diff options
| -rw-r--r-- | fs/binfmt_elf.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 13d053982dd7..96370e3e3687 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -13,6 +13,7 @@ #include <linux/module.h> #include <linux/kernel.h> #include <linux/fs.h> +#include <linux/log2.h> #include <linux/mm.h> #include <linux/mman.h> #include <linux/errno.h> @@ -421,6 +422,26 @@ static int elf_read(struct file *file, void *buf, size_t len, loff_t pos) return 0; } +static unsigned long maximum_alignment(struct elf_phdr *cmds, int nr) +{ + unsigned long alignment = 0; + int i; + + for (i = 0; i < nr; i++) { + if (cmds[i].p_type == PT_LOAD) { + unsigned long p_align = cmds[i].p_align; + + /* skip non-power of two alignments as invalid */ + if (!is_power_of_2(p_align)) + continue; + alignment = max(alignment, p_align); + } + } + + /* ensure we align to at least one page */ + return ELF_PAGEALIGN(alignment); +} + /** * load_elf_phdrs() - load ELF program headers * @elf_ex: ELF header of the binary whose program headers should be loaded @@ -1008,6 +1029,7 @@ out_free_interp: int elf_prot, elf_flags; unsigned long k, vaddr; unsigned long total_size = 0; + unsigned long alignment; if (elf_ppnt->p_type != PT_LOAD) continue; @@ -1086,6 +1108,9 @@ out_free_interp: load_bias = ELF_ET_DYN_BASE; if (current->flags & PF_RANDOMIZE) load_bias += arch_mmap_rnd(); + alignment = maximum_alignment(elf_phdata, elf_ex->e_phnum); + if (alignment) + load_bias &= ~(alignment - 1); elf_flags |= MAP_FIXED; } else load_bias = 0; |