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authorNicolas Pitre <nicolas.pitre@linaro.org>2016-07-24 17:30:26 +0200
committerGreg Ungerer <gerg@linux-m68k.org>2016-07-28 05:29:12 +0200
commit472f95f32d5aa07eda96a6b2578b85d7b27c5110 (patch)
treee066d346cba4ca529016be057f3294ecd3e2fd98 /fs
parentbinfmt_flat: add MMU-specific support (diff)
downloadlinux-472f95f32d5aa07eda96a6b2578b85d7b27c5110.tar.xz
linux-472f95f32d5aa07eda96a6b2578b85d7b27c5110.zip
binfmt_flat: allow compressed flat binary format to work on MMU systems
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@linaro.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/binfmt_flat.c44
1 files changed, 42 insertions, 2 deletions
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 506139bfdc9e..9b2917a30294 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))