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Commit 472f95f3 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Greg Ungerer
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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: default avatarNicolas Pitre <nico@linaro.org>
Reviewed-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
Signed-off-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
parent 015feacf

fs/binfmt_flat.c

+42 −2
Original line number Diff line number Diff line
@@ -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))