From patchwork Sun Nov 10 15:49:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13869967 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 58E5984E1C; Sun, 10 Nov 2024 15:50:04 +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=1731253804; cv=none; b=ay8TrA3s9Xw6kSErJZz9URidyMjy4kBJx2wwT1ZHBbp0B3vWI57CFQZ9fVIh0JsQ+67khB6mk9sJ5T05VjhVkoT+KaqgNVwjs8CLxrMhC2z8SwFcX686iCrXB5G0bWzuLR0z093XZsPbVjohd8nMg7jtlwCk9kErZgwQH01PUKE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731253804; c=relaxed/simple; bh=VwgU/FJ/MOK68HNLI5n7pBBrw9lEjFt14etIqRD5i6k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=S6F8vb2r6H9JFc2gaIL/jS6Jh3WgDoQLdWjxiw84xZCLf1dO+cVtVP6pAsYozCEVKCIR4h+9xS3/A5vjbxAcM/GLuSzutDvcfbFTxDudWTBaThLAfhC8l774t/wWsY8e0l+BycW2800xdmt9GTtxxuAkbOXcQjvTSyk0756MiBs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Q9/IzJ8w; 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="Q9/IzJ8w" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20085C4CECD; Sun, 10 Nov 2024 15:49:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731253804; bh=VwgU/FJ/MOK68HNLI5n7pBBrw9lEjFt14etIqRD5i6k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q9/IzJ8wdps9bpHwjQ+zxPgXJa5XixDTXnG4KfzruHMahWL0SvESQzPzau2HhKJ+m bVzwGHB+dItk2MDt/0SlXOesciaZeA4wyNcB/pIWu6SWIAAAn6qDg5QtQ72/95NEth YjX2QB57/7Q/Oy3dv/4Q7nFO0sigULNp3kvqySrHCkooWvO5SddFTa+3JDfCVhgYIC HsjSxF2hoHnfVkWwHBTlAzDy6MrtIbLGtQH/iKflYeX+g+rWIAw4YipXjJvgyoCxsH XLTd1lSWdAPrPyQOqlMj2qa+OHc88VyWFuQTEDpOmCcu7iDkRGy7L8sQsVN52b5edk KQxQpuD0boz6A== From: "Masami Hiramatsu (Google)" To: Alexei Starovoitov , Steven Rostedt , Florent Revest Cc: linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Alexei Starovoitov , Jiri Olsa , Alan Maguire , Mark Rutland , linux-arch@vger.kernel.org, Catalin Marinas , Will Deacon , Paul Walmsley , Palmer Dabbelt , Albert Ou Subject: [PATCH v19 06/19] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs Date: Mon, 11 Nov 2024 00:49:57 +0900 Message-ID: <173125379786.172790.567610414442463419.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <173125372214.172790.6929368952404083802.stgit@devnote2> References: <173125372214.172790.6929368952404083802.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Masami Hiramatsu (Google) Add ftrace_partial_regs() which converts the ftrace_regs to pt_regs. This is for the eBPF which needs this to keep the same pt_regs interface to access registers. Thus when replacing the pt_regs with ftrace_regs in fprobes (which is used by kprobe_multi eBPF event), this will be used. If the architecture defines its own ftrace_regs, this copies partial registers to pt_regs and returns it. If not, ftrace_regs is the same as pt_regs and ftrace_partial_regs() will return ftrace_regs::regs. Signed-off-by: Masami Hiramatsu (Google) Acked-by: Florent Revest Cc: Steven Rostedt Cc: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou --- Changes in v18: - Fix to use sizeof() for calculating array size. Changes in v14: - Add riscv change. Changes in v8: - Add the reason why this required in changelog. Changes from previous series: NOTHING, just forward ported. --- arch/arm64/include/asm/ftrace.h | 13 +++++++++++++ arch/riscv/include/asm/ftrace.h | 14 ++++++++++++++ include/linux/ftrace.h | 17 +++++++++++++++++ 3 files changed, 44 insertions(+) diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index b5fa57b61378..09210f853f12 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -135,6 +135,19 @@ ftrace_regs_get_frame_pointer(const struct ftrace_regs *fregs) return arch_ftrace_regs(fregs)->fp; } +static __always_inline struct pt_regs * +ftrace_partial_regs(const struct ftrace_regs *fregs, struct pt_regs *regs) +{ + struct __arch_ftrace_regs *afregs = arch_ftrace_regs(fregs); + + memcpy(regs->regs, afregs->regs, sizeof(afregs->regs)); + regs->sp = afregs->sp; + regs->pc = afregs->pc; + regs->regs[29] = afregs->fp; + regs->regs[30] = afregs->lr; + return regs; +} + int ftrace_regs_query_register_offset(const char *name); int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec); diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h index 9372f8d7036f..7064a530794b 100644 --- a/arch/riscv/include/asm/ftrace.h +++ b/arch/riscv/include/asm/ftrace.h @@ -197,6 +197,20 @@ static __always_inline void ftrace_override_function_with_return(struct ftrace_r arch_ftrace_regs(fregs)->epc = arch_ftrace_regs(fregs)->ra; } +static __always_inline struct pt_regs * +ftrace_partial_regs(const struct ftrace_regs *fregs, struct pt_regs *regs) +{ + struct __arch_ftrace_regs *afregs = arch_ftrace_regs(fregs); + + memcpy(®s->a0, afregs->args, sizeof(afregs->args)); + regs->epc = afregs->epc; + regs->ra = afregs->ra; + regs->sp = afregs->sp; + regs->s0 = afregs->s0; + regs->t1 = afregs->t1; + return regs; +} + int ftrace_regs_query_register_offset(const char *name); void ftrace_graph_func(unsigned long ip, unsigned long parent_ip, diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index bf8bb6c10553..ad2b46e1d5b0 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -190,6 +190,23 @@ static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs return arch_ftrace_get_regs(fregs); } +#if !defined(CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS) || \ + defined(CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS) + +static __always_inline struct pt_regs * +ftrace_partial_regs(struct ftrace_regs *fregs, struct pt_regs *regs) +{ + /* + * If CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS=y, ftrace_regs memory + * layout is including pt_regs. So always returns that address. + * Since arch_ftrace_get_regs() will check some members and may return + * NULL, we can not use it. + */ + return &arch_ftrace_regs(fregs)->regs; +} + +#endif /* !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS || CONFIG_HAVE_FTRACE_REGS_HAVING_PT_REGS */ + /* * When true, the ftrace_regs_{get,set}_*() functions may be used on fregs. * Note: this can be true even when ftrace_get_regs() cannot provide a pt_regs.