env: fix potential stack overflow in environment functions
Most of the various environment functions create CONFIG_ENV_SIZE buffers on
the stack. At least on ARM and PPC which have 4KB stacks, this can overflow
the stack if we have large environment sizes. So move all the buffers off
the stack to static buffers.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
diff --git a/common/env_dataflash.c b/common/env_dataflash.c
index 38c9615..0591b99 100644
--- a/common/env_dataflash.c
+++ b/common/env_dataflash.c
@@ -30,6 +30,7 @@
env_t *env_ptr;
char *env_name_spec = "dataflash";
+static char env_buf[CONFIG_ENV_SIZE];
uchar env_get_char_spec(int index)
{
@@ -42,11 +43,9 @@
void env_relocate_spec(void)
{
- char buf[CONFIG_ENV_SIZE];
+ read_dataflash(CONFIG_ENV_ADDR, CONFIG_ENV_SIZE, env_buf);
- read_dataflash(CONFIG_ENV_ADDR, CONFIG_ENV_SIZE, buf);
-
- env_import(buf, 1);
+ env_import(env_buf, 1);
}
#ifdef CONFIG_ENV_OFFSET_REDUND
@@ -55,20 +54,20 @@
int saveenv(void)
{
- env_t env_new;
+ env_t *env_new = (env_t *)env_buf;
ssize_t len;
char *res;
- res = (char *)&env_new.data;
+ res = (char *)env_new->data;
len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
if (len < 0) {
error("Cannot export environment: errno = %d\n", errno);
return 1;
}
- env_new.crc = crc32(0, env_new.data, ENV_SIZE);
+ env_new->crc = crc32(0, env_new->data, ENV_SIZE);
return write_dataflash(CONFIG_ENV_ADDR,
- (unsigned long)&env_new,
+ (unsigned long)env_new,
CONFIG_ENV_SIZE);
}