FAILED: patch "[PATCH] LoongArch: BPF: Enhance the bpf_arch_text_poke() function" failed to apply to 6.18-stable tree

FAILED: patch "[PATCH] LoongArch: BPF: Enhance the bpf_arch_text_poke() function" failed to apply to 6.18-stable tree

[gregkh]

The patch below does not apply to the 6.18-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>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 73721d8676771c6c7b06d4e636cc053fc76afefd
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026010547-passenger-getting-5dde@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 73721d8676771c6c7b06d4e636cc053fc76afefd Mon Sep 17 00:00:00 2001
From: Chenghao Duan <duanchenghao@kylinos.cn>
Date: Wed, 31 Dec 2025 15:19:21 +0800
Subject: [PATCH] LoongArch: BPF: Enhance the bpf_arch_text_poke() function

Enhance the bpf_arch_text_poke() function to enable accurate location
of BPF program entry points.

When modifying the entry point of a BPF program, skip the "move t0, ra"
instruction to ensure the correct logic and copy of the jump address.

Cc: stable@vger.kernel.org
Fixes: 677e6123e3d2 ("LoongArch: BPF: Disable trampoline for kernel module function trace")
Signed-off-by: Chenghao Duan <duanchenghao@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
index 9f6e93343b6e..d1d5a65308b9 100644
--- a/arch/loongarch/net/bpf_jit.c
+++ b/arch/loongarch/net/bpf_jit.c
@@ -1309,15 +1309,30 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
 {
 	int ret;
 	bool is_call;
+	unsigned long size = 0;
+	unsigned long offset = 0;
+	void *image = NULL;
+	char namebuf[KSYM_NAME_LEN];
 	u32 old_insns[LOONGARCH_LONG_JUMP_NINSNS] = {[0 ... 4] = INSN_NOP};
 	u32 new_insns[LOONGARCH_LONG_JUMP_NINSNS] = {[0 ... 4] = INSN_NOP};
 
 	/* Only poking bpf text is supported. Since kernel function entry
 	 * is set up by ftrace, we rely on ftrace to poke kernel functions.
 	 */
-	if (!is_bpf_text_address((unsigned long)ip))
+	if (!__bpf_address_lookup((unsigned long)ip, &size, &offset, namebuf))
 		return -ENOTSUPP;
 
+	image = ip - offset;
+
+	/* zero offset means we're poking bpf prog entry */
+	if (offset == 0) {
+		/* skip to the nop instruction in bpf prog entry:
+		 * move t0, ra
+		 * nop
+		 */
+		ip = image + LOONGARCH_INSN_SIZE;
+	}
+
 	is_call = old_t == BPF_MOD_CALL;
 	ret = emit_jump_or_nops(old_addr, ip, old_insns, is_call);
 	if (ret)

Re: FAILED: patch "[PATCH] LoongArch: BPF: Enhance the bpf_arch_text_poke() function" failed to apply to 6.18-stable tree

[陈华才]

Hi, Greg,

Please use:
https://lore.kernel.org/loongarch/20260106025502.951868-1-chenhuacai@loongson.cn/T/#u

Huacai


> -----原始邮件-----
> 发件人: gregkh@linuxfoundation.org
> 发送时间:2026-01-05 20:59:48 (星期一)
> 收件人: duanchenghao@kylinos.cn, chenhuacai@loongson.cn
> 抄送: stable@vger.kernel.org
> 主题: FAILED: patch "[PATCH] LoongArch: BPF: Enhance the bpf_arch_text_poke() function" failed to apply to 6.18-stable tree
> 
> 
> The patch below does not apply to the 6.18-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>.
> 
> To reproduce the conflict and resubmit, you may use the following commands:
> 
> git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
> git checkout FETCH_HEAD
> git cherry-pick -x 73721d8676771c6c7b06d4e636cc053fc76afefd
> # <resolve conflicts, build, test, etc.>
> git commit -s
> git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026010547-passenger-getting-5dde@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..
> 
> Possible dependencies:
> 
> 
> 
> thanks,
> 
> greg k-h
> 
> ------------------ original commit in Linus's tree ------------------
> 
> From 73721d8676771c6c7b06d4e636cc053fc76afefd Mon Sep 17 00:00:00 2001
> From: Chenghao Duan <duanchenghao@kylinos.cn>
> Date: Wed, 31 Dec 2025 15:19:21 +0800
> Subject: [PATCH] LoongArch: BPF: Enhance the bpf_arch_text_poke() function
> 
> Enhance the bpf_arch_text_poke() function to enable accurate location
> of BPF program entry points.
> 
> When modifying the entry point of a BPF program, skip the "move t0, ra"
> instruction to ensure the correct logic and copy of the jump address.
> 
> Cc: stable@vger.kernel.org
> Fixes: 677e6123e3d2 ("LoongArch: BPF: Disable trampoline for kernel module function trace")
> Signed-off-by: Chenghao Duan <duanchenghao@kylinos.cn>
> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> 
> diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
> index 9f6e93343b6e..d1d5a65308b9 100644
> --- a/arch/loongarch/net/bpf_jit.c
> +++ b/arch/loongarch/net/bpf_jit.c
> @@ -1309,15 +1309,30 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
>  {
>  	int ret;
>  	bool is_call;
> +	unsigned long size = 0;
> +	unsigned long offset = 0;
> +	void *image = NULL;
> +	char namebuf[KSYM_NAME_LEN];
>  	u32 old_insns[LOONGARCH_LONG_JUMP_NINSNS] = {[0 ... 4] = INSN_NOP};
>  	u32 new_insns[LOONGARCH_LONG_JUMP_NINSNS] = {[0 ... 4] = INSN_NOP};
>  
>  	/* Only poking bpf text is supported. Since kernel function entry
>  	 * is set up by ftrace, we rely on ftrace to poke kernel functions.
>  	 */
> -	if (!is_bpf_text_address((unsigned long)ip))
> +	if (!__bpf_address_lookup((unsigned long)ip, &size, &offset, namebuf))
>  		return -ENOTSUPP;
>  
> +	image = ip - offset;
> +
> +	/* zero offset means we're poking bpf prog entry */
> +	if (offset == 0) {
> +		/* skip to the nop instruction in bpf prog entry:
> +		 * move t0, ra
> +		 * nop
> +		 */
> +		ip = image + LOONGARCH_INSN_SIZE;
> +	}
> +
>  	is_call = old_t == BPF_MOD_CALL;
>  	ret = emit_jump_or_nops(old_addr, ip, old_insns, is_call);
>  	if (ret)


本邮件及其附件含有龙芯中科的商业秘密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制或散发）本邮件及其附件中的信息。如果您错收本邮件，请您立即电话或邮件通知发件人并删除本邮件。 
This email and its attachments contain confidential information from Loongson Technology , which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this email in error, please notify the sender by phone or email immediately and delete it.