From patchwork Mon Apr 15 12:54:05 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: 13629966 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 E2E7F13BC36; Mon, 15 Apr 2024 12:54:12 +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=1713185653; cv=none; b=PBIJf5b/OY9FphnHf+MKmtZP3NVWneoQFqeb1SXQKKy+kpkzHiWqDrF1sEDt2v0EHnav0GJ74YeXxdBKtPaLDYvuxHYZt2uqh74zv6EsiEQebG/zIgZd3yAuogCp7u3DRi00+vW7uh6miRhMNN89XoiLii37njcAd9Upi8upUTg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713185653; c=relaxed/simple; bh=TFAFZorxjczl9MZT2HJZSFW3pkqLg4p2bz5N9Yr6eFA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=JsLfHgD3YwWihRfZ0I+VeDCce+ZnWVzkeQw1vYwYqt39AdlNLePU5mg6aBUj5GxSXHF+TMO/riMYnOxncCywoxW8gq/eQUk9inT3jaaB985aWHurNoqsjmmBVaPZoH6kC8qr2t1idBC64wHfE4/l/3Uv3mrOpq+CZP7jkbvvx8U= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=b2tl1BJz; 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="b2tl1BJz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E987FC2BD11; Mon, 15 Apr 2024 12:54:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713185652; bh=TFAFZorxjczl9MZT2HJZSFW3pkqLg4p2bz5N9Yr6eFA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b2tl1BJzG26OGX32bdeVJ5PyH6LcuGzWbB9riNqdV4fcAQwF5en06oPtfwVBpxsWe OAuoHz++8bpkNKVIR8N3Zalw2lMhF9ByvX9Mo5qlMiEArBX8gM+R1IPgKKhJDSYOiB O436fZzdqdEMPBictAXgNDJ2KFrb68MRcmYy6Hk4mFWUV56epuL+vxBKd87ppB8s9z i9+jm2K74QcYFZ+QOgM8YXjqa8MJh19Uhbbaw1pYesC4uBoTUjVLU1Kc0oXW3qhCI2 w1zSgZgmcjPeYHdPloeuBPABJC1MC9WgR4/VCrB6l4LwomvnHFd5M4g/EltlEtSkiK ubVwdj6FCIm9A== From: "Masami Hiramatsu (Google)" To: Alexei Starovoitov , Steven Rostedt , Florent Revest Cc: linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Mark Rutland , Peter Zijlstra , Thomas Gleixner , Guo Ren Subject: [PATCH v9 26/36] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs Date: Mon, 15 Apr 2024 21:54:05 +0900 Message-Id: <171318564576.254850.4893184815305636715.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <171318533841.254850.15841395205784342850.stgit@devnote2> References: <171318533841.254850.15841395205784342850.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 --- 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 | 11 +++++++++++ include/linux/ftrace.h | 17 +++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index ac82dc43a57d..aab2b7a0f78c 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -143,6 +143,17 @@ ftrace_regs_get_frame_pointer(const struct ftrace_regs *fregs) return fregs->fp; } +static __always_inline struct pt_regs * +ftrace_partial_regs(const struct ftrace_regs *fregs, struct pt_regs *regs) +{ + memcpy(regs->regs, fregs->regs, sizeof(u64) * 9); + regs->sp = fregs->sp; + regs->pc = fregs->pc; + regs->regs[29] = fregs->fp; + regs->regs[30] = fregs->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/include/linux/ftrace.h b/include/linux/ftrace.h index 2b35f7d851ca..9cf4c1b8b3f8 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -177,6 +177,23 @@ 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_PT_REGS_TO_FTRACE_REGS_CAST) + +static __always_inline struct pt_regs * +ftrace_partial_regs(struct ftrace_regs *fregs, struct pt_regs *regs) +{ + /* + * If CONFIG_HAVE_PT_REGS_TO_FTRACE_REGS_CAST=y, ftrace_regs memory + * layout is the same as 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 &fregs->regs; +} + +#endif /* !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS || CONFIG_HAVE_PT_REGS_TO_FTRACE_REGS_CAST */ + /* * 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.