binfmt_misc: pass binfmt_misc flags to the interpreter

It can be useful to the interpreter to know which flags are in use.

For instance, knowing if the preserve-argv[0] is in use would
allow to skip the pathname argument.

This patch uses an unused auxiliary vector, AT_FLAGS, to add a
flag to inform interpreter if the preserve-argv[0] is enabled.

Note by Helge Deller:
The real-world user of this patch is qemu-user, which needs to know
if it has to preserve the argv[0]. See Debian bug #970460.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: YunQiang Su <ysu@wavecomp.com>
URL: http://bugs.debian.org/970460
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Laurent Vivier
2020-01-28 14:25:39 +01:00
committed by Helge Deller
parent b7795074a0
commit 2347961b11
5 changed files with 19 additions and 3 deletions

View File

@ -153,7 +153,9 @@ static int load_misc_binary(struct linux_binprm *bprm)
if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE)
goto ret;
if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) {
if (fmt->flags & MISC_FMT_PRESERVE_ARGV0) {
bprm->interp_flags |= BINPRM_FLAGS_PRESERVE_ARGV0;
} else {
retval = remove_arg_zero(bprm);
if (retval)
goto ret;