From nobody Mon Feb 9 08:55:03 2026 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 BD8AC14F136; Fri, 12 Apr 2024 18:33:12 +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=1712946792; cv=none; b=Lkf/jDYSj3uym0+5TlB7zyiYi5fScVB7vkV4dAKmLWuOcj2QkN1n/Kwi8qfu67xoUibljASpVrmlHibXNZm/FAJ6qJxPvDQlwua69KfwG4fgfbBV7e0N8cmYoBUXXMutxcV6eUisNjBBdHVdG25cwpKGJCIynmSoPO5+pWx24g4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712946792; c=relaxed/simple; bh=vaVisn2Hv+xkW0BEkChkfySYlnshZGIQoNtORS9lyKU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bIBBKKCBsFzE51RwIYS32RwT9Pw1fL4MqEoGDMY83Pu4GhbEr20IAoImrhmeRJ0CdETDoWBuAvSnxp9ZDyMfkikOuE508XQm8fWxr7o/Alnwjw7RweOZx9mGmgJAwe4V/PPc6Hrl8d2mgXrh3kbY2RdkepYLH+31JpdWH7YS4Xw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hVoJ2eoK; 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="hVoJ2eoK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01BFCC2BBFC; Fri, 12 Apr 2024 18:33:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1712946792; bh=vaVisn2Hv+xkW0BEkChkfySYlnshZGIQoNtORS9lyKU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hVoJ2eoKqlPDIU5AGscdTPr6jQMwXYRf6BUQ8hk4g6Z9LR2dD7XjJzWXB4FAXJ5rq JPHZvlTy1iVsItaByVesEmels9hIQppxao7aF4gFp988sMWXPC6tCvWWLJmJfrNhuI Fo/NDXyQUjLZr6LO0dg8sgPyCHqrThbqv2MXHPWYE1bBtzPvudNJs14h/SFZV1SR8o ifKRTlztm9men99rMRxgZZ2eqCdwuQbvmjnAtoJBF/tGsoNnRzglr/2Z6K5yr03z8E DYQH4+6PqLnjtAGRkyCVBV/Z37eF0kTZVk6z73FKCWYomRikJCvR1ob8e871GXcyXD LWJbpSG/bqMJQ== From: Namhyung Kim To: Arnaldo Carvalho de Melo , Ian Rogers , Kan Liang Cc: Jiri Olsa , Adrian Hunter , Peter Zijlstra , Ingo Molnar , LKML , linux-perf-users@vger.kernel.org Subject: [PATCH 1/4] perf annotate-data: Improve debug message with location info Date: Fri, 12 Apr 2024 11:33:07 -0700 Message-ID: <20240412183310.2518474-2-namhyung@kernel.org> X-Mailer: git-send-email 2.44.0.683.g7961c838ac-goog In-Reply-To: <20240412183310.2518474-1-namhyung@kernel.org> References: <20240412183310.2518474-1-namhyung@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" To verify it found the correct variable, let's add the location expression to the debug message. $ perf --debug type-profile annotate --data-type ... ----------------------------------------------------------- find data type for 0xaf0(reg15) at schedule+0xeb CU for kernel/sched/core.c (die:0x1180523) frame base: cfa=3D0 fbreg=3D6 found "rq" in scope=3D3/4 (die: 0x11b6a00) type_offset=3D0xaf0 variable location: reg15 type=3D'struct rq' size=3D0xfc0 (die:0x11892e2) ----------------------------------------------------------- find data type for 0x7bc(reg3) at tcp_get_info+0x62 CU for net/ipv4/tcp.c (die:0x7b5f516) frame base: cfa=3D0 fbreg=3D6 offset: 1980 is bigger than size: 760 check variable "sk" failed (die: 0x7b92b2c) variable location: reg3 type=3D'struct sock' size=3D0x2f8 (die:0x7b63c3a) ----------------------------------------------------------- ... The first case is fine. It looked up a data type in r15 with offset of 0xaf0 at the schedule+0xeb. It found CU die and the frame base info and the variable "rq" was found in the scope 3/4. Its location is the r15 register and the type size is 0xfc0 which includes 0xaf0. But the second case is not good. It looked up a data type in rbx (reg3) with offset 0x7bc. It found a CU and the frame base which is good so far. And it also found a variable "sk" but the access offset is bigger than the type size (1980 vs. 760 or 0x7bc vs. 0x2f8). The variable has the right location (reg3) but I need to figure out why it accesses beyond what it's supposed to. Signed-off-by: Namhyung Kim --- tools/perf/util/annotate-data.c | 99 +++++++++++++++++++++++++++------ 1 file changed, 82 insertions(+), 17 deletions(-) diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-dat= a.c index 1cd857400038..c6eb5b2cc4d5 100644 --- a/tools/perf/util/annotate-data.c +++ b/tools/perf/util/annotate-data.c @@ -46,6 +46,7 @@ static void pr_debug_type_name(Dwarf_Die *die, enum type_= state_kind kind) { struct strbuf sb; char *str; + Dwarf_Word size =3D 0; =20 if (!debug_type_profile && verbose < 3) return; @@ -72,13 +73,67 @@ static void pr_debug_type_name(Dwarf_Die *die, enum typ= e_state_kind kind) break; } =20 + dwarf_aggregate_size(die, &size); + strbuf_init(&sb, 32); die_get_typename_from_type(die, &sb); str =3D strbuf_detach(&sb, NULL); - pr_info(" type=3D%s (die:%lx)\n", str, (long)dwarf_dieoffset(die)); + pr_info(" type=3D'%s' size=3D%#lx (die:%#lx)\n", + str, (long)size, (long)dwarf_dieoffset(die)); free(str); } =20 +static void pr_debug_location(Dwarf_Die *die, u64 pc, int reg) +{ + ptrdiff_t off =3D 0; + Dwarf_Attribute attr; + Dwarf_Addr base, start, end; + Dwarf_Op *ops; + size_t nops; + + if (!debug_type_profile && verbose < 3) + return; + + if (dwarf_attr(die, DW_AT_location, &attr) =3D=3D NULL) + return; + + while ((off =3D dwarf_getlocations(&attr, off, &base, &start, &end, &ops,= &nops)) > 0) { + if (reg !=3D DWARF_REG_PC && end < pc) + continue; + if (reg !=3D DWARF_REG_PC && start > pc) + break; + + pr_info(" variable location: "); + switch (ops->atom) { + case DW_OP_reg0 ...DW_OP_reg31: + pr_info("reg%d\n", ops->atom - DW_OP_reg0); + break; + case DW_OP_breg0 ...DW_OP_breg31: + pr_info("base=3Dreg%d, offset=3D%#lx\n", + ops->atom - DW_OP_breg0, ops->number); + break; + case DW_OP_regx: + pr_info("reg%ld\n", ops->number); + break; + case DW_OP_bregx: + pr_info("base=3Dreg%ld, offset=3D%#lx\n", + ops->number, ops->number2); + break; + case DW_OP_fbreg: + pr_info("use frame base, offset=3D%#lx\n", ops->number); + break; + case DW_OP_addr: + pr_info("address=3D%#lx\n", ops->number); + break; + default: + pr_info("unknown: code=3D%#x, number=3D%#lx\n", + ops->atom, ops->number); + break; + } + break; + } +} + /* * Type information in a register, valid when @ok is true. * The @caller_saved registers are invalidated after a function call. @@ -1404,7 +1459,7 @@ static int find_data_type_block(struct data_loc_info = *dloc, int reg, found =3D find_data_type_insn(dloc, reg, &basic_blocks, var_types, cu_die, type_die); if (found > 0) { - pr_debug_dtp("found by insn track: %#x(reg%d) type-offset=3D%#x", + pr_debug_dtp("found by insn track: %#x(reg%d) type-offset=3D%#x\n", dloc->op->offset, reg, dloc->type_offset); pr_debug_type_name(type_die, TSR_KIND_TYPE); ret =3D 0; @@ -1440,16 +1495,16 @@ static int find_data_type_die(struct data_loc_info = *dloc, Dwarf_Die *type_die) char buf[64]; =20 if (dloc->op->multi_regs) - snprintf(buf, sizeof(buf), " or reg%d", dloc->op->reg2); + snprintf(buf, sizeof(buf), "reg%d, reg%d", dloc->op->reg1, dloc->op->reg= 2); else if (dloc->op->reg1 =3D=3D DWARF_REG_PC) - snprintf(buf, sizeof(buf), " (PC)"); + snprintf(buf, sizeof(buf), "PC"); else - buf[0] =3D '\0'; + snprintf(buf, sizeof(buf), "reg%d", dloc->op->reg1); =20 pr_debug_dtp("-----------------------------------------------------------= \n"); - pr_debug_dtp("%s [%"PRIx64"] for reg%d%s offset=3D%#x in %s\n", - __func__, dloc->ip - dloc->ms->sym->start, - dloc->op->reg1, buf, dloc->op->offset, dloc->ms->sym->name); + pr_debug_dtp("find data type for %#x(%s) at %s+%#"PRIx64"\n", + dloc->op->offset, buf, dloc->ms->sym->name, + dloc->ip - dloc->ms->sym->start); =20 /* * IP is a relative instruction address from the start of the map, as @@ -1468,14 +1523,15 @@ static int find_data_type_die(struct data_loc_info = *dloc, Dwarf_Die *type_die) reg =3D loc->reg1; offset =3D loc->offset; =20 - pr_debug_dtp("CU die offset: %#lx\n", (long)dwarf_dieoffset(&cu_die)); + pr_debug_dtp("CU for %s (die:%#lx)\n", + dwarf_diename(&cu_die), (long)dwarf_dieoffset(&cu_die)); =20 if (reg =3D=3D DWARF_REG_PC) { if (get_global_var_type(&cu_die, dloc, dloc->ip, dloc->var_addr, &offset, type_die)) { dloc->type_offset =3D offset; =20 - pr_debug_dtp("found PC-rel by addr=3D%#"PRIx64" offset=3D%#x", + pr_debug_dtp("found by addr=3D%#"PRIx64" type_offset=3D%#x\n", dloc->var_addr, offset); pr_debug_type_name(type_die, TSR_KIND_TYPE); ret =3D 0; @@ -1537,13 +1593,22 @@ static int find_data_type_die(struct data_loc_info = *dloc, Dwarf_Die *type_die) pr_debug_dtp("found \"%s\" in scope=3D%d/%d (die: %#lx) ", dwarf_diename(&var_die), i+1, nr_scopes, (long)dwarf_dieoffset(&scopes[i])); - if (reg =3D=3D DWARF_REG_PC) - pr_debug_dtp("%#x(PC) offset=3D%#x", loc->offset, offset); - else if (reg =3D=3D DWARF_REG_FB || is_fbreg) - pr_debug_dtp("%#x(reg%d) stack fb_offset=3D%#x offset=3D%#x", - loc->offset, reg, fb_offset, offset); - else - pr_debug_dtp("%#x(reg%d)", loc->offset, reg); + if (reg =3D=3D DWARF_REG_PC) { + pr_debug_dtp("addr=3D%#"PRIx64" type_offset=3D%#x\n", + dloc->var_addr, offset); + } else if (reg =3D=3D DWARF_REG_FB || is_fbreg) { + pr_debug_dtp("stack_offset=3D%#x type_offset=3D%#x\n", + fb_offset, offset); + } else { + pr_debug_dtp("type_offset=3D%#x\n", offset); + } + pr_debug_location(&var_die, pc, reg); + pr_debug_type_name(type_die, TSR_KIND_TYPE); + } else { + pr_debug_dtp("check variable \"%s\" failed (die: %#lx)\n", + dwarf_diename(&var_die), + (long)dwarf_dieoffset(&var_die)); + pr_debug_location(&var_die, pc, reg); pr_debug_type_name(type_die, TSR_KIND_TYPE); } dloc->type_offset =3D offset; --=20 2.44.0.683.g7961c838ac-goog