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 256237E0E4; Thu, 2 Jan 2025 19:51:09 +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=1735847470; cv=none; b=Bkop68TBvD+1ayuaQXciA0PoUSO8XsKScKuEiN8dKtIsHGEB3PCpHyipa0SYH0YGWQI7sJaUWmAN0wqL+N+fYMWiEvEtPmA4rds7hm5oqS9k3jjXaXxwkmvYc3fEh5fXKkr8sEsY0JOWdRU0VPaId619L00KCS+2Kh9qwddCqz0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735847470; c=relaxed/simple; bh=mjqMtNDeXK1mslRpi/xgUHhTcK0L2R7SR3ifCujOr7o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dqYSA+geZJ23x0R+cQf7oQm9CIwX4RKemQL9DnGOjQT0+Q9hSrqmDgJ4PkQTwojqVxFbss814XLzMRF/Kwm3pkAoiGAgVi556efavYZH/waFVmO7JjWckWQg6WT9G48R/FnCj/3hFGpKIEyFS779GReK8wrsa2bGOVNciRshjLU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SdUoeCc6; 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="SdUoeCc6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E6D8C4CED0; Thu, 2 Jan 2025 19:51:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1735847469; bh=mjqMtNDeXK1mslRpi/xgUHhTcK0L2R7SR3ifCujOr7o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SdUoeCc6BF8wg7dwFXMeDOOPKaj+FyOug+zj7MWkABfRewrryYPFSwLHvd+0zbD1W SkSKOVs8nOPiChx03QcLWDfraLE6sn6VAr7Bev0ZqpfgBTYbZ6fwT44mXETbcfXs3K 6k0cmqaToGt1IWDfc3vLmjMRjYwQuZqTE76oZovlUM7/8M2MzIpXASC35TZT6StAxQ 9jPrIcySJ9p7y3n+MvXca2kPahHhJFpzyZbDP+jlT8Jdmfa9FqN1gPHnH/K55nReA3 UgqjFfpWokmWFZscQse++wGeYiFjpP+W5cH8Anp0AaeBj4XJqz3lxJNM6OosjYVJNR Q6G0whyF+98Xw== Date: Thu, 2 Jan 2025 16:51:06 -0300 From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Christophe Leroy , Adrian Hunter , Ian Rogers , James Clark , Jiri Olsa , Kan Liang , Linux Kernel Mailing List , linux-perf-users@vger.kernel.org Subject: Re: [BUG] perf top reports not being able to resolve kernel symbols Message-ID: References: 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-Disposition: inline In-Reply-To: On Thu, Jan 02, 2025 at 04:25:07PM -0300, Arnaldo Carvalho de Melo wrote: > root@number:~# readelf -sw /lib/modules/6.13.0-rc2/build/vmlinux | grep -B5 -A5 ' 0000000001600' > 259227: ffffffff8156e290 262 FUNC GLOBAL DEFAULT 1 zs_free > 259228: ffffffff8183a4d0 269 FUNC GLOBAL DEFAULT 1 security_inode_g[...] > 259229: ffffffff81c8d900 191 FUNC GLOBAL DEFAULT 1 devres_find > 259230: ffffffff812e11c0 16 FUNC GLOBAL DEFAULT 1 __pfx___probestu[...] > 259231: ffffffff81c985a0 16 FUNC GLOBAL DEFAULT 1 __pfx_pm_qos_sys[...] > 259232: 0000000001600000 0 NOTYPE GLOBAL DEFAULT ABS text_size > 259233: ffffffff81487f10 117 FUNC GLOBAL DEFAULT 1 shmem_read_folio_gfp > 259234: ffffffff81e08540 155 FUNC GLOBAL DEFAULT 1 __traceiter_smbu[...] > 259235: ffffffff811e13a0 16 FUNC GLOBAL DEFAULT 1 __pfx_thaw_workqueues > 259236: ffffffff81b04c70 599 FUNC GLOBAL DEFAULT 1 acpi_install_method > 259237: ffffffff81de7d40 16 FUNC GLOBAL DEFAULT 1 __pfx_psmouse_se[...] > root@number:~# > There it is, that "text_size" symbol stayed with with a prev->end equal > to prev->start and thus 0x00000000016001c1 stops being resolved, which > leads us to get to that buggy warning. > I'll put all this into a patch and send it for review, But looking further, where do those 0x00000000016001c1 addresses coming from? (gdb) p /x sample->ip $10 = 0xffffffffb7401fad (gdb) p /x al->addr $11 = 0x1601fad (gdb) bt #0 perf_event__process_sample (tool=0x7fffffff9bd0, event=0x1017400, evsel=0xf68860, sample=0x7fff8dffa470, machine=0xf8e818) at builtin-top.c:813 #1 0x0000000000447c5c in deliver_event (qe=0x7fffffff9ee8, qevent=0x1024670) at builtin-top.c:1213 #2 0x0000000000642706 in do_flush (oe=0x7fffffff9ee8, show_progress=false) at util/ordered-events.c:245 #3 0x0000000000642a5d in __ordered_events__flush (oe=0x7fffffff9ee8, how=OE_FLUSH__TOP, timestamp=0) at util/ordered-events.c:324 #4 0x0000000000642b47 in ordered_events__flush (oe=0x7fffffff9ee8, how=OE_FLUSH__TOP) at util/ordered-events.c:342 #5 0x00000000004477e9 in process_thread (arg=0x7fffffff9bd0) at builtin-top.c:1125 #6 0x00007ffff6ea5d97 in start_thread () from /lib64/libc.so.6 #7 0x00007ffff6f29c8c in clone3 () from /lib64/libc.so.6 (gdb) root@number:~# grep ffffffffb7401f /proc/kallsyms ffffffffb7401f09 t repeat_nmi ffffffffb7401f2e t end_repeat_nmi ffffffffb7401f81 t nmi_no_fsgsbase ffffffffb7401f85 t nmi_swapgs ffffffffb7401f88 t nmi_restore ffffffffb7401fb0 T entry_SYSCALL32_ignore ffffffffb7401fd0 T __pfx_clear_bhb_loop ffffffffb7401fe0 T clear_bhb_loop root@number:~# Looks like nmi_restore... Which is... 780: ffffffff82401ee8 0 NOTYPE LOCAL DEFAULT 1 nested_nmi_out 781: ffffffff82401ed0 0 NOTYPE LOCAL DEFAULT 1 nested_nmi 782: ffffffff82401eeb 0 NOTYPE LOCAL DEFAULT 1 first_nmi 783: ffffffff82401f81 0 NOTYPE LOCAL DEFAULT 1 nmi_no_fsgsbase 784: ffffffff82401f88 0 NOTYPE LOCAL DEFAULT 1 nmi_restore 785: ffffffff82401f85 0 NOTYPE LOCAL DEFAULT 1 nmi_swapgs 786: 0000000000000000 0 FILE LOCAL DEFAULT ABS syscall_64.c 787: 0000000000000000 0 FILE LOCAL DEFAULT ABS common.c 788: ffffffff810cc2b0 16 FUNC LOCAL DEFAULT 1 ia32_emulation_o[...] 789: ffffffff821e57f0 241 FUNC LOCAL DEFAULT 1 __do_fast_syscall_32 So there are symbols that are not being resolved anymore that were before your patch, namely: arch/x86/entry/entry_64.S nmi_no_fsgsbase: /* EBX == 0 -> invoke SWAPGS */ testl %ebx, %ebx jnz nmi_restore nmi_swapgs: swapgs nmi_restore: POP_REGS - Arnaldo