Hi Simon,
On Thu, Feb 01, 2018 at 10:16:46AM +0100, Simon Goldschmidt wrote:
On 01.02.2018 00:00, York Sun wrote:
On 01/30/2018 10:57 PM, Simon Goldschmidt wrote:
env_get_f calls env_get_char to load single characters from the environment. However, the return value of env_get_char was not checked for errors. Now if the env driver does not support the .get_char call, env_get_f did not notice this and looped over the whole size of the environment, calling env_get_char over 8000 times with the default settings, just to return an error in the end.
Fix this by checking if env_get_char returns < 0.
Signed-off-by: Simon Goldschmidt sgoldschmidt@de.pepperl-fuchs.com
cmd/nvedit.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/cmd/nvedit.c b/cmd/nvedit.c index a690d743cd..4cb25b8248 100644 --- a/cmd/nvedit.c +++ b/cmd/nvedit.c @@ -650,12 +650,14 @@ char *env_get(const char *name) */ int env_get_f(const char *name, char *buf, unsigned len) {
- int i, nxt;
- int i, nxt, c; for (i = 0; env_get_char(i) != '\0'; i = nxt + 1) { int val, n;
for (nxt = i; env_get_char(nxt) != '\0'; ++nxt) {
for (nxt = i; (c = env_get_char(nxt)) != '\0'; ++nxt) {if (c < 0)return c; if (nxt >= CONFIG_ENV_SIZE) return -1;@@ -666,7 +668,10 @@ int env_get_f(const char *name, char *buf, unsigned len) /* found; copy out */ for (n = 0; n < len; ++n, ++buf) {
*buf = env_get_char(val++);
c = env_get_char(val++);if (c < 0)return c;*buf = c; if (*buf == '\0') return n;Simon,
This patch looks correct. But it doesn't fix NOR flash. Do you have plan to add .get_char function to other drivers? Without that function, we cannot get env variables before relocation.
Ehrm, sorry I don't plan to do that, no: my target seems to run fine without this.
Given that only the eeprom and nvram env drivers support the get_char method, I don't know if this is widely used at all. Maybe a better fallback would be to just remove that get_char code path totally and always load from the internal (default) environment until the full environment is available (after relocation).
After all, the environment variables loaded via get_char are not CRC checked at all. To me, this is another indication that this code is not really useful and should probably be removed.
To be honest, I'm not really sure what get_char was here for in the first place, so getting rid of it sounds like a good idea :)
Maxime