From 766c580356ecca88b32c47b8128bec7d6d014533 Mon Sep 17 00:00:00 2001 From: Matt Redfearn Date: Thu, 31 Mar 2016 10:05:32 +0100 Subject: MIPS: tools: Add relocs tool This tool is based on the x86/boot/tools/relocs tool. It parses the relocations present in the vmlinux elf file, building a table of relocations that will be necessary to run the kernel from an address other than its link address. This table is inserted into the vmlinux elf, in the .data.relocs section. The table is subsequently used by the code in arch/mips/kernel/relocate.c (added later) to relocate the kernel. The tool, by default, also marks all relocation sections as 0 length. This is due to objcopy currently being unable to handle copying the relocations between 64 and 32 bit elf files as is done when building a 64 bit kernel. Signed-off-by: Matt Redfearn Cc: linux-mips@linux-mips.org Cc: kernel-hardening@lists.openwall.com Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12981/ Signed-off-by: Ralf Baechle --- arch/mips/boot/tools/relocs_main.c | 84 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 arch/mips/boot/tools/relocs_main.c (limited to 'arch/mips/boot/tools/relocs_main.c') diff --git a/arch/mips/boot/tools/relocs_main.c b/arch/mips/boot/tools/relocs_main.c new file mode 100644 index 000000000000..d8fe2343b8d0 --- /dev/null +++ b/arch/mips/boot/tools/relocs_main.c @@ -0,0 +1,84 @@ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "relocs.h" + +void die(char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + vfprintf(stderr, fmt, ap); + va_end(ap); + exit(1); +} + +static void usage(void) +{ + die("relocs [--reloc-info|--text|--bin|--keep] vmlinux\n"); +} + +int main(int argc, char **argv) +{ + int show_reloc_info, as_text, as_bin, keep_relocs; + const char *fname; + FILE *fp; + int i; + unsigned char e_ident[EI_NIDENT]; + + show_reloc_info = 0; + as_text = 0; + as_bin = 0; + keep_relocs = 0; + fname = NULL; + for (i = 1; i < argc; i++) { + char *arg = argv[i]; + + if (*arg == '-') { + if (strcmp(arg, "--reloc-info") == 0) { + show_reloc_info = 1; + continue; + } + if (strcmp(arg, "--text") == 0) { + as_text = 1; + continue; + } + if (strcmp(arg, "--bin") == 0) { + as_bin = 1; + continue; + } + if (strcmp(arg, "--keep") == 0) { + keep_relocs = 1; + continue; + } + } else if (!fname) { + fname = arg; + continue; + } + usage(); + } + if (!fname) + usage(); + + fp = fopen(fname, "r+"); + if (!fp) + die("Cannot open %s: %s\n", fname, strerror(errno)); + + if (fread(&e_ident, 1, EI_NIDENT, fp) != EI_NIDENT) + die("Cannot read %s: %s", fname, strerror(errno)); + + rewind(fp); + if (e_ident[EI_CLASS] == ELFCLASS64) + process_64(fp, as_text, as_bin, show_reloc_info, keep_relocs); + else + process_32(fp, as_text, as_bin, show_reloc_info, keep_relocs); + fclose(fp); + return 0; +} -- cgit