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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 /board/esd/cpci405
parentb218ccb5435e64ac2318bb8b6c9594ef1cc724cd (diff)
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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 'board/esd/cpci405')
-rw-r--r--board/esd/cpci405/cpci405.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/board/esd/cpci405/cpci405.c b/board/esd/cpci405/cpci405.c
index 24db883..51d3355 100644
--- a/board/esd/cpci405/cpci405.c
+++ b/board/esd/cpci405/cpci405.c
@@ -32,7 +32,7 @@
DECLARE_GLOBAL_DATA_PTR;
-extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
+extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
extern void __ft_board_setup(void *blob, bd_t *bd);
#undef FPGA_DEBUG
@@ -650,7 +650,7 @@ int OWReadByte(void)
return result;
}
-int do_onewire(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_onewire(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
unsigned short val;
int result;
@@ -698,7 +698,7 @@ U_BOOT_CMD(
/*
* Write backplane ip-address...
*/
-int do_get_bpip(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_get_bpip(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
bd_t *bd = gd->bd;
char *buf;
@@ -756,7 +756,7 @@ U_BOOT_CMD(
/*
* Set and print backplane ip...
*/
-int do_set_bpip(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_set_bpip(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
char *buf;
char str[32];