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.
Signed-off-by: Laurent Vivier <[email protected]>
---
Notes:
This can be tested with QEMU from my branch:
https://github.com/vivier/qemu/commits/binfmt-argv0
With something like:
# cp ..../qemu-ppc /chroot/powerpc/jessie
# qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
--persistent no --preserve-argv0 yes
# systemctl restart systemd-binfmt.service
# cat /proc/sys/fs/binfmt_misc/qemu-ppc
enabled
interpreter //qemu-ppc
flags: POC
offset 0
magic 7f454c4601020100000000000000000000020014
mask ffffffffffffff00fffffffffffffffffffeffff
# chroot /chroot/powerpc/jessie sh -c 'echo $0'
sh
# qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
--persistent no --preserve-argv0 no
# systemctl restart systemd-binfmt.service
# cat /proc/sys/fs/binfmt_misc/qemu-ppc
enabled
interpreter //qemu-ppc
flags: OC
offset 0
magic 7f454c4601020100000000000000000000020014
mask ffffffffffffff00fffffffffffffffffffeffff
# chroot /chroot/powerpc/jessie sh -c 'echo $0'
/bin/sh
v3: mix my patch with one from YunQiang Su and my comments on it
introduce a new flag in the uabi for the AT_FLAGS
v2: only pass special flags (remove Magic and Enabled flags)
fs/binfmt_elf.c | 5 ++++-
fs/binfmt_elf_fdpic.c | 5 ++++-
fs/binfmt_misc.c | 4 +++-
include/linux/binfmts.h | 4 ++++
include/uapi/linux/binfmts.h | 4 ++++
5 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index ecd8d2698515..ff918042ceed 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -176,6 +176,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
unsigned char k_rand_bytes[16];
int items;
elf_addr_t *elf_info;
+ elf_addr_t flags = 0;
int ei_index = 0;
const struct cred *cred = current_cred();
struct vm_area_struct *vma;
@@ -250,7 +251,9 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
NEW_AUX_ENT(AT_BASE, interp_load_addr);
- NEW_AUX_ENT(AT_FLAGS, 0);
+ if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
+ flags |= AT_FLAGS_PRESERVE_ARGV0;
+ NEW_AUX_ENT(AT_FLAGS, flags);
NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 240f66663543..abb90d82aa58 100644
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -507,6 +507,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
char __user *u_platform, *u_base_platform, *p;
int loop;
int nr; /* reset for each csp adjustment */
+ unsigned long flags = 0;
#ifdef CONFIG_MMU
/* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
@@ -647,7 +648,9 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
- NEW_AUX_ENT(AT_FLAGS, 0);
+ if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
+ flags |= AT_FLAGS_PRESERVE_ARGV0;
+ NEW_AUX_ENT(AT_FLAGS, flags);
NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index cdb45829354d..b9acdd26a654 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -154,7 +154,9 @@ 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;
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index b40fc633f3be..265b80d5fd6f 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -78,6 +78,10 @@ struct linux_binprm {
#define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
#define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
+/* if preserve the argv0 for the interpreter */
+#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
+#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
+
/* Function parameter for binfmt->coredump */
struct coredump_params {
const kernel_siginfo_t *siginfo;
diff --git a/include/uapi/linux/binfmts.h b/include/uapi/linux/binfmts.h
index 689025d9c185..a70747416130 100644
--- a/include/uapi/linux/binfmts.h
+++ b/include/uapi/linux/binfmts.h
@@ -18,4 +18,8 @@ struct pt_regs;
/* sizeof(linux_binprm->buf) */
#define BINPRM_BUF_SIZE 256
+/* if preserve the argv0 for the interpreter */
+#define AT_FLAGS_PRESERVE_ARGV0_BIT 0
+#define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
+
#endif /* _UAPI_LINUX_BINFMTS_H */
--
2.24.1
在 2020-01-28二的 14:25 +0100，Laurent Vivier写道：
> 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.
>
> Signed-off-by: Laurent Vivier <[email protected]>
Reviewed-by: YunQiang Su <[email protected]>
> ---
>
> Notes:
> This can be tested with QEMU from my branch:
>
> https://github.com/vivier/qemu/commits/binfmt-argv0
>
> With something like:
>
> # cp ..../qemu-ppc /chroot/powerpc/jessie
>
> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential
> yes \
> --persistent no --preserve-argv0 yes
> # systemctl restart systemd-binfmt.service
> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> enabled
> interpreter //qemu-ppc
> flags: POC
> offset 0
> magic 7f454c4601020100000000000000000000020014
> mask ffffffffffffff00fffffffffffffffffffeffff
> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> sh
>
> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential
> yes \
> --persistent no --preserve-argv0 no
> # systemctl restart systemd-binfmt.service
> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> enabled
> interpreter //qemu-ppc
> flags: OC
> offset 0
> magic 7f454c4601020100000000000000000000020014
> mask ffffffffffffff00fffffffffffffffffffeffff
> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> /bin/sh
>
> v3: mix my patch with one from YunQiang Su and my comments on it
> introduce a new flag in the uabi for the AT_FLAGS
> v2: only pass special flags (remove Magic and Enabled flags)
>
> fs/binfmt_elf.c | 5 ++++-
> fs/binfmt_elf_fdpic.c | 5 ++++-
> fs/binfmt_misc.c | 4 +++-
> include/linux/binfmts.h | 4 ++++
> include/uapi/linux/binfmts.h | 4 ++++
> 5 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> index ecd8d2698515..ff918042ceed 100644
> --- a/fs/binfmt_elf.c
> +++ b/fs/binfmt_elf.c
> @@ -176,6 +176,7 @@ create_elf_tables(struct linux_binprm *bprm,
> struct elfhdr *exec,
> unsigned char k_rand_bytes[16];
> int items;
> elf_addr_t *elf_info;
> + elf_addr_t flags = 0;
> int ei_index = 0;
> const struct cred *cred = current_cred();
> struct vm_area_struct *vma;
> @@ -250,7 +251,9 @@ create_elf_tables(struct linux_binprm *bprm,
> struct elfhdr *exec,
> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
> NEW_AUX_ENT(AT_BASE, interp_load_addr);
> - NEW_AUX_ENT(AT_FLAGS, 0);
> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> + NEW_AUX_ENT(AT_FLAGS, flags);
> NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
> NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred-
> >uid));
> NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred-
> >euid));
> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
> index 240f66663543..abb90d82aa58 100644
> --- a/fs/binfmt_elf_fdpic.c
> +++ b/fs/binfmt_elf_fdpic.c
> @@ -507,6 +507,7 @@ static int create_elf_fdpic_tables(struct
> linux_binprm *bprm,
> char __user *u_platform, *u_base_platform, *p;
> int loop;
> int nr; /* reset for each csp adjustment */
> + unsigned long flags = 0;
>
> #ifdef CONFIG_MMU
> /* In some cases (e.g. Hyper-Threading), we want to avoid L1
> evictions
> @@ -647,7 +648,9 @@ static int create_elf_fdpic_tables(struct
> linux_binprm *bprm,
> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
> NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
> - NEW_AUX_ENT(AT_FLAGS, 0);
> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> + NEW_AUX_ENT(AT_FLAGS, flags);
> NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
> NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred-
> >user_ns, cred->uid));
> NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred-
> >user_ns, cred->euid));
> diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
> index cdb45829354d..b9acdd26a654 100644
> --- a/fs/binfmt_misc.c
> +++ b/fs/binfmt_misc.c
> @@ -154,7 +154,9 @@ 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;
> diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
> index b40fc633f3be..265b80d5fd6f 100644
> --- a/include/linux/binfmts.h
> +++ b/include/linux/binfmts.h
> @@ -78,6 +78,10 @@ struct linux_binprm {
> #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
> #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 <<
> BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
>
> +/* if preserve the argv0 for the interpreter */
> +#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
> +#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 <<
> BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
> +
> /* Function parameter for binfmt->coredump */
> struct coredump_params {
> const kernel_siginfo_t *siginfo;
> diff --git a/include/uapi/linux/binfmts.h
> b/include/uapi/linux/binfmts.h
> index 689025d9c185..a70747416130 100644
> --- a/include/uapi/linux/binfmts.h
> +++ b/include/uapi/linux/binfmts.h
> @@ -18,4 +18,8 @@ struct pt_regs;
> /* sizeof(linux_binprm->buf) */
> #define BINPRM_BUF_SIZE 256
>
> +/* if preserve the argv0 for the interpreter */
> +#define AT_FLAGS_PRESERVE_ARGV0_BIT 0
> +#define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
> +
> #endif /* _UAPI_LINUX_BINFMTS_H */
Hi,
any comment?
I think I've addressed comments on v2.
Thanks,
Laurent
Le 28/01/2020 à 14:25, Laurent Vivier a écrit :
> 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.
>
> Signed-off-by: Laurent Vivier <[email protected]>
> ---
>
> Notes:
> This can be tested with QEMU from my branch:
>
> https://github.com/vivier/qemu/commits/binfmt-argv0
>
> With something like:
>
> # cp ..../qemu-ppc /chroot/powerpc/jessie
>
> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
> --persistent no --preserve-argv0 yes
> # systemctl restart systemd-binfmt.service
> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> enabled
> interpreter //qemu-ppc
> flags: POC
> offset 0
> magic 7f454c4601020100000000000000000000020014
> mask ffffffffffffff00fffffffffffffffffffeffff
> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> sh
>
> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
> --persistent no --preserve-argv0 no
> # systemctl restart systemd-binfmt.service
> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> enabled
> interpreter //qemu-ppc
> flags: OC
> offset 0
> magic 7f454c4601020100000000000000000000020014
> mask ffffffffffffff00fffffffffffffffffffeffff
> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> /bin/sh
>
> v3: mix my patch with one from YunQiang Su and my comments on it
> introduce a new flag in the uabi for the AT_FLAGS
> v2: only pass special flags (remove Magic and Enabled flags)
>
> fs/binfmt_elf.c | 5 ++++-
> fs/binfmt_elf_fdpic.c | 5 ++++-
> fs/binfmt_misc.c | 4 +++-
> include/linux/binfmts.h | 4 ++++
> include/uapi/linux/binfmts.h | 4 ++++
> 5 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> index ecd8d2698515..ff918042ceed 100644
> --- a/fs/binfmt_elf.c
> +++ b/fs/binfmt_elf.c
> @@ -176,6 +176,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
> unsigned char k_rand_bytes[16];
> int items;
> elf_addr_t *elf_info;
> + elf_addr_t flags = 0;
> int ei_index = 0;
> const struct cred *cred = current_cred();
> struct vm_area_struct *vma;
> @@ -250,7 +251,9 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
> NEW_AUX_ENT(AT_BASE, interp_load_addr);
> - NEW_AUX_ENT(AT_FLAGS, 0);
> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> + NEW_AUX_ENT(AT_FLAGS, flags);
> NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
> NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
> NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
> index 240f66663543..abb90d82aa58 100644
> --- a/fs/binfmt_elf_fdpic.c
> +++ b/fs/binfmt_elf_fdpic.c
> @@ -507,6 +507,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> char __user *u_platform, *u_base_platform, *p;
> int loop;
> int nr; /* reset for each csp adjustment */
> + unsigned long flags = 0;
>
> #ifdef CONFIG_MMU
> /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
> @@ -647,7 +648,9 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
> NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
> - NEW_AUX_ENT(AT_FLAGS, 0);
> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> + NEW_AUX_ENT(AT_FLAGS, flags);
> NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
> NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
> NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
> diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
> index cdb45829354d..b9acdd26a654 100644
> --- a/fs/binfmt_misc.c
> +++ b/fs/binfmt_misc.c
> @@ -154,7 +154,9 @@ 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;
> diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
> index b40fc633f3be..265b80d5fd6f 100644
> --- a/include/linux/binfmts.h
> +++ b/include/linux/binfmts.h
> @@ -78,6 +78,10 @@ struct linux_binprm {
> #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
> #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
>
> +/* if preserve the argv0 for the interpreter */
> +#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
> +#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
> +
> /* Function parameter for binfmt->coredump */
> struct coredump_params {
> const kernel_siginfo_t *siginfo;
> diff --git a/include/uapi/linux/binfmts.h b/include/uapi/linux/binfmts.h
> index 689025d9c185..a70747416130 100644
> --- a/include/uapi/linux/binfmts.h
> +++ b/include/uapi/linux/binfmts.h
> @@ -18,4 +18,8 @@ struct pt_regs;
> /* sizeof(linux_binprm->buf) */
> #define BINPRM_BUF_SIZE 256
>
> +/* if preserve the argv0 for the interpreter */
> +#define AT_FLAGS_PRESERVE_ARGV0_BIT 0
> +#define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
> +
> #endif /* _UAPI_LINUX_BINFMTS_H */
>
I'd like to have this in the kernel to be able to use it in QEMU (next
QEMU release is 28/04, freeze 17/03).
Thanks,
Laurent
Le 14/02/2020 à 13:29, Laurent Vivier a écrit :
> Hi,
>
> any comment?
>
> I think I've addressed comments on v2.
>
> Thanks,
> Laurent
>
> Le 28/01/2020 à 14:25, Laurent Vivier a écrit :
>> 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.
>>
>> Signed-off-by: Laurent Vivier <[email protected]>
>> ---
>>
>> Notes:
>> This can be tested with QEMU from my branch:
>>
>> https://github.com/vivier/qemu/commits/binfmt-argv0
>>
>> With something like:
>>
>> # cp ..../qemu-ppc /chroot/powerpc/jessie
>>
>> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
>> --persistent no --preserve-argv0 yes
>> # systemctl restart systemd-binfmt.service
>> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
>> enabled
>> interpreter //qemu-ppc
>> flags: POC
>> offset 0
>> magic 7f454c4601020100000000000000000000020014
>> mask ffffffffffffff00fffffffffffffffffffeffff
>> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
>> sh
>>
>> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
>> --persistent no --preserve-argv0 no
>> # systemctl restart systemd-binfmt.service
>> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
>> enabled
>> interpreter //qemu-ppc
>> flags: OC
>> offset 0
>> magic 7f454c4601020100000000000000000000020014
>> mask ffffffffffffff00fffffffffffffffffffeffff
>> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
>> /bin/sh
>>
>> v3: mix my patch with one from YunQiang Su and my comments on it
>> introduce a new flag in the uabi for the AT_FLAGS
>> v2: only pass special flags (remove Magic and Enabled flags)
>>
>> fs/binfmt_elf.c | 5 ++++-
>> fs/binfmt_elf_fdpic.c | 5 ++++-
>> fs/binfmt_misc.c | 4 +++-
>> include/linux/binfmts.h | 4 ++++
>> include/uapi/linux/binfmts.h | 4 ++++
>> 5 files changed, 19 insertions(+), 3 deletions(-)
>>
>> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
>> index ecd8d2698515..ff918042ceed 100644
>> --- a/fs/binfmt_elf.c
>> +++ b/fs/binfmt_elf.c
>> @@ -176,6 +176,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
>> unsigned char k_rand_bytes[16];
>> int items;
>> elf_addr_t *elf_info;
>> + elf_addr_t flags = 0;
>> int ei_index = 0;
>> const struct cred *cred = current_cred();
>> struct vm_area_struct *vma;
>> @@ -250,7 +251,9 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
>> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
>> NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
>> NEW_AUX_ENT(AT_BASE, interp_load_addr);
>> - NEW_AUX_ENT(AT_FLAGS, 0);
>> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
>> + flags |= AT_FLAGS_PRESERVE_ARGV0;
>> + NEW_AUX_ENT(AT_FLAGS, flags);
>> NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
>> NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
>> NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
>> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
>> index 240f66663543..abb90d82aa58 100644
>> --- a/fs/binfmt_elf_fdpic.c
>> +++ b/fs/binfmt_elf_fdpic.c
>> @@ -507,6 +507,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
>> char __user *u_platform, *u_base_platform, *p;
>> int loop;
>> int nr; /* reset for each csp adjustment */
>> + unsigned long flags = 0;
>>
>> #ifdef CONFIG_MMU
>> /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
>> @@ -647,7 +648,9 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
>> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
>> NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
>> NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
>> - NEW_AUX_ENT(AT_FLAGS, 0);
>> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
>> + flags |= AT_FLAGS_PRESERVE_ARGV0;
>> + NEW_AUX_ENT(AT_FLAGS, flags);
>> NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
>> NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
>> NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
>> diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
>> index cdb45829354d..b9acdd26a654 100644
>> --- a/fs/binfmt_misc.c
>> +++ b/fs/binfmt_misc.c
>> @@ -154,7 +154,9 @@ 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;
>> diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
>> index b40fc633f3be..265b80d5fd6f 100644
>> --- a/include/linux/binfmts.h
>> +++ b/include/linux/binfmts.h
>> @@ -78,6 +78,10 @@ struct linux_binprm {
>> #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
>> #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
>>
>> +/* if preserve the argv0 for the interpreter */
>> +#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
>> +#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
>> +
>> /* Function parameter for binfmt->coredump */
>> struct coredump_params {
>> const kernel_siginfo_t *siginfo;
>> diff --git a/include/uapi/linux/binfmts.h b/include/uapi/linux/binfmts.h
>> index 689025d9c185..a70747416130 100644
>> --- a/include/uapi/linux/binfmts.h
>> +++ b/include/uapi/linux/binfmts.h
>> @@ -18,4 +18,8 @@ struct pt_regs;
>> /* sizeof(linux_binprm->buf) */
>> #define BINPRM_BUF_SIZE 256
>>
>> +/* if preserve the argv0 for the interpreter */
>> +#define AT_FLAGS_PRESERVE_ARGV0_BIT 0
>> +#define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
>> +
>> #endif /* _UAPI_LINUX_BINFMTS_H */
>>
>
在 2020-01-28二的 14:25 +0100，Laurent Vivier写道：
> 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.
CC: libc-alpha.
I guess we need some review from libc people.
>
> Signed-off-by: Laurent Vivier <[email protected]>
> ---
>
> Notes:
> This can be tested with QEMU from my branch:
>
> https://github.com/vivier/qemu/commits/binfmt-argv0
>
> With something like:
>
> # cp ..../qemu-ppc /chroot/powerpc/jessie
>
> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential
> yes \
> --persistent no --preserve-argv0 yes
> # systemctl restart systemd-binfmt.service
> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> enabled
> interpreter //qemu-ppc
> flags: POC
> offset 0
> magic 7f454c4601020100000000000000000000020014
> mask ffffffffffffff00fffffffffffffffffffeffff
> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> sh
>
> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential
> yes \
> --persistent no --preserve-argv0 no
> # systemctl restart systemd-binfmt.service
> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> enabled
> interpreter //qemu-ppc
> flags: OC
> offset 0
> magic 7f454c4601020100000000000000000000020014
> mask ffffffffffffff00fffffffffffffffffffeffff
> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> /bin/sh
>
> v3: mix my patch with one from YunQiang Su and my comments on it
> introduce a new flag in the uabi for the AT_FLAGS
> v2: only pass special flags (remove Magic and Enabled flags)
>
> fs/binfmt_elf.c | 5 ++++-
> fs/binfmt_elf_fdpic.c | 5 ++++-
> fs/binfmt_misc.c | 4 +++-
> include/linux/binfmts.h | 4 ++++
> include/uapi/linux/binfmts.h | 4 ++++
> 5 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> index ecd8d2698515..ff918042ceed 100644
> --- a/fs/binfmt_elf.c
> +++ b/fs/binfmt_elf.c
> @@ -176,6 +176,7 @@ create_elf_tables(struct linux_binprm *bprm,
> struct elfhdr *exec,
> unsigned char k_rand_bytes[16];
> int items;
> elf_addr_t *elf_info;
> + elf_addr_t flags = 0;
> int ei_index = 0;
> const struct cred *cred = current_cred();
> struct vm_area_struct *vma;
> @@ -250,7 +251,9 @@ create_elf_tables(struct linux_binprm *bprm,
> struct elfhdr *exec,
> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
> NEW_AUX_ENT(AT_BASE, interp_load_addr);
> - NEW_AUX_ENT(AT_FLAGS, 0);
> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> + NEW_AUX_ENT(AT_FLAGS, flags);
> NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
> NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred-
> >uid));
> NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred-
> >euid));
> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
> index 240f66663543..abb90d82aa58 100644
> --- a/fs/binfmt_elf_fdpic.c
> +++ b/fs/binfmt_elf_fdpic.c
> @@ -507,6 +507,7 @@ static int create_elf_fdpic_tables(struct
> linux_binprm *bprm,
> char __user *u_platform, *u_base_platform, *p;
> int loop;
> int nr; /* reset for each csp adjustment */
> + unsigned long flags = 0;
>
> #ifdef CONFIG_MMU
> /* In some cases (e.g. Hyper-Threading), we want to avoid L1
> evictions
> @@ -647,7 +648,9 @@ static int create_elf_fdpic_tables(struct
> linux_binprm *bprm,
> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
> NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
> - NEW_AUX_ENT(AT_FLAGS, 0);
> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> + NEW_AUX_ENT(AT_FLAGS, flags);
> NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
> NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred-
> >user_ns, cred->uid));
> NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred-
> >user_ns, cred->euid));
> diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
> index cdb45829354d..b9acdd26a654 100644
> --- a/fs/binfmt_misc.c
> +++ b/fs/binfmt_misc.c
> @@ -154,7 +154,9 @@ 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;
> diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
> index b40fc633f3be..265b80d5fd6f 100644
> --- a/include/linux/binfmts.h
> +++ b/include/linux/binfmts.h
> @@ -78,6 +78,10 @@ struct linux_binprm {
> #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
> #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 <<
> BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
>
> +/* if preserve the argv0 for the interpreter */
> +#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
> +#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 <<
> BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
> +
> /* Function parameter for binfmt->coredump */
> struct coredump_params {
> const kernel_siginfo_t *siginfo;
> diff --git a/include/uapi/linux/binfmts.h
> b/include/uapi/linux/binfmts.h
> index 689025d9c185..a70747416130 100644
> --- a/include/uapi/linux/binfmts.h
> +++ b/include/uapi/linux/binfmts.h
> @@ -18,4 +18,8 @@ struct pt_regs;
> /* sizeof(linux_binprm->buf) */
> #define BINPRM_BUF_SIZE 256
>
> +/* if preserve the argv0 for the interpreter */
> +#define AT_FLAGS_PRESERVE_ARGV0_BIT 0
> +#define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
> +
> #endif /* _UAPI_LINUX_BINFMTS_H */
Laurent Vivier <[email protected]> 于2020年1月28日周二 下午9:25写道：
>
> 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.
>
I am suggested to post linux-arch and/or linux-api.
> Signed-off-by: Laurent Vivier <[email protected]>
> ---
>
> Notes:
> This can be tested with QEMU from my branch:
>
> https://github.com/vivier/qemu/commits/binfmt-argv0
>
> With something like:
>
> # cp ..../qemu-ppc /chroot/powerpc/jessie
>
> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
> --persistent no --preserve-argv0 yes
> # systemctl restart systemd-binfmt.service
> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> enabled
> interpreter //qemu-ppc
> flags: POC
> offset 0
> magic 7f454c4601020100000000000000000000020014
> mask ffffffffffffff00fffffffffffffffffffeffff
> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> sh
>
> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
> --persistent no --preserve-argv0 no
> # systemctl restart systemd-binfmt.service
> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> enabled
> interpreter //qemu-ppc
> flags: OC
> offset 0
> magic 7f454c4601020100000000000000000000020014
> mask ffffffffffffff00fffffffffffffffffffeffff
> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> /bin/sh
>
> v3: mix my patch with one from YunQiang Su and my comments on it
> introduce a new flag in the uabi for the AT_FLAGS
> v2: only pass special flags (remove Magic and Enabled flags)
>
> fs/binfmt_elf.c | 5 ++++-
> fs/binfmt_elf_fdpic.c | 5 ++++-
> fs/binfmt_misc.c | 4 +++-
> include/linux/binfmts.h | 4 ++++
> include/uapi/linux/binfmts.h | 4 ++++
> 5 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> index ecd8d2698515..ff918042ceed 100644
> --- a/fs/binfmt_elf.c
> +++ b/fs/binfmt_elf.c
> @@ -176,6 +176,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
> unsigned char k_rand_bytes[16];
> int items;
> elf_addr_t *elf_info;
> + elf_addr_t flags = 0;
> int ei_index = 0;
> const struct cred *cred = current_cred();
> struct vm_area_struct *vma;
> @@ -250,7 +251,9 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
> NEW_AUX_ENT(AT_BASE, interp_load_addr);
> - NEW_AUX_ENT(AT_FLAGS, 0);
> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> + NEW_AUX_ENT(AT_FLAGS, flags);
> NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
> NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
> NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
> index 240f66663543..abb90d82aa58 100644
> --- a/fs/binfmt_elf_fdpic.c
> +++ b/fs/binfmt_elf_fdpic.c
> @@ -507,6 +507,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> char __user *u_platform, *u_base_platform, *p;
> int loop;
> int nr; /* reset for each csp adjustment */
> + unsigned long flags = 0;
>
> #ifdef CONFIG_MMU
> /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
> @@ -647,7 +648,9 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
> NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
> - NEW_AUX_ENT(AT_FLAGS, 0);
> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> + NEW_AUX_ENT(AT_FLAGS, flags);
> NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
> NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
> NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
> diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
> index cdb45829354d..b9acdd26a654 100644
> --- a/fs/binfmt_misc.c
> +++ b/fs/binfmt_misc.c
> @@ -154,7 +154,9 @@ 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;
> diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
> index b40fc633f3be..265b80d5fd6f 100644
> --- a/include/linux/binfmts.h
> +++ b/include/linux/binfmts.h
> @@ -78,6 +78,10 @@ struct linux_binprm {
> #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
> #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
>
> +/* if preserve the argv0 for the interpreter */
> +#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
> +#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
> +
> /* Function parameter for binfmt->coredump */
> struct coredump_params {
> const kernel_siginfo_t *siginfo;
> diff --git a/include/uapi/linux/binfmts.h b/include/uapi/linux/binfmts.h
> index 689025d9c185..a70747416130 100644
> --- a/include/uapi/linux/binfmts.h
> +++ b/include/uapi/linux/binfmts.h
> @@ -18,4 +18,8 @@ struct pt_regs;
> /* sizeof(linux_binprm->buf) */
> #define BINPRM_BUF_SIZE 256
>
> +/* if preserve the argv0 for the interpreter */
> +#define AT_FLAGS_PRESERVE_ARGV0_BIT 0
> +#define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
> +
> #endif /* _UAPI_LINUX_BINFMTS_H */
> --
> 2.24.1
>
Ping?
Thanks,
Laurent
Le 28/01/2020 à 14:25, Laurent Vivier a écrit :
> 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.
>
> Signed-off-by: Laurent Vivier <[email protected]>
> ---
>
> Notes:
> This can be tested with QEMU from my branch:
>
> https://github.com/vivier/qemu/commits/binfmt-argv0
>
> With something like:
>
> # cp ..../qemu-ppc /chroot/powerpc/jessie
>
> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
> --persistent no --preserve-argv0 yes
> # systemctl restart systemd-binfmt.service
> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> enabled
> interpreter //qemu-ppc
> flags: POC
> offset 0
> magic 7f454c4601020100000000000000000000020014
> mask ffffffffffffff00fffffffffffffffffffeffff
> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> sh
>
> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
> --persistent no --preserve-argv0 no
> # systemctl restart systemd-binfmt.service
> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> enabled
> interpreter //qemu-ppc
> flags: OC
> offset 0
> magic 7f454c4601020100000000000000000000020014
> mask ffffffffffffff00fffffffffffffffffffeffff
> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> /bin/sh
>
> v3: mix my patch with one from YunQiang Su and my comments on it
> introduce a new flag in the uabi for the AT_FLAGS
> v2: only pass special flags (remove Magic and Enabled flags)
>
> fs/binfmt_elf.c | 5 ++++-
> fs/binfmt_elf_fdpic.c | 5 ++++-
> fs/binfmt_misc.c | 4 +++-
> include/linux/binfmts.h | 4 ++++
> include/uapi/linux/binfmts.h | 4 ++++
> 5 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> index ecd8d2698515..ff918042ceed 100644
> --- a/fs/binfmt_elf.c
> +++ b/fs/binfmt_elf.c
> @@ -176,6 +176,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
> unsigned char k_rand_bytes[16];
> int items;
> elf_addr_t *elf_info;
> + elf_addr_t flags = 0;
> int ei_index = 0;
> const struct cred *cred = current_cred();
> struct vm_area_struct *vma;
> @@ -250,7 +251,9 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
> NEW_AUX_ENT(AT_BASE, interp_load_addr);
> - NEW_AUX_ENT(AT_FLAGS, 0);
> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> + NEW_AUX_ENT(AT_FLAGS, flags);
> NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
> NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
> NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
> index 240f66663543..abb90d82aa58 100644
> --- a/fs/binfmt_elf_fdpic.c
> +++ b/fs/binfmt_elf_fdpic.c
> @@ -507,6 +507,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> char __user *u_platform, *u_base_platform, *p;
> int loop;
> int nr; /* reset for each csp adjustment */
> + unsigned long flags = 0;
>
> #ifdef CONFIG_MMU
> /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
> @@ -647,7 +648,9 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
> NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
> - NEW_AUX_ENT(AT_FLAGS, 0);
> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> + NEW_AUX_ENT(AT_FLAGS, flags);
> NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
> NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
> NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
> diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
> index cdb45829354d..b9acdd26a654 100644
> --- a/fs/binfmt_misc.c
> +++ b/fs/binfmt_misc.c
> @@ -154,7 +154,9 @@ 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;
> diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
> index b40fc633f3be..265b80d5fd6f 100644
> --- a/include/linux/binfmts.h
> +++ b/include/linux/binfmts.h
> @@ -78,6 +78,10 @@ struct linux_binprm {
> #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
> #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
>
> +/* if preserve the argv0 for the interpreter */
> +#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
> +#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
> +
> /* Function parameter for binfmt->coredump */
> struct coredump_params {
> const kernel_siginfo_t *siginfo;
> diff --git a/include/uapi/linux/binfmts.h b/include/uapi/linux/binfmts.h
> index 689025d9c185..a70747416130 100644
> --- a/include/uapi/linux/binfmts.h
> +++ b/include/uapi/linux/binfmts.h
> @@ -18,4 +18,8 @@ struct pt_regs;
> /* sizeof(linux_binprm->buf) */
> #define BINPRM_BUF_SIZE 256
>
> +/* if preserve the argv0 for the interpreter */
> +#define AT_FLAGS_PRESERVE_ARGV0_BIT 0
> +#define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
> +
> #endif /* _UAPI_LINUX_BINFMTS_H */
>
On 6/5/20 6:20 PM, Laurent Vivier wrote:
> Le 28/01/2020 à 14:25, Laurent Vivier a écrit :
>> 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.
>>
>> Signed-off-by: Laurent Vivier <[email protected]>
Acked-by: Helge Deller <[email protected]>
If nobody objects, I'd like to take this patch through the
parisc arch git tree.
It fixes a real-world problem with qemu-user which fails to
preserve the argv[0] argument when the callee of an exec is a
qemu-user target.
This problem leads to build errors on multiple Debian buildd servers
which are using qemu-user as emulation for the target machines.
For details see Debian bug:
http://bugs.debian.org/970460
Helge
>> ---
>>
>> Notes:
>> This can be tested with QEMU from my branch:
>>
>> https://github.com/vivier/qemu/commits/binfmt-argv0
>>
>> With something like:
>>
>> # cp ..../qemu-ppc /chroot/powerpc/jessie
>>
>> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
>> --persistent no --preserve-argv0 yes
>> # systemctl restart systemd-binfmt.service
>> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
>> enabled
>> interpreter //qemu-ppc
>> flags: POC
>> offset 0
>> magic 7f454c4601020100000000000000000000020014
>> mask ffffffffffffff00fffffffffffffffffffeffff
>> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
>> sh
>>
>> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
>> --persistent no --preserve-argv0 no
>> # systemctl restart systemd-binfmt.service
>> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
>> enabled
>> interpreter //qemu-ppc
>> flags: OC
>> offset 0
>> magic 7f454c4601020100000000000000000000020014
>> mask ffffffffffffff00fffffffffffffffffffeffff
>> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
>> /bin/sh
>>
>> v3: mix my patch with one from YunQiang Su and my comments on it
>> introduce a new flag in the uabi for the AT_FLAGS
>> v2: only pass special flags (remove Magic and Enabled flags)
>>
>> fs/binfmt_elf.c | 5 ++++-
>> fs/binfmt_elf_fdpic.c | 5 ++++-
>> fs/binfmt_misc.c | 4 +++-
>> include/linux/binfmts.h | 4 ++++
>> include/uapi/linux/binfmts.h | 4 ++++
>> 5 files changed, 19 insertions(+), 3 deletions(-)
>>
>> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
>> index ecd8d2698515..ff918042ceed 100644
>> --- a/fs/binfmt_elf.c
>> +++ b/fs/binfmt_elf.c
>> @@ -176,6 +176,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
>> unsigned char k_rand_bytes[16];
>> int items;
>> elf_addr_t *elf_info;
>> + elf_addr_t flags = 0;
>> int ei_index = 0;
>> const struct cred *cred = current_cred();
>> struct vm_area_struct *vma;
>> @@ -250,7 +251,9 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
>> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
>> NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
>> NEW_AUX_ENT(AT_BASE, interp_load_addr);
>> - NEW_AUX_ENT(AT_FLAGS, 0);
>> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
>> + flags |= AT_FLAGS_PRESERVE_ARGV0;
>> + NEW_AUX_ENT(AT_FLAGS, flags);
>> NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
>> NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
>> NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
>> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
>> index 240f66663543..abb90d82aa58 100644
>> --- a/fs/binfmt_elf_fdpic.c
>> +++ b/fs/binfmt_elf_fdpic.c
>> @@ -507,6 +507,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
>> char __user *u_platform, *u_base_platform, *p;
>> int loop;
>> int nr; /* reset for each csp adjustment */
>> + unsigned long flags = 0;
>>
>> #ifdef CONFIG_MMU
>> /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
>> @@ -647,7 +648,9 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
>> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
>> NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
>> NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
>> - NEW_AUX_ENT(AT_FLAGS, 0);
>> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
>> + flags |= AT_FLAGS_PRESERVE_ARGV0;
>> + NEW_AUX_ENT(AT_FLAGS, flags);
>> NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
>> NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
>> NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
>> diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
>> index cdb45829354d..b9acdd26a654 100644
>> --- a/fs/binfmt_misc.c
>> +++ b/fs/binfmt_misc.c
>> @@ -154,7 +154,9 @@ 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;
>> diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
>> index b40fc633f3be..265b80d5fd6f 100644
>> --- a/include/linux/binfmts.h
>> +++ b/include/linux/binfmts.h
>> @@ -78,6 +78,10 @@ struct linux_binprm {
>> #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
>> #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
>>
>> +/* if preserve the argv0 for the interpreter */
>> +#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
>> +#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
>> +
>> /* Function parameter for binfmt->coredump */
>> struct coredump_params {
>> const kernel_siginfo_t *siginfo;
>> diff --git a/include/uapi/linux/binfmts.h b/include/uapi/linux/binfmts.h
>> index 689025d9c185..a70747416130 100644
>> --- a/include/uapi/linux/binfmts.h
>> +++ b/include/uapi/linux/binfmts.h
>> @@ -18,4 +18,8 @@ struct pt_regs;
>> /* sizeof(linux_binprm->buf) */
>> #define BINPRM_BUF_SIZE 256
>>
>> +/* if preserve the argv0 for the interpreter */
>> +#define AT_FLAGS_PRESERVE_ARGV0_BIT 0
>> +#define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
>> +
>> #endif /* _UAPI_LINUX_BINFMTS_H */
>>
>
Helge Deller <[email protected]> 于2021年2月13日周六 下午3:40写道：
>
> On 6/5/20 6:20 PM, Laurent Vivier wrote:
> > Le 28/01/2020 à 14:25, Laurent Vivier a écrit :
> >> 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.
> >>
> >> Signed-off-by: Laurent Vivier <[email protected]>
>
> Acked-by: Helge Deller <[email protected]>
>
> If nobody objects, I'd like to take this patch through the
> parisc arch git tree.
>
Thank you. I see this patch has been in linux-next now.
@Laurent, I guess it is time to work on to push the patch for qemu?
> It fixes a real-world problem with qemu-user which fails to
> preserve the argv[0] argument when the callee of an exec is a
> qemu-user target.
> This problem leads to build errors on multiple Debian buildd servers
> which are using qemu-user as emulation for the target machines.
>
> For details see Debian bug:
> http://bugs.debian.org/970460
>
>
> Helge
>
>
> >> ---
> >>
> >> Notes:
> >> This can be tested with QEMU from my branch:
> >>
> >> https://github.com/vivier/qemu/commits/binfmt-argv0
> >>
> >> With something like:
> >>
> >> # cp ..../qemu-ppc /chroot/powerpc/jessie
> >>
> >> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
> >> --persistent no --preserve-argv0 yes
> >> # systemctl restart systemd-binfmt.service
> >> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> >> enabled
> >> interpreter //qemu-ppc
> >> flags: POC
> >> offset 0
> >> magic 7f454c4601020100000000000000000000020014
> >> mask ffffffffffffff00fffffffffffffffffffeffff
> >> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> >> sh
> >>
> >> # qemu-binfmt-conf.sh --qemu-path / --systemd ppc --credential yes \
> >> --persistent no --preserve-argv0 no
> >> # systemctl restart systemd-binfmt.service
> >> # cat /proc/sys/fs/binfmt_misc/qemu-ppc
> >> enabled
> >> interpreter //qemu-ppc
> >> flags: OC
> >> offset 0
> >> magic 7f454c4601020100000000000000000000020014
> >> mask ffffffffffffff00fffffffffffffffffffeffff
> >> # chroot /chroot/powerpc/jessie sh -c 'echo $0'
> >> /bin/sh
> >>
> >> v3: mix my patch with one from YunQiang Su and my comments on it
> >> introduce a new flag in the uabi for the AT_FLAGS
> >> v2: only pass special flags (remove Magic and Enabled flags)
> >>
> >> fs/binfmt_elf.c | 5 ++++-
> >> fs/binfmt_elf_fdpic.c | 5 ++++-
> >> fs/binfmt_misc.c | 4 +++-
> >> include/linux/binfmts.h | 4 ++++
> >> include/uapi/linux/binfmts.h | 4 ++++
> >> 5 files changed, 19 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> >> index ecd8d2698515..ff918042ceed 100644
> >> --- a/fs/binfmt_elf.c
> >> +++ b/fs/binfmt_elf.c
> >> @@ -176,6 +176,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
> >> unsigned char k_rand_bytes[16];
> >> int items;
> >> elf_addr_t *elf_info;
> >> + elf_addr_t flags = 0;
> >> int ei_index = 0;
> >> const struct cred *cred = current_cred();
> >> struct vm_area_struct *vma;
> >> @@ -250,7 +251,9 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
> >> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> >> NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
> >> NEW_AUX_ENT(AT_BASE, interp_load_addr);
> >> - NEW_AUX_ENT(AT_FLAGS, 0);
> >> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> >> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> >> + NEW_AUX_ENT(AT_FLAGS, flags);
> >> NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
> >> NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
> >> NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
> >> diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
> >> index 240f66663543..abb90d82aa58 100644
> >> --- a/fs/binfmt_elf_fdpic.c
> >> +++ b/fs/binfmt_elf_fdpic.c
> >> @@ -507,6 +507,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> >> char __user *u_platform, *u_base_platform, *p;
> >> int loop;
> >> int nr; /* reset for each csp adjustment */
> >> + unsigned long flags = 0;
> >>
> >> #ifdef CONFIG_MMU
> >> /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
> >> @@ -647,7 +648,9 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
> >> NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
> >> NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
> >> NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
> >> - NEW_AUX_ENT(AT_FLAGS, 0);
> >> + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
> >> + flags |= AT_FLAGS_PRESERVE_ARGV0;
> >> + NEW_AUX_ENT(AT_FLAGS, flags);
> >> NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
> >> NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
> >> NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
> >> diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
> >> index cdb45829354d..b9acdd26a654 100644
> >> --- a/fs/binfmt_misc.c
> >> +++ b/fs/binfmt_misc.c
> >> @@ -154,7 +154,9 @@ 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;
> >> diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
> >> index b40fc633f3be..265b80d5fd6f 100644
> >> --- a/include/linux/binfmts.h
> >> +++ b/include/linux/binfmts.h
> >> @@ -78,6 +78,10 @@ struct linux_binprm {
> >> #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2
> >> #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT)
> >>
> >> +/* if preserve the argv0 for the interpreter */
> >> +#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3
> >> +#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT)
> >> +
> >> /* Function parameter for binfmt->coredump */
> >> struct coredump_params {
> >> const kernel_siginfo_t *siginfo;
> >> diff --git a/include/uapi/linux/binfmts.h b/include/uapi/linux/binfmts.h
> >> index 689025d9c185..a70747416130 100644
> >> --- a/include/uapi/linux/binfmts.h
> >> +++ b/include/uapi/linux/binfmts.h
> >> @@ -18,4 +18,8 @@ struct pt_regs;
> >> /* sizeof(linux_binprm->buf) */
> >> #define BINPRM_BUF_SIZE 256
> >>
> >> +/* if preserve the argv0 for the interpreter */
> >> +#define AT_FLAGS_PRESERVE_ARGV0_BIT 0
> >> +#define AT_FLAGS_PRESERVE_ARGV0 (1 << AT_FLAGS_PRESERVE_ARGV0_BIT)
> >> +
> >> #endif /* _UAPI_LINUX_BINFMTS_H */
> >>
> >
>