Re: git: c21bc6f3c242 - main - ddb: Add CTF-based pretty printing

From: FreeBSD User <freebsd_at_walstatt-de.de>
Date: Fri, 22 Mar 2024 15:17:28 UTC
Am Fri, 22 Mar 2024 03:56:19 GMT
Bojan Novković <bnovkov@FreeBSD.org> schrieb:

This commit breaks buildkernel of GENERIC and custom configs, when either

options	KDB

or

options	DDB

or both are commented out:

[...]
--- kernel ---
linking kernel
ld: error: undefined symbol: db_ctf_lookup_typename
>>> referenced by link_elf_obj.c
>>>               link_elf_obj.o:(link_elf_ctf_lookup_typename)
>>> referenced by link_elf.c
>>>               link_elf.o:(link_elf_ctf_lookup_typename)
*** [kernel] Error code 1

make[2]: stopped in /usr/obj/usr/src/amd64.amd64/sys/THOR
make[2]: 1 error

make[2]: stopped in /usr/obj/usr/src/amd64.amd64/sys/THOR
      605.46 real      2122.47 user       197.81 sys

make[1]: stopped in /usr/src

make: stopped in /usr/src


> The branch main has been updated by bnovkov:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=c21bc6f3c2425de74141bfee07b609bf65b5a6b3
> 
> commit c21bc6f3c2425de74141bfee07b609bf65b5a6b3
> Author:     Bojan Novković <bnovkov@FreeBSD.org>
> AuthorDate: 2024-03-22 03:01:34 +0000
> Commit:     Bojan Novković <bnovkov@FreeBSD.org>
> CommitDate: 2024-03-22 03:03:33 +0000
> 
>     ddb: Add CTF-based pretty printing
>     
>     Add basic CTF support and a CTF-powered pretty-printer to ddb.
>     
>     The db_ctf.* files expose a basic interface for fetching type
>     data for ELF symbols, interacting with the CTF string table,
>     and translating type identifiers to type data.
>     
>     The db_pprint.c file uses those interfaces to implement
>     a pretty-printer for all kernel ELF symbols.
>     The pretty-printer works with symbol names and arbitrary addresses:
>     pprint struct thread 0xffffffff8194ad90
>     
>     Pretty-printing currently only works after the root filesystem
>     gets mounted because the CTF info is not available during
>     early boot.
>     
>     Differential Revision:  https://reviews.freebsd.org/D37899
>     Approved by: markj (mentor)
> ---
>  share/man/man4/ddb.4    |  26 +++
>  sys/conf/files          |   2 +
>  sys/ddb/db_command.c    |   1 +
>  sys/ddb/db_ctf.c        | 326 +++++++++++++++++++++++++++++++++++
>  sys/ddb/db_ctf.h        |  64 +++++++
>  sys/ddb/db_pprint.c     | 450 ++++++++++++++++++++++++++++++++++++++++++++++++
>  sys/ddb/ddb.h           |   1 +
>  sys/kern/kern_ctf.c     |  40 +++++
>  sys/kern/kern_linker.c  |  68 +++++++-
>  sys/kern/link_elf.c     |  37 ++++
>  sys/kern/link_elf_obj.c |  14 ++
>  sys/kern/linker_if.m    |  23 +++
>  sys/sys/linker.h        |   3 +
>  13 files changed, 1054 insertions(+), 1 deletion(-)
> 
> diff --git a/share/man/man4/ddb.4 b/share/man/man4/ddb.4
> index 3648c9ca58cb..f3443cbac127 100644
> --- a/share/man/man4/ddb.4
> +++ b/share/man/man4/ddb.4
> @@ -289,6 +289,32 @@ eax = xxxxxx
>  ecx = yyyyyy
>  .Ed
>  .Pp
> +.It Ic pprint Ns Oo Li / Ns Cm d depth Oc Oo Ar name Oc
> +Pretty-print symbol specified by
> +.Ar name
> +using CTF debugging data. Works for all symbols exported by the kernel and loaded kernel
> modules. +.Pp
> +If the
> +.Cm d
> +modifier has been specified, contents of structs nested up to
> +.Ar depth
> +levels deep will also be included in the output.
> +.Ed
> +.Pp
> +.It Ic pprint struct Ns Oo Li / Ns Cm d depth Ic Oc Oo Ar name Oc Ns Op Ns Ar addr
> +Print memory at
> +.Ar addr
> +as struct
> +.Ar name Ns .
> +Works for all structs defined by the kernel and loaded kernel modules.
> +.Pp
> +If the
> +.Cm d
> +modifier has been specified, contents of structs nested up to
> +.Ar depth
> +levels deep will also be included in the output.
> +.Ed
> +.Pp
>  .It Xo
>  .Ic write Ns Op Li / Ns Cm bhl
>  .Ar addr expr1 Op Ar expr2 ...
> diff --git a/sys/conf/files b/sys/conf/files
> index c902bcfdbd52..021829408c0f 100644
> --- a/sys/conf/files
> +++ b/sys/conf/files
> @@ -718,12 +718,14 @@ ddb/db_access.c			optional ddb
>  ddb/db_break.c			optional ddb
>  ddb/db_capture.c		optional ddb
>  ddb/db_command.c		optional ddb
> +ddb/db_ctf.c			optional ddb
>  ddb/db_examine.c		optional ddb
>  ddb/db_expr.c			optional ddb
>  ddb/db_input.c			optional ddb
>  ddb/db_lex.c			optional ddb
>  ddb/db_main.c			optional ddb
>  ddb/db_output.c			optional ddb
> +ddb/db_pprint.c			optional ddb
>  ddb/db_print.c			optional ddb
>  ddb/db_ps.c			optional ddb
>  ddb/db_run.c			optional ddb
> diff --git a/sys/ddb/db_command.c b/sys/ddb/db_command.c
> index 9d79e3b2a6d3..0c88d496f6b8 100644
> --- a/sys/ddb/db_command.c
> +++ b/sys/ddb/db_command.c
> @@ -163,6 +163,7 @@ static struct db_command db_cmds[] = {
>  	DB_CMD("capture",	db_capture_cmd,		CS_OWN|DB_CMD_MEMSAFE),
>  	DB_CMD("textdump",	db_textdump_cmd,	CS_OWN|DB_CMD_MEMSAFE),
>  	DB_CMD("findstack",	db_findstack_cmd,	0),
> +	DB_CMD("pprint",	db_pprint_cmd,		CS_OWN),
>  };
>  struct db_command_table db_cmd_table = LIST_HEAD_INITIALIZER(db_cmd_table);
>  
> diff --git a/sys/ddb/db_ctf.c b/sys/ddb/db_ctf.c
> new file mode 100644
> index 000000000000..03145064885c
> --- /dev/null
> +++ b/sys/ddb/db_ctf.c
> @@ -0,0 +1,326 @@
> +/*-
> + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
> + *
> + * Copyright (c) 2023 Bojan Novković <bnovkov@freebsd.org>
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#include <sys/cdefs.h>
> +#include <sys/types.h>
> +#include <sys/param.h>
> +#include <sys/systm.h>
> +#include <sys/ctype.h>
> +#include <sys/linker.h>
> +#include <sys/malloc.h>
> +#include <sys/mutex.h>
> +
> +#include <ddb/ddb.h>
> +#include <ddb/db_ctf.h>
> +
> +static const ctf_header_t *
> +db_ctf_fetch_cth(linker_ctf_t *lc)
> +{
> +	return (const ctf_header_t *)lc->ctftab;
> +}
> +
> +/*
> + * Tries to look up the ELF symbol -> CTF type identifier mapping by scanning
> + * the CTF object section.
> + */
> +static uint32_t
> +sym_to_objtoff(linker_ctf_t *lc, const Elf_Sym *sym, const Elf_Sym *symtab,
> +    const Elf_Sym *symtab_end)
> +{
> +	const ctf_header_t *hp = db_ctf_fetch_cth(lc);
> +	uint32_t objtoff = hp->cth_objtoff;
> +	const size_t idwidth = 4;
> +
> +	/* Ignore non-object symbols */
> +	if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT) {
> +		return (DB_CTF_INVALID_OFF);
> +	}
> +	/* Sanity check */
> +	if (!(sym >= symtab && sym <= symtab_end)) {
> +		return (DB_CTF_INVALID_OFF);
> +	}
> +
> +	for (const Elf_Sym *symp = symtab; symp < symtab_end; symp++) {
> +		/* Make sure we do not go beyond the objtoff section */
> +		if (objtoff >= hp->cth_funcoff) {
> +			objtoff = DB_CTF_INVALID_OFF;
> +			break;
> +		}
> +		if (symp->st_name == 0 || symp->st_shndx == SHN_UNDEF) {
> +			continue;
> +		}
> +		if (symp->st_shndx == SHN_ABS && symp->st_value == 0) {
> +			continue;
> +		}
> +
> +		/* Skip non-object symbols */
> +		if (ELF_ST_TYPE(symp->st_info) != STT_OBJECT) {
> +			continue;
> +		}
> +		if (symp == sym) {
> +			break;
> +		}
> +		objtoff += idwidth;
> +	}
> +
> +	return (objtoff);
> +}
> +
> +/*
> + * Returns the size of CTF type 't'.
> + */
> +static u_int
> +db_ctf_type_size(struct ctf_type_v3 *t)
> +{
> +	u_int vlen, kind, ssize;
> +	u_int type_struct_size, kind_size;
> +
> +	vlen = CTF_V3_INFO_VLEN(t->ctt_info);
> +	kind = CTF_V3_INFO_KIND(t->ctt_info);
> +	ssize = ((t->ctt_size == CTF_V3_LSIZE_SENT) ? CTF_TYPE_LSIZE(t) :
> +						      t->ctt_size);
> +	type_struct_size = ((t->ctt_size == CTF_V3_LSIZE_SENT) ?
> +		sizeof(struct ctf_type_v3) :
> +		sizeof(struct ctf_stype_v3));
> +
> +	switch (kind) {
> +	case CTF_K_INTEGER:
> +	case CTF_K_FLOAT:
> +		kind_size = sizeof(uint32_t);
> +		break;
> +	case CTF_K_ARRAY:
> +		kind_size = sizeof(struct ctf_array_v3);
> +		break;
> +	case CTF_K_UNION:
> +	case CTF_K_STRUCT:
> +		kind_size = vlen *
> +		    ((ssize < CTF_V3_LSTRUCT_THRESH) ?
> +			    sizeof(struct ctf_member_v3) :
> +			    sizeof(struct ctf_lmember_v3));
> +		break;
> +	case CTF_K_ENUM:
> +		kind_size = vlen * sizeof(struct ctf_enum);
> +		break;
> +	case CTF_K_FUNCTION:
> +		kind_size = vlen * sizeof(uint32_t);
> +		break;
> +	case CTF_K_UNKNOWN:
> +	case CTF_K_FORWARD:
> +	case CTF_K_POINTER:
> +	case CTF_K_TYPEDEF:
> +	case CTF_K_VOLATILE:
> +	case CTF_K_CONST:
> +	case CTF_K_RESTRICT:
> +		kind_size = 0;
> +		break;
> +	default:
> +		db_printf("Error: invalid CTF type kind encountered\n");
> +		return (-1);
> +	}
> +
> +	return (type_struct_size + kind_size);
> +}
> +
> +/*
> + * Looks up type name 'name' in the CTF string table and returns the
> + * corresponding CTF type struct, if any.
> + */
> +struct ctf_type_v3 *
> +db_ctf_typename_to_type(linker_ctf_t *lc, const char *name)
> +{
> +	const ctf_header_t *hp = db_ctf_fetch_cth(lc);
> +	char *start, *cur, *end;
> +	uint32_t stroff = hp->cth_stroff;
> +	uint32_t typeoff = hp->cth_typeoff;
> +	uint32_t name_stroff;
> +	const uint8_t *ctfstart = (const uint8_t *)hp + sizeof(ctf_header_t);
> +
> +	u_int skiplen;
> +
> +	/* Scan ctf strtab for typename. */
> +	start = cur = __DECONST(char *, hp) + sizeof(ctf_header_t) +
> +	    hp->cth_stroff;
> +	end = cur + hp->cth_strlen;
> +	while (cur < end) {
> +		if (strcmp(cur, name) == 0)
> +			break;
> +		cur += strlen(cur) + 1;
> +	}
> +	if (cur >= end)
> +		return (NULL);
> +	name_stroff = (uint32_t)(cur - start);
> +
> +	/* Scan for type containing the found stroff. */
> +	while (typeoff < stroff) {
> +		struct ctf_type_v3 *t =
> +		    (struct ctf_type_v3 *)(__DECONST(uint8_t *, ctfstart) +
> +			typeoff);
> +		/* We found the type struct */
> +		if (t->ctt_name == name_stroff) {
> +			break;
> +		}
> +		if ((skiplen = db_ctf_type_size(t)) == -1) {
> +			return (NULL);
> +		}
> +		typeoff += skiplen;
> +	}
> +	if (typeoff < stroff) {
> +		return (struct ctf_type_v3 *)(__DECONST(uint8_t *, ctfstart) +
> +		    typeoff);
> +	} else { /* A type struct was not found */
> +		return (NULL);
> +	}
> +}
> +
> +/*
> + * Wrapper used by the kernel linker CTF routines.
> + * Currently used to implement lookup of CTF types accross all loaded kernel
> + * modules.
> + */
> +bool
> +db_ctf_lookup_typename(linker_ctf_t *lc, const char *typename)
> +{
> +	return (db_ctf_typename_to_type(lc, typename) != NULL);
> +}
> +
> +/*
> + * Returns the type corresponding to the 'typeid' parameter from the CTF type
> + * section.
> + */
> +struct ctf_type_v3 *
> +db_ctf_typeid_to_type(db_ctf_sym_data_t sd, uint32_t typeid)
> +{
> +	const ctf_header_t *hp = db_ctf_fetch_cth(&sd->lc);
> +	const uint8_t *ctfstart = (const uint8_t *)hp + sizeof(ctf_header_t);
> +	uint32_t typeoff = hp->cth_typeoff;
> +	uint32_t stroff = hp->cth_stroff;
> +	/* CTF typeids start at 0x1 */
> +	size_t cur_typeid = 1;
> +	u_int skiplen;
> +
> +	/* Find corresponding type */
> +	while (typeoff < stroff) {
> +		struct ctf_type_v3 *t =
> +		    (struct ctf_type_v3 *)(__DECONST(uint8_t *, ctfstart) +
> +			typeoff);
> +
> +		/* We found the type struct */
> +		if (cur_typeid == typeid) {
> +			break;
> +		}
> +		cur_typeid++;
> +		if ((skiplen = db_ctf_type_size(t)) == -1) {
> +			return (NULL);
> +		}
> +		typeoff += skiplen;
> +	}
> +	if (typeoff < stroff) {
> +		return (struct ctf_type_v3 *)(__DECONST(uint8_t *, ctfstart) +
> +		    typeoff);
> +	} else { /* A type struct was not found */
> +		return (NULL);
> +	}
> +}
> +
> +const char *
> +db_ctf_stroff_to_str(db_ctf_sym_data_t sd, uint32_t off)
> +{
> +	const ctf_header_t *hp = db_ctf_fetch_cth(&sd->lc);
> +	uint32_t stroff = hp->cth_stroff + off;
> +	const char *ret;
> +
> +	if (stroff >= (hp->cth_stroff + hp->cth_strlen)) {
> +		return ("invalid");
> +	}
> +	ret = ((const char *)hp + sizeof(ctf_header_t)) + stroff;
> +	if (*ret == '\0') {
> +		return (NULL);
> +	}
> +
> +	return (ret);
> +}
> +
> +/*
> + * Tries to find the type of the symbol specified in 'sd->sym'.
> + */
> +struct ctf_type_v3 *
> +db_ctf_sym_to_type(db_ctf_sym_data_t sd)
> +{
> +	uint32_t objtoff, typeid;
> +	const Elf_Sym *symtab, *symtab_end;
> +
> +	if (sd->sym == NULL) {
> +		return (NULL);
> +	}
> +	symtab = sd->lc.symtab;
> +	symtab_end = symtab + sd->lc.nsym;
> +
> +	objtoff = sym_to_objtoff(&sd->lc, sd->sym, symtab, symtab_end);
> +	/* Sanity check - should not happen */
> +	if (objtoff == DB_CTF_INVALID_OFF) {
> +		db_printf("Could not find CTF object offset.\n");
> +		return (NULL);
> +	}
> +
> +	typeid = *(
> +	    const uint32_t *)(sd->lc.ctftab + sizeof(ctf_header_t) + objtoff);
> +
> +	return (db_ctf_typeid_to_type(sd, typeid));
> +}
> +
> +/*
> + * Scans the kernel file and all loaded module for symbol 'name'.
> + */
> +int
> +db_ctf_find_symbol(const char *name, db_ctf_sym_data_t sd)
> +{
> +	int error;
> +	c_linker_sym_t lsym = NULL;
> +
> +	error = linker_ctf_lookup_sym_ddb(name, &lsym, &sd->lc);
> +	if (error != 0) {
> +		db_printf(
> +		    "failed to look up symbol and CTF info for %s: error %d\n",
> +		    name, error);
> +		return (error);
> +	}
> +	sd->sym = __DECONST(Elf_Sym *, lsym);
> +
> +	return (0);
> +}
> +
> +/*
> + * Scans the kernel file and all loaded module for type specified by 'typename'.
> + */
> +struct ctf_type_v3 *
> +db_ctf_find_typename(db_ctf_sym_data_t sd, const char *typename)
> +{
> +	if (linker_ctf_lookup_typename_ddb(&sd->lc, typename) != 0) {
> +		return (NULL);
> +	}
> +	return (db_ctf_typename_to_type(&sd->lc, typename));
> +}
> diff --git a/sys/ddb/db_ctf.h b/sys/ddb/db_ctf.h
> new file mode 100644
> index 000000000000..6da5f76b6cf6
> --- /dev/null
> +++ b/sys/ddb/db_ctf.h
> @@ -0,0 +1,64 @@
> +/*-
> + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
> + *
> + * Copyright (c) 2023 Bojan Novković <bnovkov@freebsd.org>
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#ifndef _DDB_DB_CTF_H_
> +#define _DDB_DB_CTF_H_
> +
> +#include <sys/types.h>
> +#include <sys/ctf.h>
> +#include <sys/linker.h>
> +
> +#include <ddb/ddb.h>
> +#include <ddb/db_sym.h>
> +
> +#define DB_CTF_INVALID_OFF 0xffffffff
> +
> +struct db_ctf_sym_data {
> +	linker_ctf_t lc;
> +	Elf_Sym *sym;
> +};
> +
> +typedef struct db_ctf_sym_data *db_ctf_sym_data_t;
> +
> +/*
> + * Routines for finding symbols and CTF info accross all loaded linker files.
> + */
> +int db_ctf_find_symbol(const char *name, db_ctf_sym_data_t sd);
> +struct ctf_type_v3 *db_ctf_find_typename(db_ctf_sym_data_t sd,
> +    const char *typename);
> +bool db_ctf_lookup_typename(linker_ctf_t *lc, const char *typename);
> +
> +/*
> + * Routines for working with CTF data.
> + */
> +struct ctf_type_v3 *db_ctf_sym_to_type(db_ctf_sym_data_t sd);
> +const char *db_ctf_stroff_to_str(db_ctf_sym_data_t sd, uint32_t off);
> +struct ctf_type_v3 *db_ctf_typename_to_type(linker_ctf_t *lc, const char *name);
> +struct ctf_type_v3 *db_ctf_typeid_to_type(db_ctf_sym_data_t sd,
> +    uint32_t typeid);
> +
> +#endif /* !_DDB_DB_CTF_H_ */
> diff --git a/sys/ddb/db_pprint.c b/sys/ddb/db_pprint.c
> new file mode 100644
> index 000000000000..dc7582864957
> --- /dev/null
> +++ b/sys/ddb/db_pprint.c
> @@ -0,0 +1,450 @@
> +/*-
> + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
> + *
> + * Copyright (c) 2022 Bojan Novković <bnovkov@freebsd.org>
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +
> +#include <sys/param.h>
> +#include <sys/systm.h>
> +#include <sys/ctype.h>
> +#include <sys/linker.h>
> +
> +#include <machine/stdarg.h>
> +
> +#include <ddb/ddb.h>
> +#include <ddb/db_ctf.h>
> +#include <ddb/db_lex.h>
> +#include <ddb/db_sym.h>
> +#include <ddb/db_access.h>
> +
> +#define DB_PPRINT_DEFAULT_DEPTH 1
> +
> +static void db_pprint_type(db_addr_t addr, struct ctf_type_v3 *type,
> +    u_int depth);
> +
> +static u_int max_depth = DB_PPRINT_DEFAULT_DEPTH;
> +static struct db_ctf_sym_data sym_data;
> +
> +/*
> + * Pretty-prints a CTF_INT type.
> + */
> +static inline void
> +db_pprint_int(db_addr_t addr, struct ctf_type_v3 *type, u_int depth)
> +{
> +	uint32_t data;
> +	size_t type_struct_size;
> +
> +	type_struct_size = (type->ctt_size == CTF_V3_LSIZE_SENT) ?
> +		sizeof(struct ctf_type_v3) :
> +		sizeof(struct ctf_stype_v3);
> +
> +	data = db_get_value((db_expr_t)type + type_struct_size,
> +		sizeof(uint32_t), 0);
> +	u_int bits = CTF_INT_BITS(data);
> +	boolean_t sign = !!(CTF_INT_ENCODING(data) & CTF_INT_SIGNED);
> +
> +	if (db_pager_quit) {
> +		return;
> +	}
> +	if (bits > 64) {
> +		db_printf("Invalid size '%d' found for integer type\n", bits);
> +		return;
> +	}
> +	db_printf("0x%lx",
> +	    db_get_value(addr, (bits / 8) ? (bits / 8) : 1, sign));
> +}
> +
> +/*
> + * Pretty-prints a struct. Nested structs are pretty-printed up 'depth' nested
> + * levels.
> + */
> +static inline void
> +db_pprint_struct(db_addr_t addr, struct ctf_type_v3 *type, u_int depth)
> +{
> +	size_t type_struct_size;
> +	size_t struct_size;
> +	struct ctf_type_v3 *mtype;
> +	const char *mname;
> +	db_addr_t maddr;
> +	u_int vlen;
> +
> +	type_struct_size = (type->ctt_size == CTF_V3_LSIZE_SENT) ?
> +		sizeof(struct ctf_type_v3) :
> +		sizeof(struct ctf_stype_v3);
> +	struct_size = ((type->ctt_size == CTF_V3_LSIZE_SENT) ?
> +		CTF_TYPE_LSIZE(type) :
> +		type->ctt_size);
> +	vlen = CTF_V3_INFO_VLEN(type->ctt_info);
> +
> +	if (db_pager_quit) {
> +		return;
> +	}
> +	if (depth > max_depth) {
> +		db_printf("{ ... }");
> +		return;
> +	}
> +	db_printf("{\n");
> +
> +	if (struct_size < CTF_V3_LSTRUCT_THRESH) {
> +		struct ctf_member_v3 *mp, *endp;
> +
> +		mp = (struct ctf_member_v3 *)((db_addr_t)type +
> +		    type_struct_size);
> +		endp = mp + vlen;
> +		for (; mp < endp; mp++) {
> +			if (db_pager_quit) {
> +				return;
> +			}
> +			mtype = db_ctf_typeid_to_type(&sym_data, mp->ctm_type);
> +			maddr = addr + mp->ctm_offset;
> +			mname = db_ctf_stroff_to_str(&sym_data, mp->ctm_name);
> +			db_indent = depth;
> +			if (mname != NULL) {
> +				db_iprintf("%s = ", mname);
> +			} else {
> +				db_iprintf("");
> +			}
> +
> +			db_pprint_type(maddr, mtype, depth + 1);
> +			db_printf(",\n");
> +		}
> +	} else {
> +		struct ctf_lmember_v3 *mp, *endp;
> +
> +		mp = (struct ctf_lmember_v3 *)((db_addr_t)type +
> +		    type_struct_size);
> +		endp = mp + vlen;
> +		for (; mp < endp; mp++) {
> +			if (db_pager_quit) {
> +				return;
> +			}
> +			mtype = db_ctf_typeid_to_type(&sym_data, mp->ctlm_type);
> +			maddr = addr + CTF_LMEM_OFFSET(mp);
> +			mname = db_ctf_stroff_to_str(&sym_data, mp->ctlm_name);
> +			db_indent = depth;
> +			if (mname != NULL) {
> +				db_iprintf("%s = ", mname);
> +			} else {
> +				db_iprintf("");
> +			}
> +
> +			db_pprint_type(maddr, mtype, depth + 1);
> +			db_printf(",");
> +		}
> +	}
> +	db_indent = depth - 1;
> +	db_iprintf("}");
> +}
> +
> +/*
> + * Pretty-prints an array. Each array member is printed out in a separate line
> + * indented with 'depth' spaces.
> + */
> +static inline void
> +db_pprint_arr(db_addr_t addr, struct ctf_type_v3 *type, u_int depth)
> +{
> +	struct ctf_type_v3 *elem_type;
> +	struct ctf_array_v3 *arr;
> +	db_addr_t elem_addr, end;
> +	size_t type_struct_size;
> +	size_t elem_size;
> +
> +	type_struct_size = (type->ctt_size == CTF_V3_LSIZE_SENT) ?
> +		sizeof(struct ctf_type_v3) :
> +		sizeof(struct ctf_stype_v3);
> +	arr = (struct ctf_array_v3 *)((db_addr_t)type + type_struct_size);
> +	elem_type = db_ctf_typeid_to_type(&sym_data, arr->cta_contents);
> +	elem_size = ((elem_type->ctt_size == CTF_V3_LSIZE_SENT) ?
> +		CTF_TYPE_LSIZE(elem_type) :
> +		elem_type->ctt_size);
> +	elem_addr = addr;
> +	end = addr + (arr->cta_nelems * elem_size);
> +
> +	db_indent = depth;
> +	db_printf("[\n");
> +	/* Loop through and print individual elements. */
> +	for (; elem_addr < end; elem_addr += elem_size) {
> +		if (db_pager_quit) {
> +			return;
> +		}
> +		db_iprintf("");
> +		db_pprint_type(elem_addr, elem_type, depth);
> +		if ((elem_addr + elem_size) < end) {
> +			db_printf(",\n");
> +		}
> +	}
> +	db_printf("\n");
> +	db_indent = depth - 1;
> +	db_iprintf("]");
> +}
> +
> +/*
> + * Pretty-prints an enum value. Also prints out symbolic name of value, if any.
> + */
> +static inline void
> +db_pprint_enum(db_addr_t addr, struct ctf_type_v3 *type, u_int depth)
> +{
> +	struct ctf_enum *ep, *endp;
> +	size_t type_struct_size;
> +	const char *valname;
> +	db_expr_t val;
> +	u_int vlen;
> +
> +	type_struct_size = (type->ctt_size == CTF_V3_LSIZE_SENT) ?
> +		sizeof(struct ctf_type_v3) :
> +		sizeof(struct ctf_stype_v3);
> +	vlen = CTF_V3_INFO_VLEN(type->ctt_info);
> +	val = db_get_value(addr, sizeof(int), 0);
> +
> +	if (db_pager_quit) {
> +		return;
> +	}
> +	ep = (struct ctf_enum *)((db_addr_t)type + type_struct_size);
> +	endp = ep + vlen;
> +	for (; ep < endp; ep++) {
> +		if (val == ep->cte_value) {
> +			valname = db_ctf_stroff_to_str(&sym_data, ep->cte_name);
> +			if (valname != NULL)
> +				db_printf("%s (0x%lx)", valname, val);
> +			else
> +				db_printf("(0x%lx)", val);
> +			break;
> +		}
> +	}
> +}
> +
> +/*
> + * Pretty-prints a pointer. If the 'depth' parameter is less than the
> + * 'max_depth' global var, the pointer is "dereference", i.e. the contents of
> + * the memory it points to are also printed. The value of the pointer is printed
> + * otherwise.
> + */
> +static inline void
> +db_pprint_ptr(db_addr_t addr, struct ctf_type_v3 *type, u_int depth)
> +{
> +	struct ctf_type_v3 *ref_type;
> +	const char *qual = "";
> +	const char *name;
> +	db_addr_t val;
> +	u_int kind;
> +
> +	ref_type = db_ctf_typeid_to_type(&sym_data, type->ctt_type);
> +	kind = CTF_V3_INFO_KIND(ref_type->ctt_info);
> +	switch (kind) {
> +	case CTF_K_STRUCT:
> +		qual = "struct ";
> +		break;
> +	case CTF_K_VOLATILE:
> +		qual = "volatile ";
> +		break;
> +	case CTF_K_CONST:
> +		qual = "const ";
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	val = db_get_value(addr, sizeof(db_addr_t), false);
> +	if (depth < max_depth) {
> +		/* Print contents of memory pointed to by this pointer. */
> +		db_pprint_type(addr, ref_type, depth + 1);
> +	} else {
> +		name = db_ctf_stroff_to_str(&sym_data, ref_type->ctt_name);
> +		db_indent = depth;
> +		if (name != NULL)
> +			db_printf("(%s%s *) 0x%lx", qual, name, val);
> +		else
> +			db_printf("0x%lx", val);
> +	}
> +}
> +
> +/*
> + * Pretty-print dispatching function.
> + */
> +static void
> +db_pprint_type(db_addr_t addr, struct ctf_type_v3 *type, u_int depth)
> +{
> +
> +	if (db_pager_quit) {
> +		return;
> +	}
> +	if (type == NULL) {
> +		db_printf("unknown type");
> +		return;
> +	}
> +
> +	switch (CTF_V3_INFO_KIND(type->ctt_info)) {
> +	case CTF_K_INTEGER:
> +		db_pprint_int(addr, type, depth);
> +		break;
> +	case CTF_K_UNION:
> +	case CTF_K_STRUCT:
> +		db_pprint_struct(addr, type, depth);
> +		break;
> +	case CTF_K_FUNCTION:
> +	case CTF_K_FLOAT:
> +		db_indent = depth;
> +		db_iprintf("0x%lx", addr);
> +		break;
> +	case CTF_K_POINTER:
> +		db_pprint_ptr(addr, type, depth);
> +		break;
> +	case CTF_K_TYPEDEF:
> +	case CTF_K_VOLATILE:
> +	case CTF_K_RESTRICT:
> +	case CTF_K_CONST: {
> +		struct ctf_type_v3 *ref_type = db_ctf_typeid_to_type(&sym_data,
> +		    type->ctt_type);
> +		db_pprint_type(addr, ref_type, depth);
> +		break;
> +	}
> +	case CTF_K_ENUM:
> +		db_pprint_enum(addr, type, depth);
> +		break;
> +	case CTF_K_ARRAY:
> +		db_pprint_arr(addr, type, depth);
> +		break;
> +	case CTF_K_UNKNOWN:
> +	case CTF_K_FORWARD:
> +	default:
> +		break;
> +	}
> +}
> +
> +/*
> + * Symbol pretty-printing command.
> + * Syntax: pprint [/d depth] <sym_name>
> + */
> +static void
> +db_pprint_symbol_cmd(const char *name)
> +{
> +	db_addr_t addr;
> +	int db_indent_old;
> +	const char *type_name = NULL;
> +	struct ctf_type_v3 *type = NULL;
> +
> +	if (db_pager_quit) {
> +		return;
> +	}
> +	/* Clear symbol and CTF info */
> +	memset(&sym_data, 0, sizeof(struct db_ctf_sym_data));
> +	if (db_ctf_find_symbol(name, &sym_data) != 0) {
> +		db_error("Symbol not found\n");
> +	}
> +	if (ELF_ST_TYPE(sym_data.sym->st_info) != STT_OBJECT) {
> +		db_error("Symbol is not a variable\n");
> +	}
> +	addr = sym_data.sym->st_value;
> +	type = db_ctf_sym_to_type(&sym_data);
> +	if (type == NULL) {
> +		db_error("Can't find CTF type info\n");
> +	}
> +	type_name = db_ctf_stroff_to_str(&sym_data, type->ctt_name);
> +	if (type_name != NULL)
> +		db_printf("%s ", type_name);
> +	db_printf("%s = ", name);
> +
> +	db_indent_old = db_indent;
> +	db_pprint_type(addr, type, 0);
> +	db_indent = db_indent_old;
> +}
> +
> +/*
> + * Command for pretty-printing arbitrary addresses.
> + * Syntax: pprint [/d depth] struct <struct_name> <addr>
> + */
> +static void
> +db_pprint_struct_cmd(db_expr_t addr, const char *struct_name)
> +{
> +	int db_indent_old;
> +	struct ctf_type_v3 *type = NULL;
> +
> +	type = db_ctf_find_typename(&sym_data, struct_name);
> +	if (type == NULL) {
> +		db_error("Can't find CTF type info\n");
> +		return;
> +	}
> +
> +	db_printf("struct %s ", struct_name);
> +	db_printf("%p = ", (void *)addr);
> +
> +	db_indent_old = db_indent;
> +	db_pprint_type(addr, type, 0);
> +	db_indent = db_indent_old;
> +}
> +
> +/*
> + * Pretty print an address or a symbol.
> + */
> +void
> +db_pprint_cmd(db_expr_t addr, bool have_addr, db_expr_t count, char *modif)
> +{
> +	int t = 0;
> +	const char *name;
> +
> +	/* Set default depth */
> +	max_depth = DB_PPRINT_DEFAULT_DEPTH;
> +	/* Parse print modifiers */
> +	t = db_read_token();
> +	if (t == tSLASH) {
> +		t = db_read_token();
> +		if (t != tIDENT) {
> +			db_error("Invalid flag passed\n");
> +		}
> +		/* Parse desired depth level */
> +		if (strcmp(db_tok_string, "d") == 0) {
> +			t = db_read_token();
> +			if (t != tNUMBER) {
> +				db_error("Invalid depth provided\n");
> +			}
> +			max_depth = db_tok_number;
> +		} else {
> +			db_error("Invalid flag passed\n");
> +		}
> +		/* Fetch next token */
> +		t = db_read_token();
> +	}
> +	/* Parse subcomannd */
> +	if (t == tIDENT) {
> +		if (strcmp(db_tok_string, "struct") == 0) {
> +			t = db_read_token();
> +
> +			if (t != tIDENT) {
> +				db_error("Invalid struct type name provided\n");
> +			}
> +			name = db_tok_string;
> +
> +			if (db_expression(&addr) == 0) {
> +				db_error("Address not provided\n");
> +			}
> +			db_pprint_struct_cmd(addr, name);
> +		} else {
> +			name = db_tok_string;
> +			db_pprint_symbol_cmd(name);
> +		}
> +	} else {
> +		db_error("Invalid subcommand\n");
> +	}
> +	db_skip_to_eol();
> +}
> diff --git a/sys/ddb/ddb.h b/sys/ddb/ddb.h
> index 1f388efcb389..bb92fef63e94 100644
> --- a/sys/ddb/ddb.h
> +++ b/sys/ddb/ddb.h
> @@ -297,6 +297,7 @@ db_cmdfcn_t	db_trace_until_matching_cmd;
>  db_cmdfcn_t	db_unscript_cmd;
>  db_cmdfcn_t	db_watchpoint_cmd;
>  db_cmdfcn_t	db_write_cmd;
> +db_cmdfcn_t	db_pprint_cmd;
>  
>  /*
>   * Interface between DDB and the DDB output capture facility.
> diff --git a/sys/kern/kern_ctf.c b/sys/kern/kern_ctf.c
> index 748622653eb3..8a2106a15308 100644
> --- a/sys/kern/kern_ctf.c
> *** 331 LINES SKIPPED ***
> 



-- 
O. Hartmann