From patchwork Sat Jun 29 15:03:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleg Nesterov X-Patchwork-Id: 13716947 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 70B5C824A0 for ; Sat, 29 Jun 2024 15:05:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719673505; cv=none; b=JVo5vfKCrWf2imfG3+HbwLN7+A0vrpu6ioJAQnR62c4SSgDtBd7x6cHqZYmz9EOWzYTvN1GRaZZEiZ6FyK6Obb3LUxt4/rMqFXp8/7pPF3LfhtoTSc58qI82z7XYjdJYRcaTAalCmIdR8rMDzJO9imArW5mfiRju7RPtgLsUqv4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719673505; c=relaxed/simple; bh=2DTQmWqH/wkMk/0O7Leu0Bu0zxHmvBJSnT2Q6y4GAuk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=sCIm08SVrljTxcaSJpqdZWR4nXFQ8a2UjFTEdd/MYuksC9LQGvjSAFjfxs21hFHjVpRpp4EK9+Jxw18pZDUBgfMLthn4biV1adewzL4Yy0Y4KNSETqT6cEGMK3rg1YirjF/splx4jLQcYrKSpph5otMTdb9CzCpr3GRFtwwfKXc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Elb1kVmq; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Elb1kVmq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1719673502; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Hk4NhAj11FnmgdfVKtJg7NJBjEggdWwUsCGnQLGSY70=; b=Elb1kVmqCK/zEwzG02UIGQDUS79Ojgg/7D+xybVz3IcCOkrYkL+/G3qrCEtVBBHwMVu+ea /J4GJAFH1BbqTNs3zS3SnrnB6ItBokrwAKuvSLKDEqIJEQkv4gBKHMs0TV+lvWQtw1rpaQ z6Pqph+Xoo2prkPLSJLnYf2VnWjV2UU= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-180-xzfP7Ds6Np29icu3_sB1Nw-1; Sat, 29 Jun 2024 11:04:58 -0400 X-MC-Unique: xzfP7Ds6Np29icu3_sB1Nw-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D9B0719560AA; Sat, 29 Jun 2024 15:04:55 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.39.192.76]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 3892B19560AA; Sat, 29 Jun 2024 15:04:49 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Sat, 29 Jun 2024 17:03:21 +0200 (CEST) Date: Sat, 29 Jun 2024 17:03:14 +0200 From: Oleg Nesterov To: Huacai Chen Cc: Tiezhu Yang , andrii.nakryiko@gmail.com, andrii@kernel.org, bpf@vger.kernel.org, jolsa@kernel.org, kernel@xen0n.name, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, loongarch@lists.linux.dev, mhiramat@kernel.org, nathan@kernel.org, rostedt@goodmis.org Subject: [PATCH] LoongArch: make the users of larch_insn_gen_break() constant Message-ID: <20240629150313.GB4504@redhat.com> References: <20240627173806.GC21813@redhat.com> <37f79351-a051-3fa9-7bfb-960fb2762e27@loongson.cn> <20240629133747.GA4504@redhat.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 LoongArch defines UPROBE_SWBP_INSN as a function call and this breaks arch_uprobe_trampoline() which uses it to initialize a static variable. Add the new "__builtin_constant_p" helper, __emit_break(), and redefine the current users of larch_insn_gen_break() to use it. The patch adds check_emit_break() into kprobes.c and uprobes.c to test this change. They can be removed if LoongArch boots at least once, but otoh these 2 __init functions will be discarded by free_initmem(). Fixes: ff474a78cef5 ("uprobe: Add uretprobe syscall to speed up return probe") Reported-by: Nathan Chancellor Closes: https://lore.kernel.org/all/20240614174822.GA1185149@thelio-3990X/ Suggested-by: Andrii Nakryiko Signed-off-by: Oleg Nesterov Tested-by: Tiezhu Yang --- arch/loongarch/include/asm/inst.h | 3 +++ arch/loongarch/include/asm/uprobes.h | 4 ++-- arch/loongarch/kernel/kprobes.c | 12 ++++++++++-- arch/loongarch/kernel/uprobes.c | 8 ++++++++ 4 files changed, 23 insertions(+), 4 deletions(-) diff --git a/arch/loongarch/include/asm/inst.h b/arch/loongarch/include/asm/inst.h index c3993fd88aba..944482063f14 100644 --- a/arch/loongarch/include/asm/inst.h +++ b/arch/loongarch/include/asm/inst.h @@ -532,6 +532,9 @@ static inline void emit_##NAME(union loongarch_instruction *insn, \ DEF_EMIT_REG0I15_FORMAT(break, break_op) +/* like emit_break(imm) but returns a constant expression */ +#define __emit_break(imm) ((u32)((imm) | (break_op << 15))) + #define DEF_EMIT_REG0I26_FORMAT(NAME, OP) \ static inline void emit_##NAME(union loongarch_instruction *insn, \ int offset) \ diff --git a/arch/loongarch/include/asm/uprobes.h b/arch/loongarch/include/asm/uprobes.h index c8f59983f702..99a0d198927f 100644 --- a/arch/loongarch/include/asm/uprobes.h +++ b/arch/loongarch/include/asm/uprobes.h @@ -9,10 +9,10 @@ typedef u32 uprobe_opcode_t; #define MAX_UINSN_BYTES 8 #define UPROBE_XOL_SLOT_BYTES MAX_UINSN_BYTES -#define UPROBE_SWBP_INSN larch_insn_gen_break(BRK_UPROBE_BP) +#define UPROBE_SWBP_INSN __emit_break(BRK_UPROBE_BP) #define UPROBE_SWBP_INSN_SIZE LOONGARCH_INSN_SIZE -#define UPROBE_XOLBP_INSN larch_insn_gen_break(BRK_UPROBE_XOLBP) +#define UPROBE_XOLBP_INSN __emit_break(BRK_UPROBE_XOLBP) struct arch_uprobe { unsigned long resume_era; diff --git a/arch/loongarch/kernel/kprobes.c b/arch/loongarch/kernel/kprobes.c index 17b040bd6067..78cfaac52748 100644 --- a/arch/loongarch/kernel/kprobes.c +++ b/arch/loongarch/kernel/kprobes.c @@ -4,8 +4,16 @@ #include #include -#define KPROBE_BP_INSN larch_insn_gen_break(BRK_KPROBE_BP) -#define KPROBE_SSTEPBP_INSN larch_insn_gen_break(BRK_KPROBE_SSTEPBP) +#define KPROBE_BP_INSN __emit_break(BRK_KPROBE_BP) +#define KPROBE_SSTEPBP_INSN __emit_break(BRK_KPROBE_SSTEPBP) + +static __init int check_emit_break(void) +{ + BUG_ON(KPROBE_BP_INSN != larch_insn_gen_break(BRK_KPROBE_BP)); + BUG_ON(KPROBE_SSTEPBP_INSN != larch_insn_gen_break(BRK_KPROBE_SSTEPBP)); + return 0; +} +arch_initcall(check_emit_break); DEFINE_PER_CPU(struct kprobe *, current_kprobe); DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); diff --git a/arch/loongarch/kernel/uprobes.c b/arch/loongarch/kernel/uprobes.c index 87abc7137b73..90462d94c28f 100644 --- a/arch/loongarch/kernel/uprobes.c +++ b/arch/loongarch/kernel/uprobes.c @@ -7,6 +7,14 @@ #define UPROBE_TRAP_NR UINT_MAX +static __init int check_emit_break(void) +{ + BUG_ON(UPROBE_SWBP_INSN != larch_insn_gen_break(BRK_UPROBE_BP)); + BUG_ON(UPROBE_XOLBP_INSN != larch_insn_gen_break(BRK_UPROBE_XOLBP)); + return 0; +} +arch_initcall(check_emit_break); + int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long addr) {