riscv: Add kprobes supported
This patch enables "kprobe & kretprobe" to work with ftrace interface. It utilized software breakpoint as single-step mechanism. Some instructions which can't be single-step executed must be simulated in kernel execution slot, such as: branch, jal, auipc, la ... Some instructions should be rejected for probing and we use a blacklist to filter, such as: ecall, ebreak, ... We use ebreak & c.ebreak to replace origin instruction and the kprobe handler prepares an executable memory slot for out-of-line execution with a copy of the original instruction being probed. In execution slot we add ebreak behind original instruction to simulate a single-setp mechanism. The patch is based on packi's work [1] and csky's work [2]. - The kprobes_trampoline.S is all from packi's patch - The single-step mechanism is new designed for riscv without hw single-step trap - The simulation codes are from csky - Frankly, all codes refer to other archs' implementation [1] https://lore.kernel.org/linux-riscv/20181113195804.22825-1-me@packi.ch/ [2] https://lore.kernel.org/linux-csky/20200403044150.20562-9-guoren@kernel.org/ Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Patrick Stählin <me@packi.ch> Signed-off-by: Patrick Stählin <me@packi.ch> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Zong Li <zong.li@sifive.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Cc: Patrick Stählin <me@packi.ch> Cc: Palmer Dabbelt <palmerdabbelt@google.com> Cc: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Guo Ren
Palmer Dabbelt
parent
afc76b8b80
commit
c22b0bcb1d
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@ -71,6 +71,8 @@ config RISCV
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select HAVE_GCC_PLUGINS
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select HAVE_GENERIC_VDSO if MMU && 64BIT
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select HAVE_IRQ_TIME_ACCOUNTING
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select HAVE_KPROBES
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select HAVE_KRETPROBES
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select HAVE_PCI
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select HAVE_PERF_EVENTS
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select HAVE_PERF_REGS
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@ -11,4 +11,44 @@
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#include <asm-generic/kprobes.h>
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#ifdef CONFIG_KPROBES
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#include <linux/types.h>
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#include <linux/ptrace.h>
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#include <linux/percpu.h>
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#define __ARCH_WANT_KPROBES_INSN_SLOT
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#define MAX_INSN_SIZE 2
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#define flush_insn_slot(p) do { } while (0)
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#define kretprobe_blacklist_size 0
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#include <asm/probes.h>
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struct prev_kprobe {
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struct kprobe *kp;
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unsigned int status;
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};
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/* Single step context for kprobe */
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struct kprobe_step_ctx {
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unsigned long ss_pending;
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unsigned long match_addr;
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};
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/* per-cpu kprobe control block */
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struct kprobe_ctlblk {
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unsigned int kprobe_status;
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unsigned long saved_status;
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struct prev_kprobe prev_kprobe;
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struct kprobe_step_ctx ss_ctx;
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};
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void arch_remove_kprobe(struct kprobe *p);
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int kprobe_fault_handler(struct pt_regs *regs, unsigned int trapnr);
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bool kprobe_breakpoint_handler(struct pt_regs *regs);
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bool kprobe_single_step_handler(struct pt_regs *regs);
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void kretprobe_trampoline(void);
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void __kprobes *trampoline_probe_handler(struct pt_regs *regs);
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#endif /* CONFIG_KPROBES */
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#endif /* _ASM_RISCV_KPROBES_H */
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@ -0,0 +1,24 @@
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/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_RISCV_PROBES_H
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#define _ASM_RISCV_PROBES_H
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typedef u32 probe_opcode_t;
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typedef bool (probes_handler_t) (u32 opcode, unsigned long addr, struct pt_regs *);
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/* architecture specific copy of original instruction */
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struct arch_probe_insn {
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probe_opcode_t *insn;
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probes_handler_t *handler;
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/* restore address after simulation */
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unsigned long restore;
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};
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#ifdef CONFIG_KPROBES
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typedef u32 kprobe_opcode_t;
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struct arch_specific_insn {
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struct arch_probe_insn api;
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};
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#endif
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#endif /* _ASM_RISCV_PROBES_H */
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@ -30,6 +30,7 @@ obj-y += riscv_ksyms.o
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obj-y += stacktrace.o
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obj-y += cacheinfo.o
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obj-y += patch.o
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obj-y += probes/
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obj-$(CONFIG_MMU) += vdso.o vdso/
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obj-$(CONFIG_RISCV_M_MODE) += traps_misaligned.o
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@ -0,0 +1,4 @@
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# SPDX-License-Identifier: GPL-2.0
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obj-$(CONFIG_KPROBES) += kprobes.o decode-insn.o simulate-insn.o
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obj-$(CONFIG_KPROBES) += kprobes_trampoline.o
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CFLAGS_REMOVE_simulate-insn.o = $(CC_FLAGS_FTRACE)
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@ -0,0 +1,48 @@
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// SPDX-License-Identifier: GPL-2.0+
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#include <linux/kernel.h>
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#include <linux/kprobes.h>
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#include <linux/module.h>
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#include <linux/kallsyms.h>
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#include <asm/sections.h>
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#include "decode-insn.h"
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#include "simulate-insn.h"
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/* Return:
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* INSN_REJECTED If instruction is one not allowed to kprobe,
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* INSN_GOOD_NO_SLOT If instruction is supported but doesn't use its slot.
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*/
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enum probe_insn __kprobes
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riscv_probe_decode_insn(probe_opcode_t *addr, struct arch_probe_insn *api)
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{
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probe_opcode_t insn = le32_to_cpu(*addr);
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/*
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* Reject instructions list:
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*/
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RISCV_INSN_REJECTED(system, insn);
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RISCV_INSN_REJECTED(fence, insn);
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/*
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* Simulate instructions list:
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* TODO: the REJECTED ones below need to be implemented
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*/
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#ifdef CONFIG_RISCV_ISA_C
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RISCV_INSN_REJECTED(c_j, insn);
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RISCV_INSN_REJECTED(c_jr, insn);
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RISCV_INSN_REJECTED(c_jal, insn);
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RISCV_INSN_REJECTED(c_jalr, insn);
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RISCV_INSN_REJECTED(c_beqz, insn);
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RISCV_INSN_REJECTED(c_bnez, insn);
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RISCV_INSN_REJECTED(c_ebreak, insn);
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#endif
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RISCV_INSN_REJECTED(auipc, insn);
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RISCV_INSN_REJECTED(branch, insn);
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RISCV_INSN_SET_SIMULATE(jal, insn);
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RISCV_INSN_SET_SIMULATE(jalr, insn);
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return INSN_GOOD;
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}
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@ -0,0 +1,18 @@
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/* SPDX-License-Identifier: GPL-2.0+ */
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#ifndef _RISCV_KERNEL_KPROBES_DECODE_INSN_H
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#define _RISCV_KERNEL_KPROBES_DECODE_INSN_H
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#include <asm/sections.h>
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#include <asm/kprobes.h>
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enum probe_insn {
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INSN_REJECTED,
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INSN_GOOD_NO_SLOT,
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INSN_GOOD,
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};
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enum probe_insn __kprobes
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riscv_probe_decode_insn(probe_opcode_t *addr, struct arch_probe_insn *asi);
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#endif /* _RISCV_KERNEL_KPROBES_DECODE_INSN_H */
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@ -0,0 +1,398 @@
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// SPDX-License-Identifier: GPL-2.0+
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#include <linux/kprobes.h>
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#include <linux/extable.h>
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#include <linux/slab.h>
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#include <linux/stop_machine.h>
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#include <asm/ptrace.h>
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#include <linux/uaccess.h>
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#include <asm/sections.h>
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#include <asm/cacheflush.h>
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#include <asm/bug.h>
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#include <asm/patch.h>
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#include "decode-insn.h"
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DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
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DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
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static void __kprobes
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post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *);
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static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
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{
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unsigned long offset = GET_INSN_LENGTH(p->opcode);
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p->ainsn.api.restore = (unsigned long)p->addr + offset;
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patch_text(p->ainsn.api.insn, p->opcode);
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patch_text((void *)((unsigned long)(p->ainsn.api.insn) + offset),
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__BUG_INSN_32);
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}
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static void __kprobes arch_prepare_simulate(struct kprobe *p)
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{
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p->ainsn.api.restore = 0;
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}
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static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs)
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{
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struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
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if (p->ainsn.api.handler)
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p->ainsn.api.handler((u32)p->opcode,
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(unsigned long)p->addr, regs);
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post_kprobe_handler(kcb, regs);
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}
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int __kprobes arch_prepare_kprobe(struct kprobe *p)
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{
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unsigned long probe_addr = (unsigned long)p->addr;
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if (probe_addr & 0x1) {
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pr_warn("Address not aligned.\n");
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return -EINVAL;
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}
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/* copy instruction */
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p->opcode = le32_to_cpu(*p->addr);
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/* decode instruction */
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switch (riscv_probe_decode_insn(p->addr, &p->ainsn.api)) {
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case INSN_REJECTED: /* insn not supported */
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return -EINVAL;
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case INSN_GOOD_NO_SLOT: /* insn need simulation */
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p->ainsn.api.insn = NULL;
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break;
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case INSN_GOOD: /* instruction uses slot */
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p->ainsn.api.insn = get_insn_slot();
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if (!p->ainsn.api.insn)
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return -ENOMEM;
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break;
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}
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/* prepare the instruction */
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if (p->ainsn.api.insn)
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arch_prepare_ss_slot(p);
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else
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arch_prepare_simulate(p);
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return 0;
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}
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/* install breakpoint in text */
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void __kprobes arch_arm_kprobe(struct kprobe *p)
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{
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if ((p->opcode & __INSN_LENGTH_MASK) == __INSN_LENGTH_32)
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patch_text(p->addr, __BUG_INSN_32);
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else
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patch_text(p->addr, __BUG_INSN_16);
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}
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/* remove breakpoint from text */
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void __kprobes arch_disarm_kprobe(struct kprobe *p)
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{
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patch_text(p->addr, p->opcode);
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}
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void __kprobes arch_remove_kprobe(struct kprobe *p)
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{
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}
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static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
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{
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kcb->prev_kprobe.kp = kprobe_running();
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kcb->prev_kprobe.status = kcb->kprobe_status;
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}
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static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
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{
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__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
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kcb->kprobe_status = kcb->prev_kprobe.status;
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}
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static void __kprobes set_current_kprobe(struct kprobe *p)
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{
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__this_cpu_write(current_kprobe, p);
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}
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/*
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* Interrupts need to be disabled before single-step mode is set, and not
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* reenabled until after single-step mode ends.
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* Without disabling interrupt on local CPU, there is a chance of
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* interrupt occurrence in the period of exception return and start of
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* out-of-line single-step, that result in wrongly single stepping
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* into the interrupt handler.
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*/
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static void __kprobes kprobes_save_local_irqflag(struct kprobe_ctlblk *kcb,
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struct pt_regs *regs)
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{
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kcb->saved_status = regs->status;
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regs->status &= ~SR_SPIE;
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}
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static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb,
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struct pt_regs *regs)
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{
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regs->status = kcb->saved_status;
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}
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static void __kprobes
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set_ss_context(struct kprobe_ctlblk *kcb, unsigned long addr, struct kprobe *p)
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{
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unsigned long offset = GET_INSN_LENGTH(p->opcode);
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kcb->ss_ctx.ss_pending = true;
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kcb->ss_ctx.match_addr = addr + offset;
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}
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static void __kprobes clear_ss_context(struct kprobe_ctlblk *kcb)
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{
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kcb->ss_ctx.ss_pending = false;
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kcb->ss_ctx.match_addr = 0;
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}
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static void __kprobes setup_singlestep(struct kprobe *p,
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struct pt_regs *regs,
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struct kprobe_ctlblk *kcb, int reenter)
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{
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unsigned long slot;
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if (reenter) {
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save_previous_kprobe(kcb);
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set_current_kprobe(p);
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kcb->kprobe_status = KPROBE_REENTER;
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} else {
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kcb->kprobe_status = KPROBE_HIT_SS;
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}
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if (p->ainsn.api.insn) {
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/* prepare for single stepping */
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slot = (unsigned long)p->ainsn.api.insn;
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set_ss_context(kcb, slot, p); /* mark pending ss */
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/* IRQs and single stepping do not mix well. */
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kprobes_save_local_irqflag(kcb, regs);
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instruction_pointer_set(regs, slot);
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} else {
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/* insn simulation */
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arch_simulate_insn(p, regs);
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}
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}
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static int __kprobes reenter_kprobe(struct kprobe *p,
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struct pt_regs *regs,
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struct kprobe_ctlblk *kcb)
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{
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switch (kcb->kprobe_status) {
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case KPROBE_HIT_SSDONE:
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case KPROBE_HIT_ACTIVE:
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kprobes_inc_nmissed_count(p);
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setup_singlestep(p, regs, kcb, 1);
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break;
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case KPROBE_HIT_SS:
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case KPROBE_REENTER:
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pr_warn("Unrecoverable kprobe detected.\n");
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dump_kprobe(p);
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BUG();
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break;
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default:
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WARN_ON(1);
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return 0;
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}
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return 1;
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}
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static void __kprobes
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post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs)
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{
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struct kprobe *cur = kprobe_running();
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if (!cur)
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return;
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/* return addr restore if non-branching insn */
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if (cur->ainsn.api.restore != 0)
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regs->epc = cur->ainsn.api.restore;
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/* restore back original saved kprobe variables and continue */
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if (kcb->kprobe_status == KPROBE_REENTER) {
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restore_previous_kprobe(kcb);
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return;
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}
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/* call post handler */
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kcb->kprobe_status = KPROBE_HIT_SSDONE;
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if (cur->post_handler) {
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/* post_handler can hit breakpoint and single step
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* again, so we enable D-flag for recursive exception.
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*/
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cur->post_handler(cur, regs, 0);
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}
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reset_current_kprobe();
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}
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int __kprobes kprobe_fault_handler(struct pt_regs *regs, unsigned int trapnr)
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{
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struct kprobe *cur = kprobe_running();
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struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
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switch (kcb->kprobe_status) {
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case KPROBE_HIT_SS:
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case KPROBE_REENTER:
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/*
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* We are here because the instruction being single
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* stepped caused a page fault. We reset the current
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* kprobe and the ip points back to the probe address
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* and allow the page fault handler to continue as a
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* normal page fault.
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*/
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regs->epc = (unsigned long) cur->addr;
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if (!instruction_pointer(regs))
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BUG();
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if (kcb->kprobe_status == KPROBE_REENTER)
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restore_previous_kprobe(kcb);
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else
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reset_current_kprobe();
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break;
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case KPROBE_HIT_ACTIVE:
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case KPROBE_HIT_SSDONE:
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/*
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* We increment the nmissed count for accounting,
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* we can also use npre/npostfault count for accounting
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* these specific fault cases.
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*/
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kprobes_inc_nmissed_count(cur);
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/*
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* We come here because instructions in the pre/post
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* handler caused the page_fault, this could happen
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* if handler tries to access user space by
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* copy_from_user(), get_user() etc. Let the
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* user-specified handler try to fix it first.
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*/
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if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
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return 1;
|
||||
|
||||
/*
|
||||
* In case the user-specified fault handler returned
|
||||
* zero, try to fix up.
|
||||
*/
|
||||
if (fixup_exception(regs))
|
||||
return 1;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
bool __kprobes
|
||||
kprobe_breakpoint_handler(struct pt_regs *regs)
|
||||
{
|
||||
struct kprobe *p, *cur_kprobe;
|
||||
struct kprobe_ctlblk *kcb;
|
||||
unsigned long addr = instruction_pointer(regs);
|
||||
|
||||
kcb = get_kprobe_ctlblk();
|
||||
cur_kprobe = kprobe_running();
|
||||
|
||||
p = get_kprobe((kprobe_opcode_t *) addr);
|
||||
|
||||
if (p) {
|
||||
if (cur_kprobe) {
|
||||
if (reenter_kprobe(p, regs, kcb))
|
||||
return true;
|
||||
} else {
|
||||
/* Probe hit */
|
||||
set_current_kprobe(p);
|
||||
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
|
||||
|
||||
/*
|
||||
* If we have no pre-handler or it returned 0, we
|
||||
* continue with normal processing. If we have a
|
||||
* pre-handler and it returned non-zero, it will
|
||||
* modify the execution path and no need to single
|
||||
* stepping. Let's just reset current kprobe and exit.
|
||||
*
|
||||
* pre_handler can hit a breakpoint and can step thru
|
||||
* before return.
|
||||
*/
|
||||
if (!p->pre_handler || !p->pre_handler(p, regs))
|
||||
setup_singlestep(p, regs, kcb, 0);
|
||||
else
|
||||
reset_current_kprobe();
|
||||
}
|
||||
return true;
|
||||
}
|
||||
|
||||
/*
|
||||
* The breakpoint instruction was removed right
|
||||
* after we hit it. Another cpu has removed
|
||||
* either a probepoint or a debugger breakpoint
|
||||
* at this address. In either case, no further
|
||||
* handling of this interrupt is appropriate.
|
||||
* Return back to original instruction, and continue.
|
||||
*/
|
||||
return false;
|
||||
}
|
||||
|
||||
bool __kprobes
|
||||
kprobe_single_step_handler(struct pt_regs *regs)
|
||||
{
|
||||
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
||||
|
||||
if ((kcb->ss_ctx.ss_pending)
|
||||
&& (kcb->ss_ctx.match_addr == instruction_pointer(regs))) {
|
||||
clear_ss_context(kcb); /* clear pending ss */
|
||||
|
||||
kprobes_restore_local_irqflag(kcb, regs);
|
||||
|
||||
post_kprobe_handler(kcb, regs);
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
/*
|
||||
* Provide a blacklist of symbols identifying ranges which cannot be kprobed.
|
||||
* This blacklist is exposed to userspace via debugfs (kprobes/blacklist).
|
||||
*/
|
||||
int __init arch_populate_kprobe_blacklist(void)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = kprobe_add_area_blacklist((unsigned long)__irqentry_text_start,
|
||||
(unsigned long)__irqentry_text_end);
|
||||
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;
|
||||
}
|
||||
|
||||
int __init arch_init_kprobes(void)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -0,0 +1,93 @@
|
|||
/* SPDX-License-Identifier: GPL-2.0+ */
|
||||
/*
|
||||
* Author: Patrick Stählin <me@packi.ch>
|
||||
*/
|
||||
#include <linux/linkage.h>
|
||||
|
||||
#include <asm/asm.h>
|
||||
#include <asm/asm-offsets.h>
|
||||
|
||||
.text
|
||||
.altmacro
|
||||
|
||||
.macro save_all_base_regs
|
||||
REG_S x1, PT_RA(sp)
|
||||
REG_S x3, PT_GP(sp)
|
||||
REG_S x4, PT_TP(sp)
|
||||
REG_S x5, PT_T0(sp)
|
||||
REG_S x6, PT_T1(sp)
|
||||
REG_S x7, PT_T2(sp)
|
||||
REG_S x8, PT_S0(sp)
|
||||
REG_S x9, PT_S1(sp)
|
||||
REG_S x10, PT_A0(sp)
|
||||
REG_S x11, PT_A1(sp)
|
||||
REG_S x12, PT_A2(sp)
|
||||
REG_S x13, PT_A3(sp)
|
||||
REG_S x14, PT_A4(sp)
|
||||
REG_S x15, PT_A5(sp)
|
||||
REG_S x16, PT_A6(sp)
|
||||
REG_S x17, PT_A7(sp)
|
||||
REG_S x18, PT_S2(sp)
|
||||
REG_S x19, PT_S3(sp)
|
||||
REG_S x20, PT_S4(sp)
|
||||
REG_S x21, PT_S5(sp)
|
||||
REG_S x22, PT_S6(sp)
|
||||
REG_S x23, PT_S7(sp)
|
||||
REG_S x24, PT_S8(sp)
|
||||
REG_S x25, PT_S9(sp)
|
||||
REG_S x26, PT_S10(sp)
|
||||
REG_S x27, PT_S11(sp)
|
||||
REG_S x28, PT_T3(sp)
|
||||
REG_S x29, PT_T4(sp)
|
||||
REG_S x30, PT_T5(sp)
|
||||
REG_S x31, PT_T6(sp)
|
||||
.endm
|
||||
|
||||
.macro restore_all_base_regs
|
||||
REG_L x3, PT_GP(sp)
|
||||
REG_L x4, PT_TP(sp)
|
||||
REG_L x5, PT_T0(sp)
|
||||
REG_L x6, PT_T1(sp)
|
||||
REG_L x7, PT_T2(sp)
|
||||
REG_L x8, PT_S0(sp)
|
||||
REG_L x9, PT_S1(sp)
|
||||
REG_L x10, PT_A0(sp)
|
||||
REG_L x11, PT_A1(sp)
|
||||
REG_L x12, PT_A2(sp)
|
||||
REG_L x13, PT_A3(sp)
|
||||
REG_L x14, PT_A4(sp)
|
||||
REG_L x15, PT_A5(sp)
|
||||
REG_L x16, PT_A6(sp)
|
||||
REG_L x17, PT_A7(sp)
|
||||
REG_L x18, PT_S2(sp)
|
||||
REG_L x19, PT_S3(sp)
|
||||
REG_L x20, PT_S4(sp)
|
||||
REG_L x21, PT_S5(sp)
|
||||
REG_L x22, PT_S6(sp)
|
||||
REG_L x23, PT_S7(sp)
|
||||
REG_L x24, PT_S8(sp)
|
||||
REG_L x25, PT_S9(sp)
|
||||
REG_L x26, PT_S10(sp)
|
||||
REG_L x27, PT_S11(sp)
|
||||
REG_L x28, PT_T3(sp)
|
||||
REG_L x29, PT_T4(sp)
|
||||
REG_L x30, PT_T5(sp)
|
||||
REG_L x31, PT_T6(sp)
|
||||
.endm
|
||||
|
||||
ENTRY(kretprobe_trampoline)
|
||||
addi sp, sp, -(PT_SIZE_ON_STACK)
|
||||
save_all_base_regs
|
||||
|
||||
move a0, sp /* pt_regs */
|
||||
|
||||
call trampoline_probe_handler
|
||||
|
||||
/* use the result as the return-address */
|
||||
move ra, a0
|
||||
|
||||
restore_all_base_regs
|
||||
addi sp, sp, PT_SIZE_ON_STACK
|
||||
|
||||
ret
|
||||
ENDPROC(kretprobe_trampoline)
|
||||
|
|
@ -0,0 +1,85 @@
|
|||
// SPDX-License-Identifier: GPL-2.0+
|
||||
|
||||
#include <linux/bitops.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/kprobes.h>
|
||||
|
||||
#include "decode-insn.h"
|
||||
#include "simulate-insn.h"
|
||||
|
||||
static inline bool rv_insn_reg_get_val(struct pt_regs *regs, u32 index,
|
||||
unsigned long *ptr)
|
||||
{
|
||||
if (index == 0)
|
||||
*ptr = 0;
|
||||
else if (index <= 31)
|
||||
*ptr = *((unsigned long *)regs + index);
|
||||
else
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
static inline bool rv_insn_reg_set_val(struct pt_regs *regs, u32 index,
|
||||
unsigned long val)
|
||||
{
|
||||
if (index == 0)
|
||||
return false;
|
||||
else if (index <= 31)
|
||||
*((unsigned long *)regs + index) = val;
|
||||
else
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
bool __kprobes simulate_jal(u32 opcode, unsigned long addr, struct pt_regs *regs)
|
||||
{
|
||||
/*
|
||||
* 31 30 21 20 19 12 11 7 6 0
|
||||
* imm [20] | imm[10:1] | imm[11] | imm[19:12] | rd | opcode
|
||||
* 1 10 1 8 5 JAL/J
|
||||
*/
|
||||
bool ret;
|
||||
u32 imm;
|
||||
u32 index = (opcode >> 7) & 0x1f;
|
||||
|
||||
ret = rv_insn_reg_set_val(regs, index, addr + 4);
|
||||
if (!ret)
|
||||
return ret;
|
||||
|
||||
imm = ((opcode >> 21) & 0x3ff) << 1;
|
||||
imm |= ((opcode >> 20) & 0x1) << 11;
|
||||
imm |= ((opcode >> 12) & 0xff) << 12;
|
||||
imm |= ((opcode >> 31) & 0x1) << 20;
|
||||
|
||||
instruction_pointer_set(regs, addr + sign_extend32((imm), 20));
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
bool __kprobes simulate_jalr(u32 opcode, unsigned long addr, struct pt_regs *regs)
|
||||
{
|
||||
/*
|
||||
* 31 20 19 15 14 12 11 7 6 0
|
||||
* offset[11:0] | rs1 | 010 | rd | opcode
|
||||
* 12 5 3 5 JALR/JR
|
||||
*/
|
||||
bool ret;
|
||||
unsigned long base_addr;
|
||||
u32 imm = (opcode >> 20) & 0xfff;
|
||||
u32 rd_index = (opcode >> 7) & 0x1f;
|
||||
u32 rs1_index = (opcode >> 15) & 0x1f;
|
||||
|
||||
ret = rv_insn_reg_set_val(regs, rd_index, addr + 4);
|
||||
if (!ret)
|
||||
return ret;
|
||||
|
||||
ret = rv_insn_reg_get_val(regs, rs1_index, &base_addr);
|
||||
if (!ret)
|
||||
return ret;
|
||||
|
||||
instruction_pointer_set(regs, (base_addr + sign_extend32((imm), 11))&~1);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
|
@ -0,0 +1,47 @@
|
|||
/* SPDX-License-Identifier: GPL-2.0+ */
|
||||
|
||||
#ifndef _RISCV_KERNEL_PROBES_SIMULATE_INSN_H
|
||||
#define _RISCV_KERNEL_PROBES_SIMULATE_INSN_H
|
||||
|
||||
#define __RISCV_INSN_FUNCS(name, mask, val) \
|
||||
static __always_inline bool riscv_insn_is_##name(probe_opcode_t code) \
|
||||
{ \
|
||||
BUILD_BUG_ON(~(mask) & (val)); \
|
||||
return (code & (mask)) == (val); \
|
||||
} \
|
||||
bool simulate_##name(u32 opcode, unsigned long addr, \
|
||||
struct pt_regs *regs)
|
||||
|
||||
#define RISCV_INSN_REJECTED(name, code) \
|
||||
do { \
|
||||
if (riscv_insn_is_##name(code)) { \
|
||||
return INSN_REJECTED; \
|
||||
} \
|
||||
} while (0)
|
||||
|
||||
__RISCV_INSN_FUNCS(system, 0x7f, 0x73);
|
||||
__RISCV_INSN_FUNCS(fence, 0x7f, 0x0f);
|
||||
|
||||
#define RISCV_INSN_SET_SIMULATE(name, code) \
|
||||
do { \
|
||||
if (riscv_insn_is_##name(code)) { \
|
||||
api->handler = simulate_##name; \
|
||||
return INSN_GOOD_NO_SLOT; \
|
||||
} \
|
||||
} while (0)
|
||||
|
||||
__RISCV_INSN_FUNCS(c_j, 0xe003, 0xa001);
|
||||
__RISCV_INSN_FUNCS(c_jr, 0xf007, 0x8002);
|
||||
__RISCV_INSN_FUNCS(c_jal, 0xe003, 0x2001);
|
||||
__RISCV_INSN_FUNCS(c_jalr, 0xf007, 0x9002);
|
||||
__RISCV_INSN_FUNCS(c_beqz, 0xe003, 0xc001);
|
||||
__RISCV_INSN_FUNCS(c_bnez, 0xe003, 0xe001);
|
||||
__RISCV_INSN_FUNCS(c_ebreak, 0xffff, 0x9002);
|
||||
|
||||
__RISCV_INSN_FUNCS(auipc, 0x7f, 0x17);
|
||||
__RISCV_INSN_FUNCS(branch, 0x7f, 0x63);
|
||||
|
||||
__RISCV_INSN_FUNCS(jal, 0x7f, 0x6f);
|
||||
__RISCV_INSN_FUNCS(jalr, 0x707f, 0x67);
|
||||
|
||||
#endif /* _RISCV_KERNEL_PROBES_SIMULATE_INSN_H */
|
||||
|
|
@ -12,6 +12,7 @@
|
|||
#include <linux/signal.h>
|
||||
#include <linux/kdebug.h>
|
||||
#include <linux/uaccess.h>
|
||||
#include <linux/kprobes.h>
|
||||
#include <linux/mm.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/irq.h>
|
||||
|
|
@ -145,6 +146,14 @@ static inline unsigned long get_break_insn_length(unsigned long pc)
|
|||
|
||||
asmlinkage __visible void do_trap_break(struct pt_regs *regs)
|
||||
{
|
||||
#ifdef CONFIG_KPROBES
|
||||
if (kprobe_single_step_handler(regs))
|
||||
return;
|
||||
|
||||
if (kprobe_breakpoint_handler(regs))
|
||||
return;
|
||||
#endif
|
||||
|
||||
if (user_mode(regs))
|
||||
force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->epc);
|
||||
#ifdef CONFIG_KGDB
|
||||
|
|
|
|||
|
|
@ -13,6 +13,7 @@
|
|||
#include <linux/perf_event.h>
|
||||
#include <linux/signal.h>
|
||||
#include <linux/uaccess.h>
|
||||
#include <linux/kprobes.h>
|
||||
|
||||
#include <asm/ptrace.h>
|
||||
#include <asm/tlbflush.h>
|
||||
|
|
@ -213,6 +214,9 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
|
|||
tsk = current;
|
||||
mm = tsk->mm;
|
||||
|
||||
if (kprobe_page_fault(regs, cause))
|
||||
return;
|
||||
|
||||
/*
|
||||
* Fault-in kernel-space virtual memory on-demand.
|
||||
* The 'reference' page table is init_mm.pgd.
|
||||
|
|
|
|||
Loading…
Reference in New Issue