7:07 p.m.
Using the latest F7 kernel and crash I'm getting the following
error:
WARNING: cannot read linux_banner string
crash: /usr/lib/debug/lib/modules/2.6.22.1-20.fc7/vmlinux and /dev/crash
do not match!
I've tried both crash and crash -f with no luck.
I've search the mailing list and was unable to find any
thing talked about this problem... So I'm thinking this
may not be a known problem... If it is, please let me know
otherwise does anybody have idea what the problem could be?
tia,
steved.
8:12 a.m.
Steve Dickson wrote:
Using the latest F7 kernel and crash I'm getting the following
error:
WARNING: cannot read linux_banner string
crash: /usr/lib/debug/lib/modules/2.6.22.1-20.fc7/vmlinux and /dev/crash
do not match!
I've tried both crash and crash -f with no luck.
I've search the mailing list and was unable to find any
thing talked about this problem... So I'm thinking this
may not be a known problem... If it is, please let me know
otherwise does anybody have idea what the problem could be?
tia,
steved.
Steve,
In these kinds of cases, a "crash -d7" will often help
pinpointing the failure cause, i.e., such as displaying
the linux_banner string from both the vmlinux and from memory,
showing the mis-match, or in this case, the virtual address
that's being used for the linux_banner which is causing the
read-from-/dev/crash failure.
Anyway, any chance you give me access to the machine?
Thanks,
Dave
1:50 p.m.
New subject: documentation of crash flags [was: crash-4.0-4.3 and linux-2.6.22.1-20.fc7]
| From: Steve Dickson <SteveD(a)redhat.com>
| I've tried both crash and crash -f with no luck.
How did you find out about -f flag? I don't see it in crash(8) nor in
the output of crash --help.
Flags known to crash, extracted from main.c:
--memory_module
--memory_device
--no_kallsyms
--no_modules
--no_namelist_gzip
--help
--data_debug
--no_data_debug
--no_crashrc
--no_kmem_cache
--kmem_cache_delay
--readnow
--smp
--machdep
--version
--buildinfo
--shadow_page_tables
--cpus
--no_ikconfig
--hyper
--p2m_mfn
--zero_excluded
--no_panic
-f
-g
-H
-h
-e
-t
-i
-v
-s
-L
-S
-c
-d
-p
-m
Flags listed in crash(8) and output of crash --help:
-h
-v
-s
-i
-d
-S
It would be good if more of the flags were documented.
Also: getopt makes it easy to add a long option name as a synonym for
a one-character option. I think that you can use this feature to help
make options clearer. For example, --force could be added as a
synonym for -f at the cost of one more line initializing long_options.
5:06 p.m.
New subject: implementation of -h and --help [was: documentation of crash flags]linux-2.6.22.1-20.fc7]
| From: D. Hugh Redelmeier <hugh(a)mimosa.com>
| It would be good if more of the flags were documented.
|
| Also: getopt makes it easy to add a long option name as a synonym for
| a one-character option. I think that you can use this feature to help
| make options clearer. For example, --force could be added as a
| synonym for -f at the cost of one more line initializing long_options.
While I was looking at this, I found some interesting issues with -h
and --help.
There is separate and different code to implement --help and -h and
the undocumented -H flag. In fact, -h is implemented twice: once in
main.c:main() case 'h' and once in the default case! --help uses
program_usage(), -h case 'h' and -H use cmd_usage (slightly
differently), and -h default uses program_usage.
One difference is that the -H and one implementation of -h must have
an argument, the other -h must not, and neither must the --help.
Very confusing. -h and --help should optionally take an argument and
-H should not exist.
I would also claim that -h or --help should exit with status 0 but
currently they exit with status 1.
I am enclosing a patch that fixes these anomalies and does a small
amount of tidying. The resulting code is simpler and easier to
understand, at least in my eyes.
In help.c:
- Disentangle the code for program_usage(LONG_FORM) and
program_usage(SHORT_FORM).
The code for these two cases was pretty different but intermingled.
This change makes them simpler.
It makes sense that LONG_FORM exits with status 0 and that
SHORT_FORM exits with status 1 since the first is requested by the
user while the second is a response to a user error.
Note that LONG_FORM unconditionally uses less(1). This is
questionable. I didn't change this.
These two cases should probably be separate routines. After my
changes to main.c only one call with LONG_FORM remains.
In help.c cmd_usage():
- make sure that cmd_usage does not call gdb if gdb isn't initialized
(in trying to give -h help for an unrecognized command)
- add a flag MUST_HELP to cmd_usage to specify that if help isn't
found a diagnostic should be printed. This used to be the case if
the command calling cmd_usage was help but not if -h called it.
- this command still unconditionally uses less(1) for anything but a
synopsis. This should be changed.
In main.c, the long_options array:
- use the name "required_argument" in place of the magic number 1.
- make --help a synonym of 'h'
- specify that --help has an optional_argument.
In main.c main():
- in the call of getopt_long: add another ':' for -h. This means
that the argument is optional. This, in turn, means that the switch
default no longer handles -h at the end of an argument list.
- I added code to detect and report an unhandled long option. It is
easy to get the long_option table out of sync with the handlers.
Mostly this involves adding "else" a lot of places in case 0.
- ditch the code to implement --help since it is now handled by the
code for -h
- ditch the code to implement -h in the switch default since it is now
handled in case 'h'
- the case 'h' code now has to handle the fact that the -h / --help
argument is optional.
- removed -H flag which wasn't documented and is now redundant.
===================================================================
RCS file: RCS/defs.h,v
retrieving revision 1.1
diff -u -r1.1 defs.h
--- defs.h 2007/07/07 17:56:15 1.1
+++ defs.h 2007/07/16 21:34:50
@@ -2630,6 +2630,7 @@
#define SYNOPSIS (0x1)
#define COMPLETE_HELP (0x2)
#define PIPE_TO_LESS (0x4)
+#define MUST_HELP (0x8)
#define LEFT_JUSTIFY (1)
#define RIGHT_JUSTIFY (2)
===================================================================
RCS file: RCS/help.c,v
retrieving revision 1.1
diff -u -r1.1 help.c
--- help.c 2007/07/16 17:54:15 1.1
+++ help.c 2007/07/16 21:57:40
@@ -105,34 +105,27 @@
void
program_usage(int form)
{
- int i;
- char **p;
- FILE *less;
-
- if (form == LONG_FORM)
- less = popen("/usr/bin/less", "w");
- else
- less = NULL;
-
- p = program_usage_info;
+ if (form == SHORT_FORM) {
+ fprintf(fp, program_usage_info[0], pc->program_name);
+ fprintf(fp, "\nEnter \"%s -h\" for details.\n",
+ pc->program_name);
+ clean_exit(1);
+ } else {
+ char **p = program_usage_info;
+ FILE *less = popen("/usr/bin/less", "w");
- if (form == LONG_FORM) {
if (less)
fp = less;
- for (i = 0; program_usage_info[i]; i++, p++) {
- fprintf(fp, *p, pc->program_name);
+ for (; *p; p++) {
+ fprintf(fp, *p, pc->program_name);
fprintf(fp, "\n");
}
- } else {
- fprintf(fp, *p, pc->program_name);
- fprintf(fp, "\nEnter \"%s -h\" for details.\n",
- pc->program_name);
- }
- fflush(fp);
- if (less)
- pclose(less);
+ fflush(fp);
+ if (less)
+ pclose(less);
- clean_exit(1);
+ clean_exit(0);
+ }
}
@@ -397,7 +390,7 @@
if (oflag)
dump_offset_table(args[optind], FALSE);
else
- cmd_usage(args[optind], COMPLETE_HELP);
+ cmd_usage(args[optind], COMPLETE_HELP|MUST_HELP);
optind++;
} while (args[optind]);
}
@@ -4902,12 +4895,9 @@
void
cmd_usage(char *cmd, int helpflag)
{
- int i;
- int found;
char **p;
struct command_table_entry *cp;
char buf[BUFSIZE];
- struct alias_data *ad;
FILE *less;
if (helpflag & PIPE_TO_LESS) {
@@ -4939,6 +4929,8 @@
}
if (STREQ(cmd, "all")) {
+ int i;
+
display_input_info();
display_output_info();
help_init();
@@ -4959,46 +4951,50 @@
goto done_usage;
}
- found = FALSE;
-retry:
- if ((cp = get_command_table_entry(cmd))) {
- if ((p = cp->help_data))
- found = TRUE;
- }
+ /* look up command, possibly through an alias */
+ for (;;) {
+ struct alias_data *ad;
+
+ cp = get_command_table_entry(cmd);
+ if (cp != NULL)
+ break; /* found command */
+
+ /* try for an alias */
+ ad = is_alias(cmd);
+ if (ad == NULL)
+ break; /* neither command nor alias */
- /*
- * Check for alias names or gdb commands.
- */
- if (!found) {
- if ((ad = is_alias(cmd))) {
- cmd = ad->args[0];
- goto retry;
- }
+ cmd = ad->args[0];
+ cp = get_command_table_entry(cmd);
+ }
- if (helpflag == SYNOPSIS) {
- fprintf(fp,
- "No usage data for the \"%s\" command is
available.\n",
+ if (cp == NULL || (p = cp->help_data) == NULL) {
+ if (helpflag & SYNOPSIS) {
+ fprintf(fp,
+ "No usage data for the \"%s\" command"
+ " is available.\n",
cmd);
RESTART();
}
- if (STREQ(pc->curcmd, "help")) {
- if (cp)
- fprintf(fp,
- "No help data for the \"%s\" command is
available.\n",
+ if (helpflag & MUST_HELP) {
+ if (cp || !(pc->flags & GDB_INIT))
+ fprintf(fp,
+ "No help data for the \"%s\" command"
+ " is available.\n",
cmd);
else if (!gdb_pass_through(concat_args(buf, 0, FALSE),
NULL, GNU_RETURN_ON_ERROR))
fprintf(fp,
- "No help data for \"%s\" is available.\n",
- cmd);
+ "No help data for \"%s\" is available.\n",
+ cmd);
}
goto done_usage;
}
p++;
- if (helpflag == SYNOPSIS) {
+ if (helpflag & SYNOPSIS) {
p++;
fprintf(fp, "Usage: %s ", cmd);
fprintf(fp, *p, pc->program_name, pc->program_name);
===================================================================
RCS file: RCS/main.c,v
retrieving revision 1.1
diff -u -r1.1 main.c
--- main.c 2007/07/16 17:52:28 1.1
+++ main.c 2007/07/16 21:41:01
@@ -27,12 +27,12 @@
static void check_xen_hyper(void);
static struct option long_options[] = {
- {"memory_module", 1, 0, 0},
- {"memory_device", 1, 0, 0},
+ {"memory_module", required_argument, 0, 0},
+ {"memory_device", required_argument, 0, 0},
{"no_kallsyms", 0, 0, 0},
{"no_modules", 0, 0, 0},
{"no_namelist_gzip", 0, 0, 0},
- {"help", 0, 0, 0},
+ {"help", optional_argument, 0, 'h'},
{"data_debug", 0, 0, 0},
{"no_data_debug", 0, 0, 0},
{"no_crashrc", 0, 0, 0},
@@ -40,14 +40,14 @@
{"kmem_cache_delay", 0, 0, 0},
{"readnow", 0, 0, 0},
{"smp", 0, 0, 0},
- {"machdep", 1, 0, 0},
+ {"machdep", required_argument, 0, 0},
{"version", 0, 0, 0},
{"buildinfo", 0, 0, 0},
{"shadow_page_tables", 0, 0, 0},
- {"cpus", 1, 0, 0},
+ {"cpus", required_argument, 0, 0},
{"no_ikconfig", 0, 0, 0},
{"hyper", 0, 0, 0},
- {"p2m_mfn", 1, 0, 0},
+ {"p2m_mfn", required_argument, 0, 0},
{"zero_excluded", 0, 0, 0},
{"no_panic", 0, 0, 0},
{0, 0, 0, 0}
@@ -65,7 +65,7 @@
*/
opterr = 0;
optind = 0;
- while((c = getopt_long(argc, argv, "LgH:h:e:i:sSvc:d:tfp:m:",
+ while((c = getopt_long(argc, argv, "Lgh::e:i:sSvc:d:tfp:m:",
long_options, &option_index)) != -1) {
switch (c)
{
@@ -74,60 +74,55 @@
"memory_module"))
pc->memory_module = optarg;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"memory_device"))
pc->memory_device = optarg;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"no_kallsyms"))
kt->flags |= NO_KALLSYMS;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"no_modules"))
kt->flags |= NO_MODULE_ACCESS;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"no_ikconfig"))
kt->flags |= NO_IKCONFIG;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"no_namelist_gzip"))
pc->flags |= NAMELIST_NO_GZIP;
- if (STREQ(long_options[option_index].name, "help")) {
- program_usage(LONG_FORM);
- clean_exit(0);
- }
-
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"data_debug"))
pc->flags |= DATADEBUG;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"no_data_debug"))
pc->flags &= ~DATADEBUG;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"no_kmem_cache"))
vt->flags |= KMEM_CACHE_UNAVAIL;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"kmem_cache_delay"))
vt->flags |= KMEM_CACHE_DELAY;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"readnow"))
pc->flags |= READNOW;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"smp"))
kt->flags |= SMP;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"machdep"))
machdep->cmdline_arg = optarg;
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"version")) {
pc->flags |= VERSION_QUERY;
display_version();
@@ -135,30 +130,36 @@
clean_exit(0);
}
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"buildinfo")) {
dump_build_data();
clean_exit(0);
}
- if (STREQ(long_options[option_index].name,
+ else if (STREQ(long_options[option_index].name,
"shadow_page_tables"))
kt->xen_flags |= SHADOW_PAGE_TABLES;
- if (STREQ(long_options[option_index].name, "cpus"))
+ else if (STREQ(long_options[option_index].name, "cpus"))
kt->cpus_override = optarg;
- if (STREQ(long_options[option_index].name, "hyper"))
+ else if (STREQ(long_options[option_index].name, "hyper"))
pc->flags |= XEN_HYPER;
- if (STREQ(long_options[option_index].name, "p2m_mfn"))
+ else if (STREQ(long_options[option_index].name, "p2m_mfn"))
xen_kdump_p2m_mfn(optarg);
- if (STREQ(long_options[option_index].name, "zero_excluded"))
+ else if (STREQ(long_options[option_index].name, "zero_excluded"))
*diskdump_flags |= ZERO_EXCLUDED;
- if (STREQ(long_options[option_index].name, "no_panic"))
+ else if (STREQ(long_options[option_index].name, "no_panic"))
tt->flags |= PANIC_TASK_NOT_FOUND;
+
+ else {
+ error(INFO, "internal error: option %s unhandled\n",
+ long_options[option_index].name);
+ program_usage(SHORT_FORM);
+ }
break;
case 'f':
@@ -169,12 +170,19 @@
pc->flags |= KERNEL_DEBUG_QUERY;
break;
- case 'H':
- cmd_usage(optarg, COMPLETE_HELP);
- clean_exit(0);
-
case 'h':
- cmd_usage(optarg, COMPLETE_HELP|PIPE_TO_LESS);
+ /* note: long_getopt's handling of optional arguments is weak.
+ * To it, an optional argument must be part of the same argument
+ * as the flag itself (eg. --help=commands or -hcommands).
+ * We want to accept "--help commands" or "-h commands".
+ * So we must do that part ourselves.
+ */
+ if (optarg != NULL)
+ cmd_usage(optarg, COMPLETE_HELP|PIPE_TO_LESS|MUST_HELP);
+ else if (argv[optind] != NULL && argv[optind][0] != '-')
+ cmd_usage(argv[optind++], COMPLETE_HELP|PIPE_TO_LESS|MUST_HELP);
+ else
+ program_usage(LONG_FORM);
clean_exit(0);
case 'e':
@@ -238,13 +246,9 @@
break;
default:
- if (STREQ(argv[optind-1], "-h"))
- program_usage(LONG_FORM);
- else {
- error(INFO, "invalid option: %s\n",
- argv[optind-1]);
- program_usage(SHORT_FORM);
- }
+ error(INFO, "invalid option: %s\n",
+ argv[optind-1]);
+ program_usage(SHORT_FORM);
}
}
opterr = 1;
================ end ================
9:51 a.m.
New subject: implementation of -h and --help [was: documentation of crash flags]linux-2.6.22.1-20.fc7]
D. Hugh Redelmeier wrote:
In help.c cmd_usage():
- make sure that cmd_usage does not call gdb if gdb isn't initialized
(in trying to give -h help for an unrecognized command)
- add a flag MUST_HELP to cmd_usage to specify that if help isn't
found a diagnostic should be printed. This used to be the case if
the command calling cmd_usage was help but not if -h called it.
- this command still unconditionally uses less(1) for anything but a
synopsis. This should be changed.
In main.c, the long_options array:
- use the name "required_argument" in place of the magic number 1.
- make --help a synonym of 'h'
- specify that --help has an optional_argument.
In main.c main():
- in the call of getopt_long: add another ':' for -h. This means
that the argument is optional. This, in turn, means that the switch
default no longer handles -h at the end of an argument list.
- I added code to detect and report an unhandled long option. It is
easy to get the long_option table out of sync with the handlers.
Mostly this involves adding "else" a lot of places in case 0.
- ditch the code to implement --help since it is now handled by the
code for -h
- ditch the code to implement -h in the switch default since it is now
handled in case 'h'
- the case 'h' code now has to handle the fact that the -h / --help
argument is optional.
- removed -H flag which wasn't documented and is now redundant.
OK, this all looks pretty reasonable. I haven't played with it
yet because the patch doesn't apply in my working tree due to
the other previously-queued changes, but it's just patch-monkey
work.
I thought you might pick up on the damn "less" issue in the help
output... ;-)
To handle that issue, I've decided to do the same thing that
man(1) does. The man command does the same thing as crash, i.e,
it uses "/usr/bin/less -isr" by default, but allows its override
with a "MANPAGER" environment variable. So I'm going to allow users
to hang themselves with CRASHPAGER environment variable. I hadn't
thought of using it as part of the help output, but it should
work there as well.
Thanks,
Dave
12:55 p.m.
New subject: implementation of -h and --help
Dave Anderson <anderson(a)redhat.com> writes:
[...]
I thought you might pick up on the damn "less" issue in the
help
output... ;-)
To handle that issue, I've decided to do the same thing that
man(1) does. The man command does the same thing as crash, i.e,
it uses "/usr/bin/less -isr" by default, but allows its override
with a "MANPAGER" environment variable. So I'm going to allow users
to hang themselves with CRASHPAGER environment variable. I hadn't
thought of using it as part of the help output, but it should
work there as well.
man(1) says:
MANPAGER
If MANPAGER is set, its value is used as the name of the program
to use to display the man page. If not, then PAGER is used. If
that has no value either, /usr/bin/less -is is used.
Do you plan to fall back to PAGER when CRASHPAGER is not set?
1:18 p.m.
New subject: implementation of -h and --help
Markus Armbruster wrote:
Dave Anderson <anderson(a)redhat.com> writes:
[...]
>I thought you might pick up on the damn "less" issue in the help
>output... ;-)
>
>To handle that issue, I've decided to do the same thing that
>man(1) does. The man command does the same thing as crash, i.e,
>it uses "/usr/bin/less -isr" by default, but allows its override
>with a "MANPAGER" environment variable. So I'm going to allow users
>to hang themselves with CRASHPAGER environment variable. I hadn't
>thought of using it as part of the help output, but it should
>work there as well.
man(1) says:
MANPAGER
If MANPAGER is set, its value is used as the name of the program
to use to display the man page. If not, then PAGER is used. If
that has no value either, /usr/bin/less -is is used.
Do you plan to fall back to PAGER when CRASHPAGER is not set?
No, because of the reason I mentioned earlier, that being an
environment of "PAGER=/usr/bin/less" completely screws up the
user interface.
Dave
7006
days inactive
7007
days old
devel@lists.crash-utility.osci.io
6 comments
4 participants
participants (4)
-
D. Hugh Redelmeier -
Dave Anderson -
Markus Armbruster -
Steve Dickson