Let's take the simple and obvious approach by decompressing the binary
into a kernel buffer and then copying it to user space. Those who are
looking for top performance on an MMU system are unlikely to choose this
executable format anyway.
Signed-off-by: Nicolas Pitre <nico@xxxxxxxxxx>
Reviewed-by: Greg Ungerer <gerg@xxxxxxxxxxxxxx>
---
fs/binfmt_flat.c | 44 ++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 42 insertions(+), 2 deletions(-)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 7b999aebad..98cfefadb6 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -34,6 +34,7 @@
#include <linux/init.h>
#include <linux/flat.h>
#include <linux/uaccess.h>
+#include <linux/vmalloc.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
@@ -628,6 +629,7 @@ static int load_flat_file(struct linux_binprm *bprm,
* load it all in and treat it like a RAM load from now on
*/
if (flags & FLAT_FLAG_GZIP) {
+#ifndef CONFIG_MMU
result = decompress_exec(bprm, sizeof(struct flat_hdr),
(((char *)textpos) + sizeof(struct flat_hdr)),
(text_len + full_data
@@ -635,13 +637,51 @@ static int load_flat_file(struct linux_binprm *bprm,
0);
memmove((void *) datapos, (void *) realdatastart,
full_data);
+#else
+ /*
+ * This is used on MMU systems mainly for testing.
+ * Let's use a kernel buffer to simplify things.
+ */
+ long unz_text_len = text_len - sizeof(struct flat_hdr);
+ long unz_len = unz_text_len + full_data;
+ char *unz_data = vmalloc(unz_len);
+ if (!unz_data) {
+ result = -ENOMEM;
+ } else {
+ result = decompress_exec(bprm, sizeof(struct flat_hdr),
+ unz_data, unz_len, 0);
+ if (result == 0 &&
+ (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
+ unz_data, unz_text_len) ||
+ copy_to_user((void __user *)datapos,
+ unz_data + unz_text_len, full_data)))
+ result = -EFAULT;
+ vfree(unz_data);
+ }
+#endif
} else if (flags & FLAT_FLAG_GZDATA) {
result = read_code(bprm->file, textpos, 0, text_len);
- if (!IS_ERR_VALUE(result))
+ if (!IS_ERR_VALUE(result)) {
+#ifndef CONFIG_MMU
result = decompress_exec(bprm, text_len, (char *) datapos,
full_data, 0);
- } else
+#else
+ char *unz_data = vmalloc(full_data);
+ if (!unz_data) {
+ result = -ENOMEM;
+ } else {
+ result = decompress_exec(bprm, text_len,
+ unz_data, full_data, 0);
+ if (result == 0 &&
+ copy_to_user((void __user *)datapos,
+ unz_data, full_data))
+ result = -EFAULT;
+ vfree(unz_data);
+ }
#endif
+ }
+ } else
+#endif /* CONFIG_BINFMT_ZFLAT */
{
result = read_code(bprm->file, textpos, 0, text_len);
if (!IS_ERR_VALUE(result))
--
2.7.4
--
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