]> asedeno.scripts.mit.edu Git - linux.git/commitdiff
scripts/sorttable: Implement build-time ORC unwind table sorting
authorShile Zhang <shile.zhang@linux.alibaba.com>
Wed, 4 Dec 2019 00:46:32 +0000 (08:46 +0800)
committerIngo Molnar <mingo@kernel.org>
Fri, 13 Dec 2019 09:47:58 +0000 (10:47 +0100)
The ORC unwinder has two tables: .orc_unwind_ip and .orc_unwind, which
need to be sorted for binary search. Previously this sorting was done
during bootup.

Sort them at build time to speed up booting.

Add the ORC tables sorting in a parallel build process to speed up the build.

[ mingo: Rewrote the changelog and fixed some comments. ]

Suggested-by: Andy Lutomirski <luto@amacapital.net>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: linux-kbuild@vger.kernel.org
Link: https://lkml.kernel.org/r/20191204004633.88660-7-shile.zhang@linux.alibaba.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
scripts/Makefile
scripts/sorttable.c
scripts/sorttable.h

index 7491241e3a0d088bf16f361d67446164bf2de4a2..b0e962611d5062f7ee2a0e240f48d0674b28201d 100644 (file)
@@ -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
index ff98b7db20c6793f6dca2d338959264f23692c54..ec6b5e81eba190b01e258feb64ebd341d0f1c4ed 100644 (file)
@@ -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:
@@ -9,7 +13,7 @@
  * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
  *
  * Restructured to fit Linux format, as well as other updates:
- *  Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
+ * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
  */
 
 /*
index 82589ff90e259feda49d4f83dff5afbfdc88234b..a2baa2fefb137935e0fb2b45932e9106d6c86910 100644 (file)
@@ -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.
 # 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;
 }