Commit 5fc77b91 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

x86/segment: Remove .fixup usage 



Create and use EX_TYPE_ZERO_REG to clear the register and retry the
segment load on exception.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20211110101325.663529463@infradead.org
parent 1c3b9091

arch/x86/include/asm/extable_fixup_types.h

+1 −0
Original line number Diff line number Diff line
@@ -45,5 +45,6 @@ 


#define	EX_TYPE_IMM_REG			17 /* reg := (long)imm */

#define	EX_TYPE_EFAULT_REG		(EX_TYPE_IMM_REG | EX_DATA_IMM(-EFAULT))

#define	EX_TYPE_ZERO_REG		(EX_TYPE_IMM_REG | EX_DATA_IMM(0))



#endif

arch/x86/include/asm/segment.h

+1 −8
Original line number Diff line number Diff line
@@ -307,14 +307,7 @@ do { \ 
									\

	asm volatile("						\n"	\

		     "1:	movl %k0,%%" #seg "		\n"	\

									\

		     ".section .fixup,\"ax\"			\n"	\

		     "2:	xorl %k0,%k0			\n"	\

		     "		jmp 1b				\n"	\

		     ".previous					\n"	\

									\

		     _ASM_EXTABLE(1b, 2b)				\

									\

		     _ASM_EXTABLE_TYPE_REG(1b, 1b, EX_TYPE_ZERO_REG, %k0)\

		     : "+r" (__val) : : "memory");			\

} while (0)