scripts/sortextable: Handle relative entries, and other cleanups
x86 is now using relative rather than absolute addresses in its
exception table, so we add a sorter for these. If there are
relocations on the __ex_table section, they are redundant and probably
incorrect after the sort, so they are zeroed out leaving them valid
and consistent.
Also use the unaligned safe accessors from tools/{be,le}_byteshift.h
Signed-off-by: David Daney <david.daney@cavium.com>
Link: http://lkml.kernel.org/r/1335291795-26693-2-git-send-email-ddaney.cavm@gmail.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This commit is contained in:
David Daney
H. Peter Anvin
parent
706276543b
commit
d59a16836d
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@ -15,6 +15,8 @@ hostprogs-$(CONFIG_IKCONFIG) += bin2c
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hostprogs-$(BUILD_C_RECORDMCOUNT) += recordmcount
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hostprogs-$(CONFIG_BUILDTIME_EXTABLE_SORT) += sortextable
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HOSTCFLAGS_sortextable.o = -I$(srctree)/tools/include
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always := $(hostprogs-y) $(hostprogs-m)
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# The following hostprogs-y programs are only build on demand
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@ -1,7 +1,7 @@
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/*
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* sortextable.c: Sort the kernel's exception table
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*
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* Copyright 2011 Cavium, Inc.
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* Copyright 2011 - 2012 Cavium, Inc.
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*
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* Based on code taken from recortmcount.c which is:
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*
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@ -28,6 +28,9 @@
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#include <string.h>
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#include <unistd.h>
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#include <tools/be_byteshift.h>
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#include <tools/le_byteshift.h>
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static int fd_map; /* File descriptor for file being modified. */
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static int mmap_failed; /* Boolean flag. */
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static void *ehdr_curr; /* current ElfXX_Ehdr * for resource cleanup */
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@ -94,109 +97,157 @@ static void *mmap_file(char const *fname)
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return addr;
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}
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/* w8rev, w8nat, ...: Handle endianness. */
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static uint64_t w8rev(uint64_t const x)
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static uint64_t r8be(const uint64_t *x)
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{
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return ((0xff & (x >> (0 * 8))) << (7 * 8))
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| ((0xff & (x >> (1 * 8))) << (6 * 8))
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| ((0xff & (x >> (2 * 8))) << (5 * 8))
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| ((0xff & (x >> (3 * 8))) << (4 * 8))
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| ((0xff & (x >> (4 * 8))) << (3 * 8))
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| ((0xff & (x >> (5 * 8))) << (2 * 8))
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| ((0xff & (x >> (6 * 8))) << (1 * 8))
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| ((0xff & (x >> (7 * 8))) << (0 * 8));
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return get_unaligned_be64(x);
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}
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static uint32_t rbe(const uint32_t *x)
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{
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return get_unaligned_be32(x);
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}
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static uint16_t r2be(const uint16_t *x)
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{
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return get_unaligned_be16(x);
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}
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static uint64_t r8le(const uint64_t *x)
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{
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return get_unaligned_le64(x);
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}
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static uint32_t rle(const uint32_t *x)
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{
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return get_unaligned_le32(x);
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}
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static uint16_t r2le(const uint16_t *x)
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{
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return get_unaligned_le16(x);
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}
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static uint32_t w4rev(uint32_t const x)
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static void w8be(uint64_t val, uint64_t *x)
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{
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return ((0xff & (x >> (0 * 8))) << (3 * 8))
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| ((0xff & (x >> (1 * 8))) << (2 * 8))
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| ((0xff & (x >> (2 * 8))) << (1 * 8))
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| ((0xff & (x >> (3 * 8))) << (0 * 8));
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put_unaligned_be64(val, x);
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}
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static void wbe(uint32_t val, uint32_t *x)
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{
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put_unaligned_be32(val, x);
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}
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static void w2be(uint16_t val, uint16_t *x)
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{
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put_unaligned_be16(val, x);
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}
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static void w8le(uint64_t val, uint64_t *x)
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{
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put_unaligned_le64(val, x);
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}
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static void wle(uint32_t val, uint32_t *x)
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{
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put_unaligned_le32(val, x);
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}
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static void w2le(uint16_t val, uint16_t *x)
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{
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put_unaligned_le16(val, x);
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}
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static uint32_t w2rev(uint16_t const x)
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{
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return ((0xff & (x >> (0 * 8))) << (1 * 8))
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| ((0xff & (x >> (1 * 8))) << (0 * 8));
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}
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static uint64_t w8nat(uint64_t const x)
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{
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return x;
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}
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static uint32_t w4nat(uint32_t const x)
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{
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return x;
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}
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static uint32_t w2nat(uint16_t const x)
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{
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return x;
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}
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static uint64_t (*w8)(uint64_t);
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static uint32_t (*w)(uint32_t);
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static uint32_t (*w2)(uint16_t);
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static uint64_t (*r8)(const uint64_t *);
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static uint32_t (*r)(const uint32_t *);
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static uint16_t (*r2)(const uint16_t *);
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static void (*w8)(uint64_t, uint64_t *);
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static void (*w)(uint32_t, uint32_t *);
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static void (*w2)(uint16_t, uint16_t *);
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typedef void (*table_sort_t)(char *, int);
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/* 32 bit and 64 bit are very similar */
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#include "sortextable.h"
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#define SORTEXTABLE_64
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#include "sortextable.h"
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static int compare_x86_table(const void *a, const void *b)
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{
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int32_t av = (int32_t)r(a);
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int32_t bv = (int32_t)r(b);
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if (av < bv)
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return -1;
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if (av > bv)
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return 1;
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return 0;
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}
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static void sort_x86_table(char *extab_image, int image_size)
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{
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int i;
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/*
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* Do the same thing the runtime sort does, first normalize to
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* being relative to the start of the section.
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*/
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i = 0;
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while (i < image_size) {
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uint32_t *loc = (uint32_t *)(extab_image + i);
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w(r(loc) + i, loc);
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i += 4;
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}
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qsort(extab_image, image_size / 8, 8, compare_x86_table);
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/* Now denormalize. */
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i = 0;
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while (i < image_size) {
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uint32_t *loc = (uint32_t *)(extab_image + i);
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w(r(loc) - i, loc);
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i += 4;
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}
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}
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static void
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do_file(char const *const fname)
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{
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Elf32_Ehdr *const ehdr = mmap_file(fname);
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table_sort_t custom_sort;
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Elf32_Ehdr *ehdr = mmap_file(fname);
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ehdr_curr = ehdr;
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w = w4nat;
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w2 = w2nat;
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w8 = w8nat;
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switch (ehdr->e_ident[EI_DATA]) {
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static unsigned int const endian = 1;
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default:
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fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
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ehdr->e_ident[EI_DATA], fname);
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fail_file();
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break;
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case ELFDATA2LSB:
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if (*(unsigned char const *)&endian != 1) {
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/* main() is big endian, file.o is little endian. */
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w = w4rev;
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w2 = w2rev;
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w8 = w8rev;
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}
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r = rle;
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r2 = r2le;
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r8 = r8le;
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w = wle;
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w2 = w2le;
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w8 = w8le;
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break;
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case ELFDATA2MSB:
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if (*(unsigned char const *)&endian != 0) {
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/* main() is little endian, file.o is big endian. */
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w = w4rev;
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w2 = w2rev;
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w8 = w8rev;
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}
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r = rbe;
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r2 = r2be;
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r8 = r8be;
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w = wbe;
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w2 = w2be;
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w8 = w8be;
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break;
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} /* end switch */
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if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0
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|| w2(ehdr->e_type) != ET_EXEC
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|| r2(&ehdr->e_type) != ET_EXEC
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|| ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
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fprintf(stderr, "unrecognized ET_EXEC file %s\n", fname);
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fail_file();
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}
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switch (w2(ehdr->e_machine)) {
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custom_sort = NULL;
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switch (r2(&ehdr->e_machine)) {
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default:
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fprintf(stderr, "unrecognized e_machine %d %s\n",
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w2(ehdr->e_machine), fname);
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r2(&ehdr->e_machine), fname);
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fail_file();
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break;
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case EM_386:
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case EM_MIPS:
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case EM_X86_64:
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custom_sort = sort_x86_table;
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break;
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case EM_MIPS:
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break;
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} /* end switch */
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@ -207,23 +258,23 @@ do_file(char const *const fname)
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fail_file();
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break;
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case ELFCLASS32:
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if (w2(ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
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|| w2(ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
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if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr)
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|| r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
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fprintf(stderr,
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"unrecognized ET_EXEC file: %s\n", fname);
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fail_file();
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}
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do32(ehdr, fname);
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do32(ehdr, fname, custom_sort);
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break;
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case ELFCLASS64: {
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Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
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if (w2(ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
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|| w2(ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
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if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr)
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|| r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
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fprintf(stderr,
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"unrecognized ET_EXEC file: %s\n", fname);
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fail_file();
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}
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do64(ghdr, fname);
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do64(ghdr, fname, custom_sort);
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break;
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}
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} /* end switch */
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@ -1,7 +1,7 @@
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/*
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* sortextable.h
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*
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* Copyright 2011 Cavium, Inc.
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* Copyright 2011 - 2012 Cavium, Inc.
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*
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* Some of this code was taken out of recordmcount.h written by:
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*
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@ -30,6 +30,7 @@
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#undef fn_ELF_R_SYM
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#undef fn_ELF_R_INFO
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#undef uint_t
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#undef _r
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#undef _w
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#ifdef SORTEXTABLE_64
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@ -51,6 +52,7 @@
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# define fn_ELF_R_SYM fn_ELF64_R_SYM
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# define fn_ELF_R_INFO fn_ELF64_R_INFO
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# define uint_t uint64_t
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# define _r r8
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# define _w w8
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#else
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# define extable_ent_size 8
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@ -71,23 +73,24 @@
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# define fn_ELF_R_SYM fn_ELF32_R_SYM
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# define fn_ELF_R_INFO fn_ELF32_R_INFO
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# define uint_t uint32_t
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# define _r r
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# define _w w
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#endif
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static int compare_extable(const void *a, const void *b)
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{
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const uint_t *aa = a;
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const uint_t *bb = b;
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Elf_Addr av = _r(a);
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Elf_Addr bv = _r(b);
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if (_w(*aa) < _w(*bb))
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if (av < bv)
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return -1;
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if (_w(*aa) > _w(*bb))
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if (av > bv)
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return 1;
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return 0;
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}
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static void
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do_func(Elf_Ehdr *const ehdr, char const *const fname)
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do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort)
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{
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Elf_Shdr *shdr;
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Elf_Shdr *shstrtab_sec;
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@ -97,19 +100,31 @@ do_func(Elf_Ehdr *const ehdr, char const *const fname)
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Elf_Sym *sym;
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Elf_Sym *sort_needed_sym;
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Elf_Shdr *sort_needed_sec;
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Elf_Rel *relocs = NULL;
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int relocs_size;
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uint32_t *sort_done_location;
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const char *secstrtab;
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const char *strtab;
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char *extab_image;
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int extab_index = 0;
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int i;
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int idx;
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shdr = (Elf_Shdr *)((void *)ehdr + _w(ehdr->e_shoff));
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shstrtab_sec = shdr + w2(ehdr->e_shstrndx);
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secstrtab = (const char *)ehdr + _w(shstrtab_sec->sh_offset);
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for (i = 0; i < w2(ehdr->e_shnum); i++) {
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idx = w(shdr[i].sh_name);
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if (strcmp(secstrtab + idx, "__ex_table") == 0)
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shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff));
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shstrtab_sec = shdr + r2(&ehdr->e_shstrndx);
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secstrtab = (const char *)ehdr + _r(&shstrtab_sec->sh_offset);
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for (i = 0; i < r2(&ehdr->e_shnum); i++) {
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idx = r(&shdr[i].sh_name);
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if (strcmp(secstrtab + idx, "__ex_table") == 0) {
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extab_sec = shdr + i;
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extab_index = i;
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}
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if ((r(&shdr[i].sh_type) == SHT_REL ||
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r(&shdr[i].sh_type) == SHT_RELA) &&
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r(&shdr[i].sh_info) == extab_index) {
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relocs = (void *)ehdr + _r(&shdr[i].sh_offset);
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relocs_size = _r(&shdr[i].sh_size);
|
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}
|
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if (strcmp(secstrtab + idx, ".symtab") == 0)
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symtab_sec = shdr + i;
|
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if (strcmp(secstrtab + idx, ".strtab") == 0)
|
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|
|
@ -127,21 +142,29 @@ do_func(Elf_Ehdr *const ehdr, char const *const fname)
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fprintf(stderr, "no __ex_table in file: %s\n", fname);
|
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fail_file();
|
||||
}
|
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strtab = (const char *)ehdr + _w(strtab_sec->sh_offset);
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strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset);
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|
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/* Sort the table in place */
|
||||
qsort((void *)ehdr + _w(extab_sec->sh_offset),
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(_w(extab_sec->sh_size) / extable_ent_size),
|
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extable_ent_size, compare_extable);
|
||||
extab_image = (void *)ehdr + _r(&extab_sec->sh_offset);
|
||||
|
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if (custom_sort) {
|
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custom_sort(extab_image, _r(&extab_sec->sh_size));
|
||||
} else {
|
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int num_entries = _r(&extab_sec->sh_size) / extable_ent_size;
|
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qsort(extab_image, num_entries,
|
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extable_ent_size, compare_extable);
|
||||
}
|
||||
/* If there were relocations, we no longer need them. */
|
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if (relocs)
|
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memset(relocs, 0, relocs_size);
|
||||
|
||||
/* find main_extable_sort_needed */
|
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sort_needed_sym = NULL;
|
||||
for (i = 0; i < _w(symtab_sec->sh_size) / sizeof(Elf_Sym); i++) {
|
||||
sym = (void *)ehdr + _w(symtab_sec->sh_offset);
|
||||
for (i = 0; i < _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); i++) {
|
||||
sym = (void *)ehdr + _r(&symtab_sec->sh_offset);
|
||||
sym += i;
|
||||
if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
|
||||
continue;
|
||||
idx = w(sym->st_name);
|
||||
idx = r(&sym->st_name);
|
||||
if (strcmp(strtab + idx, "main_extable_sort_needed") == 0) {
|
||||
sort_needed_sym = sym;
|
||||
break;
|
||||
|
|
@ -153,16 +176,16 @@ do_func(Elf_Ehdr *const ehdr, char const *const fname)
|
|||
fname);
|
||||
fail_file();
|
||||
}
|
||||
sort_needed_sec = &shdr[w2(sort_needed_sym->st_shndx)];
|
||||
sort_needed_sec = &shdr[r2(&sort_needed_sym->st_shndx)];
|
||||
sort_done_location = (void *)ehdr +
|
||||
_w(sort_needed_sec->sh_offset) +
|
||||
_w(sort_needed_sym->st_value) -
|
||||
_w(sort_needed_sec->sh_addr);
|
||||
_r(&sort_needed_sec->sh_offset) +
|
||||
_r(&sort_needed_sym->st_value) -
|
||||
_r(&sort_needed_sec->sh_addr);
|
||||
|
||||
#if 1
|
||||
printf("sort done marker at %lx\n",
|
||||
(unsigned long) (_w(sort_needed_sec->sh_offset) +
|
||||
_w(sort_needed_sym->st_value) -
|
||||
_w(sort_needed_sec->sh_addr)));
|
||||
(unsigned long)((char *)sort_done_location - (char *)ehdr));
|
||||
#endif
|
||||
/* We sorted it, clear the flag. */
|
||||
*sort_done_location = 0;
|
||||
w(0, sort_done_location);
|
||||
}
|
||||
|
|
|
|||
Reference in New Issue