From: Christophe Leroy Date: Tue, 15 Feb 2022 12:41:05 +0000 (+0100) Subject: lkdtm: Force do_nothing() out of line X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=69b420ed8fd3917ac7073256b4929aa246b6fe31;p=linux.git 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: Christophe Leroy Acked-by: Kees Cook Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/a5dcf4d2088e6aca47ab3b4c6d5c0f7fa064e25a.1644928018.git.christophe.leroy@csgroup.eu --- diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c index 2dede2ef658f3..60b3b2fe929d8 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; }