path: root/arch/powerpc/cpu/mpc5xxx
diff options
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/powerpc/cpu/mpc5xxx
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 'arch/powerpc/cpu/mpc5xxx')
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/cpu/mpc5xxx/cpu.c b/arch/powerpc/cpu/mpc5xxx/cpu.c
index 44b8a7a6d..0c1eebd4e 100644
--- a/arch/powerpc/cpu/mpc5xxx/cpu.c
+++ b/arch/powerpc/cpu/mpc5xxx/cpu.c
@@ -78,7 +78,7 @@ int checkcpu (void)
/* ------------------------------------------------------------------------- */
-do_reset (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
+do_reset (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
ulong msr;
/* Interrupts and MMU off */
diff --git a/arch/powerpc/cpu/mpc5xxx/interrupts.c b/arch/powerpc/cpu/mpc5xxx/interrupts.c
index 16eee3a48..50455d07a 100644
--- a/arch/powerpc/cpu/mpc5xxx/interrupts.c
+++ b/arch/powerpc/cpu/mpc5xxx/interrupts.c
@@ -311,7 +311,7 @@ void irq_free_handler(int irq)
#if defined(CONFIG_CMD_IRQ)
-void do_irqinfo(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char *argv[])
+void do_irqinfo(cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char * const argv[])
int irq, re_enable;
u32 intr_ctrl;