From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 BDBF9139D; Mon, 6 Nov 2023 04:12:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from mail-pg1-f176.google.com (mail-pg1-f176.google.com [209.85.215.176]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23B48B3; Sun, 5 Nov 2023 20:12:47 -0800 (PST) Received: by mail-pg1-f176.google.com with SMTP id 41be03b00d2f7-5bda105206fso15084a12.3; Sun, 05 Nov 2023 20:12:47 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699243966; x=1699848766; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=zElg2gHoZLp6PFI5FrVwiSrAB0jQgVqcXfU6cDRFjZE=; b=u9h6RNLlRtY01nAcZSq/jIZdozxQa+KiTif6VfL4fRPG57165m9xfH7vyy6dXMqR+Q MAA9AQCoZDJ3gyEPd0t0JEn7WYwuZJIy8V9rmJFzwbf8AirXvx/RShy/hskl65Ny2FJP KsZ9W6wahmMrTD4wdlliRm0XQXkv08QTQ4URwxKubV2caSLVUPDvkvFTFqchw5VN/WY+ n+MtXSGOsvMQRbfFvp+2zhJcqXjJdRsYG4w1/3UyUicgLwiIFPI64J/kmBxxswevkROv 4OQ4yy9oCVxuBgDdulXOmsbENLrr4XBdwlURtprOlNdupHtPFazYCoHrZx/N51PGk+y3 I3Fw== X-Gm-Message-State: AOJu0YwKrJu18UOXFc178ji1vfWw34/1svPRcsxVyXHpG7cBd5gouq54 BLhQpt2DFG0ygqUOZ/bDqG2p1fK62RwvOou7U1k= X-Google-Smtp-Source: AGHT+IEHsFBCOrV2v1VPctO7UEKuD7iw/CPc+Zs5eLvi4t7HT1vLebdAv12tnMYlLwH83eCkrGUFOLJ+5Ly3flcy9t8= X-Received: by 2002:a05:6a20:e109:b0:180:d9de:2d5e with SMTP id kr9-20020a056a20e10900b00180d9de2d5emr19017424pzb.39.1699243966394; Sun, 05 Nov 2023 20:12:46 -0800 (PST) Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20231012035111.676789-1-namhyung@kernel.org> <20231012035111.676789-10-namhyung@kernel.org> <20231105173618.c3e5d9faef347f27a6c4f049@kernel.org> In-Reply-To: <20231105173618.c3e5d9faef347f27a6c4f049@kernel.org> From: Namhyung Kim Date: Sun, 5 Nov 2023 20:12:35 -0800 Message-ID: Subject: Re: [PATCH 09/48] perf dwarf-regs: Add get_dwarf_regnum() To: Masami Hiramatsu Cc: Arnaldo Carvalho de Melo , Jiri Olsa , Peter Zijlstra , Ian Rogers , Adrian Hunter , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org, Linus Torvalds , Stephane Eranian , linux-toolchains@vger.kernel.org, linux-trace-devel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sun, Nov 5, 2023 at 1:36=E2=80=AFAM Masami Hiramatsu wrote: > > On Wed, 11 Oct 2023 20:50:32 -0700 > Namhyung Kim wrote: > > > The get_dwarf_regnum() returns a DWARF register number from a register > > name string according to the psABI. Also add two pseudo encodings of > > DWARF_REG_PC which is a register that are used by PC-relative addressin= g > > and DWARF_REG_FB which is a frame base register. They need to be > > handled in a special way. > > > > I have some comments below. Sure! :) > > > Cc: Masami Hiramatsu > > Signed-off-by: Namhyung Kim > > --- > > tools/perf/arch/x86/util/dwarf-regs.c | 38 +++++++++++++++++++++++++++ > > tools/perf/util/dwarf-regs.c | 33 +++++++++++++++++++++++ > > tools/perf/util/include/dwarf-regs.h | 11 ++++++++ > > 3 files changed, 82 insertions(+) > > > > diff --git a/tools/perf/arch/x86/util/dwarf-regs.c b/tools/perf/arch/x8= 6/util/dwarf-regs.c > > index 530934805710..79835b897cae 100644 > > --- a/tools/perf/arch/x86/util/dwarf-regs.c > > +++ b/tools/perf/arch/x86/util/dwarf-regs.c > > @@ -113,3 +113,41 @@ int regs_query_register_offset(const char *name) > > return roff->offset; > > return -EINVAL; > > } > > + > > +struct dwarf_regs_idx { > > + const char *name; > > + int idx; > > +}; > > + > > +static const struct dwarf_regs_idx x86_regidx_table[] =3D { > > + { "rax", 0 }, { "eax", 0 }, { "ax", 0 }, { "al", 0 }, > > + { "rdx", 1 }, { "edx", 1 }, { "dx", 1 }, { "dl", 1 }, > > + { "rcx", 2 }, { "ecx", 2 }, { "cx", 2 }, { "cl", 2 }, > > + { "rbx", 3 }, { "edx", 3 }, { "bx", 3 }, { "bl", 3 }, > > + { "rsi", 4 }, { "esi", 4 }, { "si", 4 }, { "sil", 4 }, > > + { "rdi", 5 }, { "edi", 5 }, { "di", 5 }, { "dil", 5 }, > > + { "rbp", 6 }, { "ebp", 6 }, { "bp", 6 }, { "bpl", 6 }, > > + { "rsp", 7 }, { "esp", 7 }, { "sp", 7 }, { "spl", 7 }, > > + { "r8", 8 }, { "r8d", 8 }, { "r8w", 8 }, { "r8b", 8 }, > > + { "r9", 9 }, { "r9d", 9 }, { "r9w", 9 }, { "r9b", 9 }, > > + { "r10", 10 }, { "r10d", 10 }, { "r10w", 10 }, { "r10b", 10 }, > > + { "r11", 11 }, { "r11d", 11 }, { "r11w", 11 }, { "r11b", 11 }, > > + { "r12", 12 }, { "r12d", 12 }, { "r12w", 12 }, { "r12b", 12 }, > > + { "r13", 13 }, { "r13d", 13 }, { "r13w", 13 }, { "r13b", 13 }, > > + { "r14", 14 }, { "r14d", 14 }, { "r14w", 14 }, { "r14b", 14 }, > > + { "r15", 15 }, { "r15d", 15 }, { "r15w", 15 }, { "r15b", 15 }, > > + { "rip", DWARF_REG_PC }, > > +}; > > + > > +int get_arch_regnum(const char *name) > > +{ > > + unsigned int i; > > + > > + if (*name !=3D '%') > > + return -1; > > Isn't it better to return an error code? e.g. -EINVAL. Maybe.. any negative error code would work. > > > + > > + for (i =3D 0; i < ARRAY_SIZE(x86_regidx_table); i++) > > + if (!strcmp(x86_regidx_table[i].name, name + 1)) > > + return x86_regidx_table[i].idx; > > + return -1; > > And -ENOENT. > > > +} > > diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.= c > > index 69cfaa5953bf..28d786c7df55 100644 > > --- a/tools/perf/util/dwarf-regs.c > > +++ b/tools/perf/util/dwarf-regs.c > > @@ -5,6 +5,8 @@ > > * Written by: Masami Hiramatsu > > */ > > > > +#include > > +#include > > #include > > #include > > #include > > @@ -68,3 +70,34 @@ const char *get_dwarf_regstr(unsigned int n, unsigne= d int machine) > > } > > return NULL; > > } > > + > > +__weak int get_arch_regnum(const char *name __maybe_unused) > > +{ > > + return -1; > > And -EOPNOTSUPP. Could be -ENOTSUP. > > > +} > > + > > +/* Return DWARF register number from architecture register name */ > > +int get_dwarf_regnum(const char *name, unsigned int machine) > > +{ > > + char *regname =3D strdup(name); > > + int reg =3D -1; > > + char *p; > > + > > + if (regname =3D=3D NULL) > > + return -1; > > Here, -EINVAL. > > > + > > + /* For convenience, remove trailing characters */ > > + p =3D strpbrk(regname, " ,)"); > > + if (p) > > + *p =3D '\0'; > > + > > + switch (machine) { > > + case EM_NONE: /* Generic arch - use host arch */ > > + reg =3D get_arch_regnum(regname); > > + break; > > + default: > > + pr_err("ELF MACHINE %x is not supported.\n", machine); > > + } > > + free(regname); > > + return reg; > > +} > > diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/inc= lude/dwarf-regs.h > > index 7d99a084e82d..b515f694f55e 100644 > > --- a/tools/perf/util/include/dwarf-regs.h > > +++ b/tools/perf/util/include/dwarf-regs.h > > @@ -2,6 +2,9 @@ > > #ifndef _PERF_DWARF_REGS_H_ > > #define _PERF_DWARF_REGS_H_ > > > > +#define DWARF_REG_PC 0xd3af9c /* random number */ > > +#define DWARF_REG_FB 0xd3affb /* random number */ > > + > > Is this for other patch in the series? Yes, they are to support global and local variables later. Thanks, Namhyung > > > #ifdef HAVE_DWARF_SUPPORT > > const char *get_arch_regstr(unsigned int n); > > /* > > @@ -10,6 +13,14 @@ const char *get_arch_regstr(unsigned int n); > > * machine: ELF machine signature (EM_*) > > */ > > const char *get_dwarf_regstr(unsigned int n, unsigned int machine); > > + > > +int get_arch_regnum(const char *name); > > +/* > > + * get_dwarf_regnum - Returns DWARF regnum from register name > > + * name: architecture register name > > + * machine: ELF machine signature (EM_*) > > + */ > > +int get_dwarf_regnum(const char *name, unsigned int machine); > > #endif > > > > #ifdef HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET > > -- > > 2.42.0.655.g421f12c284-goog > > > > Thank you, > > -- > Masami Hiramatsu (Google)