compiler.h: Introduce absolute_pointer macro

absolute_pointer() disassociates a pointer from its originating symbol
type and context. Use it to prevent compiler warnings/errors such as

  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]

Such warnings may be reported by gcc 11.x for string and memory
operations on fixed addresses.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Guenter Roeck 2021-09-14 20:52:24 -07:00 committed by Linus Torvalds
parent 6880fa6c56
commit f6b5f1a569
1 changed files with 2 additions and 0 deletions

View File

@ -188,6 +188,8 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
(typeof(ptr)) (__ptr + (off)); })
#endif
#define absolute_pointer(val) RELOC_HIDE((void *)(val), 0)
#ifndef OPTIMIZER_HIDE_VAR
/* Make the optimizer believe the variable can be manipulated arbitrarily. */
#define OPTIMIZER_HIDE_VAR(var) \