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authorLinus Torvalds <torvalds@linux-foundation.org>2012-06-07 15:05:43 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-06-07 15:05:43 -0700
commit46edaedaf3842164281d0f86c41bc152f4b4d32e (patch)
treef1f3d2c9aa8ef73a9c46bf8519be635a972f4439
parent513335f964a17bd99a699b939391eb111aa5f65b (diff)
parent40af1bbdca47e5c8a2044039bb78ca8fd8b20f94 (diff)
Merge branch 'akpm' (Andrew's fixups)
Merge random fixes from Andrew Morton. * emailed from Andrew Morton <akpm@linux-foundation.org>: (11 patches) mm: correctly synchronize rss-counters at exit/exec btree: catch NULL value before it does harm btree: fix tree corruption in btree_get_prev() ipc: shm: restore MADV_REMOVE functionality on shared memory segments drivers/platform/x86/acerhdf.c: correct Boris' mail address c/r: prctl: drop VMA flags test on PR_SET_MM_ stack data assignment c/r: prctl: add ability to get clear_tid_address c/r: prctl: add minimal address test to PR_SET_MM c/r: prctl: update prctl_set_mm_exe_file() after mm->num_exe_file_vmas removal MAINTAINERS: whitespace fixes shmem: replace_page must flush_dcache and others
-rw-r--r--MAINTAINERS18
-rw-r--r--drivers/platform/x86/acerhdf.c2
-rw-r--r--fs/exec.c1
-rw-r--r--include/linux/prctl.h10
-rw-r--r--include/linux/sched.h1
-rw-r--r--ipc/shm.c12
-rw-r--r--kernel/exit.c13
-rw-r--r--kernel/fork.c8
-rw-r--r--kernel/sys.c60
-rw-r--r--lib/btree.c5
-rw-r--r--mm/shmem.c57
11 files changed, 118 insertions, 69 deletions
diff --git a/MAINTAINERS b/MAINTAINERS
index dafcba7e2312..14bc7071f9df 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1077,7 +1077,7 @@ F: drivers/media/video/s5p-fimc/
ARM/SAMSUNG S5P SERIES Multi Format Codec (MFC) SUPPORT
M: Kyungmin Park <kyungmin.park@samsung.com>
M: Kamil Debski <k.debski@samsung.com>
-M: Jeongtae Park <jtp.park@samsung.com>
+M: Jeongtae Park <jtp.park@samsung.com>
L: linux-arm-kernel@lists.infradead.org
L: linux-media@vger.kernel.org
S: Maintained
@@ -1743,10 +1743,10 @@ F: include/linux/can/platform/
CAPABILITIES
M: Serge Hallyn <serge.hallyn@canonical.com>
L: linux-security-module@vger.kernel.org
-S: Supported
+S: Supported
F: include/linux/capability.h
F: security/capability.c
-F: security/commoncap.c
+F: security/commoncap.c
F: kernel/capability.c
CELL BROADBAND ENGINE ARCHITECTURE
@@ -2146,11 +2146,11 @@ S: Orphan
F: drivers/net/wan/pc300*
CYTTSP TOUCHSCREEN DRIVER
-M: Javier Martinez Canillas <javier@dowhile0.org>
-L: linux-input@vger.kernel.org
-S: Maintained
-F: drivers/input/touchscreen/cyttsp*
-F: include/linux/input/cyttsp.h
+M: Javier Martinez Canillas <javier@dowhile0.org>
+L: linux-input@vger.kernel.org
+S: Maintained
+F: drivers/input/touchscreen/cyttsp*
+F: include/linux/input/cyttsp.h
DAMA SLAVE for AX.25
M: Joerg Reuter <jreuter@yaina.de>
@@ -5185,7 +5185,7 @@ S: Maintained
F: drivers/firmware/pcdp.*
PCI ERROR RECOVERY
-M: Linas Vepstas <linasvepstas@gmail.com>
+M: Linas Vepstas <linasvepstas@gmail.com>
L: linux-pci@vger.kernel.org
S: Supported
F: Documentation/PCI/pci-error-recovery.txt
diff --git a/drivers/platform/x86/acerhdf.c b/drivers/platform/x86/acerhdf.c
index 639db4d0aa76..2fd9d36acd15 100644
--- a/drivers/platform/x86/acerhdf.c
+++ b/drivers/platform/x86/acerhdf.c
@@ -5,7 +5,7 @@
*
* (C) 2009 - Peter Feuerer peter (a) piie.net
* http://piie.net
- * 2009 Borislav Petkov <petkovbb@gmail.com>
+ * 2009 Borislav Petkov bp (a) alien8.de
*
* Inspired by and many thanks to:
* o acerfand - Rachel Greenham
diff --git a/fs/exec.c b/fs/exec.c
index a79786a8d2c8..b926ed19301e 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -819,7 +819,6 @@ static int exec_mmap(struct mm_struct *mm)
/* Notify parent that we're no longer interested in the old VM */
tsk = current;
old_mm = current->mm;
- sync_mm_rss(old_mm);
mm_release(tsk, old_mm);
if (old_mm) {
diff --git a/include/linux/prctl.h b/include/linux/prctl.h
index 711e0a30aacc..3988012255dc 100644
--- a/include/linux/prctl.h
+++ b/include/linux/prctl.h
@@ -127,8 +127,8 @@
#define PR_SET_PTRACER 0x59616d61
# define PR_SET_PTRACER_ANY ((unsigned long)-1)
-#define PR_SET_CHILD_SUBREAPER 36
-#define PR_GET_CHILD_SUBREAPER 37
+#define PR_SET_CHILD_SUBREAPER 36
+#define PR_GET_CHILD_SUBREAPER 37
/*
* If no_new_privs is set, then operations that grant new privileges (i.e.
@@ -142,7 +142,9 @@
* asking selinux for a specific new context (e.g. with runcon) will result
* in execve returning -EPERM.
*/
-#define PR_SET_NO_NEW_PRIVS 38
-#define PR_GET_NO_NEW_PRIVS 39
+#define PR_SET_NO_NEW_PRIVS 38
+#define PR_GET_NO_NEW_PRIVS 39
+
+#define PR_GET_TID_ADDRESS 40
#endif /* _LINUX_PRCTL_H */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6029d8c54476..c688d4cc2e40 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -439,6 +439,7 @@ extern int get_dumpable(struct mm_struct *mm);
/* leave room for more dump flags */
#define MMF_VM_MERGEABLE 16 /* KSM may merge identical pages */
#define MMF_VM_HUGEPAGE 17 /* set when VM_HUGEPAGE is set on vma */
+#define MMF_EXE_FILE_CHANGED 18 /* see prctl_set_mm_exe_file() */
#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK)
diff --git a/ipc/shm.c b/ipc/shm.c
index 5e2cbfdab6fc..41c1285d697a 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -393,6 +393,16 @@ static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
return sfd->file->f_op->fsync(sfd->file, start, end, datasync);
}
+static long shm_fallocate(struct file *file, int mode, loff_t offset,
+ loff_t len)
+{
+ struct shm_file_data *sfd = shm_file_data(file);
+
+ if (!sfd->file->f_op->fallocate)
+ return -EOPNOTSUPP;
+ return sfd->file->f_op->fallocate(file, mode, offset, len);
+}
+
static unsigned long shm_get_unmapped_area(struct file *file,
unsigned long addr, unsigned long len, unsigned long pgoff,
unsigned long flags)
@@ -410,6 +420,7 @@ static const struct file_operations shm_file_operations = {
.get_unmapped_area = shm_get_unmapped_area,
#endif
.llseek = noop_llseek,
+ .fallocate = shm_fallocate,
};
static const struct file_operations shm_file_operations_huge = {
@@ -418,6 +429,7 @@ static const struct file_operations shm_file_operations_huge = {
.release = shm_release,
.get_unmapped_area = shm_get_unmapped_area,
.llseek = noop_llseek,
+ .fallocate = shm_fallocate,
};
int is_file_shm_hugepages(struct file *file)
diff --git a/kernel/exit.c b/kernel/exit.c
index 34867cc5b42a..804fb6bb8161 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -423,6 +423,7 @@ void daemonize(const char *name, ...)
* user space pages. We don't need them, and if we didn't close them
* they would be locked into memory.
*/
+ mm_release(current, current->mm);
exit_mm(current);
/*
* We don't want to get frozen, in case system-wide hibernation
@@ -640,7 +641,6 @@ static void exit_mm(struct task_struct * tsk)
struct mm_struct *mm = tsk->mm;
struct core_state *core_state;
- mm_release(tsk, mm);
if (!mm)
return;
/*
@@ -960,9 +960,13 @@ void do_exit(long code)
preempt_count());
acct_update_integrals(tsk);
- /* sync mm's RSS info before statistics gathering */
- if (tsk->mm)
- sync_mm_rss(tsk->mm);
+
+ /* Set exit_code before complete_vfork_done() in mm_release() */
+ tsk->exit_code = code;
+
+ /* Release mm and sync mm's RSS info before statistics gathering */
+ mm_release(tsk, tsk->mm);
+
group_dead = atomic_dec_and_test(&tsk->signal->live);
if (group_dead) {
hrtimer_cancel(&tsk->signal->real_timer);
@@ -975,7 +979,6 @@ void do_exit(long code)
tty_audit_exit();
audit_free(tsk);
- tsk->exit_code = code;
taskstats_exit(tsk, group_dead);
exit_mm(tsk);
diff --git a/kernel/fork.c b/kernel/fork.c
index ab5211b9e622..0560781c6904 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -619,6 +619,14 @@ void mmput(struct mm_struct *mm)
module_put(mm->binfmt->module);
mmdrop(mm);
}
+
+ /*
+ * Final rss-counter synchronization. After this point there must be
+ * no pagefaults into this mm from the current context. Otherwise
+ * mm->rss_stat will be inconsistent.
+ */
+ if (mm)
+ sync_mm_rss(mm);
}
EXPORT_SYMBOL_GPL(mmput);
diff --git a/kernel/sys.c b/kernel/sys.c
index 9ff89cb9657a..f0ec44dcd415 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1786,27 +1786,13 @@ SYSCALL_DEFINE1(umask, int, mask)
}
#ifdef CONFIG_CHECKPOINT_RESTORE
-static bool vma_flags_mismatch(struct vm_area_struct *vma,
- unsigned long required,
- unsigned long banned)
-{
- return (vma->vm_flags & required) != required ||
- (vma->vm_flags & banned);
-}
-
static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
{
+ struct vm_area_struct *vma;
struct file *exe_file;
struct dentry *dentry;
int err;
- /*
- * Setting new mm::exe_file is only allowed when no VM_EXECUTABLE vma's
- * remain. So perform a quick test first.
- */
- if (mm->num_exe_file_vmas)
- return -EBUSY;
-
exe_file = fget(fd);
if (!exe_file)
return -EBADF;
@@ -1827,17 +1813,30 @@ static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
if (err)
goto exit;
+ down_write(&mm->mmap_sem);
+
+ /*
+ * Forbid mm->exe_file change if there are mapped other files.
+ */
+ err = -EBUSY;
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (vma->vm_file && !path_equal(&vma->vm_file->f_path,
+ &exe_file->f_path))
+ goto exit_unlock;
+ }
+
/*
* The symlink can be changed only once, just to disallow arbitrary
* transitions malicious software might bring in. This means one
* could make a snapshot over all processes running and monitor
* /proc/pid/exe changes to notice unusual activity if needed.
*/
- down_write(&mm->mmap_sem);
- if (likely(!mm->exe_file))
- set_mm_exe_file(mm, exe_file);
- else
- err = -EBUSY;
+ err = -EPERM;
+ if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
+ goto exit_unlock;
+
+ set_mm_exe_file(mm, exe_file);
+exit_unlock:
up_write(&mm->mmap_sem);
exit:
@@ -1862,7 +1861,7 @@ static int prctl_set_mm(int opt, unsigned long addr,
if (opt == PR_SET_MM_EXE_FILE)
return prctl_set_mm_exe_file(mm, (unsigned int)addr);
- if (addr >= TASK_SIZE)
+ if (addr >= TASK_SIZE || addr < mmap_min_addr)
return -EINVAL;
error = -EINVAL;
@@ -1924,12 +1923,6 @@ static int prctl_set_mm(int opt, unsigned long addr,
error = -EFAULT;
goto out;
}
-#ifdef CONFIG_STACK_GROWSUP
- if (vma_flags_mismatch(vma, VM_READ | VM_WRITE | VM_GROWSUP, 0))
-#else
- if (vma_flags_mismatch(vma, VM_READ | VM_WRITE | VM_GROWSDOWN, 0))
-#endif
- goto out;
if (opt == PR_SET_MM_START_STACK)
mm->start_stack = addr;
else if (opt == PR_SET_MM_ARG_START)
@@ -1981,12 +1974,22 @@ out:
up_read(&mm->mmap_sem);
return error;
}
+
+static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
+{
+ return put_user(me->clear_child_tid, tid_addr);
+}
+
#else /* CONFIG_CHECKPOINT_RESTORE */
static int prctl_set_mm(int opt, unsigned long addr,
unsigned long arg4, unsigned long arg5)
{
return -EINVAL;
}
+static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
+{
+ return -EINVAL;
+}
#endif
SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
@@ -2124,6 +2127,9 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
else
return -EINVAL;
break;
+ case PR_GET_TID_ADDRESS:
+ error = prctl_get_tid_address(me, (int __user **)arg2);
+ break;
default:
return -EINVAL;
}
diff --git a/lib/btree.c b/lib/btree.c
index e5ec1e9c1aa5..f9a484676cb6 100644
--- a/lib/btree.c
+++ b/lib/btree.c
@@ -319,8 +319,8 @@ void *btree_get_prev(struct btree_head *head, struct btree_geo *geo,
if (head->height == 0)
return NULL;
-retry:
longcpy(key, __key, geo->keylen);
+retry:
dec_key(geo, key);
node = head->node;
@@ -351,7 +351,7 @@ retry:
}
miss:
if (retry_key) {
- __key = retry_key;
+ longcpy(key, retry_key, geo->keylen);
retry_key = NULL;
goto retry;
}
@@ -509,6 +509,7 @@ retry:
int btree_insert(struct btree_head *head, struct btree_geo *geo,
unsigned long *key, void *val, gfp_t gfp)
{
+ BUG_ON(!val);
return btree_insert_level(head, geo, key, val, 1, gfp);
}
EXPORT_SYMBOL_GPL(btree_insert);
diff --git a/mm/shmem.c b/mm/shmem.c
index 585bd220a21e..a15a466d0d1d 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -683,10 +683,21 @@ static int shmem_unuse_inode(struct shmem_inode_info *info,
mutex_lock(&shmem_swaplist_mutex);
/*
* We needed to drop mutex to make that restrictive page
- * allocation; but the inode might already be freed by now,
- * and we cannot refer to inode or mapping or info to check.
- * However, we do hold page lock on the PageSwapCache page,
- * so can check if that still has our reference remaining.
+ * allocation, but the inode might have been freed while we
+ * dropped it: although a racing shmem_evict_inode() cannot
+ * complete without emptying the radix_tree, our page lock
+ * on this swapcache page is not enough to prevent that -
+ * free_swap_and_cache() of our swap entry will only
+ * trylock_page(), removing swap from radix_tree whatever.
+ *
+ * We must not proceed to shmem_add_to_page_cache() if the
+ * inode has been freed, but of course we cannot rely on
+ * inode or mapping or info to check that. However, we can
+ * safely check if our swap entry is still in use (and here
+ * it can't have got reused for another page): if it's still
+ * in use, then the inode cannot have been freed yet, and we
+ * can safely proceed (if it's no longer in use, that tells
+ * nothing about the inode, but we don't need to unuse swap).
*/
if (!page_swapcount(*pagep))
error = -ENOENT;
@@ -730,9 +741,9 @@ int shmem_unuse(swp_entry_t swap, struct page *page)
/*
* There's a faint possibility that swap page was replaced before
- * caller locked it: it will come back later with the right page.
+ * caller locked it: caller will come back later with the right page.
*/
- if (unlikely(!PageSwapCache(page)))
+ if (unlikely(!PageSwapCache(page) || page_private(page) != swap.val))
goto out;
/*
@@ -995,21 +1006,15 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
newpage = shmem_alloc_page(gfp, info, index);
if (!newpage)
return -ENOMEM;
- VM_BUG_ON(shmem_should_replace_page(newpage, gfp));
- *pagep = newpage;
page_cache_get(newpage);
copy_highpage(newpage, oldpage);
+ flush_dcache_page(newpage);
- VM_BUG_ON(!PageLocked(oldpage));
__set_page_locked(newpage);
- VM_BUG_ON(!PageUptodate(oldpage));
SetPageUptodate(newpage);
- VM_BUG_ON(!PageSwapBacked(oldpage));
SetPageSwapBacked(newpage);
- VM_BUG_ON(!swap_index);
set_page_private(newpage, swap_index);
- VM_BUG_ON(!PageSwapCache(oldpage));
SetPageSwapCache(newpage);
/*
@@ -1019,13 +1024,24 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
spin_lock_irq(&swap_mapping->tree_lock);
error = shmem_radix_tree_replace(swap_mapping, swap_index, oldpage,
newpage);
- __inc_zone_page_state(newpage, NR_FILE_PAGES);
- __dec_zone_page_state(oldpage, NR_FILE_PAGES);
+ if (!error) {
+ __inc_zone_page_state(newpage, NR_FILE_PAGES);
+ __dec_zone_page_state(oldpage, NR_FILE_PAGES);
+ }
spin_unlock_irq(&swap_mapping->tree_lock);
- BUG_ON(error);
- mem_cgroup_replace_page_cache(oldpage, newpage);
- lru_cache_add_anon(newpage);
+ if (unlikely(error)) {
+ /*
+ * Is this possible? I think not, now that our callers check
+ * both PageSwapCache and page_private after getting page lock;
+ * but be defensive. Reverse old to newpage for clear and free.
+ */
+ oldpage = newpage;
+ } else {
+ mem_cgroup_replace_page_cache(oldpage, newpage);
+ lru_cache_add_anon(newpage);
+ *pagep = newpage;
+ }
ClearPageSwapCache(oldpage);
set_page_private(oldpage, 0);
@@ -1033,7 +1049,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
unlock_page(oldpage);
page_cache_release(oldpage);
page_cache_release(oldpage);
- return 0;
+ return error;
}
/*
@@ -1107,7 +1123,8 @@ repeat:
/* We have to do this with page locked to prevent races */
lock_page(page);
- if (!PageSwapCache(page) || page->mapping) {
+ if (!PageSwapCache(page) || page_private(page) != swap.val ||
+ page->mapping) {
error = -EEXIST; /* try again */
goto failed;
}