Messages in this thread Patch in this message | | | Date | Fri, 18 May 2007 10:29:18 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH][RESEND] PIE randomization |
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On Thu, 17 May 2007 22:24:11 +0200 (CEST) Jan Kratochvil <honza@jikos.cz> wrote:
> This patch is using mmap()'s randomization functionality in such a way > that it maps the main executable of (specially compiled/linked -pie/-fpie) > ET_DYN binaries onto a random address (in cases in which mmap() is allowed > to perform a randomization). > > Origin of this patch is in exec-shield (http://people.redhat.com/mingo/exec-shield/)
From: Andrew Morton <akpm@linux-foundation.org>
- the compiler knows how to inline things
- return -EINVAL on zero-size, not -EIO
- reduce scope of local `interp_map_addr', remove unneeded initialisation, add needed comment.
- coding-style repairs
Cc: Jan Kratochvil <honza@jikos.cz> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland McGrath <roland@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> ---
fs/binfmt_elf.c | 26 +++++++++++++++++--------- 1 files changed, 17 insertions(+), 9 deletions(-)
diff -puN fs/binfmt_elf.c~pie-randomization-fix fs/binfmt_elf.c --- a/fs/binfmt_elf.c~pie-randomization-fix +++ a/fs/binfmt_elf.c @@ -322,17 +322,17 @@ static unsigned long elf_map(struct file #endif /* !elf_map */ -static inline unsigned long total_mapping_size(struct elf_phdr *cmds, int nr) +static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr) { int i, first_idx = -1, last_idx = -1; - for (i = 0; i < nr; i++) + for (i = 0; i < nr; i++) { if (cmds[i].p_type == PT_LOAD) { last_idx = i; if (first_idx == -1) first_idx = i; } - + } if (first_idx == -1) return 0; @@ -396,8 +396,10 @@ static unsigned long load_elf_interp(str } total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum); - if (!total_size) + if (!total_size) { + error = -EINVAL; goto out_close; + } eppnt = elf_phdata; for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) { @@ -586,7 +588,8 @@ static int load_elf_binary(struct linux_ int elf_exec_fileno; int retval, i; unsigned int size; - unsigned long elf_entry, interp_load_addr = 0, interp_map_addr = 0; + unsigned long elf_entry; + unsigned long interp_load_addr = 0; unsigned long start_code, end_code, start_data, end_data; unsigned long reloc_func_desc = 0; char passed_fileno[6]; @@ -908,7 +911,7 @@ static int load_elf_binary(struct linux_ * default mmap base, as well as whatever program they * might try to exec. This is because the brk will * follow the loader, and is not movable. */ -#if defined(__i386__) || defined(__x86_64__) +#ifdef CONFIG_X86 load_bias = 0; #else load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); @@ -992,16 +995,21 @@ static int load_elf_binary(struct linux_ } if (elf_interpreter) { - if (interpreter_type == INTERPRETER_AOUT) + if (interpreter_type == INTERPRETER_AOUT) { elf_entry = load_aout_interp(&loc->interp_ex, interpreter); - else { + } else { + unsigned long interp_map_addr; /* unused */ + elf_entry = load_elf_interp(&loc->interp_elf_ex, interpreter, &interp_map_addr, load_bias); if (!BAD_ADDR(elf_entry)) { - /* load_elf_interp() returns relocation adjustment */ + /* + * load_elf_interp() returns relocation + * adjustment + */ interp_load_addr = elf_entry; elf_entry += loc->interp_elf_ex.e_entry; } _ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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