From patchwork Fri Nov 15 16:45:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shile Zhang X-Patchwork-Id: 11246805 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3FEA213BD for ; Fri, 15 Nov 2019 16:46:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 18A9120723 for ; Fri, 15 Nov 2019 16:46:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727802AbfKOQqq (ORCPT ); Fri, 15 Nov 2019 11:46:46 -0500 Received: from out30-43.freemail.mail.aliyun.com ([115.124.30.43]:35509 "EHLO out30-43.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727625AbfKOQqp (ORCPT ); Fri, 15 Nov 2019 11:46:45 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04407;MF=shile.zhang@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0TiAOFJs_1573836341; Received: from e18g09479.et15sqa.tbsite.net(mailfrom:shile.zhang@linux.alibaba.com fp:SMTPD_---0TiAOFJs_1573836341) by smtp.aliyun-inc.com(127.0.0.1); Sat, 16 Nov 2019 00:45:50 +0800 From: Shile Zhang To: Peter Zijlstra , Josh Poimboeuf , Masahiro Yamada , Michal Marek , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org Cc: "H . Peter Anvin" , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, Shile Zhang Subject: [RFC PATCH v4 6/7] scripts/sorttable: Add ORC unwind tables sort concurrently Date: Sat, 16 Nov 2019 00:45:38 +0800 Message-Id: <20191115164539.57930-7-shile.zhang@linux.alibaba.com> X-Mailer: git-send-email 2.24.0.rc2 In-Reply-To: <20191115164539.57930-1-shile.zhang@linux.alibaba.com> References: <20191115164539.57930-1-shile.zhang@linux.alibaba.com> MIME-Version: 1.0 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org ORC unwinder have two tables, .orc_unwind_ip and .orc_unwind, which needs sorted for binary search. To sort it at build time can save more CPU cycles help to speed up kernel booting. Add the ORC tables sorting in a sperated thread helps to avoid more link cost of kernel building. https://lore.kernel.org/lkml/20191108092136.GH4114@hirez.programming.kicks-ass.net/ Suggested-by: Peter Zijlstra Signed-off-by: Shile Zhang --- scripts/Makefile | 6 ++ scripts/sorttable.h | 201 ++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 202 insertions(+), 5 deletions(-) diff --git a/scripts/Makefile b/scripts/Makefile index 658d201f7f8b..d6670bd420f6 100644 --- a/scripts/Makefile +++ b/scripts/Makefile @@ -26,6 +26,12 @@ HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include HOSTLDLIBS_sign-file = -lcrypto HOSTLDLIBS_extract-cert = -lcrypto +ifdef CONFIG_UNWINDER_ORC +HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/$(ARCH)/include +HOSTCFLAGS_sorttable.o += -DUNWINDER_ORC_ENABLED +HOSTLDLIBS_sorttable = -lpthread +endif + always := $(hostprogs-y) $(hostprogs-m) # The following hostprogs-y programs are only build on demand diff --git a/scripts/sorttable.h b/scripts/sorttable.h index 82589ff90e25..41c8dd9c75fc 100644 --- a/scripts/sorttable.h +++ b/scripts/sorttable.h @@ -4,6 +4,14 @@ * * Copyright 2011 - 2012 Cavium, Inc. * + * Added ORC unwind tables sort support, and other updates: + * Copyright (C) 1999-2019 Alibaba Group Holding Limited. by: + * Shile Zhang + * + * Some of code was taken out of /lib/sort.c, and + * arch/x86/kernel/unwind_orc.c written by: + * Copyright (C) 2017 Josh Poimboeuf + * * Some of this code was taken out of recordmcount.h written by: * * Copyright 2009 John F. Reiser . All rights reserved. @@ -75,6 +83,131 @@ # define _w w #endif +#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) +/* ORC unwinder only support X86_64 */ +#include +#include +#include + +int *g_orc_ip_table; +struct orc_entry *g_orc_table; + +pthread_t orc_sort_thread; + +/** + * sort - sort an array of elements + * @base: pointer to data to sort + * @num: number of elements + * @size: size of each element + * @cmp_func: pointer to comparison function + * @swap_func: pointer to swap function + * + * This function does a heapsort on the given array. You may provide a + * swap_func function optimized to your element type. + * + * Sorting time is O(n log n) both on average and worst-case. While + * qsort is about 20% faster on average, it suffers from exploitable + * O(n*n) worst-case behavior and extra memory requirements that make + * it less suitable for kernel use. + * + * This code token out of /lib/sort.c. + */ +static void sort(void *base, size_t num, size_t size, + int (*cmp_func)(const void *, const void *), + void (*swap_func)(void *, void *, int size)) +{ + /* pre-scale counters for performance */ + int i = (num/2 - 1) * size, n = num * size, c, r; + + /* heapify */ + for ( ; i >= 0; i -= size) { + for (r = i; r * 2 + size < n; r = c) { + c = r * 2 + size; + if (c < n - size && + cmp_func(base + c, base + c + size) < 0) + c += size; + if (cmp_func(base + r, base + c) >= 0) + break; + swap_func(base + r, base + c, size); + } + } + + /* sort */ + for (i = n - size; i > 0; i -= size) { + swap_func(base, base + i, size); + for (r = 0; r * 2 + size < i; r = c) { + c = r * 2 + size; + if (c < i - size && + cmp_func(base + c, base + c + size) < 0) + c += size; + if (cmp_func(base + r, base + c) >= 0) + break; + swap_func(base + r, base + c, size); + } + } +} + +static inline unsigned long orc_ip(const int *ip) +{ + return (unsigned long)ip + *ip; +} + +static void orc_sort_swap(void *_a, void *_b, int size) +{ + struct orc_entry *orc_a, *orc_b; + struct orc_entry orc_tmp; + int *a = _a, *b = _b, tmp; + int delta = _b - _a; + + /* Swap the .orc_unwind_ip entries: */ + tmp = *a; + *a = *b + delta; + *b = tmp - delta; + + /* Swap the corresponding .orc_unwind entries: */ + orc_a = g_orc_table + (a - g_orc_ip_table); + orc_b = g_orc_table + (b - g_orc_ip_table); + orc_tmp = *orc_a; + *orc_a = *orc_b; + *orc_b = orc_tmp; +} + +static int orc_sort_cmp(const void *_a, const void *_b) +{ + struct orc_entry *orc_a; + const int *a = _a, *b = _b; + unsigned long a_val = orc_ip(a); + unsigned long b_val = orc_ip(b); + + if (a_val > b_val) + return 1; + if (a_val < b_val) + return -1; + + /* + * The "weak" section terminator entries need to always be on the left + * to ensure the lookup code skips them in favor of real entries. + * These terminator entries exist to handle any gaps created by + * whitelisted .o files which didn't get objtool generation. + */ + orc_a = g_orc_table + (a - g_orc_ip_table); + return orc_a->sp_reg == ORC_REG_UNDEFINED && !orc_a->end ? -1 : 1; +} + +static void *sort_orctable(void *arg) +{ + unsigned int *size = (unsigned int *)arg; + unsigned int num_entries; + + num_entries = *size / sizeof(int); + + sort(g_orc_ip_table, num_entries, sizeof(int), + orc_sort_cmp, orc_sort_swap); + + pthread_exit(NULL); +} +#endif + static int compare_extable(const void *a, const void *b) { Elf_Addr av = _r(a); @@ -91,6 +224,7 @@ static int do_sort(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort) { + int rc = -1; Elf_Shdr *s, *shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff)); Elf_Shdr *strtab_sec = NULL; Elf_Shdr *symtab_sec = NULL; @@ -111,6 +245,11 @@ static int do_sort(Elf_Ehdr *ehdr, int idx; unsigned int shnum; unsigned int shstrndx; +#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) + unsigned int orc_ip_size = 0; + unsigned int orc_size = 0; + unsigned int orc_num_entries = 0; +#endif shstrndx = r2(&ehdr->e_shstrndx); if (shstrndx == SHN_XINDEX) @@ -141,21 +280,61 @@ static int do_sort(Elf_Ehdr *ehdr, if (r(&s->sh_type) == SHT_SYMTAB_SHNDX) symtab_shndx = (Elf32_Word *)((const char *)ehdr + _r(&s->sh_offset)); + +#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) + /* locate the ORC unwind tables */ + if (!strcmp(secstrings + idx, ".orc_unwind_ip")) { + orc_ip_size = s->sh_size; + g_orc_ip_table = (int *)((void *)ehdr + + s->sh_offset); + } + if (!strcmp(secstrings + idx, ".orc_unwind")) { + orc_size = s->sh_size; + g_orc_table = (struct orc_entry *)((void *)ehdr + + s->sh_offset); + } +#endif + } /* for loop */ + +#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) + if (!g_orc_ip_table || !g_orc_table) { + fprintf(stderr, + "incomplete ORC unwind tables in file: %s\n", fname); + goto out; + } + + orc_num_entries = orc_ip_size / sizeof(int); + if (orc_ip_size % sizeof(int) != 0 || + orc_size % sizeof(struct orc_entry) != 0 || + orc_num_entries != orc_size / sizeof(struct orc_entry)) { + fprintf(stderr, + "inconsistent ORC unwind table entries in file: %s\n", + fname); + goto out; } + /* create thread to sort ORC unwind tables concurrently */ + if (pthread_create(&orc_sort_thread, NULL, + sort_orctable, &orc_ip_size)) { + fprintf(stderr, + "pthread_create orc_sort_thread failed '%s': %s\n", + strerror(errno), fname); + goto out; + } +#endif if (!extab_sec) { fprintf(stderr, "no __ex_table in file: %s\n", fname); - return -1; + goto out; } if (!symtab_sec) { fprintf(stderr, "no .symtab in file: %s\n", fname); - return -1; + goto out; } if (!strtab_sec) { fprintf(stderr, "no .strtab in file: %s\n", fname); - return -1; + goto out; } extab_image = (void *)ehdr + _r(&extab_sec->sh_offset); @@ -192,7 +371,7 @@ static int do_sort(Elf_Ehdr *ehdr, fprintf(stderr, "no main_extable_sort_needed symbol in file: %s\n", fname); - return -1; + goto out; } sort_needed_sec = &shdr[get_secindex(r2(&sym->st_shndx), @@ -205,6 +384,18 @@ static int do_sort(Elf_Ehdr *ehdr, /* extable has been sorted, clear the flag */ w(0, sort_needed_loc); + rc = 0; - return 0; +out: +#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) + if (orc_sort_thread) { + /* wait for ORC tables sort done */ + rc = pthread_join(orc_sort_thread, NULL); + if (rc) + fprintf(stderr, + "pthread_join orc_sort_thread failed " + "'%s': %s\n", strerror(errno), fname); + } +#endif + return rc; }