flat: tweak default stack alignment

[sfrench/cifs-2.6.git] / fs / binfmt_flat.c

diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 49566c1687d84943d9187a12ff2d1490c8ec6ad2..811384bec8de8d486a9aa7355d49b0195995e97a 100644 (file)
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -56,16 +56,19 @@
 #endif
 
 /*
- * User data (stack, data section and bss) needs to be aligned
- * for the same reasons as SLAB memory is, and to the same amount.
- * Avoid duplicating architecture specific code by using the same
- * macro as with SLAB allocation:
+ * User data (data section and bss) needs to be aligned.
+ * We pick 0x20 here because it is the max value elf2flt has always
+ * used in producing FLAT files, and because it seems to be large
+ * enough to make all the gcc alignment related tests happy.
  */
-#ifdef ARCH_SLAB_MINALIGN
-#define FLAT_DATA_ALIGN        (ARCH_SLAB_MINALIGN)
-#else
-#define FLAT_DATA_ALIGN        (sizeof(void *))
-#endif
+#define FLAT_DATA_ALIGN        (0x20)
+
+/*
+ * User data (stack) also needs to be aligned.
+ * Here we can be a bit looser than the data sections since this
+ * needs to only meet arch ABI requirements.
+ */
+#define FLAT_STACK_ALIGN       max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
 
 #define RELOC_FAILED 0xff00ff01                /* Relocation incorrect somewhere */
 #define UNLOADED_LIB 0x7ff000ff                /* Placeholder for unused library */
@@ -129,7 +132,7 @@ static unsigned long create_flat_tables(
 
        sp = (unsigned long *)p;
        sp -= (envc + argc + 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
-       sp = (unsigned long *) ((unsigned long)sp & -FLAT_DATA_ALIGN);
+       sp = (unsigned long *) ((unsigned long)sp & -FLAT_STACK_ALIGN);
        argv = sp + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
        envp = argv + (argc + 1);
 
@@ -589,7 +592,7 @@ static int load_flat_file(struct linux_binprm * bprm,
                if (IS_ERR_VALUE(result)) {
                        printk("Unable to read data+bss, errno %d\n", (int)-result);
                        do_munmap(current->mm, textpos, text_len);
-                       do_munmap(current->mm, realdatastart, data_len + extra);
+                       do_munmap(current->mm, realdatastart, len);
                        ret = result;
                        goto err;
                }
@@ -876,7 +879,7 @@ static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
        stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
        stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
        stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
-       stack_len += FLAT_DATA_ALIGN - 1;  /* reserve for upcoming alignment */
+       stack_len += FLAT_STACK_ALIGN - 1;  /* reserve for upcoming alignment */
        
        res = load_flat_file(bprm, &libinfo, 0, &stack_len);
        if (IS_ERR_VALUE(res))