| Message ID | b353a85e50ac336c385b46459a5fc43f4a6171ac.1633964380.git.christophe.leroy@csgroup.eu (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Fix LKDTM for PPC64/IA64/PARISC | expand |
On Mon, Oct 11, 2021 at 05:25:34PM +0200, Christophe Leroy wrote: > 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 <christophe.leroy@csgroup.eu> Acked-by: Kees Cook <keescook@chromium.org>
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; }
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 <christophe.leroy@csgroup.eu> --- drivers/misc/lkdtm/perms.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)