diff options
Diffstat (limited to 'arch/riscv/kernel/probes/kprobes.c')
| -rw-r--r-- | arch/riscv/kernel/probes/kprobes.c | 86 |
1 files changed, 45 insertions, 41 deletions
diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index 00088dc6da4b..8723390c7cad 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -1,15 +1,18 @@ // SPDX-License-Identifier: GPL-2.0+ +#define pr_fmt(fmt) "kprobes: " fmt + #include <linux/kprobes.h> #include <linux/extable.h> #include <linux/slab.h> #include <linux/stop_machine.h> +#include <linux/vmalloc.h> #include <asm/ptrace.h> #include <linux/uaccess.h> #include <asm/sections.h> #include <asm/cacheflush.h> #include <asm/bug.h> -#include <asm/patch.h> +#include <asm/text-patching.h> #include "decode-insn.h" @@ -21,13 +24,13 @@ post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *); static void __kprobes arch_prepare_ss_slot(struct kprobe *p) { - unsigned long offset = GET_INSN_LENGTH(p->opcode); + size_t len = GET_INSN_LENGTH(p->opcode); + u32 insn = __BUG_INSN_32; - p->ainsn.api.restore = (unsigned long)p->addr + offset; + p->ainsn.api.restore = (unsigned long)p->addr + len; - patch_text(p->ainsn.api.insn, p->opcode); - patch_text((void *)((unsigned long)(p->ainsn.api.insn) + offset), - __BUG_INSN_32); + patch_text_nosync(p->ainsn.api.insn, &p->opcode, len); + patch_text_nosync((void *)p->ainsn.api.insn + len, &insn, GET_INSN_LENGTH(insn)); } static void __kprobes arch_prepare_simulate(struct kprobe *p) @@ -46,18 +49,40 @@ static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs) post_kprobe_handler(p, kcb, regs); } -int __kprobes arch_prepare_kprobe(struct kprobe *p) +static bool __kprobes arch_check_kprobe(unsigned long addr) { - unsigned long probe_addr = (unsigned long)p->addr; + unsigned long tmp, offset; - if (probe_addr & 0x1) { - pr_warn("Address not aligned.\n"); + /* start iterating at the closest preceding symbol */ + if (!kallsyms_lookup_size_offset(addr, NULL, &offset)) + return false; - return -EINVAL; + tmp = addr - offset; + + while (tmp <= addr) { + if (tmp == addr) + return true; + + tmp += GET_INSN_LENGTH(*(u16 *)tmp); } + return false; +} + +int __kprobes arch_prepare_kprobe(struct kprobe *p) +{ + u16 *insn = (u16 *)p->addr; + + if ((unsigned long)insn & 0x1) + return -EILSEQ; + + if (!arch_check_kprobe((unsigned long)p->addr)) + return -EILSEQ; + /* copy instruction */ - p->opcode = *p->addr; + p->opcode = (kprobe_opcode_t)(*insn++); + if (GET_INSN_LENGTH(p->opcode) == 4) + p->opcode |= (kprobe_opcode_t)(*insn) << 16; /* decode instruction */ switch (riscv_probe_decode_insn(p->addr, &p->ainsn.api)) { @@ -84,29 +109,21 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) return 0; } -#ifdef CONFIG_MMU -void *alloc_insn_page(void) -{ - return __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, VMALLOC_END, - GFP_KERNEL, PAGE_KERNEL_READ_EXEC, - VM_FLUSH_RESET_PERMS, NUMA_NO_NODE, - __builtin_return_address(0)); -} -#endif - /* install breakpoint in text */ void __kprobes arch_arm_kprobe(struct kprobe *p) { - if ((p->opcode & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) - patch_text(p->addr, __BUG_INSN_32); - else - patch_text(p->addr, __BUG_INSN_16); + size_t len = GET_INSN_LENGTH(p->opcode); + u32 insn = len == 4 ? __BUG_INSN_32 : __BUG_INSN_16; + + patch_text(p->addr, &insn, len); } /* remove breakpoint from text */ void __kprobes arch_disarm_kprobe(struct kprobe *p) { - patch_text(p->addr, p->opcode); + size_t len = GET_INSN_LENGTH(p->opcode); + + patch_text(p->addr, &p->opcode, len); } void __kprobes arch_remove_kprobe(struct kprobe *p) @@ -191,7 +208,7 @@ static int __kprobes reenter_kprobe(struct kprobe *p, break; case KPROBE_HIT_SS: case KPROBE_REENTER: - pr_warn("Unrecoverable kprobe detected.\n"); + pr_warn("Failed to recover from reentered kprobes.\n"); dump_kprobe(p); BUG(); break; @@ -346,19 +363,6 @@ int __init arch_populate_kprobe_blacklist(void) return ret; } -void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) -{ - return (void *)kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); -} - -void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, - struct pt_regs *regs) -{ - ri->ret_addr = (kprobe_opcode_t *)regs->ra; - ri->fp = NULL; - regs->ra = (unsigned long) &kretprobe_trampoline; -} - int __kprobes arch_trampoline_kprobe(struct kprobe *p) { return 0; |