From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9535417BA0; Tue, 25 Jun 2024 01:29:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719278970; cv=none; b=BKU96CfFGKazbE4d+5iHM/7U/EyMIy3l+XAdZRUZ7jxQ1b0FIbDUFp8prFPw/9iOcNCIlncRud+63UxH6WBCBy8++HbE29c6UOM8cQkqWVx5peitn1A18GDH5BOS2KN6N/RDL2ZZG8IJrydpoQm7Y/VXQqcluXEkBjfwK61ijFw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719278970; c=relaxed/simple; bh=XjjssAJBNddISSmt0hM1wukuGTlEDquHwFEQeOSzgs4=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=u1TNo8SVP7nE30I+QcFTFyJ7Z7qbl96mwedPFlRa/VN92xdnfxH4Qp4w/l+6RHr8yHWm4IxhkgwWNmuJSacGVeBmRxiJ3RLRsSh0897XavXmlyEurPUeAYPQA8Jco9JPhkVa2cIpKcmOe6s8HBQR0NrpAH3AfCrGt9Rpzd6JGZU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=d6CTwfej; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="d6CTwfej" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99899C2BBFC; Tue, 25 Jun 2024 01:29:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719278970; bh=XjjssAJBNddISSmt0hM1wukuGTlEDquHwFEQeOSzgs4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=d6CTwfejUWlq+zJgBuG5rWdq1qOTX82B+zEGVzUCSgjqgs7fpj6s3Yz5WZe1QPN2x W1uBY//I9XC695m4sUPKzQl3zGPHof96/IMWCrjXlOjUWjq7ccZ8H/kG0fgyZwBeLs Bk7+JrWz1u3clZyoDeE27KNup7JoOhVgKULJysk1W44Btloay2NFMEnGhDJHmJLFIX opFouUJYR6o6qTpSXov4jauVsRE3nMGWt1I45G4/Qxpzh//V3SYjLlArMcbaPjN6xZ KdeobwIfucOxIvCoqZF6Vi48ob69tqzot8vJ926G00GvyddL9vQTR/wAx8reUaZs+L X+LXMBsbtmmiA== Date: Tue, 25 Jun 2024 10:29:25 +0900 From: Masami Hiramatsu (Google) To: Andrii Nakryiko Cc: linux-trace-kernel@vger.kernel.org, rostedt@goodmis.org, oleg@redhat.com, peterz@infradead.org, mingo@redhat.com, bpf@vger.kernel.org, jolsa@kernel.org, paulmck@kernel.org, clm@meta.com Subject: Re: [PATCH 02/12] uprobes: grab write mmap lock in unapply_uprobe() Message-Id: <20240625102925.665f2fa3b39dc7602b1321d8@kernel.org> In-Reply-To: <20240625002144.3485799-3-andrii@kernel.org> References: <20240625002144.3485799-1-andrii@kernel.org> <20240625002144.3485799-3-andrii@kernel.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 24 Jun 2024 17:21:34 -0700 Andrii Nakryiko wrote: > Given unapply_uprobe() can call remove_breakpoint() which eventually > calls uprobe_write_opcode(), which can modify a set of memory pages and > expects mm->mmap_lock held for write, it needs to have writer lock. > > Fix this by switching to mmap_write_lock()/mmap_write_unlock(). > Oops, it is an actual bug, right? Acked-by: Masami Hiramatsu (Google) Thanks, > Fixes: da1816b1caec ("uprobes: Teach handler_chain() to filter out the probed task") > Signed-off-by: Andrii Nakryiko > --- > kernel/events/uprobes.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c > index 197fbe4663b5..e896eeecb091 100644 > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -1235,7 +1235,7 @@ static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm) > struct vm_area_struct *vma; > int err = 0; > > - mmap_read_lock(mm); > + mmap_write_lock(mm); > for_each_vma(vmi, vma) { > unsigned long vaddr; > loff_t offset; > @@ -1252,7 +1252,7 @@ static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm) > vaddr = offset_to_vaddr(vma, uprobe->offset); > err |= remove_breakpoint(uprobe, mm, vaddr); > } > - mmap_read_unlock(mm); > + mmap_write_unlock(mm); > > return err; > } > -- > 2.43.0 > -- Masami Hiramatsu (Google)