Unverified Commit eb742327 authored by Guo Ren's avatar Guo Ren Committed by Palmer Dabbelt
Browse files

riscv: kprobe: Fixup misaligned load text 



The current kprobe would cause a misaligned load for the probe point.
This patch fixup it with two half-word loads instead.

Fixes: c22b0bcb ("riscv: Add kprobes supported")
Signed-off-by: default avatarGuo Ren <guoren@linux.alibaba.com>
Signed-off-by: default avatarGuo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/linux-riscv/878rhig9zj.fsf@all.your.base.are.belong.to.us/


Reported-by: default avatarBjorn Topel <bjorn.topel@gmail.com>
Reviewed-by: default avatarBjörn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20230204063531.740220-1-guoren@kernel.org


Cc: stable@vger.kernel.org
Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent cb80242c

arch/riscv/kernel/probes/kprobes.c

+5 −3
Original line number Diff line number Diff line
@@ -65,16 +65,18 @@ static bool __kprobes arch_check_kprobe(struct kprobe *p) 


int __kprobes arch_prepare_kprobe(struct kprobe *p)

{

	unsigned long probe_addr = (unsigned long)p->addr;

	u16 *insn = (u16 *)p->addr;



	if (probe_addr & 0x1)

	if ((unsigned long)insn & 0x1)

		return -EILSEQ;



	if (!arch_check_kprobe(p))

		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)) {