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 50C6818A6C4; Wed, 25 Jun 2025 06:32:33 +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=1750833153; cv=none; b=oxbkoTtY8w/557eiiAsDyoARmex4sGEhFAVPxmLo+ElfXxEVBoJLuaOQ5s43KrRhAb6/fiyxqBTOwAh8/WNwaVOvgPeEwnsZlQvM5tIvzoEztWKVh0/thD4n855hg/M7zthj85CSLSv+tlNM/md8LWjEClNjjNi919X0ZHTfMbI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750833153; c=relaxed/simple; bh=2fz72wdEOHN12Hrp4x5DN2tgOHb8xAEfLxxCTvKe0GI=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=UeeGEetFKpKBzUmoci5kxX1vNkM8V2hnXlYydoVxqZoI2y6LxMV9Pkulheo95tsfFANOnaTDmuTKVq9HOvXxpRJSekxWdIPh0kzjDoeARbfF65lIynMixc/73FDLgMneklxk2U4KIGmvF4r4w6FLaDb2ONsdPZaTPhwieaBmqWU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BDQx1S1H; 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="BDQx1S1H" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A03B2C4CEEA; Wed, 25 Jun 2025 06:32:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750833152; bh=2fz72wdEOHN12Hrp4x5DN2tgOHb8xAEfLxxCTvKe0GI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=BDQx1S1HFvbpSyi0OWj0BM2UU2EI3ELm2y4BQCLW7gQA3ZA5TFFmoCRaTsd2kTc4d EbTUTS1c9XPpIhxgG6oaJi60M3VFVBVWNe0nBcVYN8KuOk/ic9e/niIzGoFqwESOaH zFwpPTqID/wKO7RP5rJnW16KZXnKoF5vXJPnQ/6rbnW5VUmH78LRuEk0OUqBfKKssn ZE+OVSHJEk0Oc5QFITY7cGQlCUWjX2jP3hesASrMYneiRH1P+kb5lKE35vDEPrKBz2 H9JdoWR0jqYBaGaAmB7o0ulCdoSv7r0ekeVWCMAFoRWiNUefJEKCn1s6/PEKD6g5rr qjAq/bQgeOHuQ== Date: Wed, 25 Jun 2025 15:32:29 +0900 From: Masami Hiramatsu (Google) To: Jiri Olsa Cc: Oleg Nesterov , Peter Zijlstra , Andrii Nakryiko , 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 , Thomas =?UTF-8?B?V2Vpw59zY2h1aA==?= , Ingo Molnar Subject: Re: [PATCHv3 perf/core 06/22] uprobes: Add is_register argument to uprobe_write and uprobe_write_opcode Message-Id: <20250625153229.f39c1a1a99ce986380769150@kernel.org> In-Reply-To: <20250605132350.1488129-7-jolsa@kernel.org> References: <20250605132350.1488129-1-jolsa@kernel.org> <20250605132350.1488129-7-jolsa@kernel.org> X-Mailer: Sylpheed 3.8.0beta1 (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 Thu, 5 Jun 2025 15:23:33 +0200 Jiri Olsa wrote: > 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. > > Moving the detection away and passing it to uprobe_write as argument, > so it's possible to write different instructions (other than just > breakpoint and rest). Looks good to me. Acked-by: Masami Hiramatsu (Google) Thanks, > > Acked-by: Andrii Nakryiko > Acked-by: Oleg Nesterov > Signed-off-by: Jiri Olsa > --- > arch/arm/probes/uprobes/core.c | 2 +- > include/linux/uprobes.h | 5 +++-- > kernel/events/uprobes.c | 21 +++++++++++---------- > 3 files changed, 15 insertions(+), 13 deletions(-) > > diff --git a/arch/arm/probes/uprobes/core.c b/arch/arm/probes/uprobes/core.c > index 885e0c5e8c20..3d96fb41d624 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 vm_area_struct *vma, > unsigned long vaddr) > { > return uprobe_write_opcode(auprobe, vma, vaddr, > - __opcode_to_mem_arm(auprobe->bpinsn)); > + __opcode_to_mem_arm(auprobe->bpinsn), true); > } > > 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 147c4a0a1af9..518b26756469 100644 > --- a/include/linux/uprobes.h > +++ b/include/linux/uprobes.h > @@ -197,9 +197,10 @@ 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 vm_area_struct *vma, unsigned long vaddr, uprobe_opcode_t); > +extern int uprobe_write_opcode(struct arch_uprobe *auprobe, struct vm_area_struct *vma, unsigned long vaddr, uprobe_opcode_t, > + bool is_register); > extern int uprobe_write(struct arch_uprobe *auprobe, struct vm_area_struct *vma, const unsigned long opcode_vaddr, > - uprobe_opcode_t *insn, int nbytes, uprobe_write_verify_t verify); > + uprobe_opcode_t *insn, int nbytes, uprobe_write_verify_t verify, bool is_register); > 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 f7feb7417a2c..1e5dc3b30707 100644 > --- a/kernel/events/uprobes.c > +++ b/kernel/events/uprobes.c > @@ -402,10 +402,10 @@ static bool orig_page_is_identical(struct vm_area_struct *vma, > > static int __uprobe_write(struct vm_area_struct *vma, > struct folio_walk *fw, struct folio *folio, > - unsigned long insn_vaddr, uprobe_opcode_t *insn, int nbytes) > + unsigned long insn_vaddr, uprobe_opcode_t *insn, int nbytes, > + bool is_register) > { > const unsigned long vaddr = insn_vaddr & PAGE_MASK; > - const bool is_register = !!is_swbp_insn(insn); > bool pmd_mappable; > > /* For now, we'll only handle PTE-mapped folios. */ > @@ -488,26 +488,27 @@ static int __uprobe_write(struct vm_area_struct *vma, > * Return 0 (success) or a negative errno. > */ > int uprobe_write_opcode(struct arch_uprobe *auprobe, struct vm_area_struct *vma, > - const unsigned long opcode_vaddr, uprobe_opcode_t opcode) > + const unsigned long opcode_vaddr, uprobe_opcode_t opcode, > + bool is_register) > { > - return uprobe_write(auprobe, vma, opcode_vaddr, &opcode, UPROBE_SWBP_INSN_SIZE, verify_opcode); > + return uprobe_write(auprobe, vma, opcode_vaddr, &opcode, UPROBE_SWBP_INSN_SIZE, > + verify_opcode, is_register); > } > > int uprobe_write(struct arch_uprobe *auprobe, struct vm_area_struct *vma, > const unsigned long insn_vaddr, uprobe_opcode_t *insn, int nbytes, > - uprobe_write_verify_t verify) > + uprobe_write_verify_t verify, bool is_register) > { > const unsigned long vaddr = insn_vaddr & PAGE_MASK; > struct mm_struct *mm = vma->vm_mm; > struct uprobe *uprobe; > - int ret, is_register, ref_ctr_updated = 0; > + int ret, ref_ctr_updated = 0; > unsigned int gup_flags = FOLL_FORCE; > struct mmu_notifier_range range; > struct folio_walk fw; > struct folio *folio; > struct page *page; > > - is_register = is_swbp_insn(insn); > uprobe = container_of(auprobe, struct uprobe, arch); > > if (WARN_ON_ONCE(!is_cow_mapping(vma->vm_flags))) > @@ -569,7 +570,7 @@ int uprobe_write(struct arch_uprobe *auprobe, struct vm_area_struct *vma, > /* Walk the page tables again, to perform the actual update. */ > if (folio_walk_start(&fw, vma, vaddr, 0)) { > if (fw.page == page) > - ret = __uprobe_write(vma, &fw, folio, insn_vaddr, insn, nbytes); > + ret = __uprobe_write(vma, &fw, folio, insn_vaddr, insn, nbytes, is_register); > folio_walk_end(&fw, vma); > } > > @@ -611,7 +612,7 @@ int uprobe_write(struct arch_uprobe *auprobe, struct vm_area_struct *vma, > int __weak set_swbp(struct arch_uprobe *auprobe, struct vm_area_struct *vma, > unsigned long vaddr) > { > - return uprobe_write_opcode(auprobe, vma, vaddr, UPROBE_SWBP_INSN); > + return uprobe_write_opcode(auprobe, vma, vaddr, UPROBE_SWBP_INSN, true); > } > > /** > @@ -627,7 +628,7 @@ int __weak set_orig_insn(struct arch_uprobe *auprobe, > struct vm_area_struct *vma, unsigned long vaddr) > { > return uprobe_write_opcode(auprobe, vma, vaddr, > - *(uprobe_opcode_t *)&auprobe->insn); > + *(uprobe_opcode_t *)&auprobe->insn, false); > } > > /* uprobe should have guaranteed positive refcount */ > -- > 2.49.0 > -- Masami Hiramatsu (Google)