ELF Format note (13) -- segment permission, elfformat

ELF Format note (13) -- segment permission, elfformat

Ilocker: Follow Android Security (novice) QQ: 2597294287

A program that can be loaded by the system has at least one loadable segment. When the system creates a memory image with a CIDR block, it grants certain access permissions based on p_flags.

However, the actual memory access permission depends on the MMU (Memory Management Unit) of the system. The access permission granted by the system may be higher than the specified permission.

However, if PF_W is not specified, the system will not grant the write permission.

Segment permission list:

 

We can see that:

With executable permissions, you have the read permission. On the other hand, the system has the read permission, that is, the executable permission.

If you have the write permission, you must have the readable and executable permissions.