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path: root/kernel/fs/binfmt_elf_fdpic.c
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Diffstat (limited to 'kernel/fs/binfmt_elf_fdpic.c')
-rw-r--r--kernel/fs/binfmt_elf_fdpic.c68
1 files changed, 54 insertions, 14 deletions
diff --git a/kernel/fs/binfmt_elf_fdpic.c b/kernel/fs/binfmt_elf_fdpic.c
index d3634bfb7..b1adb92e6 100644
--- a/kernel/fs/binfmt_elf_fdpic.c
+++ b/kernel/fs/binfmt_elf_fdpic.c
@@ -35,6 +35,7 @@
#include <linux/elf-fdpic.h>
#include <linux/elfcore.h>
#include <linux/coredump.h>
+#include <linux/dax.h>
#include <asm/uaccess.h>
#include <asm/param.h>
@@ -103,19 +104,36 @@ static void __exit exit_elf_fdpic_binfmt(void)
core_initcall(init_elf_fdpic_binfmt);
module_exit(exit_elf_fdpic_binfmt);
-static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
+static int is_elf(struct elfhdr *hdr, struct file *file)
{
if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
return 0;
if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
return 0;
- if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
+ if (!elf_check_arch(hdr))
return 0;
if (!file->f_op->mmap)
return 0;
return 1;
}
+#ifndef elf_check_fdpic
+#define elf_check_fdpic(x) 0
+#endif
+
+#ifndef elf_check_const_displacement
+#define elf_check_const_displacement(x) 0
+#endif
+
+static int is_constdisp(struct elfhdr *hdr)
+{
+ if (!elf_check_fdpic(hdr))
+ return 1;
+ if (elf_check_const_displacement(hdr))
+ return 1;
+ return 0;
+}
+
/*****************************************************************************/
/*
* read the program headers table into memory
@@ -191,8 +209,18 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
/* check that this is a binary we know how to deal with */
retval = -ENOEXEC;
- if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
+ if (!is_elf(&exec_params.hdr, bprm->file))
+ goto error;
+ if (!elf_check_fdpic(&exec_params.hdr)) {
+#ifdef CONFIG_MMU
+ /* binfmt_elf handles non-fdpic elf except on nommu */
goto error;
+#else
+ /* nommu can only load ET_DYN (PIE) ELF */
+ if (exec_params.hdr.e_type != ET_DYN)
+ goto error;
+#endif
+ }
/* read the program header table */
retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
@@ -269,13 +297,13 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
}
- if (elf_check_const_displacement(&exec_params.hdr))
+ if (is_constdisp(&exec_params.hdr))
exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
/* perform insanity checks on the interpreter */
if (interpreter_name) {
retval = -ELIBBAD;
- if (!is_elf_fdpic(&interp_params.hdr, interpreter))
+ if (!is_elf(&interp_params.hdr, interpreter))
goto error;
interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
@@ -306,9 +334,9 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
retval = -ENOEXEC;
if (stack_size == 0)
- goto error;
+ stack_size = 131072UL; /* same as exec.c's default commit */
- if (elf_check_const_displacement(&interp_params.hdr))
+ if (is_constdisp(&interp_params.hdr))
interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
/* flush all traces of the currently running executable */
@@ -319,7 +347,10 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
/* there's now no turning back... the old userspace image is dead,
* defunct, deceased, etc.
*/
- set_personality(PER_LINUX_FDPIC);
+ if (elf_check_fdpic(&exec_params.hdr))
+ set_personality(PER_LINUX_FDPIC);
+ else
+ set_personality(PER_LINUX);
if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
current->personality |= READ_IMPLIES_EXEC;
@@ -374,10 +405,7 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
PAGE_ALIGN(current->mm->start_brk);
#else
- /* create a stack and brk area big enough for everyone
- * - the brk heap starts at the bottom and works up
- * - the stack starts at the top and works down
- */
+ /* create a stack area and zero-size brk area */
stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
if (stack_size < PAGE_SIZE * 2)
stack_size = PAGE_SIZE * 2;
@@ -400,8 +428,6 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm)
current->mm->brk = current->mm->start_brk;
current->mm->context.end_brk = current->mm->start_brk;
- current->mm->context.end_brk +=
- (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
current->mm->start_stack = current->mm->start_brk + stack_size;
#endif
@@ -1206,6 +1232,20 @@ static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
return 0;
}
+ /* support for DAX */
+ if (vma_is_dax(vma)) {
+ if (vma->vm_flags & VM_SHARED) {
+ dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags);
+ kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start,
+ vma->vm_flags, dump_ok ? "yes" : "no");
+ } else {
+ dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags);
+ kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start,
+ vma->vm_flags, dump_ok ? "yes" : "no");
+ }
+ return dump_ok;
+ }
+
/* By default, dump shared memory if mapped from an anonymous file. */
if (vma->vm_flags & VM_SHARED) {
if (file_inode(vma->vm_file)->i_nlink == 0) {