minix/sys/arch/i386/stand/lib/exec.c
Lionel Sambuc 84d9c625bf Synchronize on NetBSD-CVS (2013/12/1 12:00:00 UTC)
- Fix for possible unset uid/gid in toproto
 - Fix for default mtree style
 - Update libelf
 - Importing libexecinfo
 - Resynchronize GCC, mpc, gmp, mpfr
 - build.sh: Replace params with show-params.
     This has been done as the make target has been renamed in the same
     way, while a new target named params has been added. This new
     target generates a file containing all the parameters, instead of
     printing it on the console.
 - Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org)
     get getservbyport() out of the inner loop

Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
2014-07-28 17:05:06 +02:00

755 lines
19 KiB
C

/* $NetBSD: exec.c,v 1.55 2013/11/27 18:29:45 jakllsch Exp $ */
/*-
* Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
* All rights reserved.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Copyright (c) 1982, 1986, 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)boot.c 8.1 (Berkeley) 6/10/93
*/
/*
* Copyright (c) 1996
* Matthias Drochner. All rights reserved.
* Copyright (c) 1996
* Perry E. Metzger. All rights reserved.
*
* 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 REGENTS 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 REGENTS 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.
*
* @(#)boot.c 8.1 (Berkeley) 6/10/93
*/
/*
* starts NetBSD a.out kernel
* needs lowlevel startup from startprog.S
* This is a special version of exec.c to support use of XMS.
*/
#include <sys/param.h>
#include <sys/reboot.h>
#include <sys/reboot.h>
#include <i386/multiboot.h>
#include <lib/libsa/stand.h>
#include <lib/libkern/libkern.h>
#include "loadfile.h"
#include "libi386.h"
#include "bootinfo.h"
#include "bootmod.h"
#include "vbe.h"
#ifdef SUPPORT_PS2
#include "biosmca.h"
#endif
#define BOOT_NARGS 6
#ifndef PAGE_SIZE
#define PAGE_SIZE 4096
#endif
#define MODULE_WARNING_SEC 5
extern struct btinfo_console btinfo_console;
boot_module_t *boot_modules;
bool boot_modules_enabled = true;
bool kernel_loaded;
typedef struct userconf_command {
char *uc_text;
size_t uc_len;
struct userconf_command *uc_next;
} userconf_command_t;
userconf_command_t *userconf_commands = NULL;
static struct btinfo_framebuffer btinfo_framebuffer;
static struct btinfo_modulelist *btinfo_modulelist;
static size_t btinfo_modulelist_size;
static uint32_t image_end;
static char module_base[64] = "/";
static int howto;
static struct btinfo_userconfcommands *btinfo_userconfcommands = NULL;
static size_t btinfo_userconfcommands_size = 0;
static void module_init(const char *);
static void module_add_common(char *, uint8_t);
static void userconf_init(void);
void
framebuffer_configure(struct btinfo_framebuffer *fb)
{
if (fb)
btinfo_framebuffer = *fb;
else {
btinfo_framebuffer.physaddr = 0;
btinfo_framebuffer.flags = 0;
}
}
void
module_add(char *name)
{
return module_add_common(name, BM_TYPE_KMOD);
}
void
splash_add(char *name)
{
return module_add_common(name, BM_TYPE_IMAGE);
}
void
rnd_add(char *name)
{
return module_add_common(name, BM_TYPE_RND);
}
void
fs_add(char *name)
{
return module_add_common(name, BM_TYPE_FS);
}
static void
module_add_common(char *name, uint8_t type)
{
boot_module_t *bm, *bmp;
size_t len;
char *str;
while (*name == ' ' || *name == '\t')
++name;
bm = alloc(sizeof(boot_module_t));
len = strlen(name) + 1;
str = alloc(len);
if (bm == NULL || str == NULL) {
printf("couldn't allocate module\n");
return;
}
memcpy(str, name, len);
bm->bm_path = str;
bm->bm_next = NULL;
bm->bm_type = type;
if (boot_modules == NULL)
boot_modules = bm;
else {
for (bmp = boot_modules; bmp->bm_next;
bmp = bmp->bm_next)
;
bmp->bm_next = bm;
}
}
void
userconf_add(char *cmd)
{
userconf_command_t *uc;
size_t len;
char *text;
while (*cmd == ' ' || *cmd == '\t')
++cmd;
uc = alloc(sizeof(*uc));
if (uc == NULL) {
printf("couldn't allocate command\n");
return;
}
len = strlen(cmd) + 1;
text = alloc(len);
if (text == NULL) {
dealloc(uc, sizeof(*uc));
printf("couldn't allocate command\n");
return;
}
memcpy(text, cmd, len);
uc->uc_text = text;
uc->uc_len = len;
uc->uc_next = NULL;
if (userconf_commands == NULL)
userconf_commands = uc;
else {
userconf_command_t *ucp;
for (ucp = userconf_commands; ucp->uc_next != NULL;
ucp = ucp->uc_next)
;
ucp->uc_next = uc;
}
}
static int
common_load_kernel(const char *file, u_long *basemem, u_long *extmem,
physaddr_t loadaddr, int floppy, u_long marks[MARK_MAX])
{
int fd;
#ifdef XMS
u_long xmsmem;
physaddr_t origaddr = loadaddr;
#endif
*extmem = getextmem();
*basemem = getbasemem();
#ifdef XMS
if ((getextmem1() == 0) && (xmsmem = checkxms())) {
u_long kernsize;
/*
* With "CONSERVATIVE_MEMDETECT", extmem is 0 because
* getextmem() is getextmem1(). Without, the "smart"
* methods could fail to report all memory as well.
* xmsmem is a few kB less than the actual size, but
* better than nothing.
*/
if (xmsmem > *extmem)
*extmem = xmsmem;
/*
* Get the size of the kernel
*/
marks[MARK_START] = loadaddr;
if ((fd = loadfile(file, marks, COUNT_KERNEL)) == -1)
return EIO;
close(fd);
kernsize = marks[MARK_END];
kernsize = (kernsize + 1023) / 1024;
loadaddr = xmsalloc(kernsize);
if (!loadaddr)
return ENOMEM;
}
#endif
marks[MARK_START] = loadaddr;
if ((fd = loadfile(file, marks,
LOAD_KERNEL & ~(floppy ? LOAD_BACKWARDS : 0))) == -1)
return EIO;
close(fd);
/* If the root fs type is unusual, load its module. */
if (fsmod != NULL)
module_add(fsmod);
#if defined(__minix)
if (fsmod !=NULL && fsmod2 != NULL && strcmp(fsmod, fsmod2) != 0)
module_add(fsmod2);
#endif /* defined(__minix) */
/*
* Gather some information for the kernel. Do this after the
* "point of no return" to avoid memory leaks.
* (but before DOS might be trashed in the XMS case)
*/
#ifdef PASS_BIOSGEOM
bi_getbiosgeom();
#endif
#ifdef PASS_MEMMAP
bi_getmemmap();
#endif
#ifdef XMS
if (loadaddr != origaddr) {
/*
* We now have done our last DOS IO, so we may
* trash the OS. Copy the data from the temporary
* buffer to its real address.
*/
marks[MARK_START] -= loadaddr;
marks[MARK_END] -= loadaddr;
marks[MARK_SYM] -= loadaddr;
marks[MARK_END] -= loadaddr;
ppbcopy(loadaddr, origaddr, marks[MARK_END]);
}
#endif
marks[MARK_END] = (((u_long) marks[MARK_END] + sizeof(int) - 1)) &
(-sizeof(int));
image_end = marks[MARK_END];
kernel_loaded = true;
return 0;
}
int
exec_netbsd(const char *file, physaddr_t loadaddr, int boothowto, int floppy,
void (*callback)(void))
{
uint32_t boot_argv[BOOT_NARGS];
u_long marks[MARK_MAX];
struct btinfo_symtab btinfo_symtab;
u_long extmem;
u_long basemem;
#ifdef DEBUG
printf("exec: file=%s loadaddr=0x%lx\n",
file ? file : "NULL", loadaddr);
#endif
BI_ALLOC(32); /* ??? */
BI_ADD(&btinfo_console, BTINFO_CONSOLE, sizeof(struct btinfo_console));
howto = boothowto;
if (common_load_kernel(file, &basemem, &extmem, loadaddr, floppy, marks))
goto out;
boot_argv[0] = boothowto;
boot_argv[1] = 0;
boot_argv[2] = vtophys(bootinfo); /* old cyl offset */
boot_argv[3] = marks[MARK_END];
boot_argv[4] = extmem;
boot_argv[5] = basemem;
/* pull in any modules if necessary */
if (boot_modules_enabled) {
module_init(file);
if (btinfo_modulelist) {
BI_ADD(btinfo_modulelist, BTINFO_MODULELIST,
btinfo_modulelist_size);
}
}
userconf_init();
if (btinfo_userconfcommands != NULL)
BI_ADD(btinfo_userconfcommands, BTINFO_USERCONFCOMMANDS,
btinfo_userconfcommands_size);
#ifdef DEBUG
printf("Start @ 0x%lx [%ld=0x%lx-0x%lx]...\n", marks[MARK_ENTRY],
marks[MARK_NSYM], marks[MARK_SYM], marks[MARK_END]);
#endif
btinfo_symtab.nsym = marks[MARK_NSYM];
btinfo_symtab.ssym = marks[MARK_SYM];
btinfo_symtab.esym = marks[MARK_END];
BI_ADD(&btinfo_symtab, BTINFO_SYMTAB, sizeof(struct btinfo_symtab));
/* set new video mode if necessary */
vbe_commit();
BI_ADD(&btinfo_framebuffer, BTINFO_FRAMEBUFFER,
sizeof(struct btinfo_framebuffer));
if (callback != NULL)
(*callback)();
startprog(marks[MARK_ENTRY], BOOT_NARGS, boot_argv,
x86_trunc_page(basemem*1024));
panic("exec returned");
out:
BI_FREE();
bootinfo = 0;
return -1;
}
static void
extract_device(const char *path, char *buf, size_t buflen)
{
int i;
if (strchr(path, ':') != NULL) {
for (i = 0; i < buflen - 2 && path[i] != ':'; i++)
buf[i] = path[i];
buf[i++] = ':';
buf[i] = '\0';
} else
buf[0] = '\0';
}
static const char *
module_path(boot_module_t *bm, const char *kdev)
{
static char buf[256];
char name_buf[256], dev_buf[64];
const char *name, *name2, *p;
name = bm->bm_path;
for (name2 = name; *name2; ++name2) {
if (*name2 == ' ' || *name2 == '\t') {
strlcpy(name_buf, name, sizeof(name_buf));
if (name2 - name < sizeof(name_buf))
name_buf[name2 - name] = '\0';
name = name_buf;
break;
}
}
if ((p = strchr(name, ':')) != NULL) {
/* device specified, use it */
if (p[1] == '/')
snprintf(buf, sizeof(buf), "%s", name);
else {
p++;
extract_device(name, dev_buf, sizeof(dev_buf));
snprintf(buf, sizeof(buf), "%s%s/%s/%s.kmod",
dev_buf, module_base, p, p);
}
} else {
/* device not specified; load from kernel device if known */
if (name[0] == '/')
snprintf(buf, sizeof(buf), "%s%s", kdev, name);
else
snprintf(buf, sizeof(buf), "%s%s/%s/%s.kmod",
kdev, module_base, name, name);
}
return buf;
}
static int
module_open(boot_module_t *bm, int mode, const char *kdev, bool doload)
{
int fd;
const char *path;
/* check the expanded path first */
path = module_path(bm, kdev);
fd = open(path, mode);
if (fd != -1) {
if ((howto & AB_SILENT) == 0 && doload)
printf("Loading %s ", path);
} else {
/* now attempt the raw path provided */
fd = open(bm->bm_path, mode);
if (fd != -1 && (howto & AB_SILENT) == 0 && doload)
printf("Loading %s ", bm->bm_path);
}
if (!doload && fd == -1) {
printf("WARNING: couldn't open %s", bm->bm_path);
if (strcmp(bm->bm_path, path) != 0)
printf(" (%s)", path);
printf("\n");
}
return fd;
}
static void
module_init(const char *kernel_path)
{
struct bi_modulelist_entry *bi;
struct stat st;
const char *machine;
char kdev[64];
char *buf;
boot_module_t *bm;
size_t len;
off_t off;
int err, fd, nfail = 0;
extract_device(kernel_path, kdev, sizeof(kdev));
switch (netbsd_elf_class) {
case ELFCLASS32:
machine = "i386";
break;
case ELFCLASS64:
machine = "amd64";
break;
default:
machine = "generic";
break;
}
if (netbsd_version / 1000000 % 100 == 99) {
/* -current */
snprintf(module_base, sizeof(module_base),
"/stand/%s/%d.%d.%d/modules", machine,
netbsd_version / 100000000,
netbsd_version / 1000000 % 100,
netbsd_version / 100 % 100);
} else if (netbsd_version != 0) {
/* release */
snprintf(module_base, sizeof(module_base),
"/stand/%s/%d.%d/modules", machine,
netbsd_version / 100000000,
netbsd_version / 1000000 % 100);
}
/* First, see which modules are valid and calculate btinfo size */
len = sizeof(struct btinfo_modulelist);
for (bm = boot_modules; bm; bm = bm->bm_next) {
fd = module_open(bm, 0, kdev, false);
if (fd == -1) {
bm->bm_len = -1;
++nfail;
continue;
}
err = fstat(fd, &st);
if (err == -1 || st.st_size == -1) {
printf("WARNING: couldn't stat %s\n", bm->bm_path);
close(fd);
bm->bm_len = -1;
++nfail;
continue;
}
bm->bm_len = st.st_size;
close(fd);
len += sizeof(struct bi_modulelist_entry);
}
/* Allocate the module list */
btinfo_modulelist = alloc(len);
if (btinfo_modulelist == NULL) {
printf("WARNING: couldn't allocate module list\n");
wait_sec(MODULE_WARNING_SEC);
return;
}
memset(btinfo_modulelist, 0, len);
btinfo_modulelist_size = len;
/* Fill in btinfo structure */
buf = (char *)btinfo_modulelist;
btinfo_modulelist->num = 0;
off = sizeof(struct btinfo_modulelist);
for (bm = boot_modules; bm; bm = bm->bm_next) {
if (bm->bm_len == -1)
continue;
fd = module_open(bm, 0, kdev, true);
if (fd == -1)
continue;
image_end = (image_end + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
len = pread(fd, (void *)(uintptr_t)image_end, SSIZE_MAX);
if (len < bm->bm_len) {
if ((howto & AB_SILENT) != 0)
printf("Loading %s ", bm->bm_path);
printf(" FAILED\n");
} else {
btinfo_modulelist->num++;
bi = (struct bi_modulelist_entry *)(buf + off);
off += sizeof(struct bi_modulelist_entry);
strncpy(bi->path, bm->bm_path, sizeof(bi->path) - 1);
bi->base = image_end;
bi->len = len;
switch (bm->bm_type) {
case BM_TYPE_KMOD:
bi->type = BI_MODULE_ELF;
break;
case BM_TYPE_IMAGE:
bi->type = BI_MODULE_IMAGE;
break;
case BM_TYPE_FS:
bi->type = BI_MODULE_FS;
break;
case BM_TYPE_RND:
default:
/* safest -- rnd checks the sha1 */
bi->type = BI_MODULE_RND;
break;
}
if ((howto & AB_SILENT) == 0)
printf(" \n");
}
if (len > 0)
image_end += len;
close(fd);
}
btinfo_modulelist->endpa = image_end;
if (nfail > 0) {
printf("WARNING: %d module%s failed to load\n",
nfail, nfail == 1 ? "" : "s");
#if notyet
wait_sec(MODULE_WARNING_SEC);
#endif
}
}
static void
userconf_init(void)
{
size_t count, len;
userconf_command_t *uc;
char *buf;
off_t off;
/* Calculate the userconf commands list size */
count = 0;
for (uc = userconf_commands; uc != NULL; uc = uc->uc_next)
count++;
len = sizeof(*btinfo_userconfcommands) +
count * sizeof(struct bi_userconfcommand);
/* Allocate the userconf commands list */
btinfo_userconfcommands = alloc(len);
if (btinfo_userconfcommands == NULL) {
printf("WARNING: couldn't allocate userconf commands list\n");
return;
}
memset(btinfo_userconfcommands, 0, len);
btinfo_userconfcommands_size = len;
/* Fill in btinfo structure */
buf = (char *)btinfo_userconfcommands;
off = sizeof(*btinfo_userconfcommands);
btinfo_userconfcommands->num = 0;
for (uc = userconf_commands; uc != NULL; uc = uc->uc_next) {
struct bi_userconfcommand *bi;
bi = (struct bi_userconfcommand *)(buf + off);
strncpy(bi->text, uc->uc_text, sizeof(bi->text) - 1);
off += sizeof(*bi);
btinfo_userconfcommands->num++;
}
}
int
exec_multiboot(const char *file, char *args)
{
struct multiboot_info *mbi;
struct multiboot_module *mbm;
struct bi_modulelist_entry *bim;
int i, len;
u_long marks[MARK_MAX];
u_long extmem;
u_long basemem;
char *cmdline;
mbi = alloc(sizeof(struct multiboot_info));
mbi->mi_flags = MULTIBOOT_INFO_HAS_MEMORY;
if (common_load_kernel(file, &basemem, &extmem, 0, 0, marks))
goto out;
mbi->mi_mem_upper = extmem;
mbi->mi_mem_lower = basemem;
if (args) {
mbi->mi_flags |= MULTIBOOT_INFO_HAS_CMDLINE;
len = strlen(file) + 1 + strlen(args) + 1;
cmdline = alloc(len);
snprintf(cmdline, len, "%s %s", file, args);
mbi->mi_cmdline = (char *) vtophys(cmdline);
}
/* pull in any modules if necessary */
if (boot_modules_enabled) {
module_init(file);
if (btinfo_modulelist) {
mbm = alloc(sizeof(struct multiboot_module) *
btinfo_modulelist->num);
bim = (struct bi_modulelist_entry *)
(((char *) btinfo_modulelist) +
sizeof(struct btinfo_modulelist));
for (i = 0; i < btinfo_modulelist->num; i++) {
mbm[i].mmo_start = bim->base;
mbm[i].mmo_end = bim->base + bim->len;
mbm[i].mmo_string = (char *)vtophys(bim->path);
mbm[i].mmo_reserved = 0;
bim++;
}
mbi->mi_flags |= MULTIBOOT_INFO_HAS_MODS;
mbi->mi_mods_count = btinfo_modulelist->num;
mbi->mi_mods_addr = vtophys(mbm);
}
}
#ifdef DEBUG
printf("Start @ 0x%lx [%ld=0x%lx-0x%lx]...\n", marks[MARK_ENTRY],
marks[MARK_NSYM], marks[MARK_SYM], marks[MARK_END]);
#endif
#if 0
if (btinfo_symtab.nsym) {
mbi->mi_flags |= MULTIBOOT_INFO_HAS_ELF_SYMS;
mbi->mi_elfshdr_addr = marks[MARK_SYM];
btinfo_symtab.nsym = marks[MARK_NSYM];
btinfo_symtab.ssym = marks[MARK_SYM];
btinfo_symtab.esym = marks[MARK_END];
#endif
multiboot(marks[MARK_ENTRY], vtophys(mbi),
x86_trunc_page(mbi->mi_mem_lower*1024));
panic("exec returned");
out:
dealloc(mbi, 0);
return -1;
}
void
x86_progress(const char *fmt, ...)
{
va_list ap;
if ((howto & AB_SILENT) != 0)
return;
va_start(ap, fmt);
vprintf(fmt, ap);
va_end(ap);
}