7:06 a.m.
Hello Dave,
Here is the brief background for the patch.
We had a problem - there was a page which contained some structure which we weren't
able to identify,
but we could specify approximate size of this structure. Also it might be said that this
structure contains
two adjacent lists. But it was really difficult to tell which exactly structure it is.
So, here is a patch for such kind of functionality - you can list data structures which
size is in some range and
which contain fields of some particular type.
7:07 a.m.
New subject: [Patch 0/2] Request data structures of particular size. Crash changes.
--- crash-7.1.4/defs.h 2015-12-16 18:59:36.000000000 +0300
+++ crash-7.1.4.test/defs.h 2016-04-04 09:46:42.615294482 +0300
@@ -4340,6 +4340,7 @@
void cmd_pointer(void); /* symbols.c */
void cmd_whatis(void); /* symbols.c */
void cmd_p(void); /* symbols.c */
+void cmd_types(void); /* symbols.c */
void cmd_mount(void); /* filesys.c */
void cmd_files(void); /* filesys.c */
void cmd_fuser(void); /* filesys.c */
@@ -4874,6 +4875,7 @@
extern char *help_sys[];
extern char *help_task[];
extern char *help_timer[];
+extern char *help_types[];
extern char *help_union[];
extern char *help_vm[];
extern char *help_vtop[];
@@ -6235,7 +6237,7 @@
* gdb/symtab.c
*/
extern void gdb_command_funnel(struct gnu_request *);
-
+extern int search_matched_struct_symbols (const char *, int, int, const char ***, int
**);
/*
* gdb/symfile.c
*/
--- crash-7.1.4/global_data.c 2015-12-16 18:59:36.000000000 +0300
+++ crash-7.1.4.test/global_data.c 2016-03-31 16:35:25.753285231 +0300
@@ -114,6 +114,7 @@
{"task", cmd_task, help_task, REFRESH_TASK_TABLE},
{"test", cmd_test, NULL, HIDDEN_COMMAND},
{"timer", cmd_timer, help_timer, 0},
+ {"types", cmd_types, help_types, 0},
{"union", cmd_union, help_union, 0},
{"vm", cmd_vm, help_vm, REFRESH_TASK_TABLE},
{"vtop", cmd_vtop, help_vtop, REFRESH_TASK_TABLE},
--- crash-7.1.4/help.c 2015-12-16 18:59:36.000000000 +0300
+++ crash-7.1.4.test/help.c 2016-04-01 13:08:48.878755448 +0300
@@ -5658,6 +5658,62 @@
NULL
};
+char *help_types[] = {
+"types",
+"search declared structures with particular size and contents",
+"[-f field] -r range",
+"The arguments are as follows:\n",
+" -f field The field type (or substruct of type name) which the",
+" structure should contain",
+" -r range The range or the exact size of the structure we're",
+" looking for.",
+"\nEXAMPLES:",
+"\n1. Find all structures which have size from 190 up to 200 bytes\n\n"
+" %s> types -r 190-200",
+"192 apic",
+"192 ata_eh_context",
+"192 cper_sec_proc_generic",
+"192 cpuinfo_x86",
+"192 pebs_record_hsw",
+"196 ethtool_drvinfo",
+"196 kioctx",
+"196 vm86plus_struct",
+"200 apple_sc",
+"200 cper_pstore_record",
+"200 kernel_vm86_struct",
+"200 linux_binprm",
+"200 scsi_transport_template",
+"\n2. Find all structures which have size from 190 up to 200 bytes and",
+"which contain member of type '*list*'\n",
+" %s> types -r 190-200 -f list",
+"196 kioctx",
+"200 scsi_transport_template",
+"",
+"`struct kioctx` really has members of types `hlist_node`, `list_head`.",
+"However, the last structure is more subtle. It contains field of type",
+"`list_head` within itself.",
+"That is:",
+"`scsi_transport_template` contains member of type `transport_container`",
+"`transport_container` has `attribute_container`",
+"`attribute_container` has `list_head`.",
+"Structure `list_head` has poiners to `list_head`",
+"This is the place where algorithm triggers. It delves into the structure",
+"_only_ if the particular member is a structure, not a pointer.",
+"If it is a pointer, we only match name of type against the given pattern.",
+"\n3. Find all ths structures which have size exactly 36 bytes and which",
+"contain member of type '*list_head*'\n",
+" %s> types -r 36 -f list_head",
+"36 agp_front_data",
+"36 audit_watch",
+"36 blkio_cgroup",
+"36 blkio_policy_type",
+"36 device_domain_info",
+"36 dmar_drhd_unit",
+"36 dmar_rmrr_unit",
+"........",
+NULL
+};
+
char *help_ptob[] = {
"ptob",
"page to bytes",
--- crash-7.1.4/symbols.c 2015-12-16 18:59:36.000000000 +0300
+++ crash-7.1.4.test/symbols.c 2016-04-04 10:12:40.271317840 +0300
@@ -33,6 +33,7 @@
static int compare_syms(const void *, const void *);
static int compare_mods(const void *, const void *);
static int compare_prios(const void *v1, const void *v2);
+static int compare_size_name(const void *, const void *);
static asection *get_kernel_section(char *);
static char * get_section(ulong vaddr, char *buf);
static void symbol_dump(ulong, char *);
@@ -5976,6 +5977,74 @@
return TRUE;
}
+static int
+compare_size_name(const void *va, const void *vb) {
+ const struct {
+ char *n; int s;
+ } *a = va, *b = vb;
+
+ if (a->s == b->s)
+ return strcmp(a->n, b->n);
+ else
+ return a->s < b->s ? -1 : 1;
+}
+
+void
+cmd_types(void)
+{
+ const char *field = NULL, **out_name = NULL;
+ char *sep, tmp[16];
+
+ int lowest, highest, i, c;
+ int *out_size = NULL;
+ struct { const char *n; int s; } *struct_output;
+
+ lowest = highest = UNUSED;
+
+ while ((c = getopt(argcnt, args, "f:r:")) != EOF) {
+ switch (c)
+ {
+ case 'f':
+ field = optarg;
+ break;
+ case 'r':
+ strncpy(tmp, optarg, 15);
+ if ((sep = strstr(tmp, "-")) != NULL)
+ *(sep++) = '\0';
+
+ lowest = stol(tmp, FAULT_ON_ERROR, NULL);
+
+ if (sep)
+ highest = stol(sep, FAULT_ON_ERROR, NULL);
+ else
+ highest = lowest;
+
+ break;
+ default:
+ cmd_usage(pc->curcmd, SYNOPSIS);
+ }
+ }
+
+ if (lowest == UNUSED || highest == UNUSED)
+ error(FATAL, "You should specify range\n");
+
+ c = search_matched_struct_symbols(field, lowest, highest,
+ &out_name, &out_size);
+
+ struct_output = malloc(sizeof(*struct_output) * c);
+ for (i = 0; i < c; i++) {
+ struct_output[i].n = out_name[i];
+ struct_output[i].s = out_size[i];
+ }
+
+ qsort(struct_output, c, sizeof(*struct_output), compare_size_name);
+
+ for (i = 0; i < c; i++)
+ fprintf(fp, "%d\t%s\n", struct_output[i].s, struct_output[i].n);
+
+ free(struct_output);
+ return;
+}
static void
cmd_datatype_common(ulong flags)
{
7:08 a.m.
New subject: [Patch 0/2] Request data structures of particular size. Changes in gdb
--- gdb-7.6/gdb/psymtab.c 2016-04-04 15:27:06.043600734 +0300
+++ gdb-7.6/gdb/psymtab.c 2016-04-04 15:23:16.227597288 +0300
@@ -1335,7 +1335,13 @@
/* Go through all of the symbols stored in a partial
symtab in one loop. */
psym = objfile->global_psymbols.list + ps->globals_offset;
+#ifdef CRASH_MERGE
+ if (!name_matcher)
+ result = PST_SEARCHED_AND_FOUND;
+ while (name_matcher && keep_going)
+#else
while (keep_going)
+#endif
{
if (psym >= bound)
{
--- gdb-7.6/gdb/symtab.c 2016-04-04 15:27:06.147600736 +0300
+++ gdb-7.6/gdb/symtab.c 2016-04-04 15:22:20.155596448 +0300
@@ -3405,6 +3405,130 @@
return !data->preg_p || regexec (&data->preg, symname, 0, NULL, 0) == 0;
}
+#ifdef CRASH_MERGE
+int
+lookup_struct_contents(struct main_type *main_type, const char *field)
+{
+ int i;
+ struct field *f;
+ struct main_type *m;
+ const char *n;
+
+ if (!main_type)
+ return 0;
+
+ for (i = 0; i < main_type->nfields; i++)
+ {
+ f = main_type->flds_bnds.fields + i;
+ if (!f->type)
+ continue;
+ m = f->type->main_type;
+
+ /* Here is a recursion.
+ * If we have struct variable (not pointer),
+ * scan this inner structure
+ */
+ if (m->code == TYPE_CODE_STRUCT) {
+ if (lookup_struct_contents(m, field) == 1)
+ return 1;
+ }
+
+ if ((m->code == TYPE_CODE_PTR || m->code == TYPE_CODE_ARRAY)
+ && m->target_type)
+ m = m->target_type->main_type;
+ if (m->name)
+ n = m->name;
+ else if (m->tag_name)
+ n = m->tag_name;
+ else
+ continue;
+
+ if (strstr(n, field))
+ return 1;
+ }
+
+ return 0;
+}
+
+void
+append_struct_symbol (const char *n, int sz, const char ***out_name,
+ int **out_size, int *csz, int *cix)
+{
+ int i;
+
+ for (i = 0; i < *cix; i++)
+ if ((*out_name)[i] == n)
+ break;
+
+ if (i < *cix) // We've already collected this type
+ return;
+
+ if (*cix == *csz) {
+ *csz *= 3;
+ *out_name = xrealloc(*out_name, sizeof(*out_name) * (*csz));
+ *out_size = xrealloc(*out_size, sizeof(*out_size) * (*csz));
+ }
+ (*out_name)[*cix] = n;
+ (*out_size)[*cix] = sz;
+ (*cix)++;
+}
+
+int
+search_matched_struct_symbols (const char *field, int lowest, int highest,
+ const char ***out_name, int **out_size)
+{
+ struct symtab *s;
+ struct blockvector *bv;
+ struct block *b;
+ struct block_iterator iter;
+ struct symbol *sym;
+ struct objfile *objfile;
+ struct minimal_symbol *msymbol;
+ const char *name;
+ int size;
+ int i = 0;
+ int cix = 0, csz = 16;
+ struct partial_symtab *ps;
+
+ *out_name = xmalloc(sizeof(*out_name) * csz);
+ *out_size = xmalloc(sizeof(*out_size) * csz);
+
+ ALL_OBJFILES (objfile)
+ {
+ if (objfile->sf)
+ objfile->sf->qf->expand_symtabs_matching (objfile, NULL, NULL,
TYPES_DOMAIN, NULL);
+ }
+
+ ALL_PRIMARY_SYMTABS (objfile, s)
+ {
+ bv = BLOCKVECTOR (s);
+ for (i = GLOBAL_BLOCK; i <= STATIC_BLOCK; i++)
+ {
+ b = BLOCKVECTOR_BLOCK (bv, i);
+ ALL_BLOCK_SYMBOLS (b, iter, sym)
+ {
+ QUIT;
+
+ if (SYMBOL_CLASS (sym) == LOC_TYPEDEF)
+ {
+ name = sym->ginfo.name;
+ size = sym->type->length;
+ if (lowest >= 0 && size < lowest)
+ continue;
+ if (highest >= 0 && highest < size)
+ continue;
+ if (field && !lookup_struct_contents(sym->type->main_type,
field))
+ continue;
+ append_struct_symbol(name, size, out_name, out_size, &csz,
&cix);
+ }
+ }
+ }
+ }
+
+ return cix;
+}
+#endif
+
/* Search the symbol table for matches to the regular expression REGEXP,
returning the results in *MATCHES.
--- gdb-7.6/gdb/symtab.h 2013-02-03 18:54:16.000000000 +0300
+++ gdb-7.6/gdb/symtab.h 2016-04-04 16:05:53.335635633 +0300
@@ -1318,4 +1318,9 @@
struct cleanup *demangle_for_lookup (const char *name, enum language lang,
const char **result_name);
+void append_struct_symbol (const char *, int, const char ***, int **, int *, int *);
+int search_matched_struct_symbols (const char *, int, int, const char ***, int **);
+int lookup_struct_contents(struct main_type *, const char *);
+
+
#endif /* !defined(SYMTAB_H) */
9:51 a.m.
New subject: [Patch 0/2] Request data structures of particular size.
----- Original Message -----
Hello Dave,
Here is the brief background for the patch.
We had a problem - there was a page which contained some structure which we
weren't able to identify,
but we could specify approximate size of this structure. Also it might be
said that this structure contains
two adjacent lists. But it was really difficult to tell which exactly
structure it is.
So, here is a patch for such kind of functionality - you can list data
structures which size is in some range and
which contain fields of some particular type.
Alexandr,
The key point above is: "We had a problem"
Since 1999, there have been exactly 2 new commands added, "ipcs" and
"tree",
which address a major kernel subsystem, and support for dumping radix
or red-black tree contents.
It is very tempting to create a new crash command to address a very specific
issue. And while I appreciate the work you've put into this effort, there's no
way I'm going to add something this bug-specific to the general command set.
That being said, this patch is a prime candidate for a crash extension
module, which I am always willing to add new extension modules to the
upstream extensions page. Now, there is a complication in that you've
modified/added a signficant chunk of gdb-specific code, which is typically
not done for extension modules. However I have done it a couple times in the
past, but only if the gdb code changes do not affect the normal crash utility
interaction with gdb. For example, I'm not entirely clear on your change to
recursively_search_psymtabs() -- I'm presuming that the "name_matcher"
argument
would *always* be set to a function when the function is called by existing gdb
code? If that's true, then I would be willing to make the gdb changes for your
extension module.
Another alternative would be to make it an option to an existing command,
Perhaps the "whatis" command could be expanded?
Thanks,
Dave
3:08 a.m.
Dave,
thank you for your comment. I've also reviewed the set of existing gdb functions more
carefully. Looks like it wasn't necessary to modify existing code in gdb. It suffice
to use another function from the same structure (it hasn't been used before - that is
why I hadn't noticed it earlier).
I've also rewritten the logic within `whatis` command.
Thanks,
Alexandr
3:36 p.m.
----- Original Message -----
Dave,
thank you for your comment. I've also reviewed the set of existing gdb
functions more carefully. Looks like it wasn't necessary to modify existing
code in gdb. It suffice to use another function from the same structure (it
hasn't been used before - that is why I hadn't noticed it earlier).
OK good.
I've also rewritten the logic within `whatis` command.
Yeah, actually the whatis command looks like a good fit for this functionality.
Another few changes I'd like you to make. If you notice, there are no calls
from the top-level crash sources directly into gdb functions, but rather they
all pass through gdb_interface(), which calls into gdb_command_funnel(). It's
always been done that way in order to keep the top-level crash running in case
of a fatal bug in the execution of gdb code. Can you please rework your code
to use gdb_interface()? It should be simple -- you'll just have to add a new
GNU command, and then have gdb_command_funnel() act upon it to call your new
function.
Secondly, the only time malloc() should ever be used is if an allocation is
permanent, so please don't use it in request_types(). Use GETBUF() instead,
which will be free up the memory after the command is run if you forget to
call FREEBUF(), or should the command fail prematurely.
For the same reason, it would be preferable if you can avoid the xmalloc() and
xrealloc() calls in the gdb code. Historically the gdb cleanup code has been
a source of problems when combined with the crash utility. Would it be possible
to use GETBUF() in request_types() to pre-allocate enough space for your gdb
function to accomplish its purpose?
Thanks,
Dave
Thanks,
Alexandr
--
Crash-utility mailing list
Crash-utility(a)redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility
4:08 p.m.
----- Original Message -----
----- Original Message -----
> Dave,
>
> thank you for your comment. I've also reviewed the set of existing gdb
> functions more carefully. Looks like it wasn't necessary to modify existing
> code in gdb. It suffice to use another function from the same structure (it
> hasn't been used before - that is why I hadn't noticed it earlier).
OK good.
> I've also rewritten the logic within `whatis` command.
Yeah, actually the whatis command looks like a good fit for this
functionality.
Another few changes I'd like you to make. If you notice, there are no calls
from the top-level crash sources directly into gdb functions, but rather they
all pass through gdb_interface(), which calls into gdb_command_funnel(). It's
always been done that way in order to keep the top-level crash running in case
of a fatal bug in the execution of gdb code. Can you please rework your code
to use gdb_interface()? It should be simple -- you'll just have to add a new
GNU command, and then have gdb_command_funnel() act upon it to call your new
function.
Secondly, the only time malloc() should ever be used is if an allocation is
permanent, so please don't use it in request_types(). Use GETBUF() instead,
which will be free up the memory after the command is run if you forget to
call FREEBUF(), or should the command fail prematurely.
For the same reason, it would be preferable if you can avoid the xmalloc() and
xrealloc() calls in the gdb code. Historically the gdb cleanup code has been
a source of problems when combined with the crash utility. Would it be possible
to use GETBUF() in request_types() to pre-allocate enough space for your gdb
function to accomplish its purpose?
BTW, I admit that I am asking you to replace the xmalloc()/xrealloc() stuff without
really studying your code. But worse case, it seems like you could call into
your gdb function twice, first to quickly determine the maximum possible number of
structures of the size range, then have request_types() call GETBUF() to get the
required space, and then call back into it a second time to gather them into the
allocated space. Or perhaps you could use the gnu_request structure to pass in
the addresses of getbuf() and resizebuf(), which are used by GETBUF() and RESIZEBUF().
BTW, feel free to add new fields to the end of the gnu_request structure if it
would be helpful.
Thanks,
Dave
Dave
2:16 a.m.
New subject: [Patch 1/2] Request data structures of particular size. GDB part
Hello Dave,
I've rewritten the mentioned logic, now crash communicates with gdb by means of
gdb_interface.
--- gdb-7.6.orig/gdb/symtab.c 2016-03-23 11:43:09.000000000 +0300
+++ gdb-7.6/gdb/symtab.c 2016-04-13 09:50:53.597120297 +0300
@@ -5140,6 +5140,9 @@
static void gdb_set_crash_block(struct gnu_request *);
void gdb_command_funnel(struct gnu_request *);
+static long lookup_struct_contents(struct gnu_request *);
+static void iterate_datatypes (struct gnu_request *);
+
struct objfile *gdb_kernel_objfile = { 0 };
static ulong gdb_merge_flags = 0;
@@ -5242,6 +5245,14 @@
req->flags |= GNU_COMMAND_FAILED;
break;
+ case GNU_LOOKUP_STRUCT_CONTENTS:
+ req->value = lookup_struct_contents(req);
+ break;
+
+ case GNU_GET_NEXT_DATATYPE:
+ iterate_datatypes(req);
+ break;
+
default:
req->flags |= GNU_COMMAND_FAILED;
break;
@@ -5779,4 +5790,144 @@
else
return NULL;
}
+
+static long
+lookup_struct_contents(struct gnu_request *req)
+{
+ int i;
+ long r;
+ struct field *f;
+ struct main_type *m;
+ const char *n;
+ struct main_type *top_m = (struct main_type *)req->addr;
+#if defined(GDB_5_3) || defined(GDB_6_0) || defined(GDB_6_1) || defined(GDB_7_0)
+ char *type_name = req->typename;
+#else
+ char *type_name = req->type_name;
+#endif
+
+ if (!top_m || !type_name)
+ return 1;
+
+ for (i = 0; i < top_m->nfields; i++)
+ {
+ f = top_m->flds_bnds.fields + i;
+ if (!f->type)
+ continue;
+ m = f->type->main_type;
+
+ // If the field is an array, check the target type -
+ // it might be structure, or might not be.
+ // - struct request_sock *syn_table[0];
+ // here m->target_type->main_type->code is expected
+ // to be TYPE_CODE_PTR
+ // - struct list_head vec[TVN_SIZE];
+ // here m->target_type->main_type->code should be
+ // TYPE_CODE_STRUCT
+ if (m->code == TYPE_CODE_ARRAY && m->target_type)
+ m = m->target_type->main_type;
+
+ /* Here is a recursion.
+ * If we have struct variable (not pointer),
+ * scan this inner structure
+ */
+ if (m->code == TYPE_CODE_STRUCT) {
+ req->addr = (ulong)m;
+ r = lookup_struct_contents(req);
+ req->addr = (ulong)top_m;
+ if (r)
+ return 1;
+ }
+
+ if (m->code == TYPE_CODE_PTR && m->target_type)
+ m = m->target_type->main_type;
+ if (m->name)
+ n = m->name;
+ else if (m->tag_name)
+ n = m->tag_name;
+ else
+ continue;
+
+ if (strstr(n, type_name))
+ return 1;
+ }
+
+ return 0;
+}
+
+static void
+iterate_datatypes (struct gnu_request *req)
+{
+ static struct block_iterator bi; // Keeping this static will simplify code
+ struct block *b;
+ int do_return = 0;
+ struct {
+ char fi, i;
+ struct symtab *st;
+ struct symbol *sym;
+ struct objfile *o;
+ } *gi = (void *)req->addr2; /*Global iterator */
+
+ if (gi->fi)
+ return;
+
+ if (gi->o == NULL)
+ {
+ gi->o = current_program_space->objfiles;
+ gi->st = NULL;
+ do_return = 1; // The initial case - we don't need to make next step.
+ }
+
+ for (; gi->o; gi->o = gi->o->next, gi->st = NULL)
+ {
+ if (gi->st == NULL)
+ {
+ // Symtab `st` is nullified for every objfile
+ if (gi->o->sf)
+ gi->o->sf->qf->expand_all_symtabs(gi->o);
+ gi->st = gi->o->symtabs;
+ gi->sym = NULL;
+ }
+
+ for (; gi->st; gi->st = gi->st->next, gi->i = -1)
+ {
+ if (!gi->st->primary)
+ continue;
+
+ if (gi->i == -1)
+ {
+ gi->i = GLOBAL_BLOCK;
+ gi->sym = NULL;
+ }
+ for (; gi->i <= STATIC_BLOCK; gi->i++, gi->sym = NULL)
+ {
+ if (!gi->sym)
+ {
+ b = BLOCKVECTOR_BLOCK(BLOCKVECTOR(gi->st), gi->i);
+ gi->sym = block_iterator_first(b, &bi);
+ }
+ for (; gi->sym; gi->sym = block_iterator_next(&bi))
+ {
+ QUIT;
+
+ if (SYMBOL_CLASS (gi->sym) != LOC_TYPEDEF)
+ continue;
+
+ // Iteration 1 (do_return == 0): initialization
+ // Iteration 2 (do_return == 1): iterate symbol
+ if (do_return++ == 0)
+ continue;
+
+ // Yield the current symbol and its size
+ req->addr = (ulong)(gi->sym->type->main_type);
+ req->name = (char *)(gi->sym->ginfo.name);
+ req->length = gi->sym->type->length;
+
+ return;
+ }
+ }
+ }
+ }
+ gi->fi = 1;
+}
#endif
3:58 p.m.
New subject: [Patch 1/2] Request data structures of particular size. GDB part
----- Original Message -----
Hello Dave,
I've rewritten the mentioned logic, now crash communicates with gdb by means
of gdb_interface.
Hello Alexandr,
I've been playing with your patch for the last couple of days, and in the
interest of getting it checked in without us having to go back and forth
again and again, I have an updated version queued for crash-7.1.5:
https://github.com/crash-utility/crash/commit/7b5be97daafb840d59ff2ae303d...
First I want to thank you for getting the base functionality in place,
especially the gdb portion. But the patch did need some work -- here are a
few things that I did to it:
(1) I changed "-f field" to "-m member" simply because
"member" is used
in several other commands.
(2) I made the -r and -m options independent of one another, because it's
just as helpful to be able to search for all data structures that
contain a given member type without caring about their size.
(3) I really don't like the usage of anonymous data structures defined
in the prologue of a function, especially if it's not obvious what
they are supposed to be because of single-letter member names, and
also if they end up being declared redundantly in different functions.
So you've got this in your patch:
+static void
+append_struct_symbol (void *pout, struct gnu_request *r)
+{
+ struct {
+ int sz, idx;
+ struct { char *n; int s; } *st;
+ } *output = pout;
and this:
+static void
+request_types(int lowest, int highest, char *type_name)
+{
+ struct gnu_request request = {0};
+ struct {
+ int sz, idx;
+ struct { char *n; int s; } *st;
+ } output = {0, 0, NULL};
and then this, which actually seems to be a bug given that the
"s" member below should actually be an int instead of a ulong:
+static int
+compare_size_name(const void *va, const void *vb) {
+ const struct { char *n; ulong s; } *a = va, *b = vb;
+
So to replace those 3 instances with something more maintainable, I declared
a function that all three of the functions can use:
struct type_request {
int cnt; /* current number of entries in types array */
int idx; /* index to next entry in types array */
struct type_info { /* dynamically-sized array of collected types */
char *name;
ulong size;
} *types;
};
The same thing goes for this iterator construct, which you define in
symbols.c and then in gdb-7.6/gdb/symtab.c -- and where they don't even
look alike upon first glance:
+static void
+request_types(int lowest, int highest, char *type_name)
+{
... [ cut ] ...
+ struct { char fi, i; void * p[3]; } iter = { 0 };
which is the same as this:
+static void
+iterate_datatypes (struct gnu_request *req)
+{
... [ cut ] ...
+ struct {
+ char fi, i;
+ struct symtab *st;
+ struct symbol *sym;
+ struct objfile *o;
+ } *gi = (void *)req->addr2; /*Global iterator */
So as I suggested that you could have done, i.e., I added a new member
to the generic gnu_request data structure that gets passed from the top
level crash source down into gdb. I called it a global_iterator
structure, and clarified it by naming its members accordingly:
struct gnu_request {
int command;
char *buf;
FILE *fp;
ulong addr;
... [ cut ] ...
ulong task;
ulong debug;
struct stack_hook *hookp;
struct global_iterator {
int finished;
int block_index;
struct symtab *symtab;
struct symbol *sym;
struct objfile *obj;
} global_iterator;
};
I can envision that your new GNU_GET_NEXT_DATATYPE functionality could
be used for other purposes in the future.
(4) I changed it so GNU_LOOKUP_STRUCT_CONTENTS only gets called if -m is
used; it doesn't make much sense to call it if only -r is in play.
(5) I re-wrote the whatis help page to clarify and separate the -r and -m
usage from the traditional usage.
Again, I have to say that this is a nice feature, and that I appreciate your
efforts in getting it off the ground.
Thanks,
Dave
2:17 a.m.
New subject: [Patch 2/2] Request data structures of particular size. Crash part
--- crash-7.1.4.orig/defs.h 2015-12-16 18:59:36.000000000 +0300
+++ crash-7.1.4/defs.h 2016-04-12 15:39:58.149121279 +0300
@@ -4116,25 +4116,27 @@
/*
* GNU commands
*/
-#define GNU_DATATYPE_INIT (1)
-#define GNU_DISASSEMBLE (2)
-#define GNU_GET_LINE_NUMBER (3)
-#define GNU_PASS_THROUGH (4)
-#define GNU_GET_DATATYPE (5)
-#define GNU_COMMAND_EXISTS (6)
-#define GNU_STACK_TRACE (7)
-#define GNU_ALPHA_FRAME_OFFSET (8)
-#define GNU_FUNCTION_NUMARGS (9)
-#define GNU_RESOLVE_TEXT_ADDR (10)
-#define GNU_ADD_SYMBOL_FILE (11)
-#define GNU_DELETE_SYMBOL_FILE (12)
-#define GNU_VERSION (13)
-#define GNU_PATCH_SYMBOL_VALUES (14)
-#define GNU_GET_SYMBOL_TYPE (15)
-#define GNU_USER_PRINT_OPTION (16)
-#define GNU_SET_CRASH_BLOCK (17)
-#define GNU_GET_FUNCTION_RANGE (18)
-#define GNU_DEBUG_COMMAND (100)
+#define GNU_DATATYPE_INIT (1)
+#define GNU_DISASSEMBLE (2)
+#define GNU_GET_LINE_NUMBER (3)
+#define GNU_PASS_THROUGH (4)
+#define GNU_GET_DATATYPE (5)
+#define GNU_COMMAND_EXISTS (6)
+#define GNU_STACK_TRACE (7)
+#define GNU_ALPHA_FRAME_OFFSET (8)
+#define GNU_FUNCTION_NUMARGS (9)
+#define GNU_RESOLVE_TEXT_ADDR (10)
+#define GNU_ADD_SYMBOL_FILE (11)
+#define GNU_DELETE_SYMBOL_FILE (12)
+#define GNU_VERSION (13)
+#define GNU_PATCH_SYMBOL_VALUES (14)
+#define GNU_GET_SYMBOL_TYPE (15)
+#define GNU_USER_PRINT_OPTION (16)
+#define GNU_SET_CRASH_BLOCK (17)
+#define GNU_GET_FUNCTION_RANGE (18)
+#define GNU_GET_NEXT_DATATYPE (19)
+#define GNU_LOOKUP_STRUCT_CONTENTS (20)
+#define GNU_DEBUG_COMMAND (100)
/*
* GNU flags
*/
--- crash-7.1.4.orig/symbols.c 2015-12-16 18:59:36.000000000 +0300
+++ crash-7.1.4/symbols.c 2016-04-12 15:38:52.497120294 +0300
@@ -33,6 +33,9 @@
static int compare_syms(const void *, const void *);
static int compare_mods(const void *, const void *);
static int compare_prios(const void *v1, const void *v2);
+static int compare_size_name(const void *, const void *);
+static void append_struct_symbol (void *, struct gnu_request *);
+static void request_types(int, int, char *);
static asection *get_kernel_section(char *);
static char * get_section(ulong vaddr, char *buf);
static void symbol_dump(ulong, char *);
@@ -5976,6 +5979,16 @@
return TRUE;
}
+static int
+compare_size_name(const void *va, const void *vb) {
+ const struct { char *n; ulong s; } *a = va, *b = vb;
+
+ if (a->s == b->s)
+ return strcmp(a->n, b->n);
+ else
+ return a->s < b->s ? -1 : 1;
+}
+
static void
cmd_datatype_common(ulong flags)
{
@@ -6529,6 +6542,75 @@
fprintf(ofp, "\n");
}
+static void
+append_struct_symbol (void *pout, struct gnu_request *r)
+{
+ struct {
+ int sz, idx;
+ struct { char *n; int s; } *st;
+ } *output = pout;
+ int i, s;
+
+ for (i = 0; i < output->idx; i++)
+ if (output->st[i].n == r->name)
+ break;
+
+ if (i < output->idx) // We've already collected this type
+ return;
+
+ if (output->idx == output->sz) {
+ s = sizeof(*(output->st)) * output->sz;
+ output->st = (void *)resizebuf((void *)output->st, s, s * 3);
+ output->sz *= 3;
+ }
+ output->st[output->idx].n = r->name;
+ output->st[output->idx].s = (int)(r->length);
+ output->idx++;
+}
+
+static void
+request_types(int lowest, int highest, char *type_name)
+{
+ struct gnu_request request = {0};
+ struct {
+ int sz, idx;
+ struct { char *n; int s; } *st;
+ } output = {0, 0, NULL};
+ struct { char fi, i; void * p[3]; } iter = { 0 };
+
+ int i;
+
+ output.st = (void *)GETBUF(16 * sizeof(*(output.st)));
+ output.sz = 16;
+ request.addr2 = (ulong)&iter;
+#if defined(GDB_5_3) || defined(GDB_6_0) || defined(GDB_6_1) || defined(GDB_7_0)
+ req->typename = type_name;
+#else
+ request.type_name = type_name;
+#endif
+
+ while (!iter.fi) {
+ request.command = GNU_GET_NEXT_DATATYPE;
+ gdb_interface(&request);
+ if (!(lowest <= request.length && request.length <= highest))
+ continue;
+
+ request.command = GNU_LOOKUP_STRUCT_CONTENTS;
+ gdb_interface(&request);
+ if (!request.value)
+ continue;
+
+ append_struct_symbol(&output, &request);
+ }
+
+ qsort(output.st, output.idx, sizeof(*output.st), compare_size_name);
+
+ for (i = 0; i < output.idx; i++)
+ fprintf(fp, "%d\t%s\n", output.st[i].s, output.st[i].n);
+
+ FREEBUF(output.st);
+}
+
/*
* This command displays the definition of structures, unions, typedefs or
* text/data symbols:
@@ -6543,33 +6625,58 @@
* declaration is displayed.
* 5. For a kernel symbol name, the output is the same as if the "sym"
command
* was used.
+ * 6. If the -r and optional -f are given, then the structures/unions of
+ * specified size will be searched.
*/
void
cmd_whatis(void)
{
struct datatype_member datatype_member, *dm;
struct syment *sp;
- char buf[BUFSIZE];
+
+ char buf[BUFSIZE], *pl = buf, *ph, *field = NULL;
long len;
- int c;
+ int c, lowest, highest;
ulong flags;
dm = &datatype_member;
flags = 0;
+ lowest = highest = UNUSED;
- while ((c = getopt(argcnt, args, "o")) != EOF) {
+ while ((c = getopt(argcnt, args, "of:r:")) != EOF) {
switch(c)
{
case 'o':
flags |= SHOW_OFFSET;
break;
+ case 'f':
+ field = optarg;
+ break;
+
+ case 'r':
+ strncpy(buf, optarg, 15);
+ if ((ph = strstr(buf, "-")) != NULL)
+ *(ph++) = '\0';
+
+ highest = lowest = stol(pl, FAULT_ON_ERROR, NULL);
+
+ if (ph)
+ highest = stol(ph, FAULT_ON_ERROR, NULL);
+
+ break;
+
default:
argerrs++;
break;
}
}
+ if (!argerrs && lowest != UNUSED && highest != UNUSED) {
+ request_types(lowest, highest, field);
+ return;
+ }
+
if (argerrs || !args[optind])
cmd_usage(pc->curcmd, SYNOPSIS);
--- crash-7.1.4.orig/help.c 2015-12-16 18:59:36.000000000 +0300
+++ crash-7.1.4/help.c 2016-04-06 11:09:24.896859034 +0300
@@ -3461,9 +3461,9 @@
char *help_whatis[] = {
"whatis",
"search symbol table for data or type information",
-"[struct | union | typedef | symbol] ",
+"[[-c] [struct | union | typedef | symbol]] | [[-f field] -r range] ",
" This command displays the definition of structures, unions, typedefs or",
-" text/data symbols.\n",
+" text/data symbols, or fulfil a search of structure with particular
size.\n",
" struct a structure name. The output is the same as if the
\"struct\"",
" command was used.",
" union a union name. The output is the same as if the \"union\"
command",
@@ -3473,6 +3473,10 @@
" was used. If the typedef is a primitive datatype, the one-line",
" declaration is displayed.",
" symbol a kernel symbol. ",
+" -f field The field type (or substring of type name) which the structure",
+" should contain",
+" -r range The range or the exact size of the structure we're looking
for.",
+
"\nEXAMPLES",
" Display the definition of a linux_binfmt structure:\n",
" %s> whatis linux_binfmt",
@@ -3514,7 +3518,29 @@
" Display definition of a kdev_t typedef:\n",
" %s> whatis kdev_t",
" typedef short unsigned int kdev_t;",
-" SIZE: 2 (0x2)",
+" SIZE: 2 (0x2)\n",
+" Find all structures which have size exactly 192 bytes:\n",
+" %s> whatis -r 192",
+" 192 apic",
+" 192 ata_eh_context",
+" 192 cper_sec_proc_generic",
+" 192 cpuinfo_x86",
+" 192 pebs_record_hsw\n",
+" Find all structures which have size from 190 up to 200 bytes and which",
+" contain member of type '*list*'\n",
+" %s> whatis -r 190-200 -f list",
+" 196 kioctx",
+" 200 scsi_transport_template",
+" The structure `kioctx` really has members of types hlist_node and
list_head.",
+" However, the last structure is more subtle. It contains field of type",
+" list_head within itself.",
+" That is:",
+" scsi_transport_template` contains member of type `transport_container`,",
+" which has member of type attribute_container. The last one, in its turn,",
+" contains list_head which has poiners to list_head.",
+" This is the exact place where algorithm triggers. It delves into the",
+" structure _only_ if the particular member is a structure, not a pointer.",
+" If it is a pointer, we only match name of type against the given pattern.",
NULL
};
3:15 a.m.
New subject: [Patch 1/2] Request data structures of particular size. Crash part.
--- crash-7.1.4/defs.h 2015-12-16 18:59:36.000000000 +0300
+++ crash-7.1.4.test/defs.h 2016-04-04 09:46:42.615294482 +0300
@@ -6235,7 +6237,7 @@
* gdb/symtab.c
*/
extern void gdb_command_funnel(struct gnu_request *);
-
+extern int search_matched_struct_symbols (const char *, int, int, const char ***, int
**);
/*
* gdb/symfile.c
*/
--- crash-7.1.4/help.c 2015-12-16 18:59:36.000000000 +0300
+++ crash-7.1.4.test/help.c 2016-04-01 13:08:48.878755448 +0300
@@ -3461,9 +3461,9 @@
char *help_whatis[] = {
"whatis",
"search symbol table for data or type information",
-"[struct | union | typedef | symbol] ",
+"[[-c] [struct | union | typedef | symbol]] | [[-f field] -r range] ",
" This command displays the definition of structures, unions, typedefs or",
-" text/data symbols.\n",
+" text/data symbols, or fulfil a search of structure with particular
size.\n",
" struct a structure name. The output is the same as if the
\"struct\"",
" command was used.",
" union a union name. The output is the same as if the \"union\"
command",
@@ -3473,6 +3473,10 @@
" was used. If the typedef is a primitive datatype, the one-line",
" declaration is displayed.",
" symbol a kernel symbol. ",
+" -f field The field type (or substring of type name) which the structure",
+" should contain",
+" -r range The range or the exact size of the structure we're looking
for.",
+
"\nEXAMPLES",
" Display the definition of a linux_binfmt structure:\n",
" %s> whatis linux_binfmt",
@@ -3514,7 +3518,29 @@
" Display definition of a kdev_t typedef:\n",
" %s> whatis kdev_t",
" typedef short unsigned int kdev_t;",
-" SIZE: 2 (0x2)",
+" SIZE: 2 (0x2)\n",
+" Find all structures which have size exactly 192 bytes:\n",
+" %s> whatis -r 192",
+" 192 apic",
+" 192 ata_eh_context",
+" 192 cper_sec_proc_generic",
+" 192 cpuinfo_x86",
+" 192 pebs_record_hsw\n",
+" Find all structures which have size from 190 up to 200 bytes and which",
+" contain member of type '*list*'\n",
+" %s> whatis -r 190-200 -f list",
+" 196 kioctx",
+" 200 scsi_transport_template",
+" The structure `kioctx` really has members of types hlist_node and
list_head.",
+" However, the last structure is more subtle. It contains field of type",
+" list_head within itself.",
+" That is:",
+" scsi_transport_template` contains member of type `transport_container`,",
+" which has member of type attribute_container. The last one, in its turn,",
+" contains list_head which has poiners to list_head.",
+" This is the exact place where algorithm triggers. It delves into the",
+" structure _only_ if the particular member is a structure, not a pointer.",
+" If it is a pointer, we only match name of type against the given pattern.",
NULL
};
--- crash-7.1.4/symbols.c 2015-12-16 18:59:36.000000000 +0300
+++ crash-7.1.4.test/symbols.c 2016-04-04 10:12:40.271317840 +0300
@@ -33,6 +33,8 @@
static int compare_syms(const void *, const void *);
static int compare_mods(const void *, const void *);
static int compare_prios(const void *v1, const void *v2);
+static int compare_size_name(const void *, const void *);
+void request_types(int, int, const char *);
static asection *get_kernel_section(char *);
static char * get_section(ulong vaddr, char *buf);
static void symbol_dump(ulong, char *);
@@ -5976,6 +5977,16 @@
return TRUE;
}
+static int
+compare_size_name(const void *va, const void *vb) {
+ const struct { const char *n; int s; } *a = va, *b = vb;
+
+ if (a->s == b->s)
+ return strcmp(a->n, b->n);
+ else
+ return a->s < b->s ? -1 : 1;
+}
+
static void
cmd_datatype_common(ulong flags)
{
@@ -6529,6 +6540,38 @@
fprintf(ofp, "\n");
}
+void
+request_types(int lowest, int highest, const char *field)
+{
+ const char **out_name = NULL;
+ int i, c;
+ int *out_size = NULL;
+ struct { const char *n; int s; } *struct_output;
+
+ if (lowest == UNUSED || highest == UNUSED)
+ error(FATAL, "You should specify range\n");
+
+ c = search_matched_struct_symbols(field, lowest, highest,
+ &out_name, &out_size);
+
+ struct_output = malloc(sizeof(*struct_output) * c);
+ if (!struct_output)
+ error(FATAL, "cannot malloc struct_output\n");
+
+ for (i = 0; i < c; i++) {
+ struct_output[i].n = out_name[i];
+ struct_output[i].s = out_size[i];
+ }
+
+ qsort(struct_output, c, sizeof(*struct_output), compare_size_name);
+
+ for (i = 0; i < c; i++)
+ fprintf(fp, "%d\t%s\n", struct_output[i].s, struct_output[i].n);
+
+ free(struct_output);
+ return;
+}
+
/*
* This command displays the definition of structures, unions, typedefs or
* text/data symbols:
@@ -6543,33 +6587,59 @@
* declaration is displayed.
* 5. For a kernel symbol name, the output is the same as if the "sym"
command
* was used.
+ * 6. If the -r and optional -f are given, then the structures/unions of
+ * specified size will be searched.
*/
void
cmd_whatis(void)
{
struct datatype_member datatype_member, *dm;
struct syment *sp;
- char buf[BUFSIZE];
+
+ const char *field = NULL;
+ char buf[BUFSIZE], *pl = buf, *ph;;
long len;
- int c;
+ int c, lowest, highest;
ulong flags;
dm = &datatype_member;
flags = 0;
+ lowest = highest = UNUSED;
- while ((c = getopt(argcnt, args, "o")) != EOF) {
+ while ((c = getopt(argcnt, args, "of:r:")) != EOF) {
switch(c)
{
case 'o':
flags |= SHOW_OFFSET;
break;
+ case 'f':
+ field = optarg;
+ break;
+
+ case 'r':
+ strncpy(buf, optarg, 15);
+ if ((ph = strstr(buf, "-")) != NULL)
+ *(ph++) = '\0';
+
+ highest = lowest = stol(pl, FAULT_ON_ERROR, NULL);
+
+ if (ph)
+ highest = stol(ph, FAULT_ON_ERROR, NULL);
+
+ break;
+
default:
argerrs++;
break;
}
}
+ if (!argerrs && lowest != UNUSED && highest != UNUSED) {
+ request_types(lowest, highest, field);
+ return;
+ }
+
if (argerrs || !args[optind])
cmd_usage(pc->curcmd, SYNOPSIS);
3:16 a.m.
New subject: [Patch 2/2] Request data structures of particular size. Gdb part.
--- gdb-7.6/gdb/symtab.c 2016-04-04 15:27:06.147600736 +0300
+++ gdb-7.6/gdb/symtab.c 2016-04-04 15:22:20.155596448 +0300
@@ -3405,6 +3405,130 @@
return !data->preg_p || regexec (&data->preg, symname, 0, NULL, 0) == 0;
}
+#ifdef CRASH_MERGE
+int
+lookup_struct_contents(struct main_type *main_type, const char *field)
+{
+ int i;
+ struct field *f;
+ struct main_type *m;
+ const char *n;
+
+ if (!main_type)
+ return 0;
+
+ for (i = 0; i < main_type->nfields; i++)
+ {
+ f = main_type->flds_bnds.fields + i;
+ if (!f->type)
+ continue;
+ m = f->type->main_type;
+
+ /* Here is a recursion.
+ * If we have struct variable (not pointer),
+ * scan this inner structure
+ */
+ if (m->code == TYPE_CODE_STRUCT) {
+ if (lookup_struct_contents(m, field) == 1)
+ return 1;
+ }
+
+ if ((m->code == TYPE_CODE_PTR || m->code == TYPE_CODE_ARRAY)
+ && m->target_type)
+ m = m->target_type->main_type;
+ if (m->name)
+ n = m->name;
+ else if (m->tag_name)
+ n = m->tag_name;
+ else
+ continue;
+
+ if (strstr(n, field))
+ return 1;
+ }
+
+ return 0;
+}
+
+void
+append_struct_symbol (const char *n, int sz, const char ***out_name,
+ int **out_size, int *csz, int *cix)
+{
+ int i;
+
+ for (i = 0; i < *cix; i++)
+ if ((*out_name)[i] == n)
+ break;
+
+ if (i < *cix) // We've already collected this type
+ return;
+
+ if (*cix == *csz) {
+ *csz *= 3;
+ *out_name = xrealloc(*out_name, sizeof(*out_name) * (*csz));
+ *out_size = xrealloc(*out_size, sizeof(*out_size) * (*csz));
+ }
+ (*out_name)[*cix] = n;
+ (*out_size)[*cix] = sz;
+ (*cix)++;
+}
+
+int
+search_matched_struct_symbols (const char *field, int lowest, int highest,
+ const char ***out_name, int **out_size)
+{
+ struct symtab *s;
+ struct blockvector *bv;
+ struct block *b;
+ struct block_iterator iter;
+ struct symbol *sym;
+ struct objfile *objfile;
+ struct minimal_symbol *msymbol;
+ const char *name;
+ int size;
+ int i = 0;
+ int cix = 0, csz = 16;
+ struct partial_symtab *ps;
+
+ *out_name = xmalloc(sizeof(*out_name) * csz);
+ *out_size = xmalloc(sizeof(*out_size) * csz);
+
+ ALL_OBJFILES (objfile)
+ {
+ if (objfile->sf)
+ objfile->sf->qf->expand_all_symtabs(objfile);
+ }
+
+ ALL_PRIMARY_SYMTABS (objfile, s)
+ {
+ bv = BLOCKVECTOR (s);
+ for (i = GLOBAL_BLOCK; i <= STATIC_BLOCK; i++)
+ {
+ b = BLOCKVECTOR_BLOCK (bv, i);
+ ALL_BLOCK_SYMBOLS (b, iter, sym)
+ {
+ QUIT;
+
+ if (SYMBOL_CLASS (sym) == LOC_TYPEDEF)
+ {
+ name = sym->ginfo.name;
+ size = sym->type->length;
+ if (lowest >= 0 && size < lowest)
+ continue;
+ if (highest >= 0 && highest < size)
+ continue;
+ if (field && !lookup_struct_contents(sym->type->main_type,
field))
+ continue;
+ append_struct_symbol(name, size, out_name, out_size, &csz,
&cix);
+ }
+ }
+ }
+ }
+
+ return cix;
+}
+#endif
+
/* Search the symbol table for matches to the regular expression REGEXP,
returning the results in *MATCHES.
--- gdb-7.6/gdb/symtab.h 2013-02-03 18:54:16.000000000 +0300
+++ gdb-7.6/gdb/symtab.h 2016-04-04 16:05:53.335635633 +0300
@@ -1318,4 +1318,11 @@
struct cleanup *demangle_for_lookup (const char *name, enum language lang,
const char **result_name);
+#ifdef CRASH_MERGE
+void append_struct_symbol (const char *, int, const char ***, int **, int *, int *);
+int search_matched_struct_symbols (const char *, int, int, const char ***, int **);
+int lookup_struct_contents(struct main_type *, const char *);
+#endif
+
+
#endif /* !defined(SYMTAB_H) */
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3009
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devel@lists.crash-utility.osci.io
11 comments
2 participants
participants (2)
-
Alexandr Terekhov -
Dave Anderson