Commit Graph

601848 Commits

Author SHA1 Message Date
Chao Yu
72e1c797b5 f2fs: fix to redirty page if fail to gc data page
If we fail to move data page during foreground GC, we should give another
chance to writeback that page which was set dirty previously by writer.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-08 10:33:26 -07:00
Chao Yu
1563ac75e7 f2fs: fix to detect truncation prior rather than EIO during read
In procedure of synchonized read, after sending out the read request, reader
will try to lock the page for waiting device to finish the read jobs and
unlock the page, but meanwhile, truncater will race with reader, so after
reader get lock of the page, it should check page's mapping to detect
whether someone has truncated the page in advance, then reader has the
chance to do the retry if truncation was done, otherwise read can be failed
due to previous condition check.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-08 10:33:25 -07:00
Chao Yu
78682f7944 f2fs: fix to avoid reading out encrypted data in page cache
For encrypted inode, if user overwrites data of the inode, f2fs will read
encrypted data into page cache, and then do the decryption.

However reader can race with overwriter, and it will see encrypted data
which has not been decrypted by overwriter yet. Fix it by moving decrypting
work to background and keep page non-uptodated until data is decrypted.

Thread A				Thread B
- f2fs_file_write_iter
 - __generic_file_write_iter
  - generic_perform_write
   - f2fs_write_begin
    - f2fs_submit_page_bio
					- generic_file_read_iter
					 - do_generic_file_read
					  - lock_page_killable
					  - unlock_page
					  - copy_page_to_iter
					  hit the encrypted data in updated page
    - lock_page
    - fscrypt_decrypt_page

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-08 10:33:24 -07:00
Jaegeuk Kim
ac6f199984 f2fs: avoid latency-critical readahead of node pages
The f2fs_map_blocks is very related to the performance, so let's avoid any
latency to read ahead node pages.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-06 10:44:10 -07:00
Jaegeuk Kim
2c237ebaa4 f2fs: avoid writing node/metapages during writes
Let's keep more node/meta pages in run time.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-06 10:44:09 -07:00
Jaegeuk Kim
ad4edb8314 f2fs: produce more nids and reduce readahead nats
The readahead nat pages are more likely to be reclaimed quickly, so it'd better
to gather more free nids in advance.

And, let's keep some free nids as much as possible.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-06 10:44:08 -07:00
Jaegeuk Kim
52763a4b7a f2fs: detect host-managed SMR by feature flag
If mkfs.f2fs gives a feature flag for host-managed SMR, we can set mode=lfs
by default.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-06 10:44:07 -07:00
Jaegeuk Kim
67c3758d22 f2fs: call update_inode_page for orphan inodes
Let's store orphan inode pages right away.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-06 10:44:07 -07:00
Jaegeuk Kim
3e19886eda f2fs: report error for f2fs_parent_dir
If there is no dentry, we can report its error correctly.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-06 10:44:06 -07:00
Sheng Yong
8be0fea9c0 f2fs: find parent dentry correctly
If dotdot directory is corrupted, its slot may be ocupied by another
file. In this case, dentry[1] is not the parent directory. Rename and
cross-rename will update the inode in dentry[1] incorrectly.   This
patch finds dotdot dentry by name.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
[Jaegeuk Kim: remove wron bug_on]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-15 15:32:35 -07:00
Jaegeuk Kim
c92737ceec f2fs: fix deadlock in add_link failure
mkdir                        sync_dirty_inode
 - init_inode_metadata
   - lock_page(node)
   - make_empty_dir
                             - filemap_fdatawrite()
                              - do_writepages
                              - lock_page(data)
                              - write_page(data)
                               - lock_page(node)
   - f2fs_init_acl
    - error
   - truncate_inode_pages
    - lock_page(data)

So, we don't need to truncate data pages in this error case, which will
be done by f2fs_evict_inode.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-13 11:55:25 -07:00
Jaegeuk Kim
36abef4e79 f2fs: introduce mode=lfs mount option
This mount option is to enable original log-structured filesystem forcefully.
So, there should be no random writes for main area.

Especially, this supports host-managed SMR device.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-13 11:55:21 -07:00
Jaegeuk Kim
aa98727329 f2fs: skip clean segment for gc
If a segment in a section is clean or prefreed, we don't need to get its summary
and do gc.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-08 10:25:52 -07:00
Jaegeuk Kim
19a5f5e2ef f2fs: drop any block plugging
In f2fs, we don't need to keep block plugging for NODE and DATA writes, since
we already merged bios as much as possible.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-08 10:25:51 -07:00
Jaegeuk Kim
7dfeaa3220 f2fs: avoid reverse IO order for NODE and DATA
There is a data race between allocate_data_block() and f2fs_sbumit_page_mbio(),
which incur unnecessary reversed bio submission.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-08 10:25:50 -07:00
Jaegeuk Kim
7f319975cc f2fs: set mapping error for EIO
If EIO occurred, we need to set all the mapping to avoid any further IOs.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-08 10:25:50 -07:00
Jaegeuk Kim
e589c2c477 f2fs: control not to exceed # of cached nat entries
This is to avoid cache entry management overhead including radix tree.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-07 10:18:08 -07:00
Jaegeuk Kim
29710bcf94 f2fs: fix wrong percentage
This should be 1%, 10MB / 1GB.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-07 09:45:41 -07:00
Jaegeuk Kim
1e7c48fa9a f2fs: avoid data race between FI_DIRTY_INODE flag and update_inode
FI_DIRTY_INODE flag is not covered by inode page lock, so it can be unset
at any time like below.

Thread #1                        Thread #2
- lock_page(ipage)
- update i_fields
                                 - update i_size/i_blocks/and so on
				 - set FI_DIRTY_INODE
- reset FI_DIRTY_INODE
- set_page_dirty(ipage)

In this case, we can lose the latest i_field information.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-07 09:45:40 -07:00
Jaegeuk Kim
9a449e9c3b f2fs: remove obsolete parameter in f2fs_truncate
We don't need lock parameter, which is always true.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-07 09:45:39 -07:00
Jaegeuk Kim
338bbfa086 f2fs: avoid wrong count on dirty inodes
The number should be covered by spin_lock. Otherwise we can see wrong count
in f2fs_stat.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-07 09:45:38 -07:00
Jaegeuk Kim
9f7c45ccd6 f2fs: remove deprecated parameter
Remove deprecated paramter.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-07 09:45:37 -07:00
Jaegeuk Kim
b230e6cabf f2fs: handle writepage correctly
Previously, f2fs_write_data_pages() calls __f2fs_writepage() which calls
f2fs_write_data_page().
If f2fs_write_data_page() returns AOP_WRITEPAGE_ACTIVATE, __f2fs_writepage()
calls mapping_set_error(). But, this should not happen at every time, since
sometimes f2fs_write_data_page() tries to skip writing pages without error.
For example, volatile_write() gives EIO all the time, as Shuoran Liu pointed
out.

Reported-by: Shuoran Liu <liushuoran@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:24 -07:00
Jaegeuk Kim
eb4246dc12 f2fs: return error of f2fs_lookup
Now we can report an error to f2fs_lookup given by f2fs_find_entry.

Suggested-by: He YunLei <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:23 -07:00
Yunlong Song
0c9df7fb80 f2fs: return the errno to the caller to avoid using a wrong page
Commit aaf9607516 ("f2fs: check node page
contents all the time") pointed out that "sometimes it was reported that
its contents was missing", so it checks the page's mapping and contents.
When "nid != nid_of_node(page)", ERR_PTR(-EIO) will be returned to the
caller. However, commit e1c51b9f1d ("f2fs:
clean up node page updating flow") moves "nid != nid_of_node(page)" test
to "f2fs_bug_on(sbi, nid != nid_of_node(page))", this will return a
wrong page to the caller when F2FS_CHECK_FS is off when "sometimes it
was reported that its contents was missing" happens.

This patch restores to check node page contents all the time, and
returns the errno to make the caller known something is wrong and avoid
to use the page. This patch also moves f2fs_bug_on to its proper location.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:22 -07:00
Jaegeuk Kim
46ae957f9b f2fs: remove two steps to flush dirty data pages
If there is no cold page, we don't need to do a loop to flush dirty
data pages.

On /dev/pmem0,

1. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048 conv=fsync
 Before : 1.1 GB/s
 After  : 1.2 GB/s

2. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048
 Before : 2.2 GB/s
 After  : 2.3 GB/s

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:21 -07:00
Jaegeuk Kim
28ea6162e2 f2fs: do not skip writing data pages
For data pages, let's try to flush as much as possible in background.

On /dev/pmem0,

1. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048 conv=fsync
 Before : 800 MB/s
 After  : 1.1 GB/s

2. dd if=/dev/zero of=/mnt/test/testfile bs=1M count=2048
 Before : 1.3 GB/s
 After  : 2.2 GB/s

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:20 -07:00
Jaegeuk Kim
53aa6bbfda f2fs: inject to produce some orphan inodes
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:19 -07:00
Jaegeuk Kim
42d964016e f2fs: propagate error given by f2fs_find_entry
If we get ENOMEM or EIO in f2fs_find_entry, we should stop right away.
Otherwise, for example, we can get duplicate directory entry by ->chash and
->clevel.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:18 -07:00
Jaegeuk Kim
b93f771286 f2fs: remove writepages lock
This patch removes writepages lock.
We can improve multi-threading performance.

tiobench, 32 threads, 4KB write per fsync on SSD
Before: 25.88 MB/s
After: 28.03 MB/s

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:17 -07:00
Jaegeuk Kim
69e9e42744 f2fs: set flush_merge by default
This patch sets flush_merge by default.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:16 -07:00
Jaegeuk Kim
0a87f664d1 f2fs: detect congestion of flush command issues
If flush commands do not incur any congestion, we don't need to throw that to
dispatching queue which causes unnecessary latency.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:15 -07:00
Jaegeuk Kim
6d94c74ab8 f2fs: add lazytime mount option
This patch adds lazytime support.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:14 -07:00
Jaegeuk Kim
26de9b1171 f2fs: avoid unnecessary updating inode during fsync
If roll-forward recovery can recover i_size, we don't need to update inode's
metadata during fsync.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:13 -07:00
Jaegeuk Kim
ee6d182f2a f2fs: remove syncing inode page in all the cases
This patch reduces to call them across the whole tree.
- sync_inode_page()
- update_inode_page()
- update_inode()
- f2fs_write_inode()

Instead, checkpoint will flush all the dirty inode metadata before syncing
node pages.
Note that, this is doable, since we call mark_inode_dirty_sync() for all
inode's field change which needs to update on-disk inode as well.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:12 -07:00
Jaegeuk Kim
0f18b462b2 f2fs: flush inode metadata when checkpoint is doing
This patch registers all the inodes which have dirty metadata to sync when
checkpoint is doing.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:11 -07:00
Jaegeuk Kim
205b98221c f2fs: call mark_inode_dirty_sync for i_field changes
This patch calls mark_inode_dirty_sync() for the following on-disk inode
changes.

 -> largest
 -> ctime/mtime/atime
 -> i_current_depth
 -> i_xattr_nid
 -> i_pino
 -> i_advise
 -> i_flags
 -> i_mode

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:11 -07:00
Jaegeuk Kim
a1961246c3 f2fs: introduce f2fs_i_links_write with mark_inode_dirty_sync
This patch introduces f2fs_i_links_write() to call mark_inode_dirty_sync() when
changing inode->i_links.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:10 -07:00
Jaegeuk Kim
8edd03c870 f2fs: introduce f2fs_i_blocks_write with mark_inode_dirty_sync
This patch introduces f2fs_i_blocks_write() to call mark_inode_dirty_sync() when
changing inode->i_blocks.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:09 -07:00
Jaegeuk Kim
fc9581c809 f2fs: introduce f2fs_i_size_write with mark_inode_dirty_sync
This patch introduces f2fs_i_size_write() to call mark_inode_dirty_sync() with
i_size_write().

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:08 -07:00
Jaegeuk Kim
91942321e4 f2fs: use inode pointer for {set, clear}_inode_flag
This patch refactors to use inode pointer for set_inode_flag and
clear_inode_flag.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-02 18:05:07 -07:00
Jaegeuk Kim
1c4bf76303 Revert "f2fs: no need inc dirty pages under inode lock"
This reverts commit b951a4ec16.

 Conflicts:
	fs/f2fs/checkpoint.c
2016-06-02 18:05:06 -07:00
Linus Torvalds
4340fa5529 ARM:
- two fixes for 4.6 vgic [Christoffer]
    (cc stable)
 
  - six fixes for 4.7 vgic [Marc]
 
 x86:
  - six fixes from syzkaller reports [Paolo]
    (two of them cc stable)
 
  - allow OS X to boot [Dmitry]
 
  - don't trust compilers [Nadav]
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - two fixes for 4.6 vgic [Christoffer] (cc stable)

   - six fixes for 4.7 vgic [Marc]

  x86:
   - six fixes from syzkaller reports [Paolo] (two of them cc stable)

   - allow OS X to boot [Dmitry]

   - don't trust compilers [Nadav]"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: fix OOPS after invalid KVM_SET_DEBUGREGS
  KVM: x86: avoid vmalloc(0) in the KVM_SET_CPUID
  KVM: irqfd: fix NULL pointer dereference in kvm_irq_map_gsi
  KVM: fail KVM_SET_VCPU_EVENTS with invalid exception number
  KVM: x86: avoid vmalloc(0) in the KVM_SET_CPUID
  kvm: x86: avoid warning on repeated KVM_SET_TSS_ADDR
  KVM: Handle MSR_IA32_PERF_CTL
  KVM: x86: avoid write-tearing of TDP
  KVM: arm/arm64: vgic-new: Removel harmful BUG_ON
  arm64: KVM: vgic-v3: Relax synchronization when SRE==1
  arm64: KVM: vgic-v3: Prevent the guest from messing with ICC_SRE_EL1
  arm64: KVM: Make ICC_SRE_EL1 access return the configured SRE value
  KVM: arm/arm64: vgic-v3: Always resample level interrupts
  KVM: arm/arm64: vgic-v2: Always resample level interrupts
  KVM: arm/arm64: vgic-v3: Clear all dirty LRs
  KVM: arm/arm64: vgic-v2: Clear all dirty LRs
2016-06-02 15:08:06 -07:00
Paolo Bonzini
d14bdb553f KVM: x86: fix OOPS after invalid KVM_SET_DEBUGREGS
MOV to DR6 or DR7 causes a #GP if an attempt is made to write a 1 to
any of bits 63:32.  However, this is not detected at KVM_SET_DEBUGREGS
time, and the next KVM_RUN oopses:

   general protection fault: 0000 [#1] SMP
   CPU: 2 PID: 14987 Comm: a.out Not tainted 4.4.9-300.fc23.x86_64 #1
   Hardware name: LENOVO 2325F51/2325F51, BIOS G2ET32WW (1.12 ) 05/30/2012
   [...]
   Call Trace:
    [<ffffffffa072c93d>] kvm_arch_vcpu_ioctl_run+0x141d/0x14e0 [kvm]
    [<ffffffffa071405d>] kvm_vcpu_ioctl+0x33d/0x620 [kvm]
    [<ffffffff81241648>] do_vfs_ioctl+0x298/0x480
    [<ffffffff812418a9>] SyS_ioctl+0x79/0x90
    [<ffffffff817a0f2e>] entry_SYSCALL_64_fastpath+0x12/0x71
   Code: 55 83 ff 07 48 89 e5 77 27 89 ff ff 24 fd 90 87 80 81 0f 23 fe 5d c3 0f 23 c6 5d c3 0f 23 ce 5d c3 0f 23 d6 5d c3 0f 23 de 5d c3 <0f> 23 f6 5d c3 0f 0b 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00
   RIP  [<ffffffff810639eb>] native_set_debugreg+0x2b/0x40
    RSP <ffff88005836bd50>

Testcase (beautified/reduced from syzkaller output):

    #include <unistd.h>
    #include <sys/syscall.h>
    #include <string.h>
    #include <stdint.h>
    #include <linux/kvm.h>
    #include <fcntl.h>
    #include <sys/ioctl.h>

    long r[8];

    int main()
    {
        struct kvm_debugregs dr = { 0 };

        r[2] = open("/dev/kvm", O_RDONLY);
        r[3] = ioctl(r[2], KVM_CREATE_VM, 0);
        r[4] = ioctl(r[3], KVM_CREATE_VCPU, 7);

        memcpy(&dr,
               "\x5d\x6a\x6b\xe8\x57\x3b\x4b\x7e\xcf\x0d\xa1\x72"
               "\xa3\x4a\x29\x0c\xfc\x6d\x44\x00\xa7\x52\xc7\xd8"
               "\x00\xdb\x89\x9d\x78\xb5\x54\x6b\x6b\x13\x1c\xe9"
               "\x5e\xd3\x0e\x40\x6f\xb4\x66\xf7\x5b\xe3\x36\xcb",
               48);
        r[7] = ioctl(r[4], KVM_SET_DEBUGREGS, &dr);
        r[6] = ioctl(r[4], KVM_RUN, 0);
    }

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-06-02 17:38:50 +02:00
Paolo Bonzini
f8c1b85b25 KVM: x86: avoid vmalloc(0) in the KVM_SET_CPUID
This causes an ugly dmesg splat.  Beautified syzkaller testcase:

    #include <unistd.h>
    #include <sys/syscall.h>
    #include <sys/ioctl.h>
    #include <fcntl.h>
    #include <linux/kvm.h>

    long r[8];

    int main()
    {
        struct kvm_irq_routing ir = { 0 };
        r[2] = open("/dev/kvm", O_RDWR);
        r[3] = ioctl(r[2], KVM_CREATE_VM, 0);
        r[4] = ioctl(r[3], KVM_SET_GSI_ROUTING, &ir);
        return 0;
    }

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-06-02 17:38:50 +02:00
Paolo Bonzini
c622a3c21e KVM: irqfd: fix NULL pointer dereference in kvm_irq_map_gsi
Found by syzkaller:

    BUG: unable to handle kernel NULL pointer dereference at 0000000000000120
    IP: [<ffffffffa0797202>] kvm_irq_map_gsi+0x12/0x90 [kvm]
    PGD 6f80b067 PUD b6535067 PMD 0
    Oops: 0000 [#1] SMP
    CPU: 3 PID: 4988 Comm: a.out Not tainted 4.4.9-300.fc23.x86_64 #1
    [...]
    Call Trace:
     [<ffffffffa0795f62>] irqfd_update+0x32/0xc0 [kvm]
     [<ffffffffa0796c7c>] kvm_irqfd+0x3dc/0x5b0 [kvm]
     [<ffffffffa07943f4>] kvm_vm_ioctl+0x164/0x6f0 [kvm]
     [<ffffffff81241648>] do_vfs_ioctl+0x298/0x480
     [<ffffffff812418a9>] SyS_ioctl+0x79/0x90
     [<ffffffff817a1062>] tracesys_phase2+0x84/0x89
    Code: b5 71 a7 e0 5b 41 5c 41 5d 5d f3 c3 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 8b 8f 10 2e 00 00 31 c0 48 89 e5 <39> 91 20 01 00 00 76 6a 48 63 d2 48 8b 94 d1 28 01 00 00 48 85
    RIP  [<ffffffffa0797202>] kvm_irq_map_gsi+0x12/0x90 [kvm]
     RSP <ffff8800926cbca8>
    CR2: 0000000000000120

Testcase:

    #include <unistd.h>
    #include <sys/syscall.h>
    #include <string.h>
    #include <stdint.h>
    #include <linux/kvm.h>
    #include <fcntl.h>
    #include <sys/ioctl.h>

    long r[26];

    int main()
    {
        memset(r, -1, sizeof(r));
        r[2] = open("/dev/kvm", 0);
        r[3] = ioctl(r[2], KVM_CREATE_VM, 0);

        struct kvm_irqfd ifd;
        ifd.fd = syscall(SYS_eventfd2, 5, 0);
        ifd.gsi = 3;
        ifd.flags = 2;
        ifd.resamplefd = ifd.fd;
        r[25] = ioctl(r[3], KVM_IRQFD, &ifd);
        return 0;
    }

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-06-02 17:38:50 +02:00
Paolo Bonzini
78e546c824 KVM: fail KVM_SET_VCPU_EVENTS with invalid exception number
This cannot be returned by KVM_GET_VCPU_EVENTS, so it is okay to return
EINVAL.  It causes a WARN from exception_type:

    WARNING: CPU: 3 PID: 16732 at arch/x86/kvm/x86.c:345 exception_type+0x49/0x50 [kvm]()
    CPU: 3 PID: 16732 Comm: a.out Tainted: G        W       4.4.6-300.fc23.x86_64 #1
    Hardware name: LENOVO 2325F51/2325F51, BIOS G2ET32WW (1.12 ) 05/30/2012
     0000000000000286 000000006308a48b ffff8800bec7fcf8 ffffffff813b542e
     0000000000000000 ffffffffa0966496 ffff8800bec7fd30 ffffffff810a40f2
     ffff8800552a8000 0000000000000000 00000000002c267c 0000000000000001
    Call Trace:
     [<ffffffff813b542e>] dump_stack+0x63/0x85
     [<ffffffff810a40f2>] warn_slowpath_common+0x82/0xc0
     [<ffffffff810a423a>] warn_slowpath_null+0x1a/0x20
     [<ffffffffa0924809>] exception_type+0x49/0x50 [kvm]
     [<ffffffffa0934622>] kvm_arch_vcpu_ioctl_run+0x10a2/0x14e0 [kvm]
     [<ffffffffa091c04d>] kvm_vcpu_ioctl+0x33d/0x620 [kvm]
     [<ffffffff81241248>] do_vfs_ioctl+0x298/0x480
     [<ffffffff812414a9>] SyS_ioctl+0x79/0x90
     [<ffffffff817a04ee>] entry_SYSCALL_64_fastpath+0x12/0x71
    ---[ end trace b1a0391266848f50 ]---

Testcase (beautified/reduced from syzkaller output):

    #include <unistd.h>
    #include <sys/syscall.h>
    #include <string.h>
    #include <stdint.h>
    #include <fcntl.h>
    #include <sys/ioctl.h>
    #include <linux/kvm.h>

    long r[31];

    int main()
    {
        memset(r, -1, sizeof(r));
        r[2] = open("/dev/kvm", O_RDONLY);
        r[3] = ioctl(r[2], KVM_CREATE_VM, 0);
        r[7] = ioctl(r[3], KVM_CREATE_VCPU, 0);

        struct kvm_vcpu_events ve = {
                .exception.injected = 1,
                .exception.nr = 0xd4
        };
        r[27] = ioctl(r[7], KVM_SET_VCPU_EVENTS, &ve);
        r[30] = ioctl(r[7], KVM_RUN, 0);
        return 0;
    }

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-06-02 17:38:50 +02:00
Paolo Bonzini
83676e9238 KVM: x86: avoid vmalloc(0) in the KVM_SET_CPUID
This causes an ugly dmesg splat.  Beautified syzkaller testcase:

    #include <unistd.h>
    #include <sys/syscall.h>
    #include <sys/ioctl.h>
    #include <fcntl.h>
    #include <linux/kvm.h>

    long r[8];

    int main()
    {
        struct kvm_cpuid2 c = { 0 };
        r[2] = open("/dev/kvm", O_RDWR);
        r[3] = ioctl(r[2], KVM_CREATE_VM, 0);
        r[4] = ioctl(r[3], KVM_CREATE_VCPU, 0x8);
        r[7] = ioctl(r[4], KVM_SET_CPUID, &c);
        return 0;
    }

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-06-02 17:38:50 +02:00
Paolo Bonzini
b21629da12 kvm: x86: avoid warning on repeated KVM_SET_TSS_ADDR
Found by syzkaller:

    WARNING: CPU: 3 PID: 15175 at arch/x86/kvm/x86.c:7705 __x86_set_memory_region+0x1dc/0x1f0 [kvm]()
    CPU: 3 PID: 15175 Comm: a.out Tainted: G        W       4.4.6-300.fc23.x86_64 #1
    Hardware name: LENOVO 2325F51/2325F51, BIOS G2ET32WW (1.12 ) 05/30/2012
     0000000000000286 00000000950899a7 ffff88011ab3fbf0 ffffffff813b542e
     0000000000000000 ffffffffa0966496 ffff88011ab3fc28 ffffffff810a40f2
     00000000000001fd 0000000000003000 ffff88014fc50000 0000000000000000
    Call Trace:
     [<ffffffff813b542e>] dump_stack+0x63/0x85
     [<ffffffff810a40f2>] warn_slowpath_common+0x82/0xc0
     [<ffffffff810a423a>] warn_slowpath_null+0x1a/0x20
     [<ffffffffa09251cc>] __x86_set_memory_region+0x1dc/0x1f0 [kvm]
     [<ffffffffa092521b>] x86_set_memory_region+0x3b/0x60 [kvm]
     [<ffffffffa09bb61c>] vmx_set_tss_addr+0x3c/0x150 [kvm_intel]
     [<ffffffffa092f4d4>] kvm_arch_vm_ioctl+0x654/0xbc0 [kvm]
     [<ffffffffa091d31a>] kvm_vm_ioctl+0x9a/0x6f0 [kvm]
     [<ffffffff81241248>] do_vfs_ioctl+0x298/0x480
     [<ffffffff812414a9>] SyS_ioctl+0x79/0x90
     [<ffffffff817a04ee>] entry_SYSCALL_64_fastpath+0x12/0x71

Testcase:

    #include <unistd.h>
    #include <sys/ioctl.h>
    #include <fcntl.h>
    #include <string.h>
    #include <linux/kvm.h>

    long r[8];

    int main()
    {
        memset(r, -1, sizeof(r));
	r[2] = open("/dev/kvm", O_RDONLY|O_TRUNC);
        r[3] = ioctl(r[2], KVM_CREATE_VM, 0x0ul);
        r[5] = ioctl(r[3], KVM_SET_TSS_ADDR, 0x20000000ul);
        r[7] = ioctl(r[3], KVM_SET_TSS_ADDR, 0x20000000ul);
        return 0;
    }

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-06-02 17:38:50 +02:00
Dmitry Bilunov
0c2df2a1af KVM: Handle MSR_IA32_PERF_CTL
Intel CPUs having Turbo Boost feature implement an MSR to provide a
control interface via rdmsr/wrmsr instructions. One could detect the
presence of this feature by issuing one of these instructions and
handling the #GP exception which is generated in case the referenced MSR
is not implemented by the CPU.

KVM's vCPU model behaves exactly as a real CPU in this case by injecting
a fault when MSR_IA32_PERF_CTL is called (which KVM does not support).
However, some operating systems use this register during an early boot
stage in which their kernel is not capable of handling #GP correctly,
causing #DP and finally a triple fault effectively resetting the vCPU.

This patch implements a dummy handler for MSR_IA32_PERF_CTL to avoid the
crashes.

Signed-off-by: Dmitry Bilunov <kmeaw@yandex-team.ru>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-06-02 17:38:50 +02:00