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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/powerpc/cpu/mpc83xx
parentb218ccb5435e64ac2318bb8b6c9594ef1cc724cd (diff)
downloadu-boot-linaro-stable-54841ab50c20d6fa6c9cc3eb826989da3a22d934.tar.gz
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/mpc83xx')
-rw-r--r--arch/powerpc/cpu/mpc83xx/cpu.c2
-rw-r--r--arch/powerpc/cpu/mpc83xx/ecc.c2
-rw-r--r--arch/powerpc/cpu/mpc83xx/interrupts.c2
-rw-r--r--arch/powerpc/cpu/mpc83xx/speed.c2
4 files changed, 4 insertions, 4 deletions
diff --git a/arch/powerpc/cpu/mpc83xx/cpu.c b/arch/powerpc/cpu/mpc83xx/cpu.c
index d3be90976..b664c641a 100644
--- a/arch/powerpc/cpu/mpc83xx/cpu.c
+++ b/arch/powerpc/cpu/mpc83xx/cpu.c
@@ -192,7 +192,7 @@ void upmconfig (uint upm, uint *table, uint size)
int
-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;
#ifndef MPC83xx_RESET
diff --git a/arch/powerpc/cpu/mpc83xx/ecc.c b/arch/powerpc/cpu/mpc83xx/ecc.c
index f3942b411..8dadd64b4 100644
--- a/arch/powerpc/cpu/mpc83xx/ecc.c
+++ b/arch/powerpc/cpu/mpc83xx/ecc.c
@@ -98,7 +98,7 @@ void ecc_print_status(void)
ddr->capture_attributes & ECC_CAPT_ATTR_VLD);
}
-int do_ecc(cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
+int do_ecc(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
volatile ddr83xx_t *ddr = &immap->ddr;
diff --git a/arch/powerpc/cpu/mpc83xx/interrupts.c b/arch/powerpc/cpu/mpc83xx/interrupts.c
index faffbaf83..446af27c6 100644
--- a/arch/powerpc/cpu/mpc83xx/interrupts.c
+++ b/arch/powerpc/cpu/mpc83xx/interrupts.c
@@ -90,7 +90,7 @@ void timer_interrupt_cpu (struct pt_regs *regs)
*/
void
-do_irqinfo(cmd_tbl_t *cmdtp, bd_t *bd, int flag, int argc, char *argv[])
+do_irqinfo(cmd_tbl_t *cmdtp, bd_t *bd, int flag, int argc, char * const argv[])
{
}
diff --git a/arch/powerpc/cpu/mpc83xx/speed.c b/arch/powerpc/cpu/mpc83xx/speed.c
index 500eef1e9..b5076a9af 100644
--- a/arch/powerpc/cpu/mpc83xx/speed.c
+++ b/arch/powerpc/cpu/mpc83xx/speed.c
@@ -497,7 +497,7 @@ ulong get_bus_freq(ulong dummy)
return gd->csb_clk;
}
-int do_clocks (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
+int do_clocks (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
{
char buf[32];