binfmt_flat: add MMU-specific support

Not much else to do at this point except for the different stack setups.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

1 files changed, 13 insertions, 3 deletions

diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 83e507137112..506139bfdc9e 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -537,7 +537,7 @@ static int load_flat_file(struct linux_binprm *bprm,
          * case,  and then the fully copied to RAM case which lumps
          * it all together.
          */
-        if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
+        if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
                 /*
                  * this should give us a ROM ptr,  but if it doesn't we don't
                  * really care
@@ -677,7 +677,9 @@ static int load_flat_file(struct linux_binprm *bprm,
                  */
                 current->mm->start_brk = datapos + data_len + bss_len;
                 current->mm->brk = (current->mm->start_brk + 3) & ~3;
+#ifndef CONFIG_MMU
                 current->mm->context.end_brk = memp + memp_size - stack_len;
+#endif
         }
 
         if (flags & FLAT_FLAG_KTRACE) {
@@ -870,7 +872,7 @@ static int load_flat_binary(struct linux_binprm *bprm)
 {
         struct lib_info libinfo;
         struct pt_regs *regs = current_pt_regs();
-        unsigned long stack_len;
+        unsigned long stack_len = 0;
         unsigned long start_addr;
         int res;
         int i, j;
@@ -884,7 +886,9 @@ static int load_flat_binary(struct linux_binprm *bprm)
          * pedantic and include space for the argv/envp array as it may have
          * a lot of entries.
          */
-        stack_len = PAGE_SIZE * MAX_ARG_PAGES - bprm->p;  /* the strings */
+#ifndef CONFIG_MMU
+        stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
+#endif
         stack_len += (bprm->argc + 1) * sizeof(char *);   /* the argv array */
         stack_len += (bprm->envc + 1) * sizeof(char *);   /* the envp array */
         stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
@@ -912,6 +916,11 @@ static int load_flat_binary(struct linux_binprm *bprm)
 
         set_binfmt(&flat_format);
 
+#ifdef CONFIG_MMU
+        res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
+        if (!res)
+                res = create_flat_tables(bprm, bprm->p);
+#else
         /* Stash our initial stack pointer into the mm structure */
         current->mm->start_stack =
                 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
@@ -921,6 +930,7 @@ static int load_flat_binary(struct linux_binprm *bprm)
         res = transfer_args_to_stack(bprm, &current->mm->start_stack);
         if (!res)
                 res = create_flat_tables(bprm, current->mm->start_stack);
+#endif
         if (res)
                 return res;