path: root/arch/powerpc/cpu/mpc86xx
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/mpc86xx
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/mpc86xx')
3 files changed, 3 insertions, 3 deletions
diff --git a/arch/powerpc/cpu/mpc86xx/cpu.c b/arch/powerpc/cpu/mpc86xx/cpu.c
index 188757587..9064e7803 100644
--- a/arch/powerpc/cpu/mpc86xx/cpu.c
+++ b/arch/powerpc/cpu/mpc86xx/cpu.c
@@ -124,7 +124,7 @@ 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[])
volatile immap_t *immap = (immap_t *)CONFIG_SYS_IMMR;
volatile ccsr_gur_t *gur = &immap->im_gur;
diff --git a/arch/powerpc/cpu/mpc86xx/interrupts.c b/arch/powerpc/cpu/mpc86xx/interrupts.c
index c78fc7225..d8ad6d30d 100644
--- a/arch/powerpc/cpu/mpc86xx/interrupts.c
+++ b/arch/powerpc/cpu/mpc86xx/interrupts.c
@@ -101,7 +101,7 @@ void irq_free_handler(int vec)
* irqinfo - print information about PCI devices,not implemented.
-int do_irqinfo(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+int do_irqinfo(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
return 0;
diff --git a/arch/powerpc/cpu/mpc86xx/mp.c b/arch/powerpc/cpu/mpc86xx/mp.c
index b4a0faacd..24eb30aaa 100644
--- a/arch/powerpc/cpu/mpc86xx/mp.c
+++ b/arch/powerpc/cpu/mpc86xx/mp.c
@@ -66,7 +66,7 @@ int cpu_disable(int nr)
return 0;
-int cpu_release(int nr, int argc, char *argv[])
+int cpu_release(int nr, int argc, char * const argv[])
/* dummy function so common/cmd_mp.c will build
* should be implemented in the future */