kernel_optimize_test/tools
Kemeng Shi 78886f3ed3 perf symbols: Fix arm64 gap between kernel start and module end
During execution of command 'perf report' in my arm64 virtual machine,
this error message is showed:

failed to process sample

__symbol__inc_addr_samples(860): ENOMEM! sym->name=__this_module,
    start=0x1477100, addr=0x147dbd8, end=0x80002000, func: 0

The error is caused with path:
cmd_report
 __cmd_report
  perf_session__process_events
   __perf_session__process_events
    ordered_events__flush
     __ordered_events__flush
      oe->deliver (ordered_events__deliver_event)
       perf_session__deliver_event
        machines__deliver_event
         perf_evlist__deliver_sample
          tool->sample (process_sample_event)
           hist_entry_iter__add
            iter->add_entry_cb(hist_iter__report_callback)
             hist_entry__inc_addr_samples
              symbol__inc_addr_samples
               __symbol__inc_addr_samples
                h = annotated_source__histogram(src, evidx) (NULL)

annotated_source__histogram failed is caused with path:
...
 hist_entry__inc_addr_samples
  symbol__inc_addr_samples
   symbol__hists
    annotated_source__alloc_histograms
     src->histograms = calloc(nr_hists, sizeof_sym_hist) (failed)

Calloc failed as the symbol__size(sym) is too huge. As show in error
message: start=0x1477100, end=0x80002000, size of symbol is about 2G.

This is the same problem as 'perf annotate: Fix s390 gap between kernel
end and module start (b9c0a64901)'. Perf gets symbol information from
/proc/kallsyms in __dso__load_kallsyms. A part of symbol in /proc/kallsyms
from my virtual machine is as follows:
 #cat /proc/kallsyms | sort
 ...
 ffff000001475080 d rpfilter_mt_reg      [ip6t_rpfilter]
 ffff000001475100 d $d   [ip6t_rpfilter]
 ffff000001475100 d __this_module        [ip6t_rpfilter]
 ffff000080080000 t _head
 ffff000080080000 T _text
 ffff000080080040 t pe_header
 ...

Take line 'ffff000001475100 d __this_module [ip6t_rpfilter]' as example.
The start and end of symbol are both set to ffff000001475100 in
dso__load_all_kallsyms. Then symbols__fixup_end will set the end of symbol
to next big address to ffff000001475100 in /proc/kallsyms, ffff000080080000
in this example. Then sizeof of symbol will be about 2G and cause the
problem.

The start of module in my machine is
 ffff000000a62000 t $x   [dm_mod]

The start of kernel in my machine is
 ffff000080080000 t _head

There is a big gap between end of module and begin of kernel if a samll
amount of memory is used by module. And the last symbol in module will
have a large address range as caotaining the big gap.

Give that the module and kernel text segment sequence may change in
the future, fix this by limiting range of last symbol in module and kernel
to 4K in arch arm64.

Signed-off-by: Kemeng Shi <shikemeng@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hewenliang <hewenliang4@huawei.com>
Cc: Hu Shiyuan <hushiyuan@huawei.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: http://lore.kernel.org/lkml/33fd24c4-0d5a-9d93-9b62-dffa97c992ca@huawei.com
[ refreshed the patch on current codebase, added string.h include as strchr() is used ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-04-03 09:37:55 -03:00
..
accounting
arch x86/insn: Add Control-flow Enforcement (CET) instructions to the opcode map 2020-03-27 10:38:46 -03:00
bootconfig bootconfig: Add append value operator support 2020-02-21 09:59:39 -05:00
bpf bpftool: Don't crash on missing xlated program instructions 2020-02-07 22:29:45 +01:00
build perf tools: Add file-handle feature test 2020-04-03 09:37:55 -03:00
cgroup iocost: Fix iocost_monitor.py due to helper type mismatch 2020-01-17 11:54:35 -08:00
debugging
firewire
firmware
gpio tools: gpio: Correctly add make dependencies for gpio_utils 2019-11-13 13:46:04 +01:00
hv Tools: hv: Reopen the devices if read() or write() returns errors 2020-01-26 22:10:10 -05:00
iio tools: iio: Correctly add make dependency for iio_utils 2019-11-10 17:11:06 +00:00
include tools headers UAPI: Update tools's copy of linux/perf_event.h 2020-04-02 12:51:49 -03:00
io_uring
kvm/kvm_stat tools/kvm_stat: Fix kvm_exit filter name 2020-01-23 09:51:06 +01:00
laptop
leds
lib perf tools: Basic support for CGROUP event 2020-04-03 09:37:55 -03:00
memory-model tools/memory-model/Documentation: Add plain accesses and data races to explanation.txt 2019-10-05 11:59:44 -07:00
nfsd
objtool objtool: Fix ARCH=x86_64 build error 2020-01-22 07:54:57 +01:00
pci tools: PCI: Fix fd leakage 2019-10-29 12:04:18 +00:00
pcmcia
perf perf symbols: Fix arm64 gap between kernel start and module end 2020-04-03 09:37:55 -03:00
power cpupower: avoid multiple definition with gcc -fno-common 2020-03-02 08:53:34 -07:00
scripts tools: Let O= makes handle a relative path with -C option 2020-03-06 17:08:28 -03:00
spi
testing Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-12 16:19:19 -07:00
thermal/tmon
time
usb usbip: Fix unsafe unaligned pointer usage 2020-01-09 16:44:26 +01:00
virtio tools/virtio: xen stub 2019-10-13 09:38:27 -04:00
vm tools/vm/slabinfo: fix sanity checks enabling 2020-01-31 10:30:38 -08:00
wmi
Makefile tools: bootconfig: Add bootconfig command 2020-01-13 13:19:39 -05:00