perf script: Support using -f to override perf.data file ownership

Enable perf script to use perf.data when it is not owned by current user
or root. Change the short option name of --fields to -F to avoid confusion
with --force.

Example:

# perf record ls
# chown Yunlong.Song:Yunlong.Song perf.data
# ls -al perf.data
-rw------- 1 Yunlong.Song Yunlong.Song 28360 Apr 2 14:53 perf.data
# id
uid=0(root) gid=0(root) groups=0(root),64(pkcs11)

Before this patch:

# perf script
File perf.data not owned by current user or root (use -f to override)
# perf script -f
Error: switch `f' requires a value

usage: perf script [<options>]
or: perf script [<options>] record <script> [<record-options>] <command>
or: perf script [<options>] report <script> [script-args]
or: perf script [<options>] <script> [<record-options>] <command>
or: perf script [<options>] <top-script> [script-args]

-f, --fields <str> comma separated output fields prepend with
'type:'. Valid types: hw,sw,trace,raw. Fields:
comm,tid,pid,time,cpu,event,trace,ip,sym,dso,addr,symoff,period

As shown above, the -f option does not work at all. And -f is already
taken up by --fields, which makes --force confused, so change the short
option name of --fields to -F like what other perf commands do (e.g.
perf report -F) and use -f as the short option name of --force.

After this patch:

# perf script
File perf.data not owned by current user or root (use -f to override)
# perf script -f
:41298 41298 2590086.564226: 1 cycles: ffffffff8103efc6
native_write_msr_safe ([kernel.kallsyms])
:41298 41298 2590086.564244: 1 cycles: ffffffff8103efc6
native_write_msr_safe ([kernel.kallsyms])
:41298 41298 2590086.564249: 7 cycles: ffffffff8103efc6
native_write_msr_safe ([kernel.kallsyms])
:41298 41298 2590086.564255: 176 cycles: ffffffff8103efc6
native_write_msr_safe ([kernel.kallsyms])
ls 41298 2590086.567346: 4059 cycles: ffffffff8105a592
raise_softirq ([kernel.kallsyms])
ls 41298 2590086.567353: 3717 cycles: ffffffff8105a592
raise_softirq ([kernel.kallsyms])
ls 41298 2590086.567358: 63058 cycles: ffffffff8105a592
raise_softirq ([kernel.kallsyms])
ls 41298 2590086.567448: 1706255 cycles: 406ae0
[unknown] (/usr/bin/ls)

As shown above, the -f option really works now.

Signed-off-by: Yunlong Song <[e-mail]>
Tested-by: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Wang Nan <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-script.c

···
 			.ordering_requires_timestamps = true,
 		},
 	};
+	struct perf_data_file file = {
+		.mode = PERF_DATA_MODE_READ,
+	};
 	const struct option options[] = {
 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
 		    "dump raw trace in ASCII"),
···
 		    "When printing symbols do not display call chain"),
 	OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
 		    "Look for files with symbols relative to this directory"),
-	OPT_CALLBACK('f', "fields", NULL, "str",
+	OPT_CALLBACK('F', "fields", NULL, "str",
 		     "comma separated output fields prepend with 'type:'. "
 		     "Valid types: hw,sw,trace,raw. "
 		     "Fields: comm,tid,pid,time,cpu,event,trace,ip,sym,dso,"
···
 		    "Show the fork/comm/exit events"),
 	OPT_BOOLEAN('\0', "show-mmap-events", &script.show_mmap_events,
 		    "Show the mmap events"),
+	OPT_BOOLEAN('f', "force", &file.force, "don't complain, do it"),
 	OPT_END()
 	};
 	const char * const script_subcommands[] = { "record", "report", NULL };
···
 		"perf script [<options>] <script> [<record-options>] <command>",
 		"perf script [<options>] <top-script> [script-args]",
 		NULL
-	};
-	struct perf_data_file file = {
-		.mode = PERF_DATA_MODE_READ,
 	};
 
 	setup_scripting();