review.tizen.org Git - platform/kernel/linux-rpi.git/log

f2fs: prevent newly created inode from being dirtied incorrectly

Now, we invoke f2fs_mark_inode_dirty_sync() to make an inode dirty in
advance of creating a new node page for the inode. By this, some inodes
whose node page is not created yet can be linked into the global dirty
list.

If the checkpoint is executed at this moment, the inode will be written
back by writeback_single_inode() and finally update_inode_page() will
fail to detach the inode from the global dirty list because the inode
doesn't have a node page.

The problem is that the inode's state in VFS layer will become clean
after execution of writeback_single_inode() and it's still linked in
the global dirty list of f2fs and this will cause a kernel panic.

So, we will prevent the newly created inode from being dirtied during
the FI_NEW_INODE flag of the inode is set. We will make it dirty
right after the flag is cleared.

Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com>
Tested-by: Hobin Woo <hobin.woo@samsung.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support FIEMAP_FLAG_XATTR

This patch enables ->fiemap to handle FIEMAP_FLAG_XATTR flag for xattr
mapping info lookup purpose.

It makes f2fs passing generic/425 test in fstest.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to cover f2fs_inline_data_fiemap with inode_lock

This patch fix to cover f2fs_inline_data_fiemap with inode_lock in order
to make that interface avoiding race with mapping change.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check node page again in write end io

Check node page again in write end io in case of
data corruption during inflght IO.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to caclulate required free section correctly

When calculating required free section during file defragmenting, we
should skip holes in file, otherwise we will probably fail to defrag
sparse file with large size.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: handle newly created page when revoking inmem pages

When committing inmem pages is successful, we revoke already committed
blocks in __revoke_inmem_pages() and finally replace the committed
ones with the old blocks using f2fs_replace_block(). However, if
the committed block was newly created one, the address of the old
block is NEW_ADDR and __f2fs_replace_block() cannot handle NEW_ADDR
as new_blkaddr properly and a kernel panic occurrs.

Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Tested-by: Shu Tan <shu.tan@samsung.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add resgid and resuid to reserve root blocks

This patch adds mount options to reserve some blocks via resgid=%u,resuid=%u.
It only activates with reserve_root=%u.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: implement cgroup writeback support

Cgroup writeback requires explicit support from the filesystem.
f2fs's data and node writeback IOs go through __write_data_page,
which sets fio for submiting IOs. So, we add io_wbc for fio,
associate bios with blkcg by invoking wbc_init_bio() and
account IOs issuing by wbc_account_io().
In addtion, f2fs_fill_super() is updated to set SB_I_CGROUPWB.

Meta writeback IOs is left alone by this patch and will always be
attributed to the root cgroup.

The results show that f2fs can throttle writeback nicely for
data writing and file creating.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove unused pend_list_tag

In commit 78997b569f56 ("f2fs: split discard policy"), we have get rid
of using pend_list_tag field in struct discard_cmd_control, but forgot
to remove it, now do it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid high cpu usage in discard thread

We take very long time to finish generic/476, this is because we will
check consistence of all discard entries in global rb tree while
traversing all different granularity pending lists, even when the list
is empty, in order to avoid that unneeded overhead, we have to skip
the check when coming up an empty list.

generic/476 time consumption:
cost
Before patch & w/o consistence check 57s
Before patch & w/ consistence check 1426s
After patch 78s

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: make local functions static

Fixes the following sparse warnings:

fs/f2fs/segment.c:887:6: warning:
symbol '__check_sit_bitmap' was not declared. Should it be static?
fs/f2fs/segment.c:1327:6: warning:
symbol 'f2fs_wait_discard_bio' was not declared. Should it be static?
fs/f2fs/super.c:1661:5: warning:
symbol 'f2fs_get_projid' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add reserved blocks for root user

This patch allows root to reserve some blocks via mount option.

"-o reserve_root=N" means N x 4KB-sized blocks for root only.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: check segment type in __f2fs_replace_block

In some case, the node blocks has wrong blkaddr whose segment type is
NODE, e.g., recover inode has missing xattr flag and the blkaddr is in
the xattr range. Since fsck.f2fs does not check the recovery nodes, this
will cause __f2fs_replace_block change the curseg of node and do the
update_sit_entry(sbi, new_blkaddr, 1) with no next_blkoff refresh, as a
result, when recovery process write checkpoint and sync nodes, the
next_blkoff of curseg is used in the segment bit map, then it will
cause f2fs_bug_on. So let's check segment type in __f2fs_replace_block.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: update inode info to inode page for new file

After checkpoint,
1. creat a new file A ,(with dirty inode && dirty inode page && xattr info)
2. backgroud wb write back file A inode page (without update from inode cache)
3. fsync file A, write back inode page of file A with inode cache info
4. sudden power off before new checkpoint

In this case, recovery process will try to recover a zero inode
page. Inline xattr flag of file A will be miss and xattr info
will be taken as blkaddr index.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: show precise # of blocks that user/root can use

Let's show precise # of blocks that user/root can use through bavail and bfree
respectively.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up unneeded declaration

Commit 6afc662e68b5 ("f2fs: support flexible inline xattr size")
declared f2fs_sb_has_flexible_inline_xattr in f2fs.h for latter being
used in get_inline_xattr_addrs, but in latter version, related code
has been changed, leave f2fs_sb_has_flexible_inline_xattr w/o any
users. Let's remove it for cleanup.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: continue to do direct IO if we only preallocate partial blocks

While doing direct IO, if we run out-of-space when we preallocate blocks,
we should not return ENOSPC error directly, instead, we should continue
to do following direct IO, which will keep directIO of f2fs acting like
other filesystems.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: enable quota at remount from r to w

We have to enable quota only when remounting from read to write. Otherwise,
we'll get remount failure. (e.g., write to write case)

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: skip stop_checkpoint for user data writes

We can give another chance to write user data, which can resolve
generic/441.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix missing error number for xattr operation

This fixes generic/449 hang problem caused by no ENOSPC forever which should be
returned by setxattr under disk full scenario.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: recover directory operations by fsync

This fixes generic/342 which doesn't recover renamed file which was fsynced
before. It will be done via another fsync on newly created file.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: return error during fill_super

Let's avoid BUG_ON during fill_super, when on-disk was totall corrupted.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix an error case of missing update inode page

-Thread A                             Thread B

-write_checkpoint
-block_operations
  -f2fs_unlock_all                    -f2fs_sync_file
                                       -f2fs_write_inode
                                        -f2fs_inode_synced
    -f2fs_sync_inode_meta
     -sync_node_pages
                                        -set_page_drity

In this case, if sudden power off without next new checkpoint,
the last inode page update will lost. wb_writeback is same with
fsync.

Yunlei also reproduced the bug by:

@@ -366,7 +366,7 @@ int update_inode(struct inode *inode, struct page *node_page)
        struct extent_tree *et = F2FS_I(inode)->extent_tree;

        f2fs_inode_synced(inode);
-
+       msleep(10000);
        f2fs_wait_on_page_writeback(node_page, NODE, true);

shell 1:                                       shell2:

dd if=/dev/zero of=./test bs=1M count=10
sync
echo "hello" >> ./test
fsync test  // sleep 10s
                                               sync //return quickly
echo c > /proc/sysrq-trigger

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix potential hangtask in f2fs_trace_pid

As Jia-Ju Bai reported:

"According to fs/f2fs/trace.c, the kernel module may sleep under a spinlock.
The function call path is:
f2fs_trace_pid (acquire the spinlock)
f2fs_radix_tree_insert
cond_resched --> may sleep

I do not find a good way to fix it, so I only report.
This possible bug is found by my static analysis tool (DSAC) and my code
review."

Obviously, it's problemetic to schedule in critical region of spinlock,
which will cause uninterruptable sleep if there is no waker.

This patch changes to use mutex lock intead of spinlock to avoid this
condition.

Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: no need return value in restore summary process

No need return value in restore summary process

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use unlikely for release case

Since the variable release is only nonzero when another unlikely
case occurs, use unlikely() on it seems logical.

Signed-off-by: Fan li <fanofcode.li@samsung.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: don't return value in truncate_data_blocks_range

There is no caller cares about return value of truncate_data_blocks_range,
remove it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up f2fs_map_blocks

f2fs_map_blocks():

if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR) {
if (create) {
...
} else {
...
if (flag == F2FS_GET_BLOCK_FIEMAP &&
blkaddr == NULL_ADDR) {
...
}
if (flag != F2FS_GET_BLOCK_FIEMAP ||
blkaddr != NEW_ADDR)
goto sync_out;
}

It means we can break the loop in cases of:
a) flag != F2FS_GET_BLOCK_FIEMAP or
b) flag == F2FS_GET_BLOCK_FIEMAP && blkaddr == NULL_ADDR

Condition b) is the same as previous one, so merge operations of them
for readability.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up hash codes

f2fs_chksum and f2fs_crc32 use the same 'crc32' crypto engine, also
their implementation are almost the same, except with different
shash description context.

Introduce __f2fs_crc32 to wrap the common codes, and reuse it in
f2fs_chksum and f2fs_crc32.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix error handling in fill_super

In fill_super, if we fail to call f2fs_build_stats(), it needs to detach
from global f2fs shrink list, otherwise once system starts to shrink slab
cache, we will encounter below panic:

BUG: unable to handle kernel paging request at 00007d35
Oops: 0002 [#1] PREEMPT SMP
EIP: __lock_acquire+0x70/0x12c0
Call Trace:
lock_acquire+0xae/0x220
mutex_trylock+0xc5/0xf0
f2fs_shrink_count+0x32/0xb0 [f2fs]
shrink_slab+0xf1/0x5b0
drop_slab_node+0x35/0x60
drop_slab+0xf/0x20
drop_caches_sysctl_handler+0x79/0xc0
proc_sys_call_handler+0xa4/0xc0
proc_sys_write+0x1f/0x30
__vfs_write+0x24/0x150
SyS_write+0x44/0x90
do_fast_syscall_32+0xa1/0x1ca
entry_SYSENTER_32+0x4c/0x7b

In addition, this patch relocates f2fs_join_shrinker in fill_super to
avoid unneeded error handling of it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: spread f2fs_k{m,z}alloc

Use f2fs_k{m,z}alloc as much as possible to increase fault injection
points.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: inject fault to kvmalloc

This patch supports to inject fault into kvmalloc/kvzalloc.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: inject fault to kzalloc

This patch introduces f2fs_kzalloc based on f2fs_kmalloc in order to
support error injection for kzalloc().

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove a redundant conditional expression

Avoid checking is_inode repeatedly, and make the logic
a little bit clearer.

Signed-off-by: Fan li <fanofcode.li@samsung.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: apply write hints to select the type of segment for direct write

When blocks are allocated for direct write, select the type of
segment using the kiocb hint. But if an inode has FI_NO_ALLOC,
use the inode hint.

Signed-off-by: Hyunchul Lee <cheol.lee@lge.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: switch to fscrypt_prepare_setattr()

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: switch to fscrypt_prepare_lookup()

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: switch to fscrypt_prepare_rename()

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: switch to fscrypt_prepare_link()

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: switch to fscrypt_file_open()

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

posix_acl: convert posix_acl.a_refcount from atomic_t to refcount_t

atomic_t variables are currently used to implement reference
counters with the following properties:
- counter is initialized to 1 using atomic_set()
- a resource is freed upon counter reaching zero
- once counter reaches zero, its further
   increments aren't allowed
- counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable posix_acl.a_refcount is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

**Important note for maintainers:

Some functions from refcount_t API defined in lib/refcount.c
have different memory ordering guarantees than their atomic
counterparts.
The full comparison can be seen in
https://lkml.org/lkml/2017/11/15/57 and it is hopefully soon
in state to be merged to the documentation tree.
Normally the differences should not matter since refcount_t provides
enough guarantees to satisfy the refcounting use cases, but in
some rare cases it might matter.
Please double check that you don't have some undocumented
memory guarantees for this variable usage.

For the posix_acl.a_refcount it might make a difference
in following places:
- get_cached_acl(): increment in refcount_inc_not_zero() only
   guarantees control dependency on success vs. fully ordered
   atomic counterpart. However this operation is performed under
   rcu_read_lock(), so this should be fine.
- posix_acl_release(): decrement in refcount_dec_and_test() only
   provides RELEASE ordering and control dependency on success
   vs. fully ordered atomic counterpart

Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove repeated f2fs_bug_on

f2fs: remove repeated f2fs_bug_on which has already existed
in function invalidate_blocks.

Signed-off-by: Zhikang Zhang <zhangzhikang1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove an excess variable

Remove the variable page_idx which no one would miss.

Signed-off-by: Fan li <fanofcode.li@samsung.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix lock dependency in between dio_rwsem & i_mmap_sem

test/generic/208 reports a potential deadlock as below:

Chain exists of:
  &mm->mmap_sem --> &fi->i_mmap_sem --> &fi->dio_rwsem[WRITE]

Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&fi->dio_rwsem[WRITE]);
                               lock(&fi->i_mmap_sem);
                               lock(&fi->dio_rwsem[WRITE]);
  lock(&mm->mmap_sem);

This patch changes the lock dependency as below in fallocate() to
fix this issue:
- dio_rwsem
- i_mmap_sem

Fixes: bb06664a534b ("f2fs: avoid race in between GC and block exchange")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove unused parameter

Commit d260081ccf37 ("f2fs: change recovery policy of xattr node block")
removes the use of blkaddr, which is no longer used. So remove the
parameter.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: still write data if preallocate only partial blocks

If there is not enough space left, f2fs_preallocate_blocks may only
preallocte partial blocks. As a result, the write operation fails
but i_blocks is not 0. To avoid this, f2fs should write data in
non-preallocation way and write as many data as the size of i_blocks.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce sysfs readdir_ra to readahead inode block in readdir

This patch introduces a sysfs interface readdir_ra to enable/disable
readaheading inode block in f2fs_readdir. When readdir_ra is enabled,
it improves the performance of "readdir + stat".

For 300,000 files:
time find /data/test > /dev/null
disable readdir_ra: 1m25.69s real 0m01.94s user 0m50.80s system
enable readdir_ra: 0m18.55s real 0m00.44s user 0m15.39s system

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix concurrent problem for updating free bitmap

alloc_nid_failed and scan_nat_page can be called at the same time,
and we haven't protected add_free_nid and update_free_nid_bitmap
with the same nid_list_lock. That could lead to

Thread A Thread B
- __build_free_nids
- scan_nat_page
- add_free_nid
- alloc_nid_failed
- update_free_nid_bitmap
- update_free_nid_bitmap

scan_nat_page will clear the free bitmap since the nid is PREALLOC_NID,
but alloc_nid_failed needs to set the free bitmap. This results in
free nid with free bitmap cleared.
This patch update the bitmap under the same nid_list_lock in add_free_nid.
And use __GFP_NOFAIL to make sure to update status of free nid correctly.

Signed-off-by: Fan li <fanofcode.li@samsung.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove unneeded memory footprint accounting

We forgot to remov memory footprint accounting of per-cpu type
variables, fix it.

Fixes: 35782b233f37 ("f2fs: remove percpu_count due to performance regression")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: no need to read nat block if nat_block_bitmap is set

No need to read nat block if nat_block_bitmap is set.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: reserve nid resource for quota sysfile

During mkfs, quota sysfiles have already occupied nid resource,
it needs to adjust remaining available nid count in kernel side.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Merge tag 'for-linus-20171218' of git://git.infradead.org/linux-mtd

Pull MTD fixes from Richard Weinberger:
"This contains the following regression fixes:

   - fix bitflip handling in brcmnand and gpmi nand drivers

   - revert a bad device tree binding for spi-nor

   - fix a copy&paste error in gpio-nand driver

   - fix a too strict length check in mtd core"

* tag 'for-linus-20171218' of git://git.infradead.org/linux-mtd:
  mtd: Fix mtd_check_oob_ops()
  mtd: nand: gpio: Fix ALE gpio configuration
  mtd: nand: brcmnand: Zero bitflip is not an error
  mtd: nand: gpmi: Fix failure when a erased page has a bitflip at BBM
  Revert "dt-bindings: mtd: add sst25wf040b and en25s64 to sip-nor list"

Merge branch 'parisc-4.15-2' of git://git./linux/kernel/git/deller/parisc-linux

Pull parisc fixes from Helge Deller:
"There are two important fixes here:

   - Add PCI quirks to disable built-in a serial AUX and a graphics
     cards from specific GSP (management board) PCI cards. This fixes
     boot via serial console on rp3410 and rp3440 machines.

   - Revert the "Re-enable interrups early" patch which was added to
     kernel v4.10. It can trigger stack overflows and thus silent data
     corruption. With this patch reverted we can lower our thread stack
     back to 16kb again.

  The other patches are minor cleanups: avoid duplicate includes,
  indenting fixes, correctly align variable in asm code"

* 'parisc-4.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Reduce thread stack to 16 kb
  Revert "parisc: Re-enable interrupts early"
  parisc: remove duplicate includes
  parisc: Hide Diva-built-in serial aux and graphics card
  parisc: Align os_hpmc_size on word boundary
  parisc: Fix indenting in puts()

Merge branch 'WIP.x86-pti.entry-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 syscall entry code changes for PTI from Ingo Molnar:
"The main changes here are Andy Lutomirski's changes to switch the
  x86-64 entry code to use the 'per CPU entry trampoline stack'. This,
  besides helping fix KASLR leaks (the pending Page Table Isolation
  (PTI) work), also robustifies the x86 entry code"

* 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
  x86/cpufeatures: Make CPU bugs sticky
  x86/paravirt: Provide a way to check for hypervisors
  x86/paravirt: Dont patch flush_tlb_single
  x86/entry/64: Make cpu_entry_area.tss read-only
  x86/entry: Clean up the SYSENTER_stack code
  x86/entry/64: Remove the SYSENTER stack canary
  x86/entry/64: Move the IST stacks into struct cpu_entry_area
  x86/entry/64: Create a per-CPU SYSCALL entry trampoline
  x86/entry/64: Return to userspace from the trampoline stack
  x86/entry/64: Use a per-CPU trampoline stack for IDT entries
  x86/espfix/64: Stop assuming that pt_regs is on the entry stack
  x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0
  x86/entry: Remap the TSS into the CPU entry area
  x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct
  x86/dumpstack: Handle stack overflow on all stacks
  x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss
  x86/kasan/64: Teach KASAN about the cpu_entry_area
  x86/mm/fixmap: Generalize the GDT fixmap mechanism, introduce struct cpu_entry_area
  x86/entry/gdt: Put per-CPU GDT remaps in ascending order
  x86/dumpstack: Add get_stack_info() support for the SYSENTER stack
  ...

mtd: Fix mtd_check_oob_ops()

The mtd_check_oob_ops() helper verifies if the operation defined by the
user is correct.

Fix the check that verifies if the entire requested area exists. This
check is too restrictive and will fail anytime the last data byte of the
very last page is included in an operation.

Fixes: 5cdd929da53d ("mtd: Add sanity checks in mtd_write/read_oob()")
Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Revert "exec: avoid RLIMIT_STACK races with prlimit()"

This reverts commit 04e35f4495dd560db30c25efca4eecae8ec8c375.

SELinux runs with secureexec for all non-"noatsecure" domain transitions,
which means lots of processes end up hitting the stack hard-limit change
that was introduced in order to fix a race with prlimit(). That race fix
will need to be redesigned.

Reported-by: Laura Abbott <labbott@redhat.com>
Reported-by: Tomáš Trnka <trnka@scm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge branch 'WIP.x86-pti.base-for-linus' of git://git./linux/kernel/git/tip/tip

Pull Page Table Isolation (PTI) v4.14 backporting base tree from Ingo Molnar:
"This tree contains the v4.14 PTI backport preparatory tree, which
  consists of four merges of upstream trees and 7 cherry-picked commits,
  which the upcoming PTI work depends on"

NOTE! The resulting tree is exactly the same as the original base tree
(ie the diff between this commit and its immediate first parent is
empty).

The only reason for this merge is literally to have a common point for
the actual PTI changes so that the commits can be shared in both the
4.15 and 4.14 trees.

* 'WIP.x86-pti.base-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/kasan: Don't use vmemmap_populate() to initialize shadow
  locking/barriers: Convert users of lockless_dereference() to READ_ONCE()
  locking/barriers: Add implicit smp_read_barrier_depends() to READ_ONCE()
  bpf: fix build issues on um due to mising bpf_perf_event.h
  perf/x86: Enable free running PEBS for REGS_USER/INTR
  x86: Make X86_BUG_FXSAVE_LEAK detectable in CPUID on AMD
  x86/cpufeature: Add User-Mode Instruction Prevention definitions

Merge branch 'WIP.x86-pti.base.prep-for-linus' of git://git./linux/kernel/git/tip/tip

Pull Page Table Isolation (PTI) preparatory tree from Ingo Molnar:
"This does a rename to free up linux/pti.h to be used by the upcoming
page table isolation feature"

* 'WIP.x86-pti.base.prep-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
drivers/misc/intel/pti: Rename the header file to free up the namespace

Merge branch 'timers-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull timer fix from Thomas Gleixner:
"A single bugfix which prevents arbitrary sigev_notify values in
posix-timers"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-timer: Properly check sigevent->sigev_notify

Merge tag 'dmaengine-fix-4.15-rc4' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine fixes from Vinod Koul:
"This time consisting of fixes in a bunch of drivers and the dmatest
  module:

   - Fix for disable clk on error path in fsl-edma driver
   - Disable clk fail fix in jz4740 driver
   - Fix long pending bug in dmatest driver for dangling pointer
   - Fix potential NULL pointer dereference in at_hdmac driver
   - Error handling path in ioat driver"

* tag 'dmaengine-fix-4.15-rc4' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: fsl-edma: disable clks on all error paths
  dmaengine: jz4740: disable/unprepare clk if probe fails
  dmaengine: dmatest: move callback wait queue to thread context
  dmaengine: at_hdmac: fix potential NULL pointer dereference in atc_prep_dma_interleaved
  dmaengine: ioat: Fix error handling path

cramfs: fix MTD dependency

With CONFIG_MTD=m and CONFIG_CRAMFS=y, we now get a link failure:

  fs/cramfs/inode.o: In function `cramfs_mount': inode.c:(.text+0x220): undefined reference to `mount_mtd'
  fs/cramfs/inode.o: In function `cramfs_mtd_fill_super':
  inode.c:(.text+0x6d8): undefined reference to `mtd_point'
  inode.c:(.text+0xae4): undefined reference to `mtd_unpoint'

This adds a more specific Kconfig dependency to avoid the broken
configuration.

Alternatively we could make CRAMFS itself depend on "MTD || !MTD" with a
similar result.

Fixes: 99c18ce580c6 ("cramfs: direct memory access support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge branch 'for-linus' of git://git./linux/kernel/git/viro/vfs

Pull vfs fixes from Al Viro:
"The alloc_super() one is a regression in this merge window, lazytime
  thing is older..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  VFS: Handle lazytime in do_mount()
  alloc_super(): do ->s_umount initialization earlier

Merge tag 'ext4_for_stable' of git://git./linux/kernel/git/tytso/ext4

Pull ext4 fixes from Ted Ts'o:
"Fix a regression which caused us to fail to interpret symlinks in very
  ancient ext3 file system images.

  Also fix two xfstests failures, one of which could cause an OOPS, plus
  an additional bug fix caught by fuzz testing"

* tag 'ext4_for_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix crash when a directory's i_size is too small
  ext4: add missing error check in __ext4_new_inode()
  ext4: fix fdatasync(2) after fallocate(2) operation
  ext4: support fast symlinks from ext3 file systems

parisc: Reduce thread stack to 16 kb

In testing, I found that the thread stack can be 16 kB when using an irq
stack. Without it, the thread stack needs to be 32 kB. Currently, the irq
stack is 32 kB. While it probably could be 16 kB, I would prefer to leave it
as is for safety.

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>

Revert "parisc: Re-enable interrupts early"

This reverts commit 5c38602d83e584047906b41b162ababd4db4106d.

Interrupts can't be enabled early because the register saves are done on
the thread stack prior to switching to the IRQ stack.  This caused stack
overflows and the thread stack needed increasing to 32k.  Even then,
stack overflows still occasionally occurred.

Background:
Even with a 32 kB thread stack, I have seen instances where the thread
stack overflowed on the mx3210 buildd.  Detection of stack overflow only
occurs when we have an external interrupt.  When an external interrupt
occurs, we switch to the thread stack if we are not already on a kernel
stack.  Then, registers and specials are saved to the kernel stack.

The bug occurs in intr_return where interrupts are reenabled prior to
returning from the interrupt.  This was done incase we need to schedule
or deliver signals.  However, it introduces the possibility that
multiple external interrupts may occur on the thread stack and cause a
stack overflow.  These might not be detected and cause the kernel to
misbehave in random ways.

This patch changes the code back to only reenable interrupts when we are
going to schedule or deliver signals.  As a result, we generally return
from an interrupt before reenabling interrupts.  This minimizes the
growth of the thread stack.

Fixes: 5c38602d83e5 ("parisc: Re-enable interrupts early")
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org> # v4.10+
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: remove duplicate includes

These duplicate includes have been found with scripts/checkincludes.pl
but they have been removed manually to avoid removing false positives.

Signed-off-by: Pravin Shedge <pravin.shedge4linux@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>

parisc: Hide Diva-built-in serial aux and graphics card

Diva GSP card has built-in serial AUX port and ATI graphic card which simply
don't work and which both don't have external connectors. User Guides even
mention that those devices shouldn't be used.
So, prevent that Linux drivers try to enable those devices.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v3.0+

parisc: Align os_hpmc_size on word boundary

The os_hpmc_size variable sometimes wasn't aligned at word boundary and thus
triggered the unaligned fault handler at startup.
Fix it by aligning it properly.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.14+

parisc: Fix indenting in puts()

Static analysis tools complain that we intended to have curly braces
around this indent block. In this case this assumption is wrong, so fix
the indenting.

Fixes: 2f3c7b8137ef ("parisc: Add core code for self-extracting kernel")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.14+

x86/cpufeatures: Make CPU bugs sticky

There is currently no way to force CPU bug bits like CPU feature bits. That
makes it impossible to set a bug bit once at boot and have it stick for all
upcoming CPUs.

Extend the force set/clear arrays to handle bug bits as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.992156574@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/paravirt: Provide a way to check for hypervisors

There is no generic way to test whether a kernel is running on a specific
hypervisor. But that's required to prevent the upcoming user address space
separation feature in certain guest modes.

Make the hypervisor type enum unconditionally available and provide a
helper function which allows to test for a specific type.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.912938129@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/paravirt: Dont patch flush_tlb_single

native_flush_tlb_single() will be changed with the upcoming
PAGE_TABLE_ISOLATION feature. This requires to have more code in
there than INVLPG.

Remove the paravirt patching for it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Cc: michael.schwarz@iaik.tugraz.at
Cc: moritz.lipp@iaik.tugraz.at
Cc: richard.fellner@student.tugraz.at
Link: https://lkml.kernel.org/r/20171204150606.828111617@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry/64: Make cpu_entry_area.tss read-only

The TSS is a fairly juicy target for exploits, and, now that the TSS
is in the cpu_entry_area, it's no longer protected by kASLR.  Make it
read-only on x86_64.

On x86_32, it can't be RO because it's written by the CPU during task
switches, and we use a task gate for double faults.  I'd also be
nervous about errata if we tried to make it RO even on configurations
without double fault handling.

[ tglx: AMD confirmed that there is no problem on 64-bit with TSS RO.  So
   it's probably safe to assume that it's a non issue, though Intel
   might have been creative in that area. Still waiting for
   confirmation. ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bpetkov@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.733700132@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry: Clean up the SYSENTER_stack code

The existing code was a mess, mainly because C arrays are nasty. Turn
SYSENTER_stack into a struct, add a helper to find it, and do all the
obvious cleanups this enables.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bpetkov@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.653244723@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry/64: Remove the SYSENTER stack canary

Now that the SYSENTER stack has a guard page, there's no need for a canary
to detect overflow after the fact.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.572577316@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry/64: Move the IST stacks into struct cpu_entry_area

The IST stacks are needed when an IST exception occurs and are accessed
before any kernel code at all runs.  Move them into struct cpu_entry_area.

The IST stacks are unlike the rest of cpu_entry_area: they're used even for
entries from kernel mode.  This means that they should be set up before we
load the final IDT.  Move cpu_entry_area setup to trap_init() for the boot
CPU and set it up for all possible CPUs at once in native_smp_prepare_cpus().

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.480598743@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry/64: Create a per-CPU SYSCALL entry trampoline

Handling SYSCALL is tricky: the SYSCALL handler is entered with every
single register (except FLAGS), including RSP, live.  It somehow needs
to set RSP to point to a valid stack, which means it needs to save the
user RSP somewhere and find its own stack pointer.  The canonical way
to do this is with SWAPGS, which lets us access percpu data using the
%gs prefix.

With PAGE_TABLE_ISOLATION-like pagetable switching, this is
problematic.  Without a scratch register, switching CR3 is impossible, so
%gs-based percpu memory would need to be mapped in the user pagetables.
Doing that without information leaks is difficult or impossible.

Instead, use a different sneaky trick.  Map a copy of the first part
of the SYSCALL asm at a different address for each CPU.  Now RIP
varies depending on the CPU, so we can use RIP-relative memory access
to access percpu memory.  By putting the relevant information (one
scratch slot and the stack address) at a constant offset relative to
RIP, we can make SYSCALL work without relying on %gs.

A nice thing about this approach is that we can easily switch it on
and off if we want pagetable switching to be configurable.

The compat variant of SYSCALL doesn't have this problem in the first
place -- there are plenty of scratch registers, since we don't care
about preserving r8-r15.  This patch therefore doesn't touch SYSCALL32
at all.

This patch actually seems to be a small speedup.  With this patch,
SYSCALL touches an extra cache line and an extra virtual page, but
the pipeline no longer stalls waiting for SWAPGS.  It seems that, at
least in a tight loop, the latter outweights the former.

Thanks to David Laight for an optimization tip.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bpetkov@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.403607157@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry/64: Return to userspace from the trampoline stack

By itself, this is useless.  It gives us the ability to run some final code
before exit that cannnot run on the kernel stack.  This could include a CR3
switch a la PAGE_TABLE_ISOLATION or some kernel stack erasing, for
example.  (Or even weird things like *changing* which kernel stack gets
used as an ASLR-strengthening mechanism.)

The SYSRET32 path is not covered yet.  It could be in the future or
we could just ignore it and force the slow path if needed.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.306546484@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry/64: Use a per-CPU trampoline stack for IDT entries

Historically, IDT entries from usermode have always gone directly
to the running task's kernel stack. Rearrange it so that we enter on
a per-CPU trampoline stack and then manually switch to the task's stack.
This touches a couple of extra cachelines, but it gives us a chance
to run some code before we touch the kernel stack.

The asm isn't exactly beautiful, but I think that fully refactoring
it can wait.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.225330557@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/espfix/64: Stop assuming that pt_regs is on the entry stack

When we start using an entry trampoline, a #GP from userspace will
be delivered on the entry stack, not on the task stack. Fix the
espfix64 #DF fixup to set up #GP according to TSS.SP0, rather than
assuming that pt_regs + 1 == SP0. This won't change anything
without an entry stack, but it will make the code continue to work
when an entry stack is added.

While we're at it, improve the comments to explain what's actually
going on.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.130778051@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0

On 64-bit kernels, we used to assume that TSS.sp0 was the current
top of stack. With the addition of an entry trampoline, this will
no longer be the case. Store the current top of stack in TSS.sp1,
which is otherwise unused but shares the same cacheline.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.050864668@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry: Remap the TSS into the CPU entry area

This has a secondary purpose: it puts the entry stack into a region
with a well-controlled layout. A subsequent patch will take
advantage of this to streamline the SYSCALL entry code to be able to
find it more easily.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bpetkov@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.962042855@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct

SYSENTER_stack should have reliable overflow detection, which
means that it needs to be at the bottom of a page, not the top.
Move it to the beginning of struct tss_struct and page-align it.

Also add an assertion to make sure that the fixed hardware TSS
doesn't cross a page boundary.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.881827433@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/dumpstack: Handle stack overflow on all stacks

We currently special-case stack overflow on the task stack. We're
going to start putting special stacks in the fixmap with a custom
layout, so they'll have guard pages, too. Teach the unwinder to be
able to unwind an overflow of any of the stacks.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.802057305@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss

A future patch will move SYSENTER_stack to the beginning of cpu_tss
to help detect overflow. Before this can happen, fix several code
paths that hardcode assumptions about the old layout.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.722425540@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/kasan/64: Teach KASAN about the cpu_entry_area

The cpu_entry_area will contain stacks. Make sure that KASAN has
appropriate shadow mappings for them.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: kasan-dev@googlegroups.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.642806442@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/fixmap: Generalize the GDT fixmap mechanism, introduce struct cpu_entry_area

Currently, the GDT is an ad-hoc array of pages, one per CPU, in the
fixmap. Generalize it to be an array of a new 'struct cpu_entry_area'
so that we can cleanly add new things to it.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.563271721@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry/gdt: Put per-CPU GDT remaps in ascending order

We currently have CPU 0's GDT at the top of the GDT range and
higher-numbered CPUs at lower addresses. This happens because the
fixmap is upside down (index 0 is the top of the fixmap).

Flip it so that GDTs are in ascending order by virtual address.
This will simplify a future patch that will generalize the GDT
remap to contain multiple pages.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.471561421@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/dumpstack: Add get_stack_info() support for the SYSENTER stack

get_stack_info() doesn't currently know about the SYSENTER stack, so
unwinding will fail if we entered the kernel on the SYSENTER stack
and haven't fully switched off.  Teach get_stack_info() about the
SYSENTER stack.

With future patches applied that run part of the entry code on the
SYSENTER stack and introduce an intentional BUG(), I would get:

  PANIC: double fault, error_code: 0x0
  ...
  RIP: 0010:do_error_trap+0x33/0x1c0
  ...
  Call Trace:
  Code: ...

With this patch, I get:

  PANIC: double fault, error_code: 0x0
  ...
  Call Trace:
   <SYSENTER>
   ? async_page_fault+0x36/0x60
   ? invalid_op+0x22/0x40
   ? async_page_fault+0x36/0x60
   ? sync_regs+0x3c/0x40
   ? sync_regs+0x2e/0x40
   ? error_entry+0x6c/0xd0
   ? async_page_fault+0x36/0x60
   </SYSENTER>
  Code: ...

which is a lot more informative.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.392711508@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry/64: Allocate and enable the SYSENTER stack

This will simplify future changes that want scratch variables early in
the SYSENTER handler -- they'll be able to spill registers to the
stack. It also lets us get rid of a SWAPGS_UNSAFE_STACK user.

This does not depend on CONFIG_IA32_EMULATION=y because we'll want the
stack space even without IA32 emulation.

As far as I can tell, the reason that this wasn't done from day 1 is
that we use IST for #DB and #BP, which is IMO rather nasty and causes
a lot more problems than it solves. But, since #DB uses IST, we don't
actually need a real stack for SYSENTER (because SYSENTER with TF set
will invoke #DB on the IST stack rather than the SYSENTER stack).

I want to remove IST usage from these vectors some day, and this patch
is a prerequisite for that as well.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.312726423@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/irq/64: Print the offending IP in the stack overflow warning

In case something goes wrong with unwind (not unlikely in case of
overflow), print the offending IP where we detected the overflow.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.231677119@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/irq: Remove an old outdated comment about context tracking races

That race has been fixed and code cleaned up for a while now.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.150551639@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/unwinder: Handle stack overflows more gracefully

There are at least two unwinder bugs hindering the debugging of
stack-overflow crashes:

- It doesn't deal gracefully with the case where the stack overflows and
  the stack pointer itself isn't on a valid stack but the
  to-be-dereferenced data *is*.

- The ORC oops dump code doesn't know how to print partial pt_regs, for the
  case where if we get an interrupt/exception in *early* entry code
  before the full pt_regs have been saved.

Fix both issues.

http://lkml.kernel.org/r/20171126024031.uxi4numpbjm5rlbr@treble

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bpetkov@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.071425003@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/unwinder/orc: Dont bail on stack overflow

If the stack overflows into a guard page and the ORC unwinder should work
well: by construction, there can't be any meaningful data in the guard page
because no writes to the guard page will have succeeded.

But there is a bug that prevents unwinding from working correctly: if the
starting register state has RSP pointing into a stack guard page, the ORC
unwinder bails out immediately.

Instead of bailing out immediately check whether the next page up is a
valid check page and if so analyze that. As a result the ORC unwinder will
start the unwind.

Tested by intentionally overflowing the task stack. The result is an
accurate call trace instead of a trace consisting purely of '?' entries.

There are a few other bugs that are triggered if the unwinder encounters a
stack overflow after the first step, but they are outside the scope of this
fix.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150604.991389777@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry/64/paravirt: Use paravirt-safe macro to access eflags

Commit 1d3e53e8624a ("x86/entry/64: Refactor IRQ stacks and make them
NMI-safe") added DEBUG_ENTRY_ASSERT_IRQS_OFF macro that acceses eflags
using 'pushfq' instruction when testing for IF bit. On PV Xen guests
looking at IF flag directly will always see it set, resulting in 'ud2'.

Introduce SAVE_FLAGS() macro that will use appropriate save_fl pv op when
running paravirt.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/20171204150604.899457242@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/kasan: Don't use vmemmap_populate() to initialize shadow

[ Note, this is a Git cherry-pick of the following commit:

    d17a1d97dc20: ("x86/mm/kasan: don't use vmemmap_populate() to initialize shadow")

  ... for easier x86 PTI code testing and back-porting. ]

The KASAN shadow is currently mapped using vmemmap_populate() since that
provides a semi-convenient way to map pages into init_top_pgt.  However,
since that no longer zeroes the mapped pages, it is not suitable for
KASAN, which requires zeroed shadow memory.

Add kasan_populate_shadow() interface and use it instead of
vmemmap_populate().  Besides, this allows us to take advantage of
gigantic pages and use them to populate the shadow, which should save us
some memory wasted on page tables and reduce TLB pressure.

Link: http://lkml.kernel.org/r/20171103185147.2688-2-pasha.tatashin@oracle.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

locking/barriers: Convert users of lockless_dereference() to READ_ONCE()

[ Note, this is a Git cherry-pick of the following commit:

506458efaf15 ("locking/barriers: Convert users of lockless_dereference() to READ_ONCE()")

... for easier x86 PTI code testing and back-porting. ]

READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it
can be used instead of lockless_dereference() without any change in
semantics.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>