[PATCH v1 07/10] lkdtm: Force do_nothing() out of line
From: Christophe Leroy <hidden>
Date: 2021-10-11 15:27:31
Also in:
linux-arch, linux-mm, lkml
Subsystem:
char and misc drivers, linux kernel dump test module (lkdtm), the rest · Maintainers:
Arnd Bergmann, Greg Kroah-Hartman, Kees Cook, Linus Torvalds
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: Christophe Leroy <redacted> --- drivers/misc/lkdtm/perms.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c
index 2dede2ef658f..60b3b2fe929d 100644
--- a/drivers/misc/lkdtm/perms.c
+++ b/drivers/misc/lkdtm/perms.c@@ -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; }
--
2.31.1