From patchwork Mon Jun 17 01:48:00 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: 13699868 X-Patchwork-Delegate: bpf@iogearbox.net 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 D0AE1160884; Mon, 17 Jun 2024 01:48:07 +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=1718588887; cv=none; b=c3srDuAcFEwEMS7Qz4S4CIJztz4gLTALqye/bzXANXGBbvQBF0vAafL8CGEU/1FOp+ktMYwwgG6Nu4oDfHZv5NsVmR0agh4lPnGXnBlDwKelxV0to2Fc6ax6ze5dCbJuVhnDB8Za58yZ5U0z3Yi2rtZjAFE9fbjJPddApdJ7ZX0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718588887; c=relaxed/simple; bh=v+ndCkQC6hxxweJTYXdlfbViE3auXeHXe5Z/+0ut9Lo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=kJx106dQtZzQeZu0Dk5uewpS0hMM3FQJITf2FCYeKj77PjYcvN0v2cXWUo/ArXiocQDU03Xk0HtDPckuRC5V7gJNyInNbAZlJMn754iBruUOszELhKEBmkk3Xe0t9DIBdzk/yx9RdAGNvVOW4XvQV1DTm9fgwRZ+QEx0tkZ1a/I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HNDHGKDz; 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="HNDHGKDz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F4E3C2BBFC; Mon, 17 Jun 2024 01:48:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718588887; bh=v+ndCkQC6hxxweJTYXdlfbViE3auXeHXe5Z/+0ut9Lo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HNDHGKDzy6rd3s+qEqA0235h9i07HSM9SPUjS6hwOod4+rQdDpudjsziDNqe5nGWR YrF+AmrsG5nE9rnvypi+X6mVqVOMDfehbf2uJOTdUWfgQtaj3GiWSuEvoEYV3u0P1/ UCMX1pJEK8w61jwQM/jd08m16X4r8rpZtL4JB2rNWwCvXLHVb8VWeEYrEsP6nXymrI f2kujOX2b+4asY4YPRoFsfaJ+Vkk287lk4UWuqKUDFB4hljVrnO59tFOZAQ94eGBOq FJLtPSpoL3i2Hq/MHSA73MN+mDTNOlwueSBGgZk+eTCjNFIZPvSpA83Cnwg8M0ALqI +LV+d5w35QBjA== 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 v11 08/18] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs Date: Mon, 17 Jun 2024 10:48:00 +0900 Message-Id: <171858888079.288820.8680496982210564353.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <171858878797.288820.237119113242007537.stgit@devnote2> References: <171858878797.288820.237119113242007537.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 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/include/linux/ftrace.h b/include/linux/ftrace.h index fa578748f7d2..8e5da4dfb669 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.