scripts/sorttable: Implement build-time ORC unwind table sorting (57fa1899) · Commits · 戴 / test

scripts/Makefile

+9 −0

Original line number	Diff line number	Diff line
		@@ -24,6 +24,15 @@ HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include
		HOSTLDLIBS_sign-file = -lcrypto
		HOSTLDLIBS_extract-cert = -lcrypto

		ifdef CONFIG_UNWINDER_ORC
		ifeq ($(ARCH),x86_64)
		ARCH := x86
		endif
		HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/x86/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

scripts/sorttable.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -2,6 +2,10 @@
		/*
		* sorttable.c: Sort the kernel's table
		*
		* Added ORC unwind tables sort support and other updates:
		* Copyright (C) 1999-2019 Alibaba Group Holding Limited. by:
		* Shile Zhang <shile.zhang@linux.alibaba.com>
		*
		* Copyright 2011 - 2012 Cavium, Inc.
		*
		* Based on code taken from recortmcount.c which is:

scripts/sorttable.h

+175 −5

Original line number	Diff line number	Diff line
		@@ -2,8 +2,15 @@
		/*
		* sorttable.h
		*
		* Added ORC unwind tables sort support and other updates:
		* Copyright (C) 1999-2019 Alibaba Group Holding Limited. by:
		* Shile Zhang <shile.zhang@linux.alibaba.com>
		*
		* Copyright 2011 - 2012 Cavium, Inc.
		*
		* Some of code was taken out of arch/x86/kernel/unwind_orc.c, written by:
		* Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
		*
		* Some of this code was taken out of recordmcount.h written by:
		*
		* Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
		@@ -75,6 +82,104 @@
		# define _w w
		#endif

		#if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED)
		/* ORC unwinder only support X86_64 */
		#include <errno.h>
		#include <pthread.h>
		#include <asm/orc_types.h>

		#define ERRSTR_MAXSZ 256

		char g_err[ERRSTR_MAXSZ];
		int *g_orc_ip_table;
		struct orc_entry *g_orc_table;

		pthread_t orc_sort_thread;

		static inline unsigned long orc_ip(const int *ip)
		{
		return (unsigned long)ip + *ip;
		}

		static int orc_sort_cmp(const void _a, const void _b)
		{
		struct orc_entry *orc_a;
		const int a = g_orc_ip_table + (int *)_a;
		const int b = g_orc_ip_table + (int *)_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)
		{
		int i;
		int *idxs = NULL;
		int *tmp_orc_ip_table = NULL;
		struct orc_entry *tmp_orc_table = NULL;
		unsigned int orc_ip_size = (unsigned int )arg;
		unsigned int num_entries = *orc_ip_size / sizeof(int);
		unsigned int orc_size = num_entries * sizeof(struct orc_entry);

		idxs = (int )malloc(orc_ip_size);
		if (!idxs) {
		snprintf(g_err, ERRSTR_MAXSZ, "malloc idxs: %s",
		strerror(errno));
		pthread_exit(g_err);
		}

		tmp_orc_ip_table = (int )malloc(orc_ip_size);
		if (!tmp_orc_ip_table) {
		snprintf(g_err, ERRSTR_MAXSZ, "malloc tmp_orc_ip_table: %s",
		strerror(errno));
		pthread_exit(g_err);
		}

		tmp_orc_table = (struct orc_entry *)malloc(orc_size);
		if (!tmp_orc_table) {
		snprintf(g_err, ERRSTR_MAXSZ, "malloc tmp_orc_table: %s",
		strerror(errno));
		pthread_exit(g_err);
		}

		/* initialize indices array, convert ip_table to absolute address */
		for (i = 0; i < num_entries; i++) {
		idxs[i] = i;
		tmp_orc_ip_table[i] = g_orc_ip_table[i] + i * sizeof(int);
		}
		memcpy(tmp_orc_table, g_orc_table, orc_size);

		qsort(idxs, num_entries, sizeof(int), orc_sort_cmp);

		for (i = 0; i < num_entries; i++) {
		if (idxs[i] == i)
		continue;

		/* convert back to relative address */
		g_orc_ip_table[i] = tmp_orc_ip_table[idxs[i]] - i * sizeof(int);
		g_orc_table[i] = tmp_orc_table[idxs[i]];
		}

		free(idxs);
		free(tmp_orc_ip_table);
		free(tmp_orc_table);
		pthread_exit(NULL);
		}
		#endif

		static int compare_extable(const void a, const void b)
		{
		Elf_Addr av = _r(a);
		@@ -91,6 +196,7 @@ 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 +217,11 @@ 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 +252,61 @@ 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 +343,7 @@ 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 +356,25 @@ 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) {
		void *retval = NULL;
		/* wait for ORC tables sort done */
		rc = pthread_join(orc_sort_thread, &retval);
		if (rc)
		fprintf(stderr,
		"pthread_join failed '%s': %s\n",
		strerror(errno), fname);
		else if (retval) {
		rc = -1;
		fprintf(stderr,
		"failed to sort ORC tables '%s': %s\n",
		(char *)retval, fname);
		}
		}
		#endif
		return rc;
		}

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