[PATCH v1 3/5] Calculate CRC64 over the .text area
binutils@emagii.com
binutils@emagii.com
Fri Feb 17 13:54:44 GMT 2023
From: Ulf Samuelsson <binutils@emagii.com>
Signed-off-by: Ulf Samuelsson <binutils@emagii.com>
---
ld/Makefile.am | 2 +-
ld/checksum.h | 48 ++++++++
ld/ldlang.c | 308 +++++++++++++++++++++++++++++++++++++++++++++++++
ld/ldlang.h | 8 ++
ld/ldmain.c | 1 +
5 files changed, 366 insertions(+), 1 deletion(-)
create mode 100755 ld/checksum.h
diff --git a/ld/Makefile.am b/ld/Makefile.am
index 760225c5b88..91b024d1cba 100644
--- a/ld/Makefile.am
+++ b/ld/Makefile.am
@@ -481,7 +481,7 @@ CFILES = ldctor.c ldemul.c ldexp.c ldfile.c ldlang.c \
plugin.c ldbuildid.c ldelf.c ldelfgen.c \
pdb.c
-HFILES = ld.h ldctor.h ldemul.h ldexp.h ldfile.h \
+HFILES = checksum.h ld.h ldctor.h ldemul.h ldexp.h ldfile.h \
ldlang.h ldlex.h ldmain.h ldmisc.h ldver.h \
ldwrite.h mri.h deffile.h pe-dll.h pep-dll.h \
elf-hints-local.h plugin.h ldbuildid.h ldelf.h ldelfgen.h \
diff --git a/ld/checksum.h b/ld/checksum.h
new file mode 100755
index 00000000000..16a8db170e7
--- /dev/null
+++ b/ld/checksum.h
@@ -0,0 +1,48 @@
+/*
+ * Library: libcrc
+ * Author: Lammert Bies
+ *
+ * This file is licensed under the MIT License as stated below
+ *
+ * Copyright (c) 2016 Lammert Bies
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#ifndef CHECKSUM_H
+#define CHECKSUM_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define CRC_POLY_64 0x42F0E1EBA9EA3693ull
+#define CRC_POLY_64_ISO 0xD800000000000000ull
+#define CRC_START_64 0x0000000000000000ull
+#define CRC_START_64_INV 0xFFFFFFFFFFFFFFFFull
+
+#define CRC_ADDRESS "___CRC64___"
+#define CRC_START "___CRC64_START___"
+#define CRC_END "___CRC64_END___"
+#define CRC_TABLE "___CRC64_TABLE___"
+
+bfd_vma crc_64 (const unsigned char *input_str, size_t num_bytes);
+bfd_vma crc_64_inv(const unsigned char *input_str, size_t num_bytes);
+
+#endif /* CHECKSUM_H */
diff --git a/ld/ldlang.c b/ld/ldlang.c
index 2852a4222d3..5e424770f46 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -18,6 +18,8 @@
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
+#define DEBUG_CRC 1
+
#include "sysdep.h"
#include <limits.h>
#include "bfd.h"
@@ -42,6 +44,8 @@
#include "demangle.h"
#include "hashtab.h"
#include "elf-bfd.h"
+#include "checksum.h"
+
#if BFD_SUPPORTS_PLUGINS
#include "plugin.h"
#endif /* BFD_SUPPORTS_PLUGINS */
@@ -145,6 +149,11 @@ int lang_statement_iteration = 0;
/* Count times through one_lang_size_sections_pass after mark phase. */
static int lang_sizing_iteration = 0;
+/* CRC calculation on output section */
+bfd_vma crc64_poly = CRC_POLY_64; /* Default Polynome is CRC64 ECMA */
+bfd_vma *crc64_tab = NULL;
+bool crc64_invert= false;
+
/* Return TRUE if the PATTERN argument is a wildcard pattern.
Although backslashes are treated specially if a pattern contains
wildcards, we do not consider the mere presence of a backslash to
@@ -8524,6 +8533,305 @@ lang_add_attribute (enum statement_enum attribute)
new_statement (attribute, sizeof (lang_statement_header_type), stat_ptr);
}
+/*
+ * bfd_vma *init_crc64_tab( bfd_vma poly ) ;
+ *
+ * For optimal speed, the CRC64 calculation uses a table with pre-calculated
+ * bit patterns which are used in the XOR operations in the program.
+ * init_crc64_tab is copyright (c) 2016 Lammert Bies
+ */
+static
+bfd_vma *init_crc64_tab( bfd_vma poly ) {
+
+ bfd_vma i;
+ bfd_vma j;
+ bfd_vma c;
+ bfd_vma crc;
+ bfd_vma *crc_tab;
+
+ crc_tab = malloc(256 * sizeof(bfd_vma));
+ if (crc_tab == NULL)
+ return NULL;
+
+ for (i=0; i<256; i++) {
+
+ crc = 0;
+ c = i << 56;
+
+ for (j=0; j<8; j++) {
+
+ if ( ( crc ^ c ) & 0x8000000000000000ull )
+ crc = ( crc << 1 ) ^ poly;
+ else
+ crc = crc << 1;
+
+ c = c << 1;
+ }
+
+ crc_tab[i] = crc;
+ }
+ return crc_tab;
+
+} /* init_crc64_tab */
+
+/*
+ * The function crc_64_inv() calculates in one pass the CRC64 64 bit CRC
+ * value for a byte string that is passed to the function together with a
+ * parameter indicating the length.
+ * This is used for CRC64-WE
+ * crc_64_inv is copyright (c) 2016 Lammert Bies
+ */
+
+bfd_vma crc_64_inv( const unsigned char *input_str, size_t num_bytes ) {
+
+ bfd_vma crc;
+ const unsigned char *ptr;
+ size_t a;
+
+ crc = CRC_START_64_INV;
+ ptr = input_str;
+
+ if ( ptr != NULL ) {
+ for (a=0; a<num_bytes; a++) {
+ crc = (crc << 8) ^
+ crc64_tab[
+ ((crc >> 56) ^ (bfd_vma) *ptr++) &
+ 0x00000000000000FFull
+ ];
+ }
+ }
+
+ return crc ^ 0xFFFFFFFFFFFFFFFFull;
+
+} /* crc_64_inv */
+
+/*
+ * bfd_vma crc_64( const unsigned char *input_str, size_t num_bytes );
+ *
+ * The function crc_64() calculates in one pass the 64 bit CRC value
+ * for a byte string that is passed to the function together with a
+ * parameter indicating the length.
+ * This is used for CRC64-ECMA and CRC64-ISO
+ * crc_64 is copyright (c) 2016 Lammert Bies
+ */
+
+bfd_vma crc_64(const unsigned char *input_str, size_t num_bytes)
+{
+ bfd_vma crc;
+ const unsigned char *ptr;
+ size_t a;
+ if (crc64_invert)
+ return crc_64_inv(input_str, num_bytes);
+ crc = CRC_START_64;
+ ptr = input_str;
+ if ( ptr != NULL ) {
+ for (a=0; a<num_bytes; a++) {
+ crc = (crc << 8) ^
+ crc64_tab[
+ ((crc >> 56) ^ (bfd_vma) *ptr++) &
+ 0x00000000000000FFull
+ ];
+ }
+ }
+ return crc;
+} /* crc_64 */
+
+extern void lang_add_crc_syndrome(bool invert, bfd_vma poly)
+{
+ crc64_poly = poly; /* Set the polynom */
+ crc64_invert = invert;
+#if (DEBUG_CRC == 1)
+ printf("Adding Syndrome: 0x%08lx\n", poly);
+#endif
+ lang_add_data (QUAD, exp_intop (0)); /* Reserve room for the ECC value */
+ if (crc64_tab == NULL)
+ {
+ crc64_tab = init_crc64_tab(crc64_poly);
+ }
+ else
+ {
+ einfo (_("%P:%pS: warning: CRC polynome declared twice (ignored)\n"),
+ NULL);
+ }
+}
+
+extern void lang_add_crc_table(void)
+{
+ if (crc64_tab == NULL)
+ {
+ crc64_tab = init_crc64_tab(crc64_poly);
+ if (crc64_tab == NULL)
+ {
+ einfo (_("%F%P: can not allocate memory for CRC table: %E\n"));
+ return;
+ }
+ }
+ for (bfd_vma i = 0 ; i < 256 ; i++)
+ {
+ lang_add_data (QUAD, exp_intop (crc64_tab[i]));
+ }
+}
+
+static bool symbol_lookup(char *name, bfd_vma *val)
+{
+ struct bfd_link_hash_entry *h;
+ h = bfd_link_hash_lookup (link_info.hash, name,
+ false, false, true);
+ if (h != NULL)
+ {
+ if ((h->type == bfd_link_hash_defined
+ || h->type == bfd_link_hash_defweak)
+ && h->u.def.section->output_section != NULL)
+ {
+ *val = (h->u.def.value
+ + bfd_section_vma (h->u.def.section->output_section)
+ + h->u.def.section->output_offset);
+ return true;
+ }
+ }
+ return false;
+}
+
+#if (DEBUG_CRC == 1)
+static void output_hex(char *prompt, unsigned char *section,
+ bfd_vma address, bfd_vma sz)
+{
+ bfd_vma *vma_section = (bfd_vma *) section;
+ bfd_vma size = (sz)/sizeof(bfd_vma);
+ printf("%s:\n", prompt);
+ for (bfd_vma i = 0 ; i < size ; i+=8)
+ {
+ printf("0x%08lx: 0x%016lx 0x%016lx 0x%016lx 0x%016lx\n",
+ address + (i*sizeof(bfd_vma)),
+ vma_section[i+0],
+ vma_section[i+1],
+ vma_section[i+2],
+ vma_section[i+3]);
+ }
+}
+#endif
+
+void lang_generate_crc(void)
+{
+ bfd_vma crc64, start, end;
+ bfd_vma crc;
+ bool can_do_crc;
+ bool crc_in_section;
+ asection *ts;
+ unsigned char *text_section = NULL;
+
+ /* These symbols must be present, for CRC to be generated */
+ /* They are all defined in the CRC <syndrome> statement
+ * If the user defines them without the CRC <syndrome>
+ * the ECMA algorithm will be used.
+ * Should we consider using a value which cannot be parser by the linker?
+ * I.E. CRC-64 is never an identifier
+ */
+ can_do_crc = symbol_lookup(CRC_ADDRESS, &crc64) &&
+ symbol_lookup(CRC_START, &start) &&
+ symbol_lookup(CRC_END, &end);
+
+ if (!can_do_crc)
+ return;
+
+ /*
+ * Get the '.text' section
+ * Is there a risk that CRC needs to be calculated on more than .text?
+ * We do not support that...
+ */
+ ts = bfd_get_section_by_name (link_info.output_bfd, entry_section);
+ if (ts == NULL)
+ einfo (_("%P:%pS: Cannot retrieve '.text' section\n"), NULL);
+
+ bfd_vma text_start = ts->lma;
+ bfd_vma text_end = ts->lma + ts->size;
+
+#if (DEBUG_CRC == 1)
+ printf("%s: [0x%08lx .. 0x%08lx]\n",
+ ts->name,
+ text_start,
+ text_end);
+#endif
+
+ crc_in_section =
+ ((text_start <= crc64) && (crc64 <= text_end)) &&
+ ((text_start <= start) && (start <= text_end)) &&
+ ((text_start <= end) && (end <= text_end));
+
+ if (!crc_in_section)
+ {
+ einfo (_("%P:%pS: warning: CRC area outside the '.text' section\n"
+ "CRC generation aborted\n"), NULL);
+ /*
+ * Maybe we should printout the text section start and end
+ * as well as the boundaries of the CRC check area.
+ */
+ return;
+ }
+
+ /* Get the contents of the '.text' area so we can calculate the CRC */
+ if (!bfd_malloc_and_get_section(link_info.output_bfd,
+ ts->output_section,
+ (bfd_byte **) &text_section))
+ {
+ einfo (_("%P:%pS: warning: '.text' section contents unavailable\n"
+ "CRC generation aborted\n"), NULL);
+ return;
+ }
+
+#if (DEBUG_CRC == 1)
+ output_hex("Before CRC", text_section, ts->vma, 64);
+#endif
+
+ /* Calculate and set the CRC */
+ {
+ /*
+ * The '.text' area does not neccessarily start at 0x0000,
+ * so we have to shift the indices.
+ */
+ bfd_vma _crc64 = crc64 - ts->vma;
+ bfd_vma _start = start - ts->vma;
+ bfd_vma _end = end - ts->vma;
+
+ /* This is the CRC calculation which we worked so hard for */
+ crc = crc_64(&text_section[_start] , _end - _start);
+
+ /*
+ * The '.text' contents are no longer needed.
+ * It is but a copy of the contents, and will therefore be stale
+ * after we updated the CRC.
+ * Remove it, before we try to set the CRC, to simplify the code logic.
+ */
+ free(text_section);
+
+ /* Set the 64-bit CRC64 at CRC_ADDRESS */
+ if (!bfd_set_section_contents(link_info.output_bfd,
+ ts->output_section,
+ &crc,
+ _crc64,
+ sizeof(bfd_vma)))
+ {
+ einfo (_("%P:%pS: warning: updating CRC failed\n"
+ "CRC generation aborted\n"), NULL);
+ return;
+ }
+ }
+
+#if (DEBUG_CRC == 1)
+ printf("CRC [0x%016lx] update at 0x%08lx succeeded\n", crc, crc64);
+
+ /* In order to see the updated contents, we have to it them again */
+ if (bfd_malloc_and_get_section(link_info.output_bfd,
+ ts->output_section,
+ (bfd_byte **) &text_section))
+ {
+ output_hex("After CRC", text_section, ts->vma, 64);
+ output_hex("Full Section After CRC", text_section, ts->vma, ts->size);
+ free(text_section);
+ }
+#endif
+}
+
void
lang_startup (const char *name)
{
diff --git a/ld/ldlang.h b/ld/ldlang.h
index 2300fa5b2a3..94ca4a9f239 100644
--- a/ld/ldlang.h
+++ b/ld/ldlang.h
@@ -632,6 +632,14 @@ extern lang_output_section_statement_type *lang_output_section_statement_lookup
(const char *, int, int);
extern lang_output_section_statement_type *next_matching_output_section_statement
(lang_output_section_statement_type *, int);
+extern void lang_add_crc_syndrome
+ (bool, bfd_vma);
+extern void lang_add_crc_table
+ (void);
+extern void lang_set_crc_region
+ (union etree_union *start, union etree_union *end);
+extern void lang_generate_crc
+ (void);
extern void ldlang_add_undef
(const char *const, bool);
extern void ldlang_add_require_defined
diff --git a/ld/ldmain.c b/ld/ldmain.c
index 25cc89b72f9..8b57b2dc5fc 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -527,6 +527,7 @@ main (int argc, char **argv)
ldwrite ();
+ lang_generate_crc(); /* Calculate and store CRC on request */
if (config.map_file != NULL)
lang_map ();
if (command_line.cref)
--
2.17.1
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