The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Possible dependencies:

eb7423273cc9 ("riscv: kprobe: Fixup misaligned load text") 9c89bb8e3272 ("kprobes: treewide: Cleanup the error messages for kprobes")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From eb7423273cc9922ee2d05bf660c034d7d515bb91 Mon Sep 17 00:00:00 2001 From: Guo Ren guoren@kernel.org Date: Sat, 4 Feb 2023 01:35:31 -0500 Subject: [PATCH] riscv: kprobe: Fixup misaligned load text MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

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

diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index 41c7481afde3..2bedec37d092 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)) {