s390/jump_label: Switch to relative references (13ddb52c) · Commits · 戴 / test

arch/s390/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -120,6 +120,7 @@ config S390
		select HAVE_ALIGNED_STRUCT_PAGE if SLUB
		select HAVE_ARCH_AUDITSYSCALL
		select HAVE_ARCH_JUMP_LABEL
		select HAVE_ARCH_JUMP_LABEL_RELATIVE
		select CPU_NO_EFFICIENT_FFS if !HAVE_MARCH_Z9_109_FEATURES
		select HAVE_ARCH_SECCOMP_FILTER
		select HAVE_ARCH_SOFT_DIRTY

+16 −24

Original line number	Diff line number	Diff line
		@@ -14,41 +14,33 @@
		* We use a brcl 0,2 instruction for jump labels at compile time so it
		* can be easily distinguished from a hotpatch generated instruction.
		*/
		static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
		static inline bool arch_static_branch(struct static_key *key, bool branch)
		{
		asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n"
		".pushsection __jump_table,\"aw\"\n"
		".balign 8\n"
		".quad 0b, %l[label], %0\n"
		".long 0b-.,%l[label]-.\n"
		".quad %0-.\n"
		".popsection\n"
		: : "X" (&((char *)key)[branch]) : : label);

		return false;
		label:
		return true;
		}

		static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
		static inline bool arch_static_branch_jump(struct static_key *key, bool branch)
		{
		asm_volatile_goto("0: brcl 15,%l[label]\n"
		".pushsection __jump_table,\"aw\"\n"
		".balign 8\n"
		".quad 0b, %l[label], %0\n"
		".long 0b-.,%l[label]-.\n"
		".quad %0-.\n"
		".popsection\n"
		: : "X" (&((char *)key)[branch]) : : label);

		return false;
		label:
		return true;
		}

		typedef unsigned long jump_label_t;

		struct jump_entry {
		jump_label_t code;
		jump_label_t target;
		jump_label_t key;
		};

		#endif /* __ASSEMBLY__ */
		#endif

+6 −5

Original line number	Diff line number	Diff line
		@@ -33,13 +33,13 @@ static void jump_label_make_branch(struct jump_entry entry, struct insn insn)
		{
		/* brcl 15,offset */
		insn->opcode = 0xc0f4;
		insn->offset = (entry->target - entry->code) >> 1;
		insn->offset = (jump_entry_target(entry) - jump_entry_code(entry)) >> 1;
		}

		static void jump_label_bug(struct jump_entry entry, struct insn expected,
		struct insn *new)
		{
		unsigned char ipc = (unsigned char )entry->code;
		unsigned char ipc = (unsigned char )jump_entry_code(entry);
		unsigned char ipe = (unsigned char )expected;
		unsigned char ipn = (unsigned char )new;

		@@ -59,6 +59,7 @@ static void __jump_label_transform(struct jump_entry *entry,
		enum jump_label_type type,
		int init)
		{
		void code = (void )jump_entry_code(entry);
		struct insn old, new;

		if (type == JUMP_LABEL_JMP) {
		@@ -69,13 +70,13 @@ static void __jump_label_transform(struct jump_entry *entry,
		jump_label_make_nop(entry, &new);
		}
		if (init) {
		if (memcmp((void *)entry->code, &orignop, sizeof(orignop)))
		if (memcmp(code, &orignop, sizeof(orignop)))
		jump_label_bug(entry, &orignop, &new);
		} else {
		if (memcmp((void *)entry->code, &old, sizeof(old)))
		if (memcmp(code, &old, sizeof(old)))
		jump_label_bug(entry, &old, &new);
		}
		s390_kernel_write((void *)entry->code, &new, sizeof(new));
		s390_kernel_write(code, &new, sizeof(new));
		}

		static int __sm_arch_jump_label_transform(void *data)