On Mon, Sep 06, 2021 at 04:49:21PM -0700, Guenter Roeck wrote:
> On Mon, Sep 06, 2021 at 04:06:04PM -0700, Linus Torvalds wrote:
[ ... ]
> > - at least a couple of stringop-overread errors. Attached is a
> > possible for for one of them.
> >
I keep seeing problems like this.
drivers/net/ethernet/i825xx/82596.c: In function 'i82596_probe':
./arch/m68k/include/asm/string.h:72:25: error: '__builtin_memcpy' reading 6 bytes from a region of size 0 [-Werror=stringop-overread]
72 | #define memcpy(d, s, n) __builtin_memcpy(d, s, n)
| ^~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/ethernet/i825xx/82596.c:1147:17: note: in expansion of macro 'memcpy'
1147 | memcpy(eth_addr, (void *) 0xfffc1f2c, ETH_ALEN); /* YUCK! Get addr from NOVRAM */
| ^~~~~~
cc1: all warnings being treated as errors
It is seen with gcc 11.x whenever a memXXX or strXXX function parameter
is a pointer to a fixed address. gcc is happy if "(void *) 0xfffc1f2c"
is passed to a global function which does nothing but return the address,
such as:
void *sanitize_address(void *address)
{
return address;
}
and:
memcpy(eth_addr, sanitize_address((void *) 0xfffc1f2c), ETH_ALEN);
but that just seems weird. Is there a better solution ?
Thanks,
Guenter
