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Date: Sat, 28 Nov 2009 00:06:01 +0100
From: Jiri Slaby <jslaby@...e.cz>
To: jirislaby@...il.com
Cc: mingo@...e.hu, nhorman@...driver.com, sfr@...b.auug.org.au,
linux-kernel@...r.kernel.org, akpm@...ux-foundation.org,
marcin.slusarz@...il.com, tglx@...utronix.de, mingo@...hat.com,
hpa@...or.com, torvalds@...ux-foundation.org, oleg@...hat.com,
James Morris <jmorris@...ei.org>,
Heiko Carstens <heiko.carstens@...ibm.com>, linux-mm@...ck.org
Subject: [PATCH v3 21/27] MM: use helpers for rlimits
Make sure compiler won't do weird things with limits. E.g. fetching
them twice may return 2 different values after writable limits are
implemented.
I.e. either use newly added rlimit helpers or ACCESS_ONCE if not
applicable.
Signed-off-by: Jiri Slaby <jslaby@...e.cz>
Cc: James Morris <jmorris@...ei.org>
Cc: Heiko Carstens <heiko.carstens@...ibm.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Cc: Ingo Molnar <mingo@...e.hu>
Cc: linux-mm@...ck.org
---
mm/filemap.c | 2 +-
mm/mlock.c | 12 ++++++------
mm/mmap.c | 13 +++++++------
mm/mremap.c | 2 +-
4 files changed, 15 insertions(+), 14 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index ef169f3..8896396 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1971,7 +1971,7 @@ EXPORT_SYMBOL(iov_iter_single_seg_count);
inline int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk)
{
struct inode *inode = file->f_mapping->host;
- unsigned long limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
+ unsigned long limit = rlim_get_cur(RLIMIT_FSIZE);
if (unlikely(*pos < 0))
return -EINVAL;
diff --git a/mm/mlock.c b/mm/mlock.c
index bd6f0e4..a8ee8bf 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -25,7 +25,7 @@ int can_do_mlock(void)
{
if (capable(CAP_IPC_LOCK))
return 1;
- if (current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur != 0)
+ if (rlim_get_cur(RLIMIT_MEMLOCK) != 0)
return 1;
return 0;
}
@@ -490,7 +490,7 @@ SYSCALL_DEFINE2(mlock, unsigned long, start, size_t, len)
locked = len >> PAGE_SHIFT;
locked += current->mm->locked_vm;
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit = rlim_get_cur(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
/* check against resource limits */
@@ -553,7 +553,7 @@ SYSCALL_DEFINE1(mlockall, int, flags)
down_write(¤t->mm->mmap_sem);
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit = rlim_get_cur(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
ret = -ENOMEM;
@@ -587,7 +587,7 @@ int user_shm_lock(size_t size, struct user_struct *user)
int allowed = 0;
locked = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit = rlim_get_cur(RLIMIT_MEMLOCK);
if (lock_limit == RLIM_INFINITY)
allowed = 1;
lock_limit >>= PAGE_SHIFT;
@@ -621,12 +621,12 @@ int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
down_write(&mm->mmap_sem);
- lim = rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
+ lim = ACCESS_ONCE(rlim[RLIMIT_AS].rlim_cur) >> PAGE_SHIFT;
vm = mm->total_vm + pgsz;
if (lim < vm)
goto out;
- lim = rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
+ lim = ACCESS_ONCE(rlim[RLIMIT_MEMLOCK].rlim_cur) >> PAGE_SHIFT;
vm = mm->locked_vm + pgsz;
if (lim < vm)
goto out;
diff --git a/mm/mmap.c b/mm/mmap.c
index 73f5e4b..dc49f43 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -266,7 +266,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
* segment grow beyond its set limit the in case where the limit is
* not page aligned -Ram Gupta
*/
- rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
+ rlim = rlim_get_cur(RLIMIT_DATA);
if (rlim < RLIM_INFINITY && (brk - mm->start_brk) +
(mm->end_data - mm->start_data) > rlim)
goto out;
@@ -990,7 +990,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
unsigned long locked, lock_limit;
locked = len >> PAGE_SHIFT;
locked += mm->locked_vm;
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit = rlim_get_cur(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
if (locked > lock_limit && !capable(CAP_IPC_LOCK))
return -EAGAIN;
@@ -1565,7 +1565,7 @@ static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, uns
return -ENOMEM;
/* Stack limit test */
- if (size > rlim[RLIMIT_STACK].rlim_cur)
+ if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur))
return -ENOMEM;
/* mlock limit tests */
@@ -1573,7 +1573,8 @@ static int acct_stack_growth(struct vm_area_struct *vma, unsigned long size, uns
unsigned long locked;
unsigned long limit;
locked = mm->locked_vm + grow;
- limit = rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
+ limit = ACCESS_ONCE(rlim[RLIMIT_MEMLOCK].rlim_cur);
+ limit >>= PAGE_SHIFT;
if (locked > limit && !capable(CAP_IPC_LOCK))
return -ENOMEM;
}
@@ -2026,7 +2027,7 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
unsigned long locked, lock_limit;
locked = len >> PAGE_SHIFT;
locked += mm->locked_vm;
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit = rlim_get_cur(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
if (locked > lock_limit && !capable(CAP_IPC_LOCK))
return -EAGAIN;
@@ -2240,7 +2241,7 @@ int may_expand_vm(struct mm_struct *mm, unsigned long npages)
unsigned long cur = mm->total_vm; /* pages */
unsigned long lim;
- lim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
+ lim = rlim_get_cur(RLIMIT_AS) >> PAGE_SHIFT;
if (cur + npages > lim)
return 0;
diff --git a/mm/mremap.c b/mm/mremap.c
index 97bff25..00a384c 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -358,7 +358,7 @@ unsigned long do_mremap(unsigned long addr,
if (vma->vm_flags & VM_LOCKED) {
unsigned long locked, lock_limit;
locked = mm->locked_vm << PAGE_SHIFT;
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit = rlim_get_cur(RLIMIT_MEMLOCK);
locked += new_len - old_len;
ret = -EAGAIN;
if (locked > lock_limit && !capable(CAP_IPC_LOCK))
--
1.6.5.3
--
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