mainlining shenanigans
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Thomas Richter 313146a844 perf stat: Fix out of bounds array access in the print_counters() evlist method
Fix a compile error on F32 and gcc version 10.1 on s390 in file
utils/stat-display.c.  The error does not show up with make DEBUG=y.  In
fact the issue shows up when using both compiler options -O6 and
-D_FORTIFY_SOURCE=2 (which are omitted with DEBUG=Y).

This is the offending call chain:

print_counter_aggr()
  printout(config, -1, 0, ...)  with 2nd parm id set to -1
    aggr_printout(config, x, id --> -1, ...) which leads to this code:
		case AGGR_NONE:
                if (evsel->percore && !config->percore_show_thread) {
                        ....
                } else {
                        fprintf(config->output, "CPU%*d%s",
                                config->csv_output ? 0 : -7,
                                evsel__cpus(evsel)->map[id],
				                        ^^ id is -1 !!!!
                                config->csv_sep);
                }

This is a compiler inlining issue which is detected on s390 but not on
other plattforms.

Output before:

 # make util/stat-display.o
    .....

  util/stat-display.c: In function ‘perf_evlist__print_counters’:
  util/stat-display.c:121:4: error: array subscript -1 is below array
      bounds of ‘int[]’ [-Werror=array-bounds]
  121 |    fprintf(config->output, "CPU%*d%s",
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  122 |     config->csv_output ? 0 : -7,
      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  123 |     evsel__cpus(evsel)->map[id],
      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  124 |     config->csv_sep);
      |     ~~~~~~~~~~~~~~~~
  In file included from util/evsel.h:13,
                 from util/evlist.h:13,
                 from util/stat-display.c:9:
  /root/linux/tools/lib/perf/include/internal/cpumap.h:10:7:
  note: while referencing ‘map’
   10 |  int  map[];
      |       ^~~
  cc1: all warnings being treated as errors
  mv: cannot stat 'util/.stat-display.o.tmp': No such file or directory
  make[3]: *** [/root/linux/tools/build/Makefile.build:97: util/stat-display.o]
  Error 1
  make[2]: *** [Makefile.perf:716: util/stat-display.o] Error 2
  make[1]: *** [Makefile.perf:231: sub-make] Error 2
  make: *** [Makefile:110: util/stat-display.o] Error 2
  [root@t35lp46 perf]#

Output after:

  # make util/stat-display.o
    .....
  CC       util/stat-display.o
  [root@t35lp46 perf]#

Committer notes:

Removed the removal of {} enclosing the multiline else block, as pointed
out by Jiri Olsa.

Suggested-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20200825063304.77733-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-09-01 12:15:52 -03:00
arch x86/boot/compressed: Use builtin mem functions for decompressor 2020-08-19 11:23:45 -07:00
block block-5.9-2020-08-14 2020-08-15 20:36:42 -07:00
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Documentation spi: Fixes for v5.9 2020-08-18 14:27:12 -07:00
drivers pci-v5.9-fixes-1 2020-08-20 14:17:03 -07:00
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include dma-mapping fixes for 5.9 2020-08-20 10:48:17 -07:00
init OpenRISC updates for 5.9 2020-08-14 14:04:53 -07:00
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kernel dma-mapping fixes for 5.9 2020-08-20 10:48:17 -07:00
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mm mm/memory.c: skip spurious TLB flush for retried page fault 2020-08-18 12:02:27 -07:00
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security Merge branch 'akpm' (patches from Andrew) 2020-08-12 11:24:12 -07:00
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tools perf stat: Fix out of bounds array access in the print_counters() evlist method 2020-09-01 12:15:52 -03:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
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Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
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Makefile Linux 5.9-rc1 2020-08-16 13:04:57 -07:00
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Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.