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u-boot/api/api.c
Wolfgang Denk 54841ab50c Make sure that argv[] argument pointers are not modified. 
The hush shell dynamically allocates (and re-allocates) memory for the
argument strings in the "char *argv[]" argument vector passed to
commands.  Any code that modifies these pointers will cause serious
corruption of the malloc data structures and crash U-Boot, so make
sure the compiler can check that no such modifications are being done
by changing the code into "char * const argv[]".

This modification is the result of debugging a strange crash caused
after adding a new command, which used the following argument
processing code which has been working perfectly fine in all Unix
systems since version 6 - but not so in U-Boot:

int main (int argc, char **argv)
{
	while (--argc > 0 && **++argv == '-') {
/* ====> */	while (*++*argv) {
			switch (**argv) {
			case 'd':
				debug++;
				break;
			...
			default:
				usage ();
			}
		}
	}
	...
}

The line marked "====>" will corrupt the malloc data structures and
usually cause U-Boot to crash when the next command gets executed by
the shell.  With the modification, the compiler will prevent this with
an
	error: increment of read-only location '*argv'

N.B.: The code above can be trivially rewritten like this:

	while (--argc > 0 && **++argv == '-') {
		char *arg = *argv;
		while (*++arg) {
			switch (*arg) {
			...

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
2010-07-04 23:55:42 +02:00

664 lines
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/*
* (C) Copyright 2007 Semihalf
*
* Written by: Rafal Jaworowski <raj@semihalf.com>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
*/
#include <config.h>
#include <command.h>
#include <common.h>
#include <malloc.h>
#include <environment.h>
#include <linux/types.h>
#include <api_public.h>
#include "api_private.h"
#define DEBUG
#undef DEBUG
/* U-Boot routines needed */
extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
/*****************************************************************************
*
* This is the API core.
*
* API_ functions are part of U-Boot code and constitute the lowest level
* calls:
*
* - they know what values they need as arguments
* - their direct return value pertains to the API_ "shell" itself (0 on
* success, some error code otherwise)
* - if the call returns a value it is buried within arguments
*
****************************************************************************/
#ifdef DEBUG
#define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt, ##args); } while (0)
#else
#define debugf(fmt, args...)
#endif
typedef int (*cfp_t)(va_list argp);
static int calls_no;
/*
* pseudo signature:
*
* int API_getc(int *c)
*/
static int API_getc(va_list ap)
{
int *c;
if ((c = (int *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
*c = getc();
return 0;
}
/*
* pseudo signature:
*
* int API_tstc(int *c)
*/
static int API_tstc(va_list ap)
{
int *t;
if ((t = (int *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
*t = tstc();
return 0;
}
/*
* pseudo signature:
*
* int API_putc(char *ch)
*/
static int API_putc(va_list ap)
{
char *c;
if ((c = (char *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
putc(*c);
return 0;
}
/*
* pseudo signature:
*
* int API_puts(char **s)
*/
static int API_puts(va_list ap)
{
char *s;
if ((s = (char *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
puts(s);
return 0;
}
/*
* pseudo signature:
*
* int API_reset(void)
*/
static int API_reset(va_list ap)
{
do_reset(NULL, 0, 0, NULL);
/* NOT REACHED */
return 0;
}
/*
* pseudo signature:
*
* int API_get_sys_info(struct sys_info *si)
*
* fill out the sys_info struct containing selected parameters about the
* machine
*/
static int API_get_sys_info(va_list ap)
{
struct sys_info *si;
si = (struct sys_info *)va_arg(ap, u_int32_t);
if (si == NULL)
return API_ENOMEM;
return (platform_sys_info(si)) ? 0 : API_ENODEV;
}
/*
* pseudo signature:
*
* int API_udelay(unsigned long *udelay)
*/
static int API_udelay(va_list ap)
{
unsigned long *d;
if ((d = (unsigned long *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
udelay(*d);
return 0;
}
/*
* pseudo signature:
*
* int API_get_timer(unsigned long *current, unsigned long *base)
*/
static int API_get_timer(va_list ap)
{
unsigned long *base, *cur;
cur = (unsigned long *)va_arg(ap, u_int32_t);
if (cur == NULL)
return API_EINVAL;
base = (unsigned long *)va_arg(ap, u_int32_t);
if (base == NULL)
return API_EINVAL;
*cur = get_timer(*base);
return 0;
}
/*****************************************************************************
*
* pseudo signature:
*
* int API_dev_enum(struct device_info *)
*
*
* cookies uniqely identify the previously enumerated device instance and
* provide a hint for what to inspect in current enum iteration:
*
* - net: &eth_device struct address from list pointed to by eth_devices
*
* - storage: block_dev_desc_t struct address from &ide_dev_desc[n],
* &scsi_dev_desc[n] and similar tables
*
****************************************************************************/
static int API_dev_enum(va_list ap)
{
struct device_info *di;
/* arg is ptr to the device_info struct we are going to fill out */
di = (struct device_info *)va_arg(ap, u_int32_t);
if (di == NULL)
return API_EINVAL;
if (di->cookie == NULL) {
/* start over - clean up enumeration */
dev_enum_reset(); /* XXX shouldn't the name contain 'stor'? */
debugf("RESTART ENUM\n");
/* net device enumeration first */
if (dev_enum_net(di))
return 0;
}
/*
* The hidden assumption is there can only be one active network
* device and it is identified upon enumeration (re)start, so there's
* no point in trying to find network devices in other cases than the
* (re)start and hence the 'next' device can only be storage
*/
if (!dev_enum_storage(di))
/* make sure we mark there are no more devices */
di->cookie = NULL;
return 0;
}
static int API_dev_open(va_list ap)
{
struct device_info *di;
int err = 0;
/* arg is ptr to the device_info struct */
di = (struct device_info *)va_arg(ap, u_int32_t);
if (di == NULL)
return API_EINVAL;
/* Allow only one consumer of the device at a time */
if (di->state == DEV_STA_OPEN)
return API_EBUSY;
if (di->cookie == NULL)
return API_ENODEV;
if (di->type & DEV_TYP_STOR)
err = dev_open_stor(di->cookie);
else if (di->type & DEV_TYP_NET)
err = dev_open_net(di->cookie);
else
err = API_ENODEV;
if (!err)
di->state = DEV_STA_OPEN;
return err;
}
static int API_dev_close(va_list ap)
{
struct device_info *di;
int err = 0;
/* arg is ptr to the device_info struct */
di = (struct device_info *)va_arg(ap, u_int32_t);
if (di == NULL)
return API_EINVAL;
if (di->state == DEV_STA_CLOSED)
return 0;
if (di->cookie == NULL)
return API_ENODEV;
if (di->type & DEV_TYP_STOR)
err = dev_close_stor(di->cookie);
else if (di->type & DEV_TYP_NET)
err = dev_close_net(di->cookie);
else
/*
* In case of unknown device we cannot change its state, so
* only return error code
*/
err = API_ENODEV;
if (!err)
di->state = DEV_STA_CLOSED;
return err;
}
/*
* Notice: this is for sending network packets only, as U-Boot does not
* support writing to storage at the moment (12.2007)
*
* pseudo signature:
*
* int API_dev_write(
* struct device_info *di,
* void *buf,
* int *len
* )
*
* buf: ptr to buffer from where to get the data to send
*
* len: length of packet to be sent (in bytes)
*
*/
static int API_dev_write(va_list ap)
{
struct device_info *di;
void *buf;
int *len;
int err = 0;
/* 1. arg is ptr to the device_info struct */
di = (struct device_info *)va_arg(ap, u_int32_t);
if (di == NULL)
return API_EINVAL;
/* XXX should we check if device is open? i.e. the ->state ? */
if (di->cookie == NULL)
return API_ENODEV;
/* 2. arg is ptr to buffer from where to get data to write */
buf = (void *)va_arg(ap, u_int32_t);
if (buf == NULL)
return API_EINVAL;
/* 3. arg is length of buffer */
len = (int *)va_arg(ap, u_int32_t);
if (len == NULL)
return API_EINVAL;
if (*len <= 0)
return API_EINVAL;
if (di->type & DEV_TYP_STOR)
/*
* write to storage is currently not supported by U-Boot:
* no storage device implements block_write() method
*/
return API_ENODEV;
else if (di->type & DEV_TYP_NET)
err = dev_write_net(di->cookie, buf, *len);
else
err = API_ENODEV;
return err;
}
/*
* pseudo signature:
*
* int API_dev_read(
* struct device_info *di,
* void *buf,
* size_t *len,
* unsigned long *start
* size_t *act_len
* )
*
* buf: ptr to buffer where to put the read data
*
* len: ptr to length to be read
* - network: len of packet to read (in bytes)
* - storage: # of blocks to read (can vary in size depending on define)
*
* start: ptr to start block (only used for storage devices, ignored for
* network)
*
* act_len: ptr to where to put the len actually read
*/
static int API_dev_read(va_list ap)
{
struct device_info *di;
void *buf;
lbasize_t *len_stor, *act_len_stor;
lbastart_t *start;
int *len_net, *act_len_net;
/* 1. arg is ptr to the device_info struct */
di = (struct device_info *)va_arg(ap, u_int32_t);
if (di == NULL)
return API_EINVAL;
/* XXX should we check if device is open? i.e. the ->state ? */
if (di->cookie == NULL)
return API_ENODEV;
/* 2. arg is ptr to buffer from where to put the read data */
buf = (void *)va_arg(ap, u_int32_t);
if (buf == NULL)
return API_EINVAL;
if (di->type & DEV_TYP_STOR) {
/* 3. arg - ptr to var with # of blocks to read */
len_stor = (lbasize_t *)va_arg(ap, u_int32_t);
if (!len_stor)
return API_EINVAL;
if (*len_stor <= 0)
return API_EINVAL;
/* 4. arg - ptr to var with start block */
start = (lbastart_t *)va_arg(ap, u_int32_t);
/* 5. arg - ptr to var where to put the len actually read */
act_len_stor = (lbasize_t *)va_arg(ap, u_int32_t);
if (!act_len_stor)
return API_EINVAL;
*act_len_stor = dev_read_stor(di->cookie, buf, *len_stor, *start);
} else if (di->type & DEV_TYP_NET) {
/* 3. arg points to the var with length of packet to read */
len_net = (int *)va_arg(ap, u_int32_t);
if (!len_net)
return API_EINVAL;
if (*len_net <= 0)
return API_EINVAL;
/* 4. - ptr to var where to put the len actually read */
act_len_net = (int *)va_arg(ap, u_int32_t);
if (!act_len_net)
return API_EINVAL;
*act_len_net = dev_read_net(di->cookie, buf, *len_net);
} else
return API_ENODEV;
return 0;
}
/*
* pseudo signature:
*
* int API_env_get(const char *name, char **value)
*
* name: ptr to name of env var
*/
static int API_env_get(va_list ap)
{
char *name, **value;
if ((name = (char *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
if ((value = (char **)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
*value = getenv(name);
return 0;
}
/*
* pseudo signature:
*
* int API_env_set(const char *name, const char *value)
*
* name: ptr to name of env var
*
* value: ptr to value to be set
*/
static int API_env_set(va_list ap)
{
char *name, *value;
if ((name = (char *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
if ((value = (char *)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
setenv(name, value);
return 0;
}
/*
* pseudo signature:
*
* int API_env_enum(const char *last, char **next)
*
* last: ptr to name of env var found in last iteration
*/
static int API_env_enum(va_list ap)
{
int i, n;
char *last, **next;
last = (char *)va_arg(ap, u_int32_t);
if ((next = (char **)va_arg(ap, u_int32_t)) == NULL)
return API_EINVAL;
if (last == NULL)
/* start over */
*next = ((char *)env_get_addr(0));
else {
*next = last;
for (i = 0; env_get_char(i) != '\0'; i = n + 1) {
for (n = i; env_get_char(n) != '\0'; ++n) {
if (n >= CONFIG_ENV_SIZE) {
/* XXX shouldn't we set *next = NULL?? */
return 0;
}
}
if (envmatch((uchar *)last, i) < 0)
continue;
/* try to get next name */
i = n + 1;
if (env_get_char(i) == '\0') {
/* no more left */
*next = NULL;
return 0;
}
*next = ((char *)env_get_addr(i));
return 0;
}
}
return 0;
}
static cfp_t calls_table[API_MAXCALL] = { NULL, };
/*
* The main syscall entry point - this is not reentrant, only one call is
* serviced until finished.
*
* e.g. syscall(1, int *, u_int32_t, u_int32_t, u_int32_t, u_int32_t);
*
* call: syscall number
*
* retval: points to the return value placeholder, this is the place the
* syscall puts its return value, if NULL the caller does not
* expect a return value
*
* ... syscall arguments (variable number)
*
* returns: 0 if the call not found, 1 if serviced
*/
int syscall(int call, int *retval, ...)
{
va_list ap;
int rv;
if (call < 0 || call >= calls_no) {
debugf("invalid call #%d\n", call);
return 0;
}
if (calls_table[call] == NULL) {
debugf("syscall #%d does not have a handler\n", call);
return 0;
}
va_start(ap, retval);
rv = calls_table[call](ap);
if (retval != NULL)
*retval = rv;
return 1;
}
void api_init(void)
{
struct api_signature *sig = NULL;
/* TODO put this into linker set one day... */
calls_table[API_RSVD] = NULL;
calls_table[API_GETC] = &API_getc;
calls_table[API_PUTC] = &API_putc;
calls_table[API_TSTC] = &API_tstc;
calls_table[API_PUTS] = &API_puts;
calls_table[API_RESET] = &API_reset;
calls_table[API_GET_SYS_INFO] = &API_get_sys_info;
calls_table[API_UDELAY] = &API_udelay;
calls_table[API_GET_TIMER] = &API_get_timer;
calls_table[API_DEV_ENUM] = &API_dev_enum;
calls_table[API_DEV_OPEN] = &API_dev_open;
calls_table[API_DEV_CLOSE] = &API_dev_close;
calls_table[API_DEV_READ] = &API_dev_read;
calls_table[API_DEV_WRITE] = &API_dev_write;
calls_table[API_ENV_GET] = &API_env_get;
calls_table[API_ENV_SET] = &API_env_set;
calls_table[API_ENV_ENUM] = &API_env_enum;
calls_no = API_MAXCALL;
debugf("API initialized with %d calls\n", calls_no);
dev_stor_init();
/*
* Produce the signature so the API consumers can find it
*/
sig = malloc(sizeof(struct api_signature));
if (sig == NULL) {
printf("API: could not allocate memory for the signature!\n");
return;
}
debugf("API sig @ 0x%08x\n", sig);
memcpy(sig->magic, API_SIG_MAGIC, 8);
sig->version = API_SIG_VERSION;
sig->syscall = &syscall;
sig->checksum = 0;
sig->checksum = crc32(0, (unsigned char *)sig,
sizeof(struct api_signature));
debugf("syscall entry: 0x%08x\n", sig->syscall);
}
void platform_set_mr(struct sys_info *si, unsigned long start, unsigned long size,
int flags)
{
int i;
if (!si->mr || !size || (flags == 0))
return;
/* find free slot */
for (i = 0; i < si->mr_no; i++)
if (si->mr[i].flags == 0) {
/* insert new mem region */
si->mr[i].start = start;
si->mr[i].size = size;
si->mr[i].flags = flags;
return;
}
}
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