What could cause this pointer to be corrupted? [closed] - c

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First of all, this code is running without any issue on my linux desktop pc (x86_64) but on my Cyclone v (arm cpu/fpga), I have a segmentation fault because the value of the pointer is changing. The relevant line is the last one, during the for loop, the value of "layer->filename" is changing, it is correct during the first iteration (the address given by malloc) but it changes on the second one.
Basically, this bit of code is copying character from "buff" to "layer->filename", as you can see in the output file, the value of buff[i] is a valid character so it should not corrupt layer->filename.
If you have an idea of what could cause this issue, please let me know.
Thank you for your help.
typedef enum
{
CONV,
BN,
FC,
} layer_type;
typedef struct layer{
layer_type layer_type;
int shape[3];
char *filename;
} layer;
...
layer *layer=malloc(sizeof(layer));
char buff[30];
int i;
...
layer->filename = malloc(sizeof(char)*(n+1));
if(buff[0]=='b')
layer->layer_type=BN;
else if(buff[0]=='c')
layer->layer_type=CONV;
else
layer->layer_type=FC;
for(i=0; i<n ; i++)
*(layer->filename+i)=buff[i];
values of buff[i] and layer->name during the loop

Answer 1

Using this code
#include <stdio.h>
#include <stdlib.h>
typedef enum
{
CONV,
BN,
FC,
} layer_type;
typedef struct layer{
layer_type layer_type;
int shape[3];
char *filename;
} layer;
size_t test(size_t x) {
printf("%d\n", (int)x);
return x;
}
int main(void) {
layer *layer=malloc(test(sizeof(layer)));
return 0;
}
You can see that sizeof(layer) in the line
layer *layer=malloc(sizeof(layer));
is not the size of a structure but the size of a pointer.
This is because the name of variable is the same as the type name and the compiler treated layer in sizeof as the variable (pointer) name.
To avoid this and have it allocate the size of structure, you should change the name of type or variable to avoid confusion.
Dereferincing the pointer
layer *layer=malloc(sizeof(*layer));
also can solve this problem, but I think renaming is better.