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authorWolfgang Denk <wd@denx.de>2010-06-28 22:00:46 +0200
committerWolfgang Denk <wd@denx.de>2010-07-04 23:55:42 +0200
commit54841ab50c20d6fa6c9cc3eb826989da3a22d934 (patch)
tree400f22f0a12ff0ae6c472bed6ac648befc1744a2 /common/cmd_mem.c
parentb218ccb5435e64ac2318bb8b6c9594ef1cc724cd (diff)
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>
Diffstat (limited to 'common/cmd_mem.c')
-rw-r--r--common/cmd_mem.c40
1 files changed, 20 insertions, 20 deletions
diff --git a/common/cmd_mem.c b/common/cmd_mem.c
index 1839330760c..bcea3992dbc 100644
--- a/common/cmd_mem.c
+++ b/common/cmd_mem.c
@@ -43,7 +43,7 @@
#define PRINTF(fmt,args...)
#endif
-static int mod_mem(cmd_tbl_t *, int, int, int, char *[]);
+static int mod_mem(cmd_tbl_t *, int, int, int, char * const []);
/* Display values from last command.
* Memory modify remembered values are different from display memory.
@@ -60,7 +60,7 @@ static ulong base_address = 0;
* md{.b, .w, .l} {addr} {len}
*/
#define DISP_LINE_LEN 16
-int do_mem_md ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_md ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong addr, length;
#if defined(CONFIG_HAS_DATAFLASH)
@@ -158,16 +158,16 @@ int do_mem_md ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
return (rc);
}
-int do_mem_mm ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_mm ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
return mod_mem (cmdtp, 1, flag, argc, argv);
}
-int do_mem_nm ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_nm ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
return mod_mem (cmdtp, 0, flag, argc, argv);
}
-int do_mem_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong addr, writeval, count;
int size;
@@ -211,7 +211,7 @@ int do_mem_mw ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
}
#ifdef CONFIG_MX_CYCLIC
-int do_mem_mdc ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_mdc ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int i;
ulong count;
@@ -240,7 +240,7 @@ int do_mem_mdc ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
return 0;
}
-int do_mem_mwc ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_mwc ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int i;
ulong count;
@@ -270,7 +270,7 @@ int do_mem_mwc ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
}
#endif /* CONFIG_MX_CYCLIC */
-int do_mem_cmp (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_cmp (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong addr1, addr2, count, ngood;
int size;
@@ -355,7 +355,7 @@ int do_mem_cmp (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
return rcode;
}
-int do_mem_cp ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_cp ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong addr, dest, count;
int size;
@@ -463,7 +463,7 @@ int do_mem_cp ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
return 0;
}
-int do_mem_base (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_base (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
if (argc > 1) {
/* Set new base address.
@@ -476,7 +476,7 @@ int do_mem_base (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
return 0;
}
-int do_mem_loop (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_loop (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong addr, length, i, junk;
int size;
@@ -547,7 +547,7 @@ int do_mem_loop (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
}
#ifdef CONFIG_LOOPW
-int do_mem_loopw (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_loopw (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong addr, length, i, data;
int size;
@@ -626,7 +626,7 @@ int do_mem_loopw (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
* configured using CONFIG_SYS_ALT_MEMTEST. The complete test loops until
* interrupted by ctrl-c or by a failure of one of the sub-tests.
*/
-int do_mem_mtest (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_mtest (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
vu_long *addr, *start, *end;
ulong val;
@@ -984,7 +984,7 @@ int do_mem_mtest (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
* nm{.b, .w, .l} {addr}
*/
static int
-mod_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char *argv[])
+mod_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char * const argv[])
{
ulong addr, i;
int nbytes, size;
@@ -1089,7 +1089,7 @@ mod_mem(cmd_tbl_t *cmdtp, int incrflag, int flag, int argc, char *argv[])
#ifndef CONFIG_CRC32_VERIFY
-int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong addr, length;
ulong crc;
@@ -1120,7 +1120,7 @@ int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
#else /* CONFIG_CRC32_VERIFY */
-int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
ulong addr, length;
ulong crc;
@@ -1128,7 +1128,7 @@ int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
ulong vcrc;
int verify;
int ac;
- char **av;
+ char * const *av;
if (argc < 3) {
usage:
@@ -1175,7 +1175,7 @@ int do_mem_crc (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
#endif /* CONFIG_CRC32_VERIFY */
#ifdef CONFIG_CMD_MD5SUM
-int do_md5sum(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_md5sum(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
unsigned long addr, len;
unsigned int i;
@@ -1200,7 +1200,7 @@ int do_md5sum(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
#endif
#ifdef CONFIG_CMD_SHA1
-int do_sha1sum(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_sha1sum(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
unsigned long addr, len;
unsigned int i;
@@ -1225,7 +1225,7 @@ int do_sha1sum(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
#endif
#ifdef CONFIG_CMD_UNZIP
-int do_unzip ( cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_unzip ( cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
unsigned long src, dst;
unsigned long src_len = ~0UL, dst_len = ~0UL;