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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 /arch/arm
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 'arch/arm')
-rw-r--r--arch/arm/cpu/arm_cortexa8/mx51/clock.c2
-rw-r--r--arch/arm/cpu/arm_cortexa8/omap3/board.c2
-rw-r--r--arch/arm/lib/bootm.c2
-rw-r--r--arch/arm/lib/reset.c2
4 files changed, 4 insertions, 4 deletions
diff --git a/arch/arm/cpu/arm_cortexa8/mx51/clock.c b/arch/arm/cpu/arm_cortexa8/mx51/clock.c
index 38480ac..a27227d 100644
--- a/arch/arm/cpu/arm_cortexa8/mx51/clock.c
+++ b/arch/arm/cpu/arm_cortexa8/mx51/clock.c
@@ -269,7 +269,7 @@ u32 imx_get_fecclk(void)
/*
* Dump some core clockes.
*/
-int do_mx51_showclocks(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_mx51_showclocks(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
u32 freq;
diff --git a/arch/arm/cpu/arm_cortexa8/omap3/board.c b/arch/arm/cpu/arm_cortexa8/omap3/board.c
index d2500ca..69e56f5 100644
--- a/arch/arm/cpu/arm_cortexa8/omap3/board.c
+++ b/arch/arm/cpu/arm_cortexa8/omap3/board.c
@@ -282,7 +282,7 @@ void abort(void)
/******************************************************************************
* OMAP3 specific command to switch between NAND HW and SW ecc
*****************************************************************************/
-static int do_switch_ecc(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
+static int do_switch_ecc(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
if (argc != 2)
goto usage;
diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index 5ac1302..3101321 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -50,7 +50,7 @@ static void setup_end_tag (bd_t *bd);
static struct tag *params;
#endif /* CONFIG_SETUP_MEMORY_TAGS || CONFIG_CMDLINE_TAG || CONFIG_INITRD_TAG */
-int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images)
+int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t *images)
{
bd_t *bd = gd->bd;
char *s;
diff --git a/arch/arm/lib/reset.c b/arch/arm/lib/reset.c
index 4fcedfa..08e6acb 100644
--- a/arch/arm/lib/reset.c
+++ b/arch/arm/lib/reset.c
@@ -39,7 +39,7 @@
#include <common.h>
-int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
puts ("resetting ...\n");