From patchwork Mon Feb 24 14:01:38 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13988191 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 A1D24154430; Mon, 24 Feb 2025 14:03:04 +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=1740405784; cv=none; b=KxFic1iwvGHdkFRRtXj9W4zvgzdH3bnVVris8J7aifRqVtYuOvMcQWgpaoo15LB2ms7vAOMAgUi0td9amLFDnDcX0IjKSrWio3MBukeDR08vqRwIvRjuKJpYS/a/sZqRJmozO3tK8TY8GMOYifJebT5vk+JuqMewVuGmkP84s28= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740405784; c=relaxed/simple; bh=QWCeB0t4biaaSmaCS4hAy6KgGL7EGSZY8hy6jheG62U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mJQwEO35rDsOBm2pb+LzTJCIY9RqLWYs03cVs/cTiwbj6LRgEmkqm0I0OGfiz+THUmb1pOryH+1VjVfINpreAmwxMooZXRMvuOuNp9J3nDuk+j6qKmBnSPORVtTkugLNEa3aVs5kZVIwCuxejCsKr+p9zvQ9Mvdi3cGinEfuz4w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ITDLs+Zy; 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="ITDLs+Zy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 67E7EC4CED6; Mon, 24 Feb 2025 14:03:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740405784; bh=QWCeB0t4biaaSmaCS4hAy6KgGL7EGSZY8hy6jheG62U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ITDLs+Zy6eG7E6igcaJmRdwB1zbJ1pCGI56OhyzOz/8h2mcAZGHiWyITXSZT4FVL/ 8ZOBvGynedhfLGY37RuzvOc3Q6ptiKlXlAZZIq7l1JktLxtofTRYXcw+cmmaDyicU0 TfeEOA0rJNlr1/uk6U3ZI13G8D+g48crIOZavVrVMbtPtIdb6MgzFN0IfcRqyYXR9I 0pcxZ/q3xb+AAETbMBdRxJHojrxahchD99VJl1fRsGPgGhMFUqjbZv+RdiUbSIzhWa tofRrUCNLi7d3VVJ1BzbPiR3AfdKsk3FnmngaHa7JWoSdUEtqj4oAJAYV8O/HGHE+L Nm9Gpv4xt1Zzg== 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 RFCv2 06/18] uprobes: Add orig argument to uprobe_write and uprobe_write_opcode Date: Mon, 24 Feb 2025 15:01:38 +0100 Message-ID: <20250224140151.667679-7-jolsa@kernel.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250224140151.667679-1-jolsa@kernel.org> References: <20250224140151.667679-1-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 8867b6a168b2..1abcae9cde48 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -194,9 +194,10 @@ 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 ad5879fc2d26..2b542043089e 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); @@ -500,14 +498,14 @@ int uprobe_write(struct arch_uprobe *auprobe, struct mm_struct *mm, if (ret <= 0) 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); @@ -523,7 +521,7 @@ 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; @@ -574,7 +572,7 @@ 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) @@ -609,7 +607,7 @@ 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)