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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/m68k/cpu/mcf52x2/cpu.c
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/m68k/cpu/mcf52x2/cpu.c')
-rw-r--r--arch/m68k/cpu/mcf52x2/cpu.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/arch/m68k/cpu/mcf52x2/cpu.c b/arch/m68k/cpu/mcf52x2/cpu.c
index c4c5d50..9fb717c 100644
--- a/arch/m68k/cpu/mcf52x2/cpu.c
+++ b/arch/m68k/cpu/mcf52x2/cpu.c
@@ -38,7 +38,7 @@
DECLARE_GLOBAL_DATA_PTR;
#ifdef CONFIG_M5208
-int do_reset(cmd_tbl_t *cmdtp, bd_t *bd, int flag, int argc, char *argv[])
+int do_reset(cmd_tbl_t *cmdtp, bd_t *bd, int flag, int argc, char * const argv[])
{
volatile rcm_t *rcm = (rcm_t *)(MMAP_RCM);
@@ -142,7 +142,7 @@ int checkcpu(void)
return 0;
}
-int do_reset(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char *argv[])
+int do_reset(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char * const argv[])
{
/* Call the board specific reset actions first. */
if(board_reset) {
@@ -177,7 +177,7 @@ int watchdog_init(void)
#endif
#ifdef CONFIG_M5272
-int do_reset(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char *argv[])
+int do_reset(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char * const argv[])
{
volatile wdog_t *wdp = (wdog_t *) (MMAP_WDOG);
@@ -257,7 +257,7 @@ int watchdog_init(void)
#endif /* #ifdef CONFIG_M5272 */
#ifdef CONFIG_M5275
-int do_reset(cmd_tbl_t *cmdtp, bd_t *bd, int flag, int argc, char *argv[])
+int do_reset(cmd_tbl_t *cmdtp, bd_t *bd, int flag, int argc, char * const argv[])
{
volatile rcm_t *rcm = (rcm_t *)(MMAP_RCM);
@@ -337,7 +337,7 @@ int checkcpu(void)
return 0;
}
-int do_reset(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char *argv[])
+int do_reset(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char * const argv[])
{
MCFRESET_RCR = MCFRESET_RCR_SOFTRST;
return 0;
@@ -354,7 +354,7 @@ int checkcpu(void)
return 0;
}
-int do_reset(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char *argv[])
+int do_reset(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char * const argv[])
{
/* enable watchdog, set timeout to 0 and wait */
mbar_writeByte(MCFSIM_SYPCR, 0xc0);
@@ -384,7 +384,7 @@ int checkcpu(void)
return 0;
}
-int do_reset(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char *argv[])
+int do_reset(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char * const argv[])
{
/* enable watchdog, set timeout to 0 and wait */
mbar_writeByte(SIM_SYPCR, 0xc0);