm/nommu.c
index 66e81e7e9fe9..5189b5aed8c0 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -33,6 +33,7 @@
#include <asm/uaccess.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
#include "internal.h"
static inline __attribute__((format(printf, 1, 2)))
@@ -56,12 +57,11 @@ void no_printk(const char *fmt, ...)
no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
#endif
-#include "internal.h"
-
void *high_memory;
struct page *mem_map;
unsigned long max_mapnr;
unsigned long num_physpages;
+unsigned long highest_memmap_pfn;
struct percpu_counter vm_committed_as;
int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
int sysctl_overcommit_ratio = 50; /* default is 50% */
@@ -79,50 +79,10 @@ 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 = {
+const struct vm_operations_struct generic_file_vm_ops = {
};
/*
- * Handle all mappings that got truncated by a "truncate()"
- * system call.
- *
- * NOTE! We have to be ready to update the memory sharing
- * between the file and the memory map for a potential last
- * incomplete page. Ugly, but necessary.
- */
-int vmtruncate(struct inode *inode, loff_t offset)
-{
- struct address_space *mapping = inode->i_mapping;
- unsigned long limit;
-
- if (inode->i_size < offset)
- goto do_expand;
- i_size_write(inode, offset);
-
- truncate_inode_pages(mapping, offset);
- goto out_truncate;
-
-do_expand:
- limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
- if (limit != RLIM_INFINITY && offset > limit)
- goto out_sig;
- if (offset > inode->i_sb->s_maxbytes)
- goto out;
- i_size_write(inode, offset);
-
-out_truncate:
- if (inode->i_op->truncate)
- inode->i_op->truncate(inode);
- return 0;
-out_sig:
- send_sig(SIGXFSZ, current, 0);
-out:
- return -EFBIG;
-}
-
-EXPORT_SYMBOL(vmtruncate);
-
-/*
* Return the total memory allocated for this pointer, not
* just what the caller asked for.
*
@@ -170,21 +130,20 @@ unsigned int kobjsize(const void *objp)
}
int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long start, int nr_pages, int flags,
+ unsigned long start, int nr_pages, unsigned int foll_flags,
struct page **pages, struct vm_area_struct **vmas)
{
struct vm_area_struct *vma;
unsigned long vm_flags;
int i;
- int write = !!(flags & GUP_FLAGS_WRITE);
- int force = !!(flags & GUP_FLAGS_FORCE);
- int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS);
/* calculate required read or write permissions.
- * - if 'force' is set, we only require the "MAY" flags.
+ * If FOLL_FORCE is set, we only require the "MAY" flags.
*/
- vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
- vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
+ vm_flags = (foll_flags & FOLL_WRITE) ?
+ (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
+ vm_flags &= (foll_flags & FOLL_FORCE) ?
+ (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
for (i = 0; i < nr_pages; i++) {
vma = find_vma(mm, start);
@@ -192,8 +151,8 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
goto finish_or_fault;
/* protect what we can, including chardevs */
- if (vma->vm_flags & (VM_IO | VM_PFNMAP) ||
- (!ignore && !(vm_flags & vma->vm_flags)))
+ if ((vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
+ !(vm_flags & vma->vm_flags))
goto finish_or_fault;
if (pages) {
@@ -212,7 +171,6 @@ finish_or_fault:
return i ? : -EFAULT;
}
-
/*
* get a list of pages in an address range belonging to the specified process
* and indicate the VMA that covers each page
@@ -227,9 +185,9 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
int flags = 0;
if (write)
- flags |= GUP_FLAGS_WRITE;
+ flags |= FOLL_WRITE;
if (force)
- flags |= GUP_FLAGS_FORCE;
+ flags |= FOLL_FORCE;
return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas);
}
@@ -627,6 +585,22 @@ static void put_nommu_region(struct vm_region *region)
}
/*
+ * update protection on a vma
+ */
+static void protect_vma(struct vm_area_struct *vma, unsigned long flags)
+{
+#ifdef CONFIG_MPU
+ struct mm_struct *mm = vma->vm_mm;
+ long start = vma->vm_start & PAGE_MASK;
+ while (start < vma->vm_end) {
+ protect_page(mm, start, flags);
+ start += PAGE_SIZE;
+ }
+ update_protections(mm);
+#endif
+}
+
+/*
* 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
@@ -645,6 +619,8 @@ static void add_vma_to_mm(struct mm_struct *mm, struct vm_area_struct *vma)
mm->map_count++;
vma->vm_mm = mm;
+ protect_vma(vma, vma->vm_flags);
+
/* add the VMA to the mapping */
if (vma->vm_file) {
mapping = vma->vm_file->f_mapping;
@@ -707,6 +683,8 @@ static void delete_vma_from_mm(struct vm_area_struct *vma)
kenter("%p", vma);
+ protect_vma(vma, 0);
+
mm->map_count--;
if (mm->mmap_cache == vma)
mm->mmap_cache = NULL;
@@ -848,7 +826,7 @@ static int validate_mmap_request(struct file *file,
int ret;
/* do the simple checks first */
- if (flags & MAP_FIXED || addr) {
+ if (flags & MAP_FIXED) {
printk(KERN_DEBUG
"%d: Can't do fixed-address/overlay mmap of RAM\n",
current->pid);
@@ -1056,7 +1034,7 @@ static int do_mmap_shared_file(struct vm_area_struct *vma)
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;
+ return 0;
}
if (ret != -ENOSYS)
return ret;
@@ -1073,7 +1051,8 @@ static int do_mmap_shared_file(struct vm_area_struct *vma)
*/
static int do_mmap_private(struct vm_area_struct *vma,
struct vm_region *region,
- unsigned long len)
+ unsigned long len,
+ unsigned long capabilities)
{
struct page *pages;
unsigned long total, point, n, rlen;
@@ -1084,13 +1063,13 @@ static int do_mmap_private(struct vm_area_struct *vma,
* shared mappings on devices or memory
* - VM_MAYSHARE will be set if it may attempt to share
*/
- if (vma->vm_file) {
+ if (capabilities & BDI_CAP_MAP_DIRECT) {
ret = vma->vm_file->f_op->mmap(vma->vm_file, vma);
if (ret == 0) {
/* shouldn't return success if we're not sharing */
BUG_ON(!(vma->vm_flags & VM_MAYSHARE));
vma->vm_region->vm_top = vma->vm_region->vm_end;
- return ret;
+ return 0;
}
if (ret != -ENOSYS)
return ret;
@@ -1203,9 +1182,6 @@ unsigned long do_mmap_pgoff(struct file *file,
kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff);
- if (!(flags & MAP_FIXED))
- addr = round_hint_to_min(addr);
-
/* decide whether we should attempt the mapping, and if so what sort of
* mapping */
ret = validate_mmap_request(file, addr, len, prot, flags, pgoff,
@@ -1215,6 +1191,9 @@ unsigned long do_mmap_pgoff(struct file *file,
return ret;
}
+ /* we ignore the address hint */
+ addr = 0;
+
/* 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);
@@ -1328,7 +1307,7 @@ unsigned long do_mmap_pgoff(struct file *file,
* - this is the hook for quasi-memory character devices to
* tell us the location of a shared mapping
*/
- if (file && file->f_op->get_unmapped_area) {
+ if (capabilities & BDI_CAP_MAP_DIRECT) {
addr = file->f_op->get_unmapped_area(file, addr, len,
pgoff, flags);
if (IS_ERR((void *) addr)) {
@@ -1352,15 +1331,17 @@ unsigned long do_mmap_pgoff(struct file *file,
}
vma->vm_region = region;
- add_nommu_region(region);
- /* set up the mapping */
+ /* set up the mapping
+ * - the region is filled in if BDI_CAP_MAP_DIRECT is still set
+ */
if (file && vma->vm_flags & VM_SHARED)
ret = do_mmap_shared_file(vma);
else
- ret = do_mmap_private(vma, region, len);
+ ret = do_mmap_private(vma, region, len, capabilities);
if (ret < 0)
- goto error_put_region;
+ goto error_just_free;
+ add_nommu_region(region);
/* okay... we have a mapping; now we have to register it */
result = vma->vm_start;
@@ -1378,19 +1359,6 @@ share:
kleave(" = %lx", result);
return result;
-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);
- }
- kmem_cache_free(vm_area_cachep, vma);
- }
- kleave(" = %d [pr]", ret);
- return ret;
-
error_just_free:
up_write(&nommu_region_sem);
error:
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.