Commit 69b420ed authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

lkdtm: Force do_nothing() out of line 



LKDTM tests display that the run do_nothing() at a given
address, but in reality do_nothing() is inlined into the
caller.

Force it out of line so that it really runs text at the
displayed address.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a5dcf4d2088e6aca47ab3b4c6d5c0f7fa064e25a.1644928018.git.christophe.leroy@csgroup.eu
parent e1478d8e

drivers/misc/lkdtm/perms.c

+2 −2
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ 
/* This is non-const, so it will end up in the .data section. */

static u8 data_area[EXEC_SIZE];



/* This is cost, so it will end up in the .rodata section. */

/* This is const, so it will end up in the .rodata section. */

static const unsigned long rodata = 0xAA55AA55;



/* This is marked __ro_after_init, so it should ultimately be .rodata. */
@@ -31,7 +31,7 @@ static unsigned long ro_after_init __ro_after_init = 0x55AA5500; 
 * This just returns to the caller. It is designed to be copied into

 * non-executable memory regions.

 */

static void do_nothing(void)

static noinline void do_nothing(void)

{

	return;

}