From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752365AbeEVK5N (ORCPT ); Tue, 22 May 2018 06:57:13 -0400 Received: from mga17.intel.com ([192.55.52.151]:56463 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751354AbeEVK5I (ORCPT ); Tue, 22 May 2018 06:57:08 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,429,1520924400"; d="scan'208";a="60711646" From: Adrian Hunter To: Thomas Gleixner , Arnaldo Carvalho de Melo Cc: Ingo Molnar , Peter Zijlstra , Andy Lutomirski , "H. Peter Anvin" , Andi Kleen , Alexander Shishkin , Dave Hansen , Joerg Roedel , Jiri Olsa , linux-kernel@vger.kernel.org, x86@kernel.org Subject: [PATCH V3 17/17] perf buildid-cache: kcore_copy: Amend the offset of sections that remap kernel text Date: Tue, 22 May 2018 13:54:45 +0300 Message-Id: <1526986485-6562-18-git-send-email-adrian.hunter@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1526986485-6562-1-git-send-email-adrian.hunter@intel.com> References: <1526986485-6562-1-git-send-email-adrian.hunter@intel.com> Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org x86 PTI entry trampolines all map to the same physical page. If that is reflected in the program headers of /proc/kcore, then do the same for the copy of kcore. Signed-off-by: Adrian Hunter --- tools/perf/util/symbol-elf.c | 53 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 51 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 584966913aeb..29770ea61768 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1390,6 +1390,7 @@ struct phdr_data { u64 addr; u64 len; struct list_head node; + struct phdr_data *remaps; }; struct sym_data { @@ -1597,16 +1598,62 @@ static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf) return 0; } +static void kcore_copy__find_remaps(struct kcore_copy_info *kci) +{ + struct phdr_data *p, *k = NULL; + u64 kend; + + if (!kci->stext) + return; + + /* Find phdr that corresponds to the kernel map (contains stext) */ + kcore_copy__for_each_phdr(kci, p) { + u64 pend = p->addr + p->len - 1; + + if (p->addr <= kci->stext && pend >= kci->stext) { + k = p; + break; + } + } + + if (!k) + return; + + kend = k->offset + k->len; + + /* Find phdrs that remap the kernel */ + kcore_copy__for_each_phdr(kci, p) { + u64 pend = p->offset + p->len; + + if (p == k) + continue; + + if (p->offset >= k->offset && pend <= kend) + p->remaps = k; + } +} + static void kcore_copy__layout(struct kcore_copy_info *kci) { struct phdr_data *p; off_t rel = 0; + kcore_copy__find_remaps(kci); + kcore_copy__for_each_phdr(kci, p) { - p->rel = rel; - rel += p->len; + if (!p->remaps) { + p->rel = rel; + rel += p->len; + } kci->phnum += 1; } + + kcore_copy__for_each_phdr(kci, p) { + struct phdr_data *k = p->remaps; + + if (k) + p->rel = p->offset - k->offset + k->rel; + } } static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir, @@ -1821,6 +1868,8 @@ int kcore_copy(const char *from_dir, const char *to_dir) kcore_copy__for_each_phdr(&kci, p) { off_t offs = p->rel + offset; + if (p->remaps) + continue; if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len)) goto out_extract_close; } -- 1.9.1