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-rw-r--r--fs/binfmt_elf.c25
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;