From patchwork Sun Sep 15 09:11:03 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: 13804729 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 6409F2E822; Sun, 15 Sep 2024 09:11:09 +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=1726391469; cv=none; b=WE+rpgf+m5t3wswq6Gk5dRlYfJA2j893WR43Vsrv0g0Fj+2P6YDDtpAja6tee1WhSKASi8vdVsJI83DVzc1gqrff9Che16Al9J1E2539cOPqll/FQej4OKAG7ArbWF3G7/i0YTF9S9GyR2rOdmYQGEYgjHCh71vk3YMDuS3NYis= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726391469; c=relaxed/simple; bh=qY+sHzbXQZpWGAHIfO/SJUlQuPBYvVIhmPx03bMzAg0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=mdnIvCmsG4TDFcuYQlD1F17DcA0dgG4CSmt8QJCi0xS9/2FB9l02Ad7SlqWoAxolCoJRZwnz2prjNQq+1XsFpRfwKEsoF0+UtkttegqoDkbBp/fJIMGoVdaWCHi6zGc2ABJ29cP/72eG9dV0VmQgTvtIMc4UQQn2lDbKkB2Jxpg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Z4cDITL6; 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="Z4cDITL6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E4B18C4CEC3; Sun, 15 Sep 2024 09:11:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726391469; bh=qY+sHzbXQZpWGAHIfO/SJUlQuPBYvVIhmPx03bMzAg0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z4cDITL62brHS/le2p2QDJoXziKTQSEvxQJg0y7LyAtQhvTGQhQmXaqnbaBcHrlFY tl0/JduiDCiRBg9tr/eYSdw5y3oR/WqBJg+0OyzNCNFkBqn6TmCur1WMRdRU9WX2wk LVTB7imYHYS30dWOHcmcnkwmiWjnDcAnEnUMH6Hqr6NmUXgdhb0+R+fXXMId8WbBry 2k21Ygil/jK9P7TU2NX9+IRWE7T6DdbSkq+fWNQ1/ECPmjCTAi4sHmKpp7Vk46uLN0 ypd4x6f7bT1o9arNZ1aJ36WBN3KdHYPmHiVJIaCgXza89HoAyPGMV+9sJNNW7Fikir kWj+u/+szt3cw== 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 , linux-arch@vger.kernel.org Subject: [PATCH v15 08/19] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs Date: Sun, 15 Sep 2024 18:11:03 +0900 Message-Id: <172639146339.366111.5820487904166214151.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <172639136989.366111.11359590127009702129.stgit@devnote2> References: <172639136989.366111.11359590127009702129.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 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 | 11 +++++++++++ arch/riscv/include/asm/ftrace.h | 12 ++++++++++++ include/linux/ftrace.h | 17 +++++++++++++++++ 3 files changed, 40 insertions(+) diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index dffaab3dd1f1..5cd587afab6d 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -132,6 +132,17 @@ 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/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h index e9f364ce9fe8..897779dec402 100644 --- a/arch/riscv/include/asm/ftrace.h +++ b/arch/riscv/include/asm/ftrace.h @@ -193,6 +193,18 @@ static __always_inline void ftrace_override_function_with_return(struct ftrace_r fregs->epc = fregs->ra; } +static __always_inline struct pt_regs * +ftrace_partial_regs(const struct ftrace_regs *fregs, struct pt_regs *regs) +{ + memcpy(®s->a0, fregs->args, sizeof(u64) * 8); + regs->epc = fregs->epc; + regs->ra = fregs->ra; + regs->sp = fregs->sp; + regs->s0 = fregs->s0; + regs->t1 = fregs->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 35b5ed8867ca..d6b92a4091b9 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -176,6 +176,23 @@ 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.