From f4bbf51050a1e1dd485e9cd89eef4619a7453d71 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 8 Jan 2009 12:04:47 +0000 Subject: [PATCH] FDPIC: Don't attempt to expand the userspace stack to fill the space allocated Stop the ELF-FDPIC binfmt from attempting to expand the userspace stack and brk segments to fill the space actually allocated for it. The space allocated may be rounded up by mmap(), and may be wasted. However, finding out how much space we actually obtained uses the contentious kobjsize() function which we'd like to get rid of as it doesn't necessarily work for all slab allocators. Signed-off-by: David Howells Tested-by: Mike Frysinger Acked-by: Paul Mundt --- fs/binfmt_elf_fdpic.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 22baf1b1349..f3e72c5c19f 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -168,9 +168,6 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm, struct elf_fdpic_params exec_params, interp_params; struct elf_phdr *phdr; unsigned long stack_size, entryaddr; -#ifndef CONFIG_MMU - unsigned long fullsize; -#endif #ifdef ELF_FDPIC_PLAT_INIT unsigned long dynaddr; #endif @@ -390,11 +387,6 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm, goto error_kill; } - /* expand the stack mapping to use up the entire allocation granule */ - fullsize = kobjsize((char *) current->mm->start_brk); - if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size, - fullsize, 0, 0))) - stack_size = fullsize; up_write(¤t->mm->mmap_sem); current->mm->brk = current->mm->start_brk;