summaryrefslogtreecommitdiff
path: root/mm/mmap.c
diff options
context:
space:
mode:
authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-06-10 05:30:17 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-06-10 05:30:17 -0300
commitd635711daa98be86d4c7fd01499c34f566b54ccb (patch)
treeaa5cc3760a27c3d57146498cb82fa549547de06c /mm/mmap.c
parentc91265cd0efb83778f015b4d4b1129bd2cfd075e (diff)
Linux-libre 4.6.2-gnu
Diffstat (limited to 'mm/mmap.c')
-rw-r--r--mm/mmap.c176
1 files changed, 40 insertions, 136 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index fdd163e22..7328b7436 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -37,12 +37,12 @@
#include <linux/khugepaged.h>
#include <linux/uprobes.h>
#include <linux/rbtree_augmented.h>
-#include <linux/sched/sysctl.h>
#include <linux/notifier.h>
#include <linux/memory.h>
#include <linux/printk.h>
#include <linux/userfaultfd_k.h>
#include <linux/moduleparam.h>
+#include <linux/pkeys.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
@@ -123,130 +123,6 @@ void vma_set_page_prot(struct vm_area_struct *vma)
}
}
-
-int sysctl_overcommit_memory __read_mostly = OVERCOMMIT_GUESS; /* heuristic overcommit */
-int sysctl_overcommit_ratio __read_mostly = 50; /* default is 50% */
-unsigned long sysctl_overcommit_kbytes __read_mostly;
-int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
-unsigned long sysctl_user_reserve_kbytes __read_mostly = 1UL << 17; /* 128MB */
-unsigned long sysctl_admin_reserve_kbytes __read_mostly = 1UL << 13; /* 8MB */
-/*
- * Make sure vm_committed_as in one cacheline and not cacheline shared with
- * other variables. It can be updated by several CPUs frequently.
- */
-struct percpu_counter vm_committed_as ____cacheline_aligned_in_smp;
-
-/*
- * The global memory commitment made in the system can be a metric
- * that can be used to drive ballooning decisions when Linux is hosted
- * as a guest. On Hyper-V, the host implements a policy engine for dynamically
- * balancing memory across competing virtual machines that are hosted.
- * Several metrics drive this policy engine including the guest reported
- * memory commitment.
- */
-unsigned long vm_memory_committed(void)
-{
- return percpu_counter_read_positive(&vm_committed_as);
-}
-EXPORT_SYMBOL_GPL(vm_memory_committed);
-
-/*
- * Check that a process has enough memory to allocate a new virtual
- * mapping. 0 means there is enough memory for the allocation to
- * succeed and -ENOMEM implies there is not.
- *
- * We currently support three overcommit policies, which are set via the
- * vm.overcommit_memory sysctl. See Documentation/vm/overcommit-accounting
- *
- * Strict overcommit modes added 2002 Feb 26 by Alan Cox.
- * Additional code 2002 Jul 20 by Robert Love.
- *
- * cap_sys_admin is 1 if the process has admin privileges, 0 otherwise.
- *
- * Note this is a helper function intended to be used by LSMs which
- * wish to use this logic.
- */
-int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin)
-{
- long free, allowed, reserve;
-
- VM_WARN_ONCE(percpu_counter_read(&vm_committed_as) <
- -(s64)vm_committed_as_batch * num_online_cpus(),
- "memory commitment underflow");
-
- vm_acct_memory(pages);
-
- /*
- * Sometimes we want to use more memory than we have
- */
- if (sysctl_overcommit_memory == OVERCOMMIT_ALWAYS)
- return 0;
-
- if (sysctl_overcommit_memory == OVERCOMMIT_GUESS) {
- free = global_page_state(NR_FREE_PAGES);
- free += global_page_state(NR_FILE_PAGES);
-
- /*
- * shmem pages shouldn't be counted as free in this
- * case, they can't be purged, only swapped out, and
- * that won't affect the overall amount of available
- * memory in the system.
- */
- free -= global_page_state(NR_SHMEM);
-
- free += get_nr_swap_pages();
-
- /*
- * Any slabs which are created with the
- * SLAB_RECLAIM_ACCOUNT flag claim to have contents
- * which are reclaimable, under pressure. The dentry
- * cache and most inode caches should fall into this
- */
- free += global_page_state(NR_SLAB_RECLAIMABLE);
-
- /*
- * Leave reserved pages. The pages are not for anonymous pages.
- */
- if (free <= totalreserve_pages)
- goto error;
- else
- free -= totalreserve_pages;
-
- /*
- * Reserve some for root
- */
- if (!cap_sys_admin)
- free -= sysctl_admin_reserve_kbytes >> (PAGE_SHIFT - 10);
-
- if (free > pages)
- return 0;
-
- goto error;
- }
-
- allowed = vm_commit_limit();
- /*
- * Reserve some for root
- */
- if (!cap_sys_admin)
- allowed -= sysctl_admin_reserve_kbytes >> (PAGE_SHIFT - 10);
-
- /*
- * Don't let a single process grow so big a user can't recover
- */
- if (mm) {
- reserve = sysctl_user_reserve_kbytes >> (PAGE_SHIFT - 10);
- allowed -= min_t(long, mm->total_vm / 32, reserve);
- }
-
- if (percpu_counter_read_positive(&vm_committed_as) < allowed)
- return 0;
-error:
- vm_unacct_memory(pages);
-
- return -ENOMEM;
-}
-
/*
* Requires inode->i_mapping->i_mmap_rwsem
*/
@@ -1270,6 +1146,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
unsigned long pgoff, unsigned long *populate)
{
struct mm_struct *mm = current->mm;
+ int pkey = 0;
*populate = 0;
@@ -1309,11 +1186,17 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
if (offset_in_page(addr))
return addr;
+ if (prot == PROT_EXEC) {
+ pkey = execute_only_pkey(mm);
+ if (pkey < 0)
+ pkey = 0;
+ }
+
/* Do simple checking here so the lower-level routines won't have
* to. we assume access permissions have been handled by the open
* of the memory object, so we don't do any here.
*/
- vm_flags |= calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags) |
+ vm_flags |= calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) |
mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
if (flags & MAP_LOCKED)
@@ -2640,10 +2523,10 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
struct vm_area_struct *vma;
unsigned long populate = 0;
unsigned long ret = -EINVAL;
+ struct file *file, *prfile;
- pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. "
- "See Documentation/vm/remap_file_pages.txt.\n",
- current->comm, current->pid);
+ pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.txt.\n",
+ current->comm, current->pid);
if (prot)
return ret;
@@ -2708,9 +2591,26 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
}
vma_get_file(vma);
+ file = vma->vm_file;
+ prfile = vma->vm_prfile;
ret = do_mmap_pgoff(vma->vm_file, start, size,
prot, flags, pgoff, &populate);
- vma_fput(vma);
+ if (!IS_ERR_VALUE(ret) && file && prfile) {
+ struct vm_area_struct *new_vma;
+
+ new_vma = find_vma(mm, ret);
+ if (!new_vma->vm_prfile)
+ new_vma->vm_prfile = prfile;
+ if (new_vma != vma)
+ get_file(prfile);
+ }
+ /*
+ * two fput()s instead of vma_fput(vma),
+ * coz vma may not be available anymore.
+ */
+ fput(file);
+ if (prfile)
+ fput(prfile);
out:
up_write(&mm->mmap_sem);
if (populate)
@@ -3009,8 +2909,7 @@ bool may_expand_vm(struct mm_struct *mm, vm_flags_t flags, unsigned long npages)
if (is_data_mapping(flags) &&
mm->data_vm + npages > rlimit(RLIMIT_DATA) >> PAGE_SHIFT) {
if (ignore_rlimit_data)
- pr_warn_once("%s (%d): VmData %lu exceed data ulimit "
- "%lu. Will be forbidden soon.\n",
+ pr_warn_once("%s (%d): VmData %lu exceed data ulimit %lu. Will be forbidden soon.\n",
current->comm, current->pid,
(mm->data_vm + npages) << PAGE_SHIFT,
rlimit(RLIMIT_DATA));
@@ -3065,11 +2964,16 @@ static int special_mapping_fault(struct vm_area_struct *vma,
pgoff_t pgoff;
struct page **pages;
- if (vma->vm_ops == &legacy_special_mapping_vmops)
+ if (vma->vm_ops == &legacy_special_mapping_vmops) {
pages = vma->vm_private_data;
- else
- pages = ((struct vm_special_mapping *)vma->vm_private_data)->
- pages;
+ } else {
+ struct vm_special_mapping *sm = vma->vm_private_data;
+
+ if (sm->fault)
+ return sm->fault(sm, vma, vmf);
+
+ pages = sm->pages;
+ }
for (pgoff = vmf->pgoff; pgoff && *pages; ++pages)
pgoff--;