From 13ddb52c165ba47d153b7b040931a5cbe9220866 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 18 Sep 2018 23:51:44 -0700 Subject: s390/jump_label: Switch to relative references Enable support for relative references in jump_label entries. Signed-off-by: Heiko Carstens Signed-off-by: Ard Biesheuvel Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Cc: linux-arm-kernel@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: Arnd Bergmann Cc: Kees Cook Cc: Will Deacon Cc: Catalin Marinas Cc: Steven Rostedt Cc: Martin Schwidefsky Cc: Jessica Yu Link: https://lkml.kernel.org/r/20180919065144.25010-10-ard.biesheuvel@linaro.org --- arch/s390/Kconfig | 1 + arch/s390/include/asm/jump_label.h | 40 +++++++++++++++----------------------- arch/s390/kernel/jump_label.c | 11 ++++++----- 3 files changed, 23 insertions(+), 29 deletions(-) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 9a9c7a6fe925..12dc4c1af96c 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -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 diff --git a/arch/s390/include/asm/jump_label.h b/arch/s390/include/asm/jump_label.h index 40f651292aa7..e2d3e6c43395 100644 --- a/arch/s390/include/asm/jump_label.h +++ b/arch/s390/include/asm/jump_label.h @@ -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" - ".popsection\n" - : : "X" (&((char *)key)[branch]) : : label); - + asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n" + ".pushsection __jump_table,\"aw\"\n" + ".balign 8\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" - ".popsection\n" - : : "X" (&((char *)key)[branch]) : : label); - + asm_volatile_goto("0: brcl 15,%l[label]\n" + ".pushsection __jump_table,\"aw\"\n" + ".balign 8\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 diff --git a/arch/s390/kernel/jump_label.c b/arch/s390/kernel/jump_label.c index 43f8430fb67d..50a1798604a8 100644 --- a/arch/s390/kernel/jump_label.c +++ b/arch/s390/kernel/jump_label.c @@ -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) -- cgit