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  1. 28 Jun, 2017 1 commit
    • Jens Axboe's avatar
      block: provide bio_uninit() free freeing integrity/task associations · 9ae3b3f5
      Jens Axboe authored 
      Wen reports significant memory leaks with DIF and O_DIRECT:

"With nvme devive + T10 enabled, On a system it has 256GB and started
logging /proc/meminfo & /proc/slabinfo for every minute and in an hour
it increased by 15968128 kB or ~15+GB.. Approximately 256 MB / minute
leaking.

/proc/meminfo | grep SUnreclaim...

SUnreclaim:      6752128 kB
SUnreclaim:      6874880 kB
SUnreclaim:      7238080 kB
....
SUnreclaim:     22307264 kB
SUnreclaim:     22485888 kB
SUnreclaim:     22720256 kB

When testcases with T10 enabled call into __blkdev_direct_IO_simple,
code doesn't free memory allocated by bio_integrity_alloc. The patch
fixes the issue. HTX has been run with +60 hours without failure."

Since __blkdev_direct_IO_simple() allocates the bio on the stack, it
doesn't go through the regular bio free. This means that any ancillary
data allocated with the bio through the stack is not freed. Hence, we
can leak the integrity data associated with the bio, if the device is
using DIF/DIX.

Fix this by providing a bio_uninit() and export it, so that we can use
it to free this data. Note that this is a minimal fix for this issue.
Any current user of bio's that are allocated outside of
bio_alloc_bioset() suffers from this issue, most notably some drivers.
We will fix those in a more comprehensive patch for 4.13. This also
means that the commit marked as being fixed by this isn't the real
culprit, it's just the most obvious one out there.

Fixes: 542ff7bf ("block: new direct I/O implementation")
Reported-by: default avatarWen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
      9ae3b3f5
  3. 27 Jun, 2017 2 commits
  5. 26 Jun, 2017 3 commits
  7. 25 Jun, 2017 6 commits
  9. 24 Jun, 2017 11 commits
  11. 23 Jun, 2017 15 commits
  13. 22 Jun, 2017 2 commits
    • Randy Dunlap's avatar
      kconfig: fix sparse warnings in nconfig · ad818106
      Randy Dunlap authored 
      Fix sparse warnings in scripts/kconfig/nconf* ('make nconfig'):

../scripts/kconfig/nconf.c:1071:32: warning: Using plain integer as NULL pointer
../scripts/kconfig/nconf.c:1238:30: warning: Using plain integer as NULL pointer
../scripts/kconfig/nconf.c:511:51: warning: Using plain integer as NULL pointer
../scripts/kconfig/nconf.c:1460:6: warning: symbol 'setup_windows' was not declared. Should it be static?
../scripts/kconfig/nconf.c:274:12: warning: symbol 'current_instructions' was not declared. Should it be static?
../scripts/kconfig/nconf.c:308:22: warning: symbol 'function_keys' was not declared. Should it be static?
../scripts/kconfig/nconf.gui.c:132:17: warning: non-ANSI function declaration of function 'set_colors'
../scripts/kconfig/nconf.gui.c:195:24: warning: Using plain integer as NULL pointer

nconf.gui.o before/after files are the same.
nconf.o before/after files are the same until the 'static' function
declarations are added.
Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
      ad818106
    • Björn Töpel's avatar
      perf probe: Fix probe definition for inlined functions · 7598f8bc
      Björn Töpel authored 
      In commit 613f050d ("perf probe: Fix to probe on gcc generated
functions in modules"), the offset from symbol is, incorrectly, added
to the trace point address. This leads to incorrect probe trace points
for inlined functions and when using relative line number on symbols.

Prior this patch:
  $ perf probe -m nf_nat -D in_range
  p:probe/in_range nf_nat:in_range.isra.9+0
  $ perf probe -m i40e -D i40e_clean_rx_irq
  p:probe/i40e_clean_rx_irq i40e:i40e_napi_poll+2212
  $ perf probe -m i40e -D i40e_clean_rx_irq:16
  p:probe/i40e_clean_rx_irq i40e:i40e_lan_xmit_frame+626

After:
  $ perf probe -m nf_nat -D in_range
  p:probe/in_range nf_nat:in_range.isra.9+0
  $ perf probe -m i40e -D i40e_clean_rx_irq
  p:probe/i40e_clean_rx_irq i40e:i40e_napi_poll+1106
  $ perf probe -m i40e -D i40e_clean_rx_irq:16
  p:probe/i40e_clean_rx_irq i40e:i40e_napi_poll+2665

Committer testing:

Using 'pfunct', a tool found in the 'dwarves' package [1], one can ask what are
the functions that while not being explicitely marked as inline, were inlined
by the compiler:

  # pfunct --cc_inlined /lib/modules/4.12.0-rc4+/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko | head
  __ew32
  e1000_regdump
  e1000e_dump_ps_pages
  e1000_desc_unused
  e1000e_systim_to_hwtstamp
  e1000e_rx_hwtstamp
  e1000e_update_rdt_wa
  e1000e_update_tdt_wa
  e1000_put_txbuf
  e1000_consume_page

Then ask 'perf probe' to produce the kprobe_tracer probe definitions for two of
them:

  # perf probe -m e1000e -D e1000e_rx_hwtstamp
  p:probe/e1000e_rx_hwtstamp e1000e:e1000_receive_skb+74

  # perf probe -m e1000e -D e1000_consume_page
  p:probe/e1000_consume_page e1000e:e1000_clean_jumbo_rx_irq+876
  p:probe/e1000_consume_page_1 e1000e:e1000_clean_jumbo_rx_irq+1506
  p:probe/e1000_consume_page_2 e1000e:e1000_clean_rx_irq_ps+1074

Now lets concentrate on the 'e1000_consume_page' one, that was inlined twice in
e1000_clean_jumbo_rx_irq(), lets see what readelf says about the DWARF tags for
that function:

  $ readelf -wi /lib/modules/4.12.0-rc4+/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko
  <SNIP>
  <1><13e27b>: Abbrev Number: 121 (DW_TAG_subprogram)
    <13e27c>   DW_AT_name        : (indirect string, offset: 0xa8945): e1000_clean_jumbo_rx_irq
    <13e287>   DW_AT_low_pc      : 0x17a30
  <3><13e6ef>: Abbrev Number: 119 (DW_TAG_inlined_subroutine)
    <13e6f0>   DW_AT_abstract_origin: <0x13ed2c>
    <13e6f4>   DW_AT_low_pc      : 0x17be6
  <SNIP>
  <1><13ed2c>: Abbrev Number: 142 (DW_TAG_subprogram)
     <13ed2e>   DW_AT_name        : (indirect string, offset: 0xa54c3): e1000_consume_page

So, the first time in e1000_clean_jumbo_rx_irq() where e1000_consume_page() is
inlined is at PC 0x17be6, which subtracted from e1000_clean_jumbo_rx_irq()'s
address, gives us the offset we should use in the probe definition:

  0x17be6 - 0x17a30 = 438

but above we have 876, which is twice as much.

Lets see the second inline expansion of e1000_consume_page() in
e1000_clean_jumbo_rx_irq():

  <3><13e86e>: Abbrev Number: 119 (DW_TAG_inlined_subroutine)
    <13e86f>   DW_AT_abstract_origin: <0x13ed2c>
    <13e873>   DW_AT_low_pc      : 0x17d21

  0x17d21 - 0x17a30 = 753

So we where adding it at twice the offset from the containing function as we
should.

And then after this patch:

  # perf probe -m e1000e -D e1000e_rx_hwtstamp
  p:probe/e1000e_rx_hwtstamp e1000e:e1000_receive_skb+37

  # perf probe -m e1000e -D e1000_consume_page
  p:probe/e1000_consume_page e1000e:e1000_clean_jumbo_rx_irq+438
  p:probe/e1000_consume_page_1 e1000e:e1000_clean_jumbo_rx_irq+753
  p:probe/e1000_consume_page_2 e1000e:e1000_clean_jumbo_rx_irq+1353
  #

Which matches the two first expansions and shows that because we were
doubling the offset it would spill over the next function:

  readelf -sw /lib/modules/4.12.0-rc4+/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko
   673: 0000000000017a30  1626 FUNC    LOCAL  DEFAULT    2 e1000_clean_jumbo_rx_irq
   674: 0000000000018090  2013 FUNC    LOCAL  DEFAULT    2 e1000_clean_rx_irq_ps

This is the 3rd inline expansion of e1000_consume_page() in
e1000_clean_jumbo_rx_irq():

   <3><13ec77>: Abbrev Number: 119 (DW_TAG_inlined_subroutine)
    <13ec78>   DW_AT_abstract_origin: <0x13ed2c>
    <13ec7c>   DW_AT_low_pc      : 0x17f79

  0x17f79 - 0x17a30 = 1353

 So:

   0x17a30 + 2 * 1353 = 0x184c2

  And:

   0x184c2 - 0x18090 = 1074

Which explains the bogus third expansion for e1000_consume_page() to end up at:

   p:probe/e1000_consume_page_2 e1000e:e1000_clean_rx_irq_ps+1074

All fixed now :-)

[1] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/Signed-off-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: default avatarMagnus Karlsson <magnus.karlsson@intel.com>
Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 613f050d ("perf probe: Fix to probe on gcc generated functions in modules")
Link: http://lkml.kernel.org/r/20170621164134.5701-1-bjorn.topel@gmail.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      7598f8bc
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