Hello Ahmad,
On 31.01.24 18:15, Ahmad Fatoum wrote:
Hello Stefan,
On 31.01.24 17:56, Stefan Kerkmann wrote:
If the reallocation failed the old memory remains allocated and is never
freed, this is fixed by freeing the old memory on error.
Signed-off-by: Stefan Kerkmann <s.kerkmann@xxxxxxxxxxxxxx>
---
drivers/of/fdt.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 5c21bab5de..4f79a6120f 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -375,24 +375,37 @@ static void *memalign_realloc(void *orig, size_t oldsize, size_t newsize)
static int fdt_ensure_space(struct fdt *fdt, int dtsize)
{
+ size_t new_size;
+ void *previous;
+
/*
* We assume strings and names have a maximum length of 1024
* whereas properties can be longer. We allocate new memory
* if we have less than 1024 bytes (+ the property size left.
*/
if (fdt->str_size - fdt->str_nextofs < 1024) {
- fdt->strings = realloc(fdt->strings, fdt->str_size * 2);
- if (!fdt->strings)
+ previous = fdt->strings;
+ new_size = fdt->str_size * 2;
+
+ if ((fdt->strings = realloc(previous, new_size)) == NULL) {
IMO, it's less readable this way. I'd prefer we leave the realloc line and
then !fdt->strings check on separate lines as before.
Applied.
+ free(previous);
This could happen later in the callers (look for out_free) if one wouldn't
set fdt->strings to NULL on error. I don't feel strongly either way, so doing
it this way is fine too.
Freeing the previous memory should happen in this function IMHO. In this
way `fdt->[strings|dt]` can be set to `NULL` and the caller will get a
segfaulty reminder if they choose to ignore error returned from the
function and still access `fdt->[strings|dt]`.
Change looks good otherwise, so with first comment addressed:
Thank you :-).
Reviewed-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
Cheers,
Ahmad
return -ENOMEM;
- fdt->str_size *= 2;
+ }
+
+ fdt->str_size = new_size;
}
if (fdt->dt_size - fdt->dt_nextofs < 1024 + dtsize) {
- fdt->dt = memalign_realloc(fdt->dt, fdt->dt_size,
- fdt->dt_size * 2);
- if (!fdt->dt)
+ previous = fdt->dt;
+ new_size = fdt->dt_size * 2;
+
+ if ((fdt->dt = memalign_realloc(previous, fdt->dt_size,
+ new_size)) == NULL) {
+ free(previous);
return -ENOMEM;
- fdt->dt_size *= 2;
+ }
+
+ fdt->dt_size = new_size;
}
return 0;
Cheers
Stefan
--
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