Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 23 8月, 2019 8 次提交
  3. 22 8月, 2019 3 次提交
  5. 20 8月, 2019 4 次提交
    • L
      perf cs-etm: Support sample flags 'insn' and 'insnlen' · a4973d8f
      由 Leo Yan 提交于 
      The synthetic branch and instruction samples are missed to set
instruction related info, thus the perf tool fails to display samples
with flags '-F,+insn,+insnlen'.

The CoreSight trace decoder provides sufficient information to decide
the instruction size based on the ISA type: A64/A32 instructions are
32-bit size, but one exception is the T32 instruction size, which might
be 32-bit or 16-bit.

This patch handles these cases and it reads the instruction values from
DSO file; thus can support the flags '-F,+insn,+insnlen'.

Before:

  # perf script -F,insn,insnlen,ip,sym
                0 [unknown] ilen: 0
     ffff97174044 _start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0
     ffff97174938 _dl_start ilen: 0

  [...]

After:

  # perf script -F,insn,insnlen,ip,sym
                0 [unknown] ilen: 0
     ffff97174044 _start ilen: 4 insn: 2f 02 00 94
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54
     ffff97174938 _dl_start ilen: 4 insn: c1 ff ff 54

  [...]
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Reviewed-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190815082854.18191-1-leo.yan@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      a4973d8f
    • A
      perf report: Dump LBR callstack data by -D jointly with thread stack · d2720c3d
      由 Alexey Budankov 提交于 
      Make perf report -D command print captured LBR callstack chain when it is
collected together with raw thread stack data:

  2752673087247083 0x5d10 [0x548]: PERF_RECORD_SAMPLE(IP, 0x4002): 5841/5841: 0x40121f period: 1543862 addr: 0
  ... FP chain: nr:0
  ... branch callstack: nr:3
  .....  0: 00000000004011d0
  .....  1: 00007f393c388411
  .....  2: 0000000000401098
  ... user regs: mask 0xff0fff ABI 64-bit
  .... AX    0x34e7
  .... BX    0x7fff5f6dd3c0
  .... CX    0xffffffff
  .... DX    0x34e6
  .... SI    0x7f393c5268d0
  .... DI    0x0
  .... BP    0x401260
  .... SP    0x7fff5f6dd3c0
  .... IP    0x40121f
  .... FLAGS 0x29f
  .... CS    0x33
  .... SS    0x2b
  .... R8    0x7f393c526800
  .... R9    0x7f393c525da0
  .... R10   0xfffffffffffff70a
  .... R11   0x246
  .... R12   0x401070
  .... R13   0x7fff5f6ddcb0
  .... R14   0x0
  .... R15   0x0
  ... ustack: size 1024, offset 0x130
   . data_src: 0x5080021
   ... thread: stack_test:5841
   ...... dso: /root/abudanko/stacks/stack_test

Committer testing:

  # perf record -g --call-graph dwarf,1024 -j stack,u ls > /dev/null
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.042 MB perf.data (10 samples) ]
  #

Before:

  # perf report -D |& grep PERF_RECORD_SAMPLE -A28 | tail -29
  67538909824483 0xa7a0 [0x560]: PERF_RECORD_SAMPLE(IP, 0x4002): 9721/9721: 0x7f441b2b1e20 period: 1376095 addr: 0
  ... FP chain: nr:0
  ... user regs: mask 0xff0fff ABI 64-bit
  .... AX    0x7f441b2b1000
  .... BX    0x7f441b55b970
  .... CX    0x7fff6e2db218
  .... DX    0x7fff6e2db218
  .... SI    0x7fff6e2db208
  .... DI    0x1
  .... BP    0x1
  .... SP    0x7fff6e2db178
  .... IP    0x7f441b2b1e20
  .... FLAGS 0x20a
  .... CS    0x33
  .... SS    0x2b
  .... R8    0x1
  .... R9    0x7f441b371c18
  .... R10   0x7f441b5a5f10
  .... R11   0x202
  .... R12   0x7fff6e2db208
  .... R13   0x7fff6e2db218
  .... R14   0x7f441b5a7150
  .... R15   0x0
  ... ustack: size 1024, offset 0x148
   . data_src: 0x5080021
   ... thread: ls:9721
   ...... dso: /usr/lib64/libpthread-2.29.so

  0xad00 [0x60]: event: 10
  #

After:

  # perf report -D |& grep PERF_RECORD_SAMPLE -A31 | tail -32
  67538909824483 0xa7a0 [0x560]: PERF_RECORD_SAMPLE(IP, 0x4002): 9721/9721: 0x7f441b2b1e20 period: 1376095 addr: 0
  ... FP chain: nr:0
  ... branch callstack: nr:4
  .....  0: 00007f441b2b1e20
  .....  1: 00007f441b58af1a
  .....  2: 00007f441b58b0e1
  .....  3: 00007f441b57c145
  ... user regs: mask 0xff0fff ABI 64-bit
  .... AX    0x7f441b2b1000
  .... BX    0x7f441b55b970
  .... CX    0x7fff6e2db218
  .... DX    0x7fff6e2db218
  .... SI    0x7fff6e2db208
  .... DI    0x1
  .... BP    0x1
  .... SP    0x7fff6e2db178
  .... IP    0x7f441b2b1e20
  .... FLAGS 0x20a
  .... CS    0x33
  .... SS    0x2b
  .... R8    0x1
  .... R9    0x7f441b371c18
  .... R10   0x7f441b5a5f10
  .... R11   0x202
  .... R12   0x7fff6e2db208
  .... R13   0x7fff6e2db218
  .... R14   0x7f441b5a7150
  .... R15   0x0
  ... ustack: size 1024, offset 0x148
   . data_src: 0x5080021
   ... thread: ls:9721
   ...... dso: /usr/lib64/libpthread-2.29.so
  #
Signed-off-by: NAlexey Budankov <alexey.budankov@linux.intel.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/aa82e5dd-def2-0ca8-a064-db9e2e8ad076@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      d2720c3d
    • A
      perf record: Enable LBR callstack capture jointly with thread stack · 25663496
      由 Alexey Budankov 提交于 
      Enable '-j stack' applicability together with '--call-graph dwarf'
option so thread stack data and LBR call stack could be captured
jointly:

  $ perf record -g --call-graph dwarf,1024 -j stack,u -- stack_test

Collected LBR call stack can be used to augment DWARF call stack
calculated from the raw thread stack data and to provide more
comprehensive call stack information for cases when collected SIZE is
not enough to cover complete thread stack.

Such cases are typical for workloads that allocate large arrays of data
on its threads stacks or the possible SIZE to collect can't be large
enough due to workload nature or system configuration and this is where
hardware captured LBR call stacks can provide missing stack frames.
Possible DWARF plus LBR call stacks consolidation algorithm description
follows.

With this patch set perf report command UI currently ignores collected
LBR call stack data and still provides DWARF based call stacks
information.

  ===========================================================================

  Overview:

   Legend:

   THS - thread stack
   CTX - thread register context
   SWS - software stack
   SSF - skipped stack frames
   PSS - Perf sample stack

   ip,sp,bp - HW registers values
   d        - allocated stack regions
   kip      - ip address in the kernel space
   K        - captured thread stack size

        THS

       -----
       |   |<-stack bottom
        ...
       |---|
       |ip4|
       |---|         PSS = SWS(THS(K))
       |   |
   --> |   |
   |   |d3 |                  user/
   |   |---|         user PSS kernel PSS
   |   |ip3|         ------   ------
   |   |---|         |SSF |   |SSF |
   |   |   |          ....     ....
   |   |   |         ------   ------
   |   |d2 |         | -1 |   | -1 |
       |---|   user  ------   ------
   K   |ip2|   CTX   |ip3 |   |ip3 |
       |---|         |----|   |----|
   |   |d1 |   ...   |ip2 | , |ip2 |
   |   |---|  |---|  |----|   |----|
   |   |ip1|  |bp0|  |ip1 |   |ip1 |
   |   |---|  |---|  |----|   |----|
   |   |   |  |ip0|->|ip0 |   |ip0 |<-user stack top
   |   |   |  |---|  ------   ------
   |   |   |<-|sp0|<-stack    |kip0|<-kernel stack bottom
   --> -----  -----   top     |----|
                              |kip1|
                              |----|
		              |kip2|
		              |----|
                               ....
			      |    |<-kernel stack top
                              ------

  Algorithm details:

   Legend:

   HWS - hardware stack
   K-SWS - kernel software stack

			 BRANCH
			 TABLE

		 HWS      ip   ip
			  from to
		 ------  -----------
		 |ip7`|  |ip7`|    |
		 |----|  |----|----|
		 |ip6`|  |ip6`|    |
	user PSS |----|  |----|----|
		 |ip5`|  |ip5`|    |
	------   |----|  |----|----|
	| -1 |   |ip4`|  |ip4`|    |
	------   |----|  |----|----|
	|ip3 |~~~|ip3`|  |ip3`|    |
	|----|   |----|  |----|----|
	|ip2 |~~~|ip2`|  |ip2`|    |
	|----| 	 |----|  |----|----|
	|ip1 |~~~|ip1`|  |ip1`|ip0`|
	|----| 	 |----|  -----------
	|ip0 |~~~|ip0`|<---------'
	------   ------

	1. if (sym(ipj) == sym(ipj`)), j=0-3 ===> user PSS
	2. ipj`                      , j=4-7 ===> user PSS

  Augmented PSS = A_SWS(SWS(THS(K)), HWS):

	         user/
       user PSS  kernel PSS

	------   ------
	|ip7`|   |ip7`|<-user PSS bottom
	|----|   |----|
	|ip6`|   |ip6`|
	|----|   |----|
    HWS	|ip5`|   |ip5`|
	|----|   |----|
	|ip4`|   |ip4`|
	------   ------
	|ip3 |   |ip3 |
	|----|   |----|
    SWS |ip2 |   |ip2 |
	|----|   |----|
	|ip1 |   |ip1 |
	|----|   |----|
	|ip0 |   |ip0 |<-user PSS top
	------   ------
		 |kip0|<-kernel PSS bottom
		 |----|
		 |kip1|
	   K-SWS |----|
		 |kip2|
		 |----|
		 |kip3|<-kernel PSS top
		 ------

                  APSS

Committer testing:

Before:

  # perf record -g --call-graph dwarf,1024 -j stack,u ls > /dev/null
  unknown branch filter stack, check man page

   Usage: perf record [<options>] [<command>]
      or: perf record [<options>] -- <command> [<options>]

      -j, --branch-filter <branch filter mask>
                            branch stack filter modes
  # perf record -g --call-graph dwarf,1024 -j u ls > /dev/null
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.054 MB perf.data (12 samples) ]
  # perf evlist -v
  cycles: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ADDR|CALLCHAIN|PERIOD|BRANCH_STACK|REGS_USER|STACK_USER|DATA_SRC, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 3, mmap_data: 1, sample_id_all: 1, exclude_guest: 1, exclude_callchain_user: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, branch_sample_type: ANY, sample_regs_user: 0xff0fff, sample_stack_user: 1024
   #

After:

  # perf record -g --call-graph dwarf,1024 -j stack,u ls > /dev/null
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.044 MB perf.data (11 samples) ]
  [root@quaco ~]# perf evlist -v
  cycles: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ADDR|CALLCHAIN|PERIOD|BRANCH_STACK|REGS_USER|STACK_USER|DATA_SRC, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 3, mmap_data: 1, sample_id_all: 1, exclude_guest: 1, exclude_callchain_user: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, branch_sample_type: USER|CALL_STACK, sample_regs_user: 0xff0fff, sample_stack_user: 1024
  #
Signed-off-by: NAlexey Budankov <alexey.budankov@linux.intel.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/e9e00090-66fb-d2a4-c90f-1d12344f7788@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      25663496
    • A
      perf evsel: Add comment for 'idx' member in 'struct perf_sample_id · 3c84e65a
      由 Adrian Hunter 提交于 
      The 'idx' member was added as preparation for AUX area sampling. Add a
comment to describe why.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/83ff264f-84c3-5372-8976-dd9293d20c6f@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      3c84e65a
  7. 16 8月, 2019 4 次提交
    • J
      perf unwind: Remove unnecessary test · e2736219
      由 John Keeping 提交于 
      If dwarf_callchain_users is false, then unwind__prepare_access() will
not set unwind_libunwind_ops so the remaining test here is sufficient.
Signed-off-by: NJohn Keeping <john@metanate.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: john keeping <john@metanate.com>
Link: http://lkml.kernel.org/r/20190815100146.28842-3-john@metanate.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      e2736219
    • J
      perf unwind: Fix libunwind when tid != pid · e8ba2906
      由 John Keeping 提交于 
      Commit e5adfc3e ("perf map: Synthesize maps only for thread group
leader") changed the recording side so that we no longer get mmap events
for threads other than the thread group leader (when synthesising these
events for threads which exist before perf is started).

When a file recorded after this change is loaded, the lack of mmap
records mean that unwinding is not set up for any other threads.

This can be seen in a simple record/report scenario:

	perf record --call-graph=dwarf -t $TID
	perf report

If $TID is a process ID then the report will show call graphs, but if
$TID is a secondary thread the output is as if --call-graph=none was
specified.

Following the rationale in that commit, move the libunwind fields into
struct map_groups and update the libunwind functions to take this
instead of the struct thread.  This is only required for
unwind__finish_access which must now be called from map_groups__delete
and the others are changed for symmetry.

Note that unwind__get_entries keeps the thread argument since it is
required for symbol lookup and the libdw unwind provider uses the thread
ID.
Signed-off-by: NJohn Keeping <john@metanate.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: e5adfc3e ("perf map: Synthesize maps only for thread group leader")
Link: http://lkml.kernel.org/r/20190815100146.28842-2-john@metanate.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      e8ba2906
    • J
      perf map: Use zalloc for map_groups · ab6cd0e5
      由 John Keeping 提交于 
      In the next commit we will add new fields to map_groups and we need
these to be null if no value is assigned.  The simplest way to achieve
this is to request zeroed memory from the allocator.
Signed-off-by: NJohn Keeping <john@metanate.com>
Reviewed-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: john keeping <john@metanate.com>
Link: http://lkml.kernel.org/r/20190815100146.28842-1-john@metanate.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      ab6cd0e5
    • A
      perf top: Add --switch-on/--switch-off events · 2f53ae34
      由 Arnaldo Carvalho de Melo 提交于 
      Just like 'perf trace' and 'perf script', should be useful for instance
to only consider samples after the initialization phase of some
workload.

The man page has some examples and considerations about its current
interface, that still doesn't handle the on/off events in a special way,
behaving just like when multiple events are specified, i.e.:

- In non-group mode (when the event list is not enclosed in {}) show a
  a menu to allow choosing which event the user wants to see in the
  histograms browser

- In group mode, be it using {} or asking for --group, show one column
  per event.

Try for instance:

  # perf top -e '{cycles,instructions,probe:icmp_rcv}' --switch-on=probe:icmp_rcv

Replace probe:icmp_rcv, that I put in place using:

  # perf probe icmp_rcv:59

To hit when broadcast packets arrive, with a probe installed after an
initialization phase is over or after some other point of interest, some
garbage collection, etc, and also use --switch-off, for instance, on a
probe installed after said garbage collection is over.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: William Cohen <wcohen@redhat.com>
Link: https://lkml.kernel.org/n/tip-c7q7qjeqtyvc9mkeipxza6ne@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      2f53ae34
  9. 15 8月, 2019 7 次提交
  11. 14 8月, 2019 9 次提交
  13. 13 8月, 2019 3 次提交
  15. 09 8月, 2019 2 次提交
    • T
      perf annotate: Fix s390 gap between kernel end and module start · b9c0a649
      由 Thomas Richter 提交于 
      During execution of command 'perf top' the error message:

   Not enough memory for annotating '__irf_end' symbol!)

is emitted from this call sequence:
  __cmd_top
    perf_top__mmap_read
      perf_top__mmap_read_idx
        perf_event__process_sample
          hist_entry_iter__add
            hist_iter__top_callback
              perf_top__record_precise_ip
                hist_entry__inc_addr_samples
                  symbol__inc_addr_samples
                    symbol__get_annotation
                      symbol__alloc_hist

In this function the size of symbol __irf_end is calculated. The size of
a symbol is the difference between its start and end address.

When the symbol was read the first time, its start and end was set to:

   symbol__new: __irf_end 0xe954d0-0xe954d0

which is correct and maps with /proc/kallsyms:

   root@s8360046:~/linux-4.15.0/tools/perf# fgrep _irf_end /proc/kallsyms
   0000000000e954d0 t __irf_end
   root@s8360046:~/linux-4.15.0/tools/perf#

In function symbol__alloc_hist() the end of symbol __irf_end is

  symbol__alloc_hist sym:__irf_end start:0xe954d0 end:0x3ff80045a8

which is identical with the first module entry in /proc/kallsyms

This results in a symbol size of __irf_req for histogram analyses of
70334140059072 bytes and a malloc() for this requested size fails.

The root cause of this is function
  __dso__load_kallsyms()
  +-> symbols__fixup_end()

Function symbols__fixup_end() enlarges the last symbol in the kallsyms
map:

   # fgrep __irf_end /proc/kallsyms
   0000000000e954d0 t __irf_end
   #

to the start address of the first module:
   # cat /proc/kallsyms | sort  | egrep ' [tT] '
   ....
   0000000000e952d0 T __security_initcall_end
   0000000000e954d0 T __initramfs_size
   0000000000e954d0 t __irf_end
   000003ff800045a8 T fc_get_event_number       [scsi_transport_fc]
   000003ff800045d0 t store_fc_vport_disable    [scsi_transport_fc]
   000003ff800046a8 T scsi_is_fc_rport  [scsi_transport_fc]
   000003ff800046d0 t fc_target_setup   [scsi_transport_fc]

On s390 the kernel is located around memory address 0x200, 0x10000 or
0x100000, depending on linux version. Modules however start some- where
around 0x3ff xxxx xxxx.

This is different than x86 and produces a large gap for which histogram
allocation fails.

Fix this by detecting the kernel's last symbol and do no adjustment for
it. Introduce a weak function and handle s390 specifics.
Reported-by: NKlaus Theurich <klaus.theurich@de.ibm.com>
Signed-off-by: NThomas Richter <tmricht@linux.ibm.com>
Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20190724122703.3996-2-tmricht@linux.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b9c0a649
    • T
      perf record: Fix module size on s390 · 12a6d294
      由 Thomas Richter 提交于 
      On s390 the modules loaded in memory have the text segment located after
the GOT and Relocation table. This can be seen with this output:

  [root@m35lp76 perf]# fgrep qeth /proc/modules
  qeth 151552 1 qeth_l2, Live 0x000003ff800b2000
  ...
  [root@m35lp76 perf]# cat /sys/module/qeth/sections/.text
  0x000003ff800b3990
  [root@m35lp76 perf]#

There is an offset of 0x1990 bytes. The size of the qeth module is
151552 bytes (0x25000 in hex).

The location of the GOT/relocation table at the beginning of a module is
unique to s390.

commit 203d8a4a ("perf s390: Fix 'start' address of module's map")
adjusts the start address of a module in the map structures, but does
not adjust the size of the modules. This leads to overlapping of module
maps as this example shows:

[root@m35lp76 perf] # ./perf report -D
     0 0 0xfb0 [0xa0]: PERF_RECORD_MMAP -1/0: [0x3ff800b3990(0x25000)
          @ 0]:  x /lib/modules/.../qeth.ko.xz
     0 0 0x1050 [0xb0]: PERF_RECORD_MMAP -1/0: [0x3ff800d85a0(0x8000)
          @ 0]:  x /lib/modules/.../ip6_tables.ko.xz

The module qeth.ko has an adjusted start address modified to b3990, but
its size is unchanged and the module ends at 0x3ff800d8990.  This end
address overlaps with the next modules start address of 0x3ff800d85a0.

When the size of the leading GOT/Relocation table stored in the
beginning of the text segment (0x1990 bytes) is subtracted from module
qeth end address, there are no overlaps anymore:

   0x3ff800d8990 - 0x1990 = 0x0x3ff800d7000

which is the same as

   0x3ff800b2000 + 0x25000 = 0x0x3ff800d7000.

To fix this issue, also adjust the modules size in function
arch__fix_module_text_start(). Add another function parameter named size
and reduce the size of the module when the text segment start address is
changed.

Output after:
     0 0 0xfb0 [0xa0]: PERF_RECORD_MMAP -1/0: [0x3ff800b3990(0x23670)
          @ 0]:  x /lib/modules/.../qeth.ko.xz
     0 0 0x1050 [0xb0]: PERF_RECORD_MMAP -1/0: [0x3ff800d85a0(0x7a60)
          @ 0]:  x /lib/modules/.../ip6_tables.ko.xz
Reported-by: NStefan Liebler <stli@linux.ibm.com>
Signed-off-by: NThomas Richter <tmricht@linux.ibm.com>
Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: stable@vger.kernel.org
Fixes: 203d8a4a ("perf s390: Fix 'start' address of module's map")
Link: http://lkml.kernel.org/r/20190724122703.3996-1-tmricht@linux.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      12a6d294