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Groups > linux.kernel > #1648724
| From | Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.18 06/59] dm bufio: avoid a possible ABBA deadlock |
| Date | 2017-05-23 23:20 +0200 |
| Message-ID | <tKpnH-w5-3@gated-at.bofh.it> (permalink) |
| References | <tKpe1-rD-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mikulas Patocka <mpatocka@redhat.com>
commit 1b0fb5a5b2dc0dddcfa575060441a7176ba7ac37 upstream.
__get_memory_limit() tests if dm_bufio_cache_size changed and calls
__cache_size_refresh() if it did. It takes dm_bufio_clients_lock while
it already holds the client lock. However, lock ordering is violated
because in cleanup_old_buffers() dm_bufio_clients_lock is taken before
the client lock.
This results in a possible deadlock and lockdep engine warning.
Fix this deadlock by changing mutex_lock() to mutex_trylock(). If the
lock can't be taken, it will be re-checked next time when a new buffer
is allocated.
Also add "unlikely" to the if condition, so that the optimizer assumes
that the condition is false.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/md/dm-bufio.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -862,10 +862,11 @@ static void __get_memory_limit(struct dm
{
unsigned long buffers;
- if (ACCESS_ONCE(dm_bufio_cache_size) != dm_bufio_cache_size_latch) {
- mutex_lock(&dm_bufio_clients_lock);
- __cache_size_refresh();
- mutex_unlock(&dm_bufio_clients_lock);
+ if (unlikely(ACCESS_ONCE(dm_bufio_cache_size) != dm_bufio_cache_size_latch)) {
+ if (mutex_trylock(&dm_bufio_clients_lock)) {
+ __cache_size_refresh();
+ mutex_unlock(&dm_bufio_clients_lock);
+ }
}
buffers = dm_bufio_cache_size_per_client >>
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[PATCH 3.18 00/59] 3.18.55-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 31/59] USB: serial: io_ti: fix div-by-zero in set_termios Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 18/59] USB: serial: ftdi_sio: fix setting latency for unprivileged users Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 52/59] stackprotector: Increase the per-task stack canarys random range from 32 bits to 64 bits on 64-bit platforms Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 44/59] ARM: dts: at91: sama5d3_xplained: fix ADC vref Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 58/59] drivers: char: mem: Check for address space wraparound with mmap() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 27/59] USB: iowarrior: fix info ioctl on big-endian hosts Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 48/59] xc2028: Fix use-after-free bug properly Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 55/59] tracing/kprobes: Enforce kprobes teardown after testing Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 20/59] usb: host: xhci-plat: propagate return value of platform_get_irq() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 05/59] dm btree: fix for dm_btree_find_lowest_key() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 40/59] [media] zr364xx: enforce minimum size when reading header Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 24/59] [media] mceusb: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 42/59] [media] cx231xx-audio: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 09/59] mwifiex: pcie: fix cmd_buf use-after-free in remove/reset Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 16/59] iio: dac: ad7303: fix channel description Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 11/59] regulator: tps65023: Fix inverted core enable logic. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 34/59] tty: Prevent ldisc drivers from re-using stale tty fields Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
Re: [PATCH 3.18 34/59] tty: Prevent ldisc drivers from re-using stale tty fields Alan Cox <gnomes@lxorguk.ukuu.org.uk> - 2017-05-24 15:50 +0200
Re: [PATCH 3.18 34/59] tty: Prevent ldisc drivers from re-using stale tty fields Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-24 17:10 +0200
[PATCH 3.18 46/59] arm64: uaccess: ensure extension of access_ok() addr Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 30/59] USB: serial: mct_u232: fix big-endian baud-rate handling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 32/59] USB: hub: fix SS hub-descriptor handling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 41/59] [media] cx231xx-cards: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 47/59] arm64: documentation: document tagged pointer stack constraints Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 13/59] cdc-acm: fix possible invalid access when processing notification Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 50/59] metag/uaccess: Fix access_ok() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 54/59] osf_wait4(): fix infoleak Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 49/59] mm/huge_memory.c: respect FOLL_FORCE/FOLL_COW for thp Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 51/59] metag/uaccess: Check access_ok in strncpy_from_user Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 33/59] USB: hub: fix non-SS hub-descriptor handling Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 45/59] ARM: dts: at91: sama5d3_xplained: not all ADC channels are available Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 28/59] usb: serial: option: add Telit ME910 support Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 15/59] of: fdt: add missing allocation-failure check Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 26/59] usb: musb: tusb6010_omap: Do not reset the other directions packet size Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 23/59] [media] usbvision: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 53/59] uwb: fix device quirk on big-endian hosts Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 56/59] PCI: Fix pci_mmap_fits() for HAVE_PCI_RESOURCE_TO_USER platforms Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 36/59] iio: proximity: as3935: fix as3935_write Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:10 +0200
[PATCH 3.18 17/59] pid_ns: Sleep in TASK_INTERRUPTIBLE in zap_pid_ns_processes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 06/59] dm bufio: avoid a possible ABBA deadlock Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 19/59] USB: serial: ftdi_sio: add Olimex ARM-USB-TINY(H) PIDs Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 12/59] ath9k_htc: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 22/59] net: irda: irda-usb: fix firmware name on big-endian hosts Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 25/59] [media] ttusb2: limit messages to buffer size Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 14/59] of: fix sparse warning in of_pci_range_parser_one Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 04/59] USB: core: replace %p with %pK Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 08/59] dm space map disk: fix some book keeping in the disk space map Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 07/59] dm thin metadata: call precommit before saving the roots Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 39/59] [media] dib0700: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 38/59] [media] s5p-mfc: Fix unbalanced call to clock management Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 43/59] powerpc/pseries: Fix of_node_put() underflow during DLPAR remove Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 37/59] [media] gspca: konica: add missing endpoint sanity check Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 03/59] char: lp: fix possible integer overflow in lp_setup() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 02/59] watchdog: pcwd_usb: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
[PATCH 3.18 01/59] USB: ene_usb6250: fix DMA to the stack Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-23 23:20 +0200
Re: [PATCH 3.18 00/59] 3.18.55-stable review Guenter Roeck <linux@roeck-us.net> - 2017-05-24 17:50 +0200
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