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authorWolfgang Denk <wd@denx.de>2010-06-28 20:00:46 (GMT)
committerWolfgang Denk <wd@denx.de>2010-07-04 21:55:42 (GMT)
commit54841ab50c20d6fa6c9cc3eb826989da3a22d934 (patch)
tree400f22f0a12ff0ae6c472bed6ac648befc1744a2 /board/BuS
parentb218ccb5435e64ac2318bb8b6c9594ef1cc724cd (diff)
downloadu-boot-54841ab50c20d6fa6c9cc3eb826989da3a22d934.tar.xz
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/BuS')
-rw-r--r--board/BuS/EB+MCF-EV123/EB+MCF-EV123.c2
-rw-r--r--board/BuS/eb_cpux9k2/cpux9k2.c2
2 files changed, 2 insertions, 2 deletions
diff --git a/board/BuS/EB+MCF-EV123/EB+MCF-EV123.c b/board/BuS/EB+MCF-EV123/EB+MCF-EV123.c
index 2fc3eaf..1f76dd9 100644
--- a/board/BuS/EB+MCF-EV123/EB+MCF-EV123.c
+++ b/board/BuS/EB+MCF-EV123/EB+MCF-EV123.c
@@ -193,7 +193,7 @@ int drv_video_init(void)
/*---------------------------------------------------------------------------*/
#ifdef CONFIG_VIDEO
-int do_brightness(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_brightness(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int rcode = 0;
ulong side;
diff --git a/board/BuS/eb_cpux9k2/cpux9k2.c b/board/BuS/eb_cpux9k2/cpux9k2.c
index 1f22275..bbceaf3 100644
--- a/board/BuS/eb_cpux9k2/cpux9k2.c
+++ b/board/BuS/eb_cpux9k2/cpux9k2.c
@@ -348,7 +348,7 @@ void __led_set(led_id_t mask, int state)
/*---------------------------------------------------------------------------*/
-int do_brightness(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_brightness(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
int rcode = 0;
ulong side;