diff options
| -rw-r--r-- | arch/parisc/Kconfig | 2 | ||||
| -rw-r--r-- | arch/parisc/include/asm/jump_label.h | 43 | ||||
| -rw-r--r-- | arch/parisc/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/parisc/kernel/jump_label.c | 55 | ||||
| -rw-r--r-- | arch/parisc/kernel/vmlinux.lds.S | 3 |
5 files changed, 104 insertions, 0 deletions
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index 26c215570adf..c971256a74d2 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -45,6 +45,8 @@ config PARISC select HAVE_DEBUG_STACKOVERFLOW select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_HASH + select HAVE_ARCH_JUMP_LABEL + select HAVE_ARCH_JUMP_LABEL_RELATIVE select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_TRACEHOOK select HAVE_REGS_AND_STACK_ACCESS_API diff --git a/arch/parisc/include/asm/jump_label.h b/arch/parisc/include/asm/jump_label.h new file mode 100644 index 000000000000..7efb1aa2f7f8 --- /dev/null +++ b/arch/parisc/include/asm/jump_label.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_PARISC_JUMP_LABEL_H +#define _ASM_PARISC_JUMP_LABEL_H + +#ifndef __ASSEMBLY__ + +#include <linux/types.h> +#include <asm/assembly.h> + +#define JUMP_LABEL_NOP_SIZE 4 + +static __always_inline bool arch_static_branch(struct static_key *key, bool branch) +{ + asm_volatile_goto("1:\n\t" + "nop\n\t" + ".pushsection __jump_table, \"aw\"\n\t" + ".word 1b - ., %l[l_yes] - .\n\t" + __stringify(ASM_ULONG_INSN) " %c0 - .\n\t" + ".popsection\n\t" + : : "i" (&((char *)key)[branch]) : : l_yes); + + return false; +l_yes: + return true; +} + +static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch) +{ + asm_volatile_goto("1:\n\t" + "b,n %l[l_yes]\n\t" + ".pushsection __jump_table, \"aw\"\n\t" + ".word 1b - ., %l[l_yes] - .\n\t" + __stringify(ASM_ULONG_INSN) " %c0 - .\n\t" + ".popsection\n\t" + : : "i" (&((char *)key)[branch]) : : l_yes); + + return false; +l_yes: + return true; +} + +#endif /* __ASSEMBLY__ */ +#endif diff --git a/arch/parisc/kernel/Makefile b/arch/parisc/kernel/Makefile index b818b28c8a99..fc0df5c44468 100644 --- a/arch/parisc/kernel/Makefile +++ b/arch/parisc/kernel/Makefile @@ -33,5 +33,6 @@ obj-$(CONFIG_64BIT) += perf.o perf_asm.o $(obj64-y) obj-$(CONFIG_PARISC_CPU_TOPOLOGY) += topology.o obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o +obj-$(CONFIG_JUMP_LABEL) += jump_label.o obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_KPROBES) += kprobes.o diff --git a/arch/parisc/kernel/jump_label.c b/arch/parisc/kernel/jump_label.c new file mode 100644 index 000000000000..d2f3cb12e282 --- /dev/null +++ b/arch/parisc/kernel/jump_label.c @@ -0,0 +1,55 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019 Helge Deller <deller@gmx.de> + * + * Based on arch/arm64/kernel/jump_label.c + */ +#include <linux/kernel.h> +#include <linux/jump_label.h> +#include <linux/bug.h> +#include <asm/alternative.h> +#include <asm/patch.h> + +static inline int reassemble_17(int as17) +{ + return (((as17 & 0x10000) >> 16) | + ((as17 & 0x0f800) << 5) | + ((as17 & 0x00400) >> 8) | + ((as17 & 0x003ff) << 3)); +} + +void arch_jump_label_transform(struct jump_entry *entry, + enum jump_label_type type) +{ + void *addr = (void *)jump_entry_code(entry); + u32 insn; + + if (type == JUMP_LABEL_JMP) { + void *target = (void *)jump_entry_target(entry); + int distance = target - addr; + /* + * Encode the PA1.1 "b,n" instruction with a 17-bit + * displacement. In case we hit the BUG(), we could use + * another branch instruction with a 22-bit displacement on + * 64-bit CPUs instead. But this seems sufficient for now. + */ + distance -= 8; + BUG_ON(distance > 262143 || distance < -262144); + insn = 0xe8000002 | reassemble_17(distance >> 2); + } else { + insn = INSN_NOP; + } + + patch_text(addr, insn); +} + +void arch_jump_label_transform_static(struct jump_entry *entry, + enum jump_label_type type) +{ + /* + * We use the architected NOP in arch_static_branch, so there's no + * need to patch an identical NOP over the top of it here. The core + * will call arch_jump_label_transform from a module notifier if the + * NOP needs to be replaced by a branch. + */ +} diff --git a/arch/parisc/kernel/vmlinux.lds.S b/arch/parisc/kernel/vmlinux.lds.S index c3b1b9c24ede..a8be7a47fcc0 100644 --- a/arch/parisc/kernel/vmlinux.lds.S +++ b/arch/parisc/kernel/vmlinux.lds.S @@ -18,6 +18,9 @@ *(.data..vm0.pgd) \ *(.data..vm0.pte) +/* No __ro_after_init data in the .rodata section - which will always be ro */ +#define RO_AFTER_INIT_DATA + #include <asm-generic/vmlinux.lds.h> /* needed for the processor specific cache alignment size */ |
