From: Guo Ren guoren@linux.alibaba.com
[ Upstream commit eb7423273cc9922ee2d05bf660c034d7d515bb91 ]
The current kprobe would cause a misaligned load for the probe point. This patch fixup it with two half-word loads instead.
Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported") Signed-off-by: Guo Ren guoren@linux.alibaba.com Signed-off-by: Guo Ren guoren@kernel.org Link: https://lore.kernel.org/linux-riscv/878rhig9zj.fsf@all.your.base.are.belong.... Reported-by: Bjorn Topel bjorn.topel@gmail.com Reviewed-by: Björn Töpel bjorn@kernel.org Link: https://lore.kernel.org/r/20230204063531.740220-1-guoren@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt palmer@rivosinc.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/kernel/probes/kprobes.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index b53aa0209e079..7548b1d62509c 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -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)) {