From mboxrd@z Thu Jan 1 00:00:00 1970 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 B33BF1C05; Sun, 5 Nov 2023 08:36:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lgdbL1ug" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6161C433C7; Sun, 5 Nov 2023 08:36:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699173384; bh=cq1uyWY//yo7TAcMVEgPAIfwQ/7UUGgpAXQ4/ztZPIs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=lgdbL1ughmbn5SdYS5NIgJkGd+qRDZYZOzn5e9qsvTMSftldjyJfIbdv7XZSfB1sP hOazaIlNu3WlZho88+1iQRAbdZaATP66mIlHR8fGOdVPho9yyq+teZCAvJQOju4bmD h06LFkWCYRAJHzr4EGBaYfoPKs4NMzpGgZ6LahhFjLup4TPfkjbL1Bf1t4ooKdXhzL budJSW4Q4gqzydby7ppFXZGRbFTiQ0peo4w6Zwo0HAWtjjU5oYlcFbpPsaLqtsQefC XrC8TCmAe8x5lUitirZZ7cDk145QcshXEfvm0XZbOSc5o08UvdjSBcbuL/uQvrgwCf CNKoNfupxJRHw== Date: Sun, 5 Nov 2023 17:36:18 +0900 From: Masami Hiramatsu (Google) To: Namhyung Kim 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 , Masami Hiramatsu , linux-toolchains@vger.kernel.org, linux-trace-devel@vger.kernel.org Subject: Re: [PATCH 09/48] perf dwarf-regs: Add get_dwarf_regnum() Message-Id: <20231105173618.c3e5d9faef347f27a6c4f049@kernel.org> In-Reply-To: <20231012035111.676789-10-namhyung@kernel.org> References: <20231012035111.676789-1-namhyung@kernel.org> <20231012035111.676789-10-namhyung@kernel.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 addressing > and DWARF_REG_FB which is a frame base register. They need to be > handled in a special way. > I have some comments below. > 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/x86/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[] = { > + { "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 != '%') > + return -1; Isn't it better to return an error code? e.g. -EINVAL. > + > + for (i = 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, unsigned int machine) > } > return NULL; > } > + > +__weak int get_arch_regnum(const char *name __maybe_unused) > +{ > + return -1; And -EOPNOTSUPP. > +} > + > +/* Return DWARF register number from architecture register name */ > +int get_dwarf_regnum(const char *name, unsigned int machine) > +{ > + char *regname = strdup(name); > + int reg = -1; > + char *p; > + > + if (regname == NULL) > + return -1; Here, -EINVAL. > + > + /* For convenience, remove trailing characters */ > + p = strpbrk(regname, " ,)"); > + if (p) > + *p = '\0'; > + > + switch (machine) { > + case EM_NONE: /* Generic arch - use host arch */ > + reg = 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/include/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? > #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)