mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
308 lines
7.7 KiB
308 lines
7.7 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* Copyright (C) 2015 Imagination Technologies |
|
* Author: Alex Smith <[email protected]> |
|
*/ |
|
|
|
/* |
|
* This tool is used to generate the real VDSO images from the raw image. It |
|
* first patches up the MIPS ABI flags and GNU attributes sections defined in |
|
* elf.S to have the correct name and type. It then generates a C source file |
|
* to be compiled into the kernel containing the VDSO image data and a |
|
* mips_vdso_image struct for it, including symbol offsets extracted from the |
|
* image. |
|
* |
|
* We need to be passed both a stripped and unstripped VDSO image. The stripped |
|
* image is compiled into the kernel, but we must also patch up the unstripped |
|
* image's ABI flags sections so that it can be installed and used for |
|
* debugging. |
|
*/ |
|
|
|
#include <sys/mman.h> |
|
#include <sys/stat.h> |
|
#include <sys/types.h> |
|
|
|
#include <byteswap.h> |
|
#include <elf.h> |
|
#include <errno.h> |
|
#include <fcntl.h> |
|
#include <inttypes.h> |
|
#include <stdarg.h> |
|
#include <stdbool.h> |
|
#include <stdio.h> |
|
#include <stdlib.h> |
|
#include <string.h> |
|
#include <unistd.h> |
|
|
|
/* Define these in case the system elf.h is not new enough to have them. */ |
|
#ifndef SHT_GNU_ATTRIBUTES |
|
# define SHT_GNU_ATTRIBUTES 0x6ffffff5 |
|
#endif |
|
#ifndef SHT_MIPS_ABIFLAGS |
|
# define SHT_MIPS_ABIFLAGS 0x7000002a |
|
#endif |
|
|
|
enum { |
|
ABI_O32 = (1 << 0), |
|
ABI_N32 = (1 << 1), |
|
ABI_N64 = (1 << 2), |
|
|
|
ABI_ALL = ABI_O32 | ABI_N32 | ABI_N64, |
|
}; |
|
|
|
/* Symbols the kernel requires offsets for. */ |
|
static struct { |
|
const char *name; |
|
const char *offset_name; |
|
unsigned int abis; |
|
} vdso_symbols[] = { |
|
{ "__vdso_sigreturn", "off_sigreturn", ABI_O32 }, |
|
{ "__vdso_rt_sigreturn", "off_rt_sigreturn", ABI_ALL }, |
|
{} |
|
}; |
|
|
|
static const char *program_name; |
|
static const char *vdso_name; |
|
static unsigned char elf_class; |
|
static unsigned int elf_abi; |
|
static bool need_swap; |
|
static FILE *out_file; |
|
|
|
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ |
|
# define HOST_ORDER ELFDATA2LSB |
|
#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ |
|
# define HOST_ORDER ELFDATA2MSB |
|
#endif |
|
|
|
#define BUILD_SWAP(bits) \ |
|
static uint##bits##_t swap_uint##bits(uint##bits##_t val) \ |
|
{ \ |
|
return need_swap ? bswap_##bits(val) : val; \ |
|
} |
|
|
|
BUILD_SWAP(16) |
|
BUILD_SWAP(32) |
|
BUILD_SWAP(64) |
|
|
|
#define __FUNC(name, bits) name##bits |
|
#define _FUNC(name, bits) __FUNC(name, bits) |
|
#define FUNC(name) _FUNC(name, ELF_BITS) |
|
|
|
#define __ELF(x, bits) Elf##bits##_##x |
|
#define _ELF(x, bits) __ELF(x, bits) |
|
#define ELF(x) _ELF(x, ELF_BITS) |
|
|
|
/* |
|
* Include genvdso.h twice with ELF_BITS defined differently to get functions |
|
* for both ELF32 and ELF64. |
|
*/ |
|
|
|
#define ELF_BITS 64 |
|
#include "genvdso.h" |
|
#undef ELF_BITS |
|
|
|
#define ELF_BITS 32 |
|
#include "genvdso.h" |
|
#undef ELF_BITS |
|
|
|
static void *map_vdso(const char *path, size_t *_size) |
|
{ |
|
int fd; |
|
struct stat stat; |
|
void *addr; |
|
const Elf32_Ehdr *ehdr; |
|
|
|
fd = open(path, O_RDWR); |
|
if (fd < 0) { |
|
fprintf(stderr, "%s: Failed to open '%s': %s\n", program_name, |
|
path, strerror(errno)); |
|
return NULL; |
|
} |
|
|
|
if (fstat(fd, &stat) != 0) { |
|
fprintf(stderr, "%s: Failed to stat '%s': %s\n", program_name, |
|
path, strerror(errno)); |
|
close(fd); |
|
return NULL; |
|
} |
|
|
|
addr = mmap(NULL, stat.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, |
|
0); |
|
if (addr == MAP_FAILED) { |
|
fprintf(stderr, "%s: Failed to map '%s': %s\n", program_name, |
|
path, strerror(errno)); |
|
close(fd); |
|
return NULL; |
|
} |
|
|
|
/* ELF32/64 header formats are the same for the bits we're checking. */ |
|
ehdr = addr; |
|
|
|
if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0) { |
|
fprintf(stderr, "%s: '%s' is not an ELF file\n", program_name, |
|
path); |
|
close(fd); |
|
return NULL; |
|
} |
|
|
|
elf_class = ehdr->e_ident[EI_CLASS]; |
|
switch (elf_class) { |
|
case ELFCLASS32: |
|
case ELFCLASS64: |
|
break; |
|
default: |
|
fprintf(stderr, "%s: '%s' has invalid ELF class\n", |
|
program_name, path); |
|
close(fd); |
|
return NULL; |
|
} |
|
|
|
switch (ehdr->e_ident[EI_DATA]) { |
|
case ELFDATA2LSB: |
|
case ELFDATA2MSB: |
|
need_swap = ehdr->e_ident[EI_DATA] != HOST_ORDER; |
|
break; |
|
default: |
|
fprintf(stderr, "%s: '%s' has invalid ELF data order\n", |
|
program_name, path); |
|
close(fd); |
|
return NULL; |
|
} |
|
|
|
if (swap_uint16(ehdr->e_machine) != EM_MIPS) { |
|
fprintf(stderr, |
|
"%s: '%s' has invalid ELF machine (expected EM_MIPS)\n", |
|
program_name, path); |
|
close(fd); |
|
return NULL; |
|
} else if (swap_uint16(ehdr->e_type) != ET_DYN) { |
|
fprintf(stderr, |
|
"%s: '%s' has invalid ELF type (expected ET_DYN)\n", |
|
program_name, path); |
|
close(fd); |
|
return NULL; |
|
} |
|
|
|
*_size = stat.st_size; |
|
close(fd); |
|
return addr; |
|
} |
|
|
|
static bool patch_vdso(const char *path, void *vdso) |
|
{ |
|
if (elf_class == ELFCLASS64) |
|
return patch_vdso64(path, vdso); |
|
else |
|
return patch_vdso32(path, vdso); |
|
} |
|
|
|
static bool get_symbols(const char *path, void *vdso) |
|
{ |
|
if (elf_class == ELFCLASS64) |
|
return get_symbols64(path, vdso); |
|
else |
|
return get_symbols32(path, vdso); |
|
} |
|
|
|
int main(int argc, char **argv) |
|
{ |
|
const char *dbg_vdso_path, *vdso_path, *out_path; |
|
void *dbg_vdso, *vdso; |
|
size_t dbg_vdso_size, vdso_size, i; |
|
|
|
program_name = argv[0]; |
|
|
|
if (argc < 4 || argc > 5) { |
|
fprintf(stderr, |
|
"Usage: %s <debug VDSO> <stripped VDSO> <output file> [<name>]\n", |
|
program_name); |
|
return EXIT_FAILURE; |
|
} |
|
|
|
dbg_vdso_path = argv[1]; |
|
vdso_path = argv[2]; |
|
out_path = argv[3]; |
|
vdso_name = (argc > 4) ? argv[4] : ""; |
|
|
|
dbg_vdso = map_vdso(dbg_vdso_path, &dbg_vdso_size); |
|
if (!dbg_vdso) |
|
return EXIT_FAILURE; |
|
|
|
vdso = map_vdso(vdso_path, &vdso_size); |
|
if (!vdso) |
|
return EXIT_FAILURE; |
|
|
|
/* Patch both the VDSOs' ABI flags sections. */ |
|
if (!patch_vdso(dbg_vdso_path, dbg_vdso)) |
|
return EXIT_FAILURE; |
|
if (!patch_vdso(vdso_path, vdso)) |
|
return EXIT_FAILURE; |
|
|
|
if (msync(dbg_vdso, dbg_vdso_size, MS_SYNC) != 0) { |
|
fprintf(stderr, "%s: Failed to sync '%s': %s\n", program_name, |
|
dbg_vdso_path, strerror(errno)); |
|
return EXIT_FAILURE; |
|
} else if (msync(vdso, vdso_size, MS_SYNC) != 0) { |
|
fprintf(stderr, "%s: Failed to sync '%s': %s\n", program_name, |
|
vdso_path, strerror(errno)); |
|
return EXIT_FAILURE; |
|
} |
|
|
|
out_file = fopen(out_path, "w"); |
|
if (!out_file) { |
|
fprintf(stderr, "%s: Failed to open '%s': %s\n", program_name, |
|
out_path, strerror(errno)); |
|
return EXIT_FAILURE; |
|
} |
|
|
|
fprintf(out_file, "/* Automatically generated - do not edit */\n"); |
|
fprintf(out_file, "#include <linux/linkage.h>\n"); |
|
fprintf(out_file, "#include <linux/mm.h>\n"); |
|
fprintf(out_file, "#include <asm/vdso.h>\n"); |
|
fprintf(out_file, "static int vdso_mremap(\n"); |
|
fprintf(out_file, " const struct vm_special_mapping *sm,\n"); |
|
fprintf(out_file, " struct vm_area_struct *new_vma)\n"); |
|
fprintf(out_file, "{\n"); |
|
fprintf(out_file, " current->mm->context.vdso =\n"); |
|
fprintf(out_file, " (void *)(new_vma->vm_start);\n"); |
|
fprintf(out_file, " return 0;\n"); |
|
fprintf(out_file, "}\n"); |
|
|
|
/* Write out the stripped VDSO data. */ |
|
fprintf(out_file, |
|
"static unsigned char vdso_data[PAGE_ALIGN(%zu)] __page_aligned_data = {\n\t", |
|
vdso_size); |
|
for (i = 0; i < vdso_size; i++) { |
|
if (!(i % 10)) |
|
fprintf(out_file, "\n\t"); |
|
fprintf(out_file, "0x%02x, ", ((unsigned char *)vdso)[i]); |
|
} |
|
fprintf(out_file, "\n};\n"); |
|
|
|
/* Preallocate a page array. */ |
|
fprintf(out_file, |
|
"static struct page *vdso_pages[PAGE_ALIGN(%zu) / PAGE_SIZE];\n", |
|
vdso_size); |
|
|
|
fprintf(out_file, "struct mips_vdso_image vdso_image%s%s = {\n", |
|
(vdso_name[0]) ? "_" : "", vdso_name); |
|
fprintf(out_file, "\t.data = vdso_data,\n"); |
|
fprintf(out_file, "\t.size = PAGE_ALIGN(%zu),\n", vdso_size); |
|
fprintf(out_file, "\t.mapping = {\n"); |
|
fprintf(out_file, "\t\t.name = \"[vdso]\",\n"); |
|
fprintf(out_file, "\t\t.pages = vdso_pages,\n"); |
|
fprintf(out_file, "\t\t.mremap = vdso_mremap,\n"); |
|
fprintf(out_file, "\t},\n"); |
|
|
|
/* Calculate and write symbol offsets to <output file> */ |
|
if (!get_symbols(dbg_vdso_path, dbg_vdso)) { |
|
unlink(out_path); |
|
fclose(out_file); |
|
return EXIT_FAILURE; |
|
} |
|
|
|
fprintf(out_file, "};\n"); |
|
fclose(out_file); |
|
|
|
return EXIT_SUCCESS; |
|
}
|
|
|