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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2016-07-24 11:30:26 -0400 |
|---|---|---|
| committer | Greg Ungerer <gerg@linux-m68k.org> | 2016-07-28 13:29:12 +1000 |
| commit | 472f95f32d5aa07eda96a6b2578b85d7b27c5110 (patch) | |
| tree | e066d346cba4ca529016be057f3294ecd3e2fd98 /fs/binfmt_flat.c | |
| parent | 015feacf932108429f59b511b29d7e98a629e333 (diff) | |
| download | lwn-472f95f32d5aa07eda96a6b2578b85d7b27c5110.tar.gz lwn-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/binfmt_flat.c')
| -rw-r--r-- | fs/binfmt_flat.c | 44 |
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)) |