FAILED: patch "[PATCH] riscv: kprobe: Fixup misaligned load text" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

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.to.us/
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)) {