From nobody Wed Nov 27 03:39:58 2024 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 6E548157A59; Tue, 15 Oct 2024 01:30:10 +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=1728955810; cv=none; b=GL+u3LZ36S7NoKuCZB/lO6lgkAnCmbRdX1rUDN+P7VA2f4e7MUUkHULy7P/IFAs8P4bIj+Z70gY0ufnkl6Rw7CYNeX39p58QFPWb4P5I7gdGYidCwVxyWAak45mO4fln1PsYMRgLLuVDheXzk4otgk4JiKOHdlg7SLN8TUXFz84= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728955810; c=relaxed/simple; bh=QRF9M2xphmC8GHYF+2/Solebug/BAUi1+lNBOtQ4Uxo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=m6/XS9LNeSBze3EbxxDTVmMDaxLWFxxwZvXE8H4BJSX7RrM8n2GwspFtu8EAS0Y9r2Ar/aWv6uXkKXNMi0gVeM7W5U4yFRQPQDOsaGhzqRMkoxW/TYY76HEw+oOzkZZM0QEeulNiAgKE2uER2yumLP/jjW2hOwCwh6d2zR3Hf60= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XTZFnSO5; 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="XTZFnSO5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F387BC4CEC3; Tue, 15 Oct 2024 01:30:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728955810; bh=QRF9M2xphmC8GHYF+2/Solebug/BAUi1+lNBOtQ4Uxo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XTZFnSO5A4Nj0+Vj65inRigTd1ucGSItlbArP+2i01mEaEBQWXoN1PuEQ+DzTdvOT Di2qS6eR/stN7JbnUpxn8DfiV5euSZP+Cv57/ODN9v72suhTQSPxNFiVDyvzNQdYiP E3OaejlTtJgYFo/J21HTuky/V+SbcTDiYybpcFw8e4DD3cvzk3RNIdBaH28o4+iMMX Oq2/qYfMSXOI74GctHCurCJQlIP7/wsRxMcGaOV2qzn1br2kvRmSNEq6gLPDkw+vtA GQPPbapIBaJTkac9/Ddn7gV58CZ6vJSmmdq2sFKADhgayswt4a/E+fqwYtnK0PF/Xi 7vZcI8AvMWlgw== 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 v16 08/18] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs Date: Tue, 15 Oct 2024 10:30:05 +0900 Message-ID: <172895580509.107311.5505089514069270667.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <172895571278.107311.14000164546881236558.stgit@devnote2> References: <172895571278.107311.14000164546881236558.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable 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 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 | 14 ++++++++++++++ include/linux/ftrace.h | 17 +++++++++++++++++ 3 files changed, 42 insertions(+) diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrac= e.h index b5fa57b61378..d344c69eb01e 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -135,6 +135,17 @@ ftrace_regs_get_frame_pointer(const struct ftrace_regs= *fregs) return arch_ftrace_regs(fregs)->fp; } =20 +static __always_inline struct pt_regs * +ftrace_partial_regs(const struct ftrace_regs *fregs, struct pt_regs *regs) +{ + memcpy(regs->regs, arch_ftrace_regs(fregs)->regs, sizeof(u64) * 9); + regs->sp =3D arch_ftrace_regs(fregs)->sp; + regs->pc =3D arch_ftrace_regs(fregs)->pc; + regs->regs[29] =3D arch_ftrace_regs(fregs)->fp; + regs->regs[30] =3D arch_ftrace_regs(fregs)->lr; + return regs; +} + int ftrace_regs_query_register_offset(const char *name); =20 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/ftrac= e.h index 9372f8d7036f..17e0a13cc386 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_w= ith_return(struct ftrace_r arch_ftrace_regs(fregs)->epc =3D arch_ftrace_regs(fregs)->ra; } =20 +static __always_inline struct pt_regs * +ftrace_partial_regs(const struct ftrace_regs *fregs, struct pt_regs *regs) +{ + struct __arch_ftrace_regs *afregs =3D arch_ftrace_regs(fregs); + + memcpy(®s->a0, afregs->args, sizeof(u64) * 8); + regs->epc =3D afregs->epc; + regs->ra =3D afregs->ra; + regs->sp =3D afregs->sp; + regs->s0 =3D afregs->s0; + regs->t1 =3D afregs->t1; + return regs; +} + int ftrace_regs_query_register_offset(const char *name); =20 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); } =20 +#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=3Dy, 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.