Commit 2b6ff7de authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

x86/ibt: Dont generate ENDBR in .discard.text 



Having ENDBR in discarded sections can easily lead to relocations into
discarded sections which the linkers aren't really fond of. Objtool
also shouldn't generate them, but why tempt fate.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.054842742@infradead.org
parent e8d61bdf

arch/x86/include/asm/setup.h

+2 −1
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 


#include <linux/linkage.h>

#include <asm/page_types.h>

#include <asm/ibt.h>



#ifdef __i386__
@@ -119,7 +120,7 @@ void *extend_brk(size_t size, size_t align); 
 * executable.)

 */

#define RESERVE_BRK(name,sz)						\

	static void __section(".discard.text") __used notrace		\

	static void __section(".discard.text") __noendbr __used notrace	\

	__brk_reservation_fn_##name##__(void) {				\

		asm volatile (						\

			".pushsection .brk_reservation,\"aw\",@nobits;" \