From patchwork Thu Mar 20 11:41:41 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 14023778 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 38EFA21D5A4; Thu, 20 Mar 2025 11:43:13 +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=1742470995; cv=none; b=cLrR0VuLYPSid98hDDKwtn2pZtQ+wVhg/qRzdF3qXmdWbjOAOp1yMJp1N7JALWDhfwXctTMb2xMQn3FDWPkCw6d/+8kGOtqA4+/BuKW2EOYVoXw0+Jgo6VcAYiKCaa3Jh7cM3UpJFSx487Q7UQSZKIdEECzzTB0I6Svo/xjdVnw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742470995; c=relaxed/simple; bh=KSU2ukmX7mTdL+gi1iAK50sclTPx//DkxFIN2MWYSOc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UF0xdx5aY9xwWmm98A9k+FrofFySOuq1zMJbBIDEmg3bW2J3yxyoBb9zyZ4cY1OqIY75/0O7TmDNiOg18AbVJC8rjLfCF3IsoWu9fRJppqpvHuDeGzHgGBIMm6RMlkOt0rXu+JrxGOEvmA8Gu0yYiRZSmqzCGKYDNhsJsCrID48= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KGsrVw+O; 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="KGsrVw+O" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D719CC4CEDD; Thu, 20 Mar 2025 11:43:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742470993; bh=KSU2ukmX7mTdL+gi1iAK50sclTPx//DkxFIN2MWYSOc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KGsrVw+OteQ4vN4d4UHHiX3IFrPepawTkyn0Z1Rvk3QBApsGvtCSejGOUZCC3mDUE cKU3reTjWSWUDQLjlUCEOfbNqGxUJ7nsFlphi3+hij6wdPec5GW1y4UdT5ut5UJ/Q4 dbpy6TkZep6virva1P5qeCMLg2yZd8HSXy2r1CG0hyQYitYwhlb6O/QCDU5f1aHWyc /am0pVp2J9/ptjV17X/uqDwjTkUl6EusX5MKG2kCYAAOK/DpjeQFUp+tGsDwI/teSf SejijpCJUz8KES81irEOd58Y61i0iWrvSdbhXC7dPRVHn9ohQ0QSCtiFA+k2EqahOJ RpJB9I3YAF1IA== From: Jiri Olsa To: Oleg Nesterov , Peter Zijlstra , Andrii Nakryiko Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, x86@kernel.org, Song Liu , Yonghong Song , John Fastabend , Hao Luo , Steven Rostedt , Masami Hiramatsu , Alan Maguire , David Laight , =?utf-8?q?Thomas_Wei=C3=9Fschuh?= Subject: [PATCH RFCv3 06/23] uprobes: Add orig argument to uprobe_write and uprobe_write_opcode Date: Thu, 20 Mar 2025 12:41:41 +0100 Message-ID: <20250320114200.14377-7-jolsa@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250320114200.14377-1-jolsa@kernel.org> References: <20250320114200.14377-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-State: RFC The uprobe_write has special path to restore the original page when we write original instruction back. This happens when uprobe_write detects that we want to write anything else but breakpoint instruction. In following changes we want to use uprobe_write function for multiple updates, so adding new function argument to denote that this is the original instruction update. This way uprobe_write can make appropriate checks and restore the original page when possible. Signed-off-by: Jiri Olsa --- arch/arm/probes/uprobes/core.c | 2 +- include/linux/uprobes.h | 5 +++-- kernel/events/uprobes.c | 22 ++++++++++------------ 3 files changed, 14 insertions(+), 15 deletions(-) diff --git a/arch/arm/probes/uprobes/core.c b/arch/arm/probes/uprobes/core.c index f5f790c6e5f8..54a90b565285 100644 --- a/arch/arm/probes/uprobes/core.c +++ b/arch/arm/probes/uprobes/core.c @@ -30,7 +30,7 @@ int set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr) { return uprobe_write_opcode(auprobe, mm, vaddr, - __opcode_to_mem_arm(auprobe->bpinsn)); + __opcode_to_mem_arm(auprobe->bpinsn), false); } bool arch_uprobe_ignore(struct arch_uprobe *auprobe, struct pt_regs *regs) diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index c69a05775394..1b6a4e2b5464 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -196,9 +196,10 @@ extern bool is_swbp_insn(uprobe_opcode_t *insn); extern bool is_trap_insn(uprobe_opcode_t *insn); extern unsigned long uprobe_get_swbp_addr(struct pt_regs *regs); extern unsigned long uprobe_get_trap_addr(struct pt_regs *regs); -extern int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t); +extern int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, + uprobe_opcode_t, bool); extern int uprobe_write(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, - uprobe_opcode_t *insn, int nbytes, uprobe_write_verify_t verify); + uprobe_opcode_t *insn, int nbytes, uprobe_write_verify_t verify, bool orig); extern struct uprobe *uprobe_register(struct inode *inode, loff_t offset, loff_t ref_ctr_offset, struct uprobe_consumer *uc); extern int uprobe_apply(struct uprobe *uprobe, struct uprobe_consumer *uc, bool); extern void uprobe_unregister_nosync(struct uprobe *uprobe, struct uprobe_consumer *uc); diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 7ff1f07c8f79..92fed5e50ec1 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -471,25 +471,23 @@ static int update_ref_ctr(struct uprobe *uprobe, struct mm_struct *mm, * Return 0 (success) or a negative errno. */ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, - unsigned long vaddr, uprobe_opcode_t opcode) + unsigned long vaddr, uprobe_opcode_t opcode, bool orig) { - return uprobe_write(auprobe, mm, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE, verify_opcode); + return uprobe_write(auprobe, mm, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE, verify_opcode, orig); } int uprobe_write(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t *insn, - int nbytes, uprobe_write_verify_t verify) + int nbytes, uprobe_write_verify_t verify, bool orig) { struct page *old_page, *new_page; struct vm_area_struct *vma; - int ret, is_register; + int ret; bool orig_page_huge = false; unsigned int gup_flags = FOLL_FORCE; - is_register = is_swbp_insn(insn); - retry: - if (is_register) + if (!orig) gup_flags |= FOLL_SPLIT_PMD; /* Read the page with vaddr into memory */ old_page = get_user_page_vma_remote(mm, vaddr, gup_flags, &vma); @@ -505,14 +503,14 @@ int uprobe_write(struct arch_uprobe *auprobe, struct mm_struct *mm, goto put_old; } - if (WARN(!is_register && PageCompound(old_page), + if (WARN(orig && PageCompound(old_page), "uprobe unregister should never work on compound page\n")) { ret = -EINVAL; goto put_old; } ret = 0; - if (!is_register && !PageAnon(old_page)) + if (orig && !PageAnon(old_page)) goto put_old; ret = anon_vma_prepare(vma); @@ -528,7 +526,7 @@ int uprobe_write(struct arch_uprobe *auprobe, struct mm_struct *mm, copy_highpage(new_page, old_page); uprobe_copy_to_page(new_page, vaddr, insn, nbytes); - if (!is_register) { + if (orig) { struct page *orig_page; pgoff_t index; @@ -579,7 +577,7 @@ int uprobe_write(struct arch_uprobe *auprobe, struct mm_struct *mm, */ int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr) { - return uprobe_write_opcode(auprobe, mm, vaddr, UPROBE_SWBP_INSN); + return uprobe_write_opcode(auprobe, mm, vaddr, UPROBE_SWBP_INSN, false); } static int set_swbp_refctr(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr) @@ -614,7 +612,7 @@ int __weak set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr) { return uprobe_write_opcode(auprobe, mm, vaddr, - *(uprobe_opcode_t *)&auprobe->insn); + *(uprobe_opcode_t *)&auprobe->insn, true); } static int set_orig_refctr(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr)