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  1. 31 7月, 2019 24 次提交
  3. 28 7月, 2019 16 次提交
    • G
      Linux 4.19.62 · 64f46940
      由 Greg Kroah-Hartman 提交于
      64f46940
    • V
      net: sched: verify that q!=NULL before setting q->flags · 60e9babf
      由 Vlad Buslov 提交于 
      commit 503d81d428bd598430f7f9d02021634e1a8139a0 upstream.

In function int tc_new_tfilter() q pointer can be NULL when adding filter
on a shared block. With recent change that resets TCQ_F_CAN_BYPASS after
filter creation, following NULL pointer dereference happens in case parent
block is shared:

[  212.925060] BUG: kernel NULL pointer dereference, address: 0000000000000010
[  212.925445] #PF: supervisor write access in kernel mode
[  212.925709] #PF: error_code(0x0002) - not-present page
[  212.925965] PGD 8000000827923067 P4D 8000000827923067 PUD 827924067 PMD 0
[  212.926302] Oops: 0002 [#1] SMP KASAN PTI
[  212.926539] CPU: 18 PID: 2617 Comm: tc Tainted: G    B             5.2.0+ #512
[  212.926938] Hardware name: Supermicro SYS-2028TP-DECR/X10DRT-P, BIOS 2.0b 03/30/2017
[  212.927364] RIP: 0010:tc_new_tfilter+0x698/0xd40
[  212.927633] Code: 74 0d 48 85 c0 74 08 48 89 ef e8 03 aa 62 00 48 8b 84 24 a0 00 00 00 48 8d 78 10 48 89 44 24 18 e8 4d 0c 6b ff 48 8b 44 24 18 <83> 60 10 f
b 48 85 ed 0f 85 3d fe ff ff e9 4f fe ff ff e8 81 26 f8
[  212.928607] RSP: 0018:ffff88884fd5f5d8 EFLAGS: 00010296
[  212.928905] RAX: 0000000000000000 RBX: 0000000000000000 RCX: dffffc0000000000
[  212.929201] RDX: 0000000000000007 RSI: 0000000000000004 RDI: 0000000000000297
[  212.929402] RBP: ffff88886bedd600 R08: ffffffffb91d4b51 R09: fffffbfff7616e4d
[  212.929609] R10: fffffbfff7616e4c R11: ffffffffbb0b7263 R12: ffff88886bc61040
[  212.929803] R13: ffff88884fd5f950 R14: ffffc900039c5000 R15: ffff88835e927680
[  212.929999] FS:  00007fe7c50b6480(0000) GS:ffff88886f980000(0000) knlGS:0000000000000000
[  212.930235] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  212.930394] CR2: 0000000000000010 CR3: 000000085bd04002 CR4: 00000000001606e0
[  212.930588] Call Trace:
[  212.930682]  ? tc_del_tfilter+0xa40/0xa40
[  212.930811]  ? __lock_acquire+0x5b5/0x2460
[  212.930948]  ? find_held_lock+0x85/0xa0
[  212.931081]  ? tc_del_tfilter+0xa40/0xa40
[  212.931201]  rtnetlink_rcv_msg+0x4ab/0x5f0
[  212.931332]  ? rtnl_dellink+0x490/0x490
[  212.931454]  ? lockdep_hardirqs_on+0x260/0x260
[  212.931589]  ? netlink_deliver_tap+0xab/0x5a0
[  212.931717]  ? match_held_lock+0x1b/0x240
[  212.931844]  netlink_rcv_skb+0xd0/0x200
[  212.931958]  ? rtnl_dellink+0x490/0x490
[  212.932079]  ? netlink_ack+0x440/0x440
[  212.932205]  ? netlink_deliver_tap+0x161/0x5a0
[  212.932335]  ? lock_downgrade+0x360/0x360
[  212.932457]  ? lock_acquire+0xe5/0x210
[  212.932579]  netlink_unicast+0x296/0x350
[  212.932705]  ? netlink_attachskb+0x390/0x390
[  212.932834]  ? _copy_from_iter_full+0xe0/0x3a0
[  212.932976]  netlink_sendmsg+0x394/0x600
[  212.937998]  ? netlink_unicast+0x350/0x350
[  212.943033]  ? move_addr_to_kernel.part.0+0x90/0x90
[  212.948115]  ? netlink_unicast+0x350/0x350
[  212.953185]  sock_sendmsg+0x96/0xa0
[  212.958099]  ___sys_sendmsg+0x482/0x520
[  212.962881]  ? match_held_lock+0x1b/0x240
[  212.967618]  ? copy_msghdr_from_user+0x250/0x250
[  212.972337]  ? lock_downgrade+0x360/0x360
[  212.976973]  ? rwlock_bug.part.0+0x60/0x60
[  212.981548]  ? __mod_node_page_state+0x1f/0xa0
[  212.986060]  ? match_held_lock+0x1b/0x240
[  212.990567]  ? find_held_lock+0x85/0xa0
[  212.994989]  ? do_user_addr_fault+0x349/0x5b0
[  212.999387]  ? lock_downgrade+0x360/0x360
[  213.003713]  ? find_held_lock+0x85/0xa0
[  213.007972]  ? __fget_light+0xa1/0xf0
[  213.012143]  ? sockfd_lookup_light+0x91/0xb0
[  213.016165]  __sys_sendmsg+0xba/0x130
[  213.020040]  ? __sys_sendmsg_sock+0xb0/0xb0
[  213.023870]  ? handle_mm_fault+0x337/0x470
[  213.027592]  ? page_fault+0x8/0x30
[  213.031316]  ? lockdep_hardirqs_off+0xbe/0x100
[  213.034999]  ? mark_held_locks+0x24/0x90
[  213.038671]  ? do_syscall_64+0x1e/0xe0
[  213.042297]  do_syscall_64+0x74/0xe0
[  213.045828]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  213.049354] RIP: 0033:0x7fe7c527c7b8
[  213.052792] Code: 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 8d 05 65 8f 0c 00 8b 00 85 c0 75 17 b8 2e 00 00 00 0f 05 <48> 3d 00 f
0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 89 54
[  213.060269] RSP: 002b:00007ffc3f7908a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  213.064144] RAX: ffffffffffffffda RBX: 000000005d34716f RCX: 00007fe7c527c7b8
[  213.068094] RDX: 0000000000000000 RSI: 00007ffc3f790910 RDI: 0000000000000003
[  213.072109] RBP: 0000000000000000 R08: 0000000000000001 R09: 00007fe7c5340cc0
[  213.076113] R10: 0000000000404ec2 R11: 0000000000000246 R12: 0000000000000080
[  213.080146] R13: 0000000000480640 R14: 0000000000000080 R15: 0000000000000000
[  213.084147] Modules linked in: act_gact cls_flower sch_ingress nfsv3 nfs_acl nfs lockd grace fscache bridge stp llc sunrpc intel_rapl_msr intel_rapl_common
[<1;69;32Msb_edac rdma_ucm rdma_cm x86_pkg_temp_thermal iw_cm intel_powerclamp ib_cm coretemp kvm_intel kvm irqbypass mlx5_ib ib_uverbs ib_core crct10dif_pclmul crc32_pc
lmul crc32c_intel ghash_clmulni_intel mlx5_core intel_cstate intel_uncore iTCO_wdt igb iTCO_vendor_support mlxfw mei_me ptp ses intel_rapl_perf mei pcspkr ipmi
_ssif i2c_i801 joydev enclosure pps_core lpc_ich ioatdma wmi dca ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter acpi_pad ast i2c_algo_bit drm_vram_helpe
r ttm drm_kms_helper drm mpt3sas raid_class scsi_transport_sas
[  213.112326] CR2: 0000000000000010
[  213.117429] ---[ end trace adb58eb0a4ee6283 ]---

Verify that q pointer is not NULL before setting the 'flags' field.

Fixes: 3f05e6886a59 ("net_sched: unset TCQ_F_CAN_BYPASS when adding filters")
Signed-off-by: NVlad Buslov <vladbu@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      60e9babf
    • K
      mm: vmscan: scan anonymous pages on file refaults · c1d98b76
      由 Kuo-Hsin Yang 提交于 
      commit 2c012a4ad1a2cd3fb5a0f9307b9d219f84eda1fa upstream.

When file refaults are detected and there are many inactive file pages,
the system never reclaim anonymous pages, the file pages are dropped
aggressively when there are still a lot of cold anonymous pages and
system thrashes.  This issue impacts the performance of applications
with large executable, e.g.  chrome.

With this patch, when file refault is detected, inactive_list_is_low()
always returns true for file pages in get_scan_count() to enable
scanning anonymous pages.

The problem can be reproduced by the following test program.

---8<---
void fallocate_file(const char *filename, off_t size)
{
	struct stat st;
	int fd;

	if (!stat(filename, &st) && st.st_size >= size)
		return;

	fd = open(filename, O_WRONLY | O_CREAT, 0600);
	if (fd < 0) {
		perror("create file");
		exit(1);
	}
	if (posix_fallocate(fd, 0, size)) {
		perror("fallocate");
		exit(1);
	}
	close(fd);
}

long *alloc_anon(long size)
{
	long *start = malloc(size);
	memset(start, 1, size);
	return start;
}

long access_file(const char *filename, long size, long rounds)
{
	int fd, i;
	volatile char *start1, *end1, *start2;
	const int page_size = getpagesize();
	long sum = 0;

	fd = open(filename, O_RDONLY);
	if (fd == -1) {
		perror("open");
		exit(1);
	}

	/*
	 * Some applications, e.g. chrome, use a lot of executable file
	 * pages, map some of the pages with PROT_EXEC flag to simulate
	 * the behavior.
	 */
	start1 = mmap(NULL, size / 2, PROT_READ | PROT_EXEC, MAP_SHARED,
		      fd, 0);
	if (start1 == MAP_FAILED) {
		perror("mmap");
		exit(1);
	}
	end1 = start1 + size / 2;

	start2 = mmap(NULL, size / 2, PROT_READ, MAP_SHARED, fd, size / 2);
	if (start2 == MAP_FAILED) {
		perror("mmap");
		exit(1);
	}

	for (i = 0; i < rounds; ++i) {
		struct timeval before, after;
		volatile char *ptr1 = start1, *ptr2 = start2;
		gettimeofday(&before, NULL);
		for (; ptr1 < end1; ptr1 += page_size, ptr2 += page_size)
			sum += *ptr1 + *ptr2;
		gettimeofday(&after, NULL);
		printf("File access time, round %d: %f (sec)
", i,
		       (after.tv_sec - before.tv_sec) +
		       (after.tv_usec - before.tv_usec) / 1000000.0);
	}
	return sum;
}

int main(int argc, char *argv[])
{
	const long MB = 1024 * 1024;
	long anon_mb, file_mb, file_rounds;
	const char filename[] = "large";
	long *ret1;
	long ret2;

	if (argc != 4) {
		printf("usage: thrash ANON_MB FILE_MB FILE_ROUNDS
");
		exit(0);
	}
	anon_mb = atoi(argv[1]);
	file_mb = atoi(argv[2]);
	file_rounds = atoi(argv[3]);

	fallocate_file(filename, file_mb * MB);
	printf("Allocate %ld MB anonymous pages
", anon_mb);
	ret1 = alloc_anon(anon_mb * MB);
	printf("Access %ld MB file pages
", file_mb);
	ret2 = access_file(filename, file_mb * MB, file_rounds);
	printf("Print result to prevent optimization: %ld
",
	       *ret1 + ret2);
	return 0;
}
---8<---

Running the test program on 2GB RAM VM with kernel 5.2.0-rc5, the program
fills ram with 2048 MB memory, access a 200 MB file for 10 times.  Without
this patch, the file cache is dropped aggresively and every access to the
file is from disk.

  $ ./thrash 2048 200 10
  Allocate 2048 MB anonymous pages
  Access 200 MB file pages
  File access time, round 0: 2.489316 (sec)
  File access time, round 1: 2.581277 (sec)
  File access time, round 2: 2.487624 (sec)
  File access time, round 3: 2.449100 (sec)
  File access time, round 4: 2.420423 (sec)
  File access time, round 5: 2.343411 (sec)
  File access time, round 6: 2.454833 (sec)
  File access time, round 7: 2.483398 (sec)
  File access time, round 8: 2.572701 (sec)
  File access time, round 9: 2.493014 (sec)

With this patch, these file pages can be cached.

  $ ./thrash 2048 200 10
  Allocate 2048 MB anonymous pages
  Access 200 MB file pages
  File access time, round 0: 2.475189 (sec)
  File access time, round 1: 2.440777 (sec)
  File access time, round 2: 2.411671 (sec)
  File access time, round 3: 1.955267 (sec)
  File access time, round 4: 0.029924 (sec)
  File access time, round 5: 0.000808 (sec)
  File access time, round 6: 0.000771 (sec)
  File access time, round 7: 0.000746 (sec)
  File access time, round 8: 0.000738 (sec)
  File access time, round 9: 0.000747 (sec)

Checked the swap out stats during the test [1], 19006 pages swapped out
with this patch, 3418 pages swapped out without this patch. There are
more swap out, but I think it's within reasonable range when file backed
data set doesn't fit into the memory.

$ ./thrash 2000 100 2100 5 1 # ANON_MB FILE_EXEC FILE_NOEXEC ROUNDS
PROCESSES Allocate 2000 MB anonymous pages active_anon: 1613644,
inactive_anon: 348656, active_file: 892, inactive_file: 1384 (kB)
pswpout: 7972443, pgpgin: 478615246 Access 100 MB executable file pages
Access 2100 MB regular file pages File access time, round 0: 12.165,
(sec) active_anon: 1433788, inactive_anon: 478116, active_file: 17896,
inactive_file: 24328 (kB) File access time, round 1: 11.493, (sec)
active_anon: 1430576, inactive_anon: 477144, active_file: 25440,
inactive_file: 26172 (kB) File access time, round 2: 11.455, (sec)
active_anon: 1427436, inactive_anon: 476060, active_file: 21112,
inactive_file: 28808 (kB) File access time, round 3: 11.454, (sec)
active_anon: 1420444, inactive_anon: 473632, active_file: 23216,
inactive_file: 35036 (kB) File access time, round 4: 11.479, (sec)
active_anon: 1413964, inactive_anon: 471460, active_file: 31728,
inactive_file: 32224 (kB) pswpout: 7991449 (+ 19006), pgpgin: 489924366
(+ 11309120)

With 4 processes accessing non-overlapping parts of a large file, 30316
pages swapped out with this patch, 5152 pages swapped out without this
patch.  The swapout number is small comparing to pgpgin.

[1]: https://github.com/vovo/testing/blob/master/mem_thrash.c

Link: http://lkml.kernel.org/r/20190701081038.GA83398@google.com
Fixes: e9868505 ("mm,vmscan: only evict file pages when we have plenty")
Fixes: 7c5bd705 ("mm: memcg: only evict file pages when we have plenty")
Signed-off-by: NKuo-Hsin Yang <vovoy@chromium.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>	[4.12+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
[backported to 4.14.y, 4.19.y, 5.1.y: adjust context]
Signed-off-by: NKuo-Hsin Yang <vovoy@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c1d98b76
    • J
      KVM: nVMX: Clear pending KVM_REQ_GET_VMCS12_PAGES when leaving nested · 7560e333
      由 Jan Kiszka 提交于 
      commit cf64527bb33f6cec2ed50f89182fc4688d0056b6 upstream.

Letting this pend may cause nested_get_vmcs12_pages to run against an
invalid state, corrupting the effective vmcs of L1.

This was triggerable in QEMU after a guest corruption in L2, followed by
a L1 reset.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: NLiran Alon <liran.alon@oracle.com>
Cc: stable@vger.kernel.org
Fixes: 7f7f1ba3 ("KVM: x86: do not load vmcs12 pages while still in SMM")
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7560e333
    • P
      KVM: nVMX: do not use dangling shadow VMCS after guest reset · 967bc679
      由 Paolo Bonzini 提交于 
      commit 88dddc11a8d6b09201b4db9d255b3394d9bc9e57 upstream.

If a KVM guest is reset while running a nested guest, free_nested will
disable the shadow VMCS execution control in the vmcs01.  However,
on the next KVM_RUN vmx_vcpu_run would nevertheless try to sync
the VMCS12 to the shadow VMCS which has since been freed.

This causes a vmptrld of a NULL pointer on my machime, but Jan reports
the host to hang altogether.  Let's see how much this trivial patch fixes.
Reported-by: NJan Kiszka <jan.kiszka@siemens.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      967bc679
    • T
      ext4: allow directory holes · 3a17ca86
      由 Theodore Ts'o 提交于 
      commit 4e19d6b65fb4fc42e352ce9883649e049da14743 upstream.

The largedir feature was intended to allow ext4 directories to have
unmapped directory blocks (e.g., directory holes).  And so the
released e2fsprogs no longer enforces this for largedir file systems;
however, the corresponding change to the kernel-side code was not made.

This commit fixes this oversight.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3a17ca86
    • R
      ext4: use jbd2_inode dirty range scoping · caa4e082
      由 Ross Zwisler 提交于 
      commit 73131fbb003b3691cfcf9656f234b00da497fcd6 upstream.

Use the newly introduced jbd2_inode dirty range scoping to prevent us
from waiting forever when trying to complete a journal transaction.
Signed-off-by: NRoss Zwisler <zwisler@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      caa4e082
    • R
      jbd2: introduce jbd2_inode dirty range scoping · af3812b6
      由 Ross Zwisler 提交于 
      commit 6ba0e7dc64a5adcda2fbe65adc466891795d639e upstream.

Currently both journal_submit_inode_data_buffers() and
journal_finish_inode_data_buffers() operate on the entire address space
of each of the inodes associated with a given journal entry.  The
consequence of this is that if we have an inode where we are constantly
appending dirty pages we can end up waiting for an indefinite amount of
time in journal_finish_inode_data_buffers() while we wait for all the
pages under writeback to be written out.

The easiest way to cause this type of workload is do just dd from
/dev/zero to a file until it fills the entire filesystem.  This can
cause journal_finish_inode_data_buffers() to wait for the duration of
the entire dd operation.

We can improve this situation by scoping each of the inode dirty ranges
associated with a given transaction.  We do this via the jbd2_inode
structure so that the scoping is contained within jbd2 and so that it
follows the lifetime and locking rules for that structure.

This allows us to limit the writeback & wait in
journal_submit_inode_data_buffers() and
journal_finish_inode_data_buffers() respectively to the dirty range for
a given struct jdb2_inode, keeping us from waiting forever if the inode
in question is still being appended to.
Signed-off-by: NRoss Zwisler <zwisler@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      af3812b6
    • R
      mm: add filemap_fdatawait_range_keep_errors() · 4becd6c1
      由 Ross Zwisler 提交于 
      commit aa0bfcd939c30617385ffa28682c062d78050eba upstream.

In the spirit of filemap_fdatawait_range() and
filemap_fdatawait_keep_errors(), introduce
filemap_fdatawait_range_keep_errors() which both takes a range upon
which to wait and does not clear errors from the address space.
Signed-off-by: NRoss Zwisler <zwisler@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4becd6c1
    • T
      ext4: enforce the immutable flag on open files · c9ea4620
      由 Theodore Ts'o 提交于 
      commit 02b016ca7f99229ae6227e7b2fc950c4e140d74a upstream.

According to the chattr man page, "a file with the 'i' attribute
cannot be modified..."  Historically, this was only enforced when the
file was opened, per the rest of the description, "... and the file
can not be opened in write mode".

There is general agreement that we should standardize all file systems
to prevent modifications even for files that were opened at the time
the immutable flag is set.  Eventually, a change to enforce this at
the VFS layer should be landing in mainline.  Until then, enforce this
at the ext4 level to prevent xfstests generic/553 from failing.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c9ea4620
    • D
      ext4: don't allow any modifications to an immutable file · 29171e82
      由 Darrick J. Wong 提交于 
      commit 2e53840362771c73eb0a5ff71611507e64e8eecd upstream.

Don't allow any modifications to a file that's marked immutable, which
means that we have to flush all the writable pages to make the readonly
and we have to check the setattr/setflags parameters more closely.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      29171e82
    • P
      perf/core: Fix race between close() and fork() · 4a5cc64d
      由 Peter Zijlstra 提交于 
      commit 1cf8dfe8a661f0462925df943140e9f6d1ea5233 upstream.

Syzcaller reported the following Use-after-Free bug:

	close()						clone()

							  copy_process()
							    perf_event_init_task()
							      perf_event_init_context()
							        mutex_lock(parent_ctx->mutex)
								inherit_task_group()
								  inherit_group()
								    inherit_event()
								      mutex_lock(event->child_mutex)
								      // expose event on child list
								      list_add_tail()
								      mutex_unlock(event->child_mutex)
							        mutex_unlock(parent_ctx->mutex)

							    ...
							    goto bad_fork_*

							  bad_fork_cleanup_perf:
							    perf_event_free_task()

	  perf_release()
	    perf_event_release_kernel()
	      list_for_each_entry()
		mutex_lock(ctx->mutex)
		mutex_lock(event->child_mutex)
		// event is from the failing inherit
		// on the other CPU
		perf_remove_from_context()
		list_move()
		mutex_unlock(event->child_mutex)
		mutex_unlock(ctx->mutex)

							      mutex_lock(ctx->mutex)
							      list_for_each_entry_safe()
							        // event already stolen
							      mutex_unlock(ctx->mutex)

							    delayed_free_task()
							      free_task()

	     list_for_each_entry_safe()
	       list_del()
	       free_event()
	         _free_event()
		   // and so event->hw.target
		   // is the already freed failed clone()
		   if (event->hw.target)
		     put_task_struct(event->hw.target)
		       // WHOOPSIE, already quite dead

Which puts the lie to the the comment on perf_event_free_task():
'unexposed, unused context' not so much.

Which is a 'fun' confluence of fail; copy_process() doing an
unconditional free_task() and not respecting refcounts, and perf having
creative locking. In particular:

  82d94856 ("perf/core: Fix lock inversion between perf,trace,cpuhp")

seems to have overlooked this 'fun' parade.

Solve it by using the fact that detached events still have a reference
count on their (previous) context. With this perf_event_free_task()
can detect when events have escaped and wait for their destruction.
Debugged-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Reported-by: syzbot+a24c397a29ad22d86c98@syzkaller.appspotmail.com
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 82d94856 ("perf/core: Fix lock inversion between perf,trace,cpuhp")
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4a5cc64d
    • A
      perf/core: Fix exclusive events' grouping · 75100ec5
      由 Alexander Shishkin 提交于 
      commit 8a58ddae23796c733c5dfbd717538d89d036c5bd upstream.

So far, we tried to disallow grouping exclusive events for the fear of
complications they would cause with moving between contexts. Specifically,
moving a software group to a hardware context would violate the exclusivity
rules if both groups contain matching exclusive events.

This attempt was, however, unsuccessful: the check that we have in the
perf_event_open() syscall is both wrong (looks at wrong PMU) and
insufficient (group leader may still be exclusive), as can be illustrated
by running:

  $ perf record -e '{intel_pt//,cycles}' uname
  $ perf record -e '{cycles,intel_pt//}' uname

ultimately successfully.

Furthermore, we are completely free to trigger the exclusivity violation
by:

   perf -e '{cycles,intel_pt//}' -e '{intel_pt//,instructions}'

even though the helpful perf record will not allow that, the ABI will.

The warning later in the perf_event_open() path will also not trigger, because
it's also wrong.

Fix all this by validating the original group before moving, getting rid
of broken safeguards and placing a useful one to perf_install_in_context().
Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: mathieu.poirier@linaro.org
Cc: will.deacon@arm.com
Fixes: bed5b25a ("perf: Add a pmu capability for "exclusive" events")
Link: https://lkml.kernel.org/r/20190701110755.24646-1-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      75100ec5
    • P
      MIPS: lb60: Fix pin mappings · 0e6ef184
      由 Paul Cercueil 提交于 
      commit 1323c3b72a987de57141cabc44bf9cd83656bc70 upstream.

The pin mappings introduced in commit 636f8ba6
("MIPS: JZ4740: Qi LB60: Add pinctrl configuration for several drivers")
are completely wrong. The pinctrl driver name is incorrect, and the
function and group fields are swapped.

Fixes: 636f8ba6 ("MIPS: JZ4740: Qi LB60: Add pinctrl configuration for several drivers")
Cc: <stable@vger.kernel.org>
Signed-off-by: NPaul Cercueil <paul@crapouillou.net>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NPaul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: od@zcrc.me
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0e6ef184
    • K
      gpio: davinci: silence error prints in case of EPROBE_DEFER · dd5994ab
      由 Keerthy 提交于 
      commit 541e4095f388c196685685633c950cb9b97f8039 upstream.

Silence error prints in case of EPROBE_DEFER. This avoids
multiple/duplicate defer prints during boot.

Cc: <stable@vger.kernel.org>
Signed-off-by: NKeerthy <j-keerthy@ti.com>
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      dd5994ab
    • C
      dma-buf: Discard old fence_excl on retrying get_fences_rcu for realloc · c947cf3e
      由 Chris Wilson 提交于 
      commit f5b07b04e5f090a85d1e96938520f2b2b58e4a8e upstream.

If we have to drop the seqcount & rcu lock to perform a krealloc, we
have to restart the loop. In doing so, be careful not to lose track of
the already acquired exclusive fence.

Fixes: fedf5413 ("dma-buf: Restart reservation_object_get_fences_rcu() after writes")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: stable@vger.kernel.org #v4.10
Reviewed-by: NChristian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190604125323.21396-1-chris@chris-wilson.co.ukSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c947cf3e