* [PATCH] uapi: change TRACE_MMAP_IOCTL_GET_READER to avoid collision with TCGETS
From: Dmitry V. Levin @ 2024-06-30 21:36 UTC (permalink / raw)
To: Steven Rostedt
Cc: Vincent Donnefort, David Hildenbrand, linux-api,
linux-trace-kernel, linux-mm, linux-kernel
The number that was initially chosen for TRACE_MMAP_IOCTL_GET_READER,
unfortunately, collides with TCGETS on most of architectures.
For example, this is how strace output would look like when
support for this value of TRACE_MMAP_IOCTL_GET_READER is added:
$ strace -e ioctl stty
ioctl(0, TCGETS or TRACE_MMAP_IOCTL_GET_READER, {c_iflag=ICRNL|IXON, c_oflag=NL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR,
+c_cflag=B38400|CS8|CREAD, c_lflag=ISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) = 0
Even though ioctl numbers are inherently not unique, TCGETS
is a very traditional one, so let's change the value of
TRACE_MMAP_IOCTL_GET_READER a bit to avoid this collision.
Given that _IO('T', 0x1) is _IOC(_IOC_NONE, 'T', 0x1, 0),
something like _IOC(_IOC_NONE, 'T', 0x1, 0x1) should be OK.
Fixes: cf9f0f7c4c5bb ("tracing: Allow user-space mapping of the ring-buffer")
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
---
include/uapi/linux/trace_mmap.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/uapi/linux/trace_mmap.h b/include/uapi/linux/trace_mmap.h
index bd1066754220..cb858f1b8367 100644
--- a/include/uapi/linux/trace_mmap.h
+++ b/include/uapi/linux/trace_mmap.h
@@ -43,6 +43,6 @@ struct trace_buffer_meta {
__u64 Reserved2;
};
-#define TRACE_MMAP_IOCTL_GET_READER _IO('T', 0x1)
+#define TRACE_MMAP_IOCTL_GET_READER _IOC(_IOC_NONE, 'T', 0x1, 0x1)
#endif /* _TRACE_MMAP_H_ */
--
ldv
^ permalink raw reply related
* Re: [PATCH v23 3/5] tracing: Allow user-space mapping of the ring-buffer
From: Steven Rostedt @ 2024-06-30 12:40 UTC (permalink / raw)
To: Dmitry V. Levin
Cc: Vincent Donnefort, mhiramat, mathieu.desnoyers, kernel-team,
rdunlap, rppt, david, linux-trace-kernel, linux-mm, linux-api,
linux-kernel, Linus Torvalds
In-Reply-To: <20240630105322.GA17573@altlinux.org>
On Sun, 30 Jun 2024 13:53:23 +0300
"Dmitry V. Levin" <ldv@strace.io> wrote:
> On Fri, May 10, 2024 at 03:04:32PM +0100, Vincent Donnefort wrote:
> [...]
> > diff --git a/include/uapi/linux/trace_mmap.h b/include/uapi/linux/trace_mmap.h
> > index b682e9925539..bd1066754220 100644
> > --- a/include/uapi/linux/trace_mmap.h
> > +++ b/include/uapi/linux/trace_mmap.h
> > @@ -43,4 +43,6 @@ struct trace_buffer_meta {
> > __u64 Reserved2;
> > };
> >
> > +#define TRACE_MMAP_IOCTL_GET_READER _IO('T', 0x1)
> > +
>
> I'm sorry but among all the numbers this one was probably the least
> fortunate choice because it collides with TCGETS on most of architectures.
Hmm, that is unfortunate.
>
> For example, this is how strace output would look like when
> TRACE_MMAP_IOCTL_GET_READER support is added:
>
> $ strace -e ioctl stty
> ioctl(0, TCGETS or TRACE_MMAP_IOCTL_GET_READER, {c_iflag=ICRNL|IXON, c_oflag=NL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR, c_cflag=B38400|CS8|CREAD, c_lflag=ISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) = 0
>
> Even though ioctl numbers are inherently not unique, TCGETS is
> a very traditional one, so it would be great if you could change
> TRACE_MMAP_IOCTL_GET_READER to avoid this collision.
>
> Given that _IO('T', 0x1) is _IOC(_IOC_NONE, 'T', 0x1, 0),
> something like _IOC(_IOC_NONE, 'T', 0x1, 0x1) should be OK.
Well, it may not be too late to update this as it hasn't been
officially released in 6.10 yet. It's still only in the -rc and the
library doesn't rely on this yet (I've been holding off until 6.10 was
officially released before releasing the library that uses it).
I can send a patch this week to update it. Or feel free to send a patch
yourself.
Thanks,
-- Steve
^ permalink raw reply
* Re: [PATCH v23 3/5] tracing: Allow user-space mapping of the ring-buffer
From: Dmitry V. Levin @ 2024-06-30 10:53 UTC (permalink / raw)
To: Vincent Donnefort
Cc: rostedt, mhiramat, mathieu.desnoyers, kernel-team, rdunlap, rppt,
david, linux-trace-kernel, linux-mm, linux-api, linux-kernel
In-Reply-To: <20240510140435.3550353-4-vdonnefort@google.com>
On Fri, May 10, 2024 at 03:04:32PM +0100, Vincent Donnefort wrote:
[...]
> diff --git a/include/uapi/linux/trace_mmap.h b/include/uapi/linux/trace_mmap.h
> index b682e9925539..bd1066754220 100644
> --- a/include/uapi/linux/trace_mmap.h
> +++ b/include/uapi/linux/trace_mmap.h
> @@ -43,4 +43,6 @@ struct trace_buffer_meta {
> __u64 Reserved2;
> };
>
> +#define TRACE_MMAP_IOCTL_GET_READER _IO('T', 0x1)
> +
I'm sorry but among all the numbers this one was probably the least
fortunate choice because it collides with TCGETS on most of architectures.
For example, this is how strace output would look like when
TRACE_MMAP_IOCTL_GET_READER support is added:
$ strace -e ioctl stty
ioctl(0, TCGETS or TRACE_MMAP_IOCTL_GET_READER, {c_iflag=ICRNL|IXON, c_oflag=NL0|CR0|TAB0|BS0|VT0|FF0|OPOST|ONLCR, c_cflag=B38400|CS8|CREAD, c_lflag=ISIG|ICANON|ECHO|ECHOE|ECHOK|IEXTEN|ECHOCTL|ECHOKE, ...}) = 0
Even though ioctl numbers are inherently not unique, TCGETS is
a very traditional one, so it would be great if you could change
TRACE_MMAP_IOCTL_GET_READER to avoid this collision.
Given that _IO('T', 0x1) is _IOC(_IOC_NONE, 'T', 0x1, 0),
something like _IOC(_IOC_NONE, 'T', 0x1, 0x1) should be OK.
--
ldv
^ permalink raw reply
* Re: [PATCH] syscalls: fix sys_fanotify_mark prototype
From: Helge Deller @ 2024-06-29 21:31 UTC (permalink / raw)
To: Arnd Bergmann, Arnd Bergmann
Cc: Guenter Roeck, linux-api, linux-kernel, linux-parisc
In-Reply-To: <20240629210359.94426-1-arnd@kernel.org>
On 6/29/24 23:03, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> My earlier fix missed an incorrect function prototype that shows up on
> native 32-bit builds:
>
> In file included from fs/notify/fanotify/fanotify_user.c:14:
> include/linux/syscalls.h:248:25: error: conflicting types for 'sys_fanotify_mark'; have 'long int(int, unsigned int, u32, u32, int, const char *)' {aka 'long int(int, unsigned int, unsigned int, unsigned int, int, const char *)'}
> 1924 | SYSCALL32_DEFINE6(fanotify_mark,
> | ^~~~~~~~~~~~~~~~~
> include/linux/syscalls.h:862:17: note: previous declaration of 'sys_fanotify_mark' with type 'long int(int, unsigned int, u64, int, const char *)' {aka 'long int(int, unsigned int, long long unsigned int, int, const char *)'}
>
> On x86 and powerpc, the prototype is also wrong but hidden in an #ifdef,
> so it never caused problems.
>
> Add another alternative declaration that matches the conditional function
> definition.
>
> Fixes: 403f17a33073 ("parisc: use generic sys_fanotify_mark implementation")
> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Guenter, thanks for noticing!
Arnd, I can confirm this patch fixes the 32-bit build for hppa,
so you may add:
Tested-by: Helge Deller <deller@gmx.de>
Thank you!
Helge
> ---
> I've queued this fix in the asm-generic tree now
>
> include/linux/syscalls.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
> index 63424af87bba..fff820c3e93e 100644
> --- a/include/linux/syscalls.h
> +++ b/include/linux/syscalls.h
> @@ -859,9 +859,15 @@ asmlinkage long sys_prlimit64(pid_t pid, unsigned int resource,
> const struct rlimit64 __user *new_rlim,
> struct rlimit64 __user *old_rlim);
> asmlinkage long sys_fanotify_init(unsigned int flags, unsigned int event_f_flags);
> +#if defined(CONFIG_ARCH_SPLIT_ARG64)
> +asmlinkage long sys_fanotify_mark(int fanotify_fd, unsigned int flags,
> + unsigned int mask_1, unsigned int mask_2,
> + int dfd, const char __user * pathname);
> +#else
> asmlinkage long sys_fanotify_mark(int fanotify_fd, unsigned int flags,
> u64 mask, int fd,
> const char __user *pathname);
> +#endif
> asmlinkage long sys_name_to_handle_at(int dfd, const char __user *name,
> struct file_handle __user *handle,
> int __user *mnt_id, int flag);
^ permalink raw reply
* [PATCH] syscalls: fix sys_fanotify_mark prototype
From: Arnd Bergmann @ 2024-06-29 21:03 UTC (permalink / raw)
To: Arnd Bergmann, Helge Deller; +Cc: Guenter Roeck, linux-api, linux-kernel
From: Arnd Bergmann <arnd@arndb.de>
My earlier fix missed an incorrect function prototype that shows up on
native 32-bit builds:
In file included from fs/notify/fanotify/fanotify_user.c:14:
include/linux/syscalls.h:248:25: error: conflicting types for 'sys_fanotify_mark'; have 'long int(int, unsigned int, u32, u32, int, const char *)' {aka 'long int(int, unsigned int, unsigned int, unsigned int, int, const char *)'}
1924 | SYSCALL32_DEFINE6(fanotify_mark,
| ^~~~~~~~~~~~~~~~~
include/linux/syscalls.h:862:17: note: previous declaration of 'sys_fanotify_mark' with type 'long int(int, unsigned int, u64, int, const char *)' {aka 'long int(int, unsigned int, long long unsigned int, int, const char *)'}
On x86 and powerpc, the prototype is also wrong but hidden in an #ifdef,
so it never caused problems.
Add another alternative declaration that matches the conditional function
definition.
Fixes: 403f17a33073 ("parisc: use generic sys_fanotify_mark implementation")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
I've queued this fix in the asm-generic tree now
include/linux/syscalls.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 63424af87bba..fff820c3e93e 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -859,9 +859,15 @@ asmlinkage long sys_prlimit64(pid_t pid, unsigned int resource,
const struct rlimit64 __user *new_rlim,
struct rlimit64 __user *old_rlim);
asmlinkage long sys_fanotify_init(unsigned int flags, unsigned int event_f_flags);
+#if defined(CONFIG_ARCH_SPLIT_ARG64)
+asmlinkage long sys_fanotify_mark(int fanotify_fd, unsigned int flags,
+ unsigned int mask_1, unsigned int mask_2,
+ int dfd, const char __user * pathname);
+#else
asmlinkage long sys_fanotify_mark(int fanotify_fd, unsigned int flags,
u64 mask, int fd,
const char __user *pathname);
+#endif
asmlinkage long sys_name_to_handle_at(int dfd, const char __user *name,
struct file_handle __user *handle,
int __user *mnt_id, int flag);
--
2.39.2
^ permalink raw reply related
* Re: [PATCH v18 2/5] random: add vgetrandom_alloc() syscall
From: Jason A. Donenfeld @ 2024-06-28 14:11 UTC (permalink / raw)
To: Thomas Gleixner
Cc: Aleksa Sarai, linux-kernel, patches, linux-crypto, linux-api, x86,
Greg Kroah-Hartman, Adhemerval Zanella Netto, Carlos O'Donell,
Florian Weimer, Arnd Bergmann, Jann Horn, Christian Brauner,
David Hildenbrand
In-Reply-To: <Zn7D_YBC2SXTa_jX@zx2c4.com>
On Fri, Jun 28, 2024 at 4:09 PM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> perhaps definitely to deal with,
What?! I meant "definitely easier to deal with".
^ permalink raw reply
* Re: [PATCH v18 2/5] random: add vgetrandom_alloc() syscall
From: Jason A. Donenfeld @ 2024-06-28 14:09 UTC (permalink / raw)
To: Thomas Gleixner
Cc: Aleksa Sarai, linux-kernel, patches, linux-crypto, linux-api, x86,
Greg Kroah-Hartman, Adhemerval Zanella Netto, Carlos O'Donell,
Florian Weimer, Arnd Bergmann, Jann Horn, Christian Brauner,
David Hildenbrand
In-Reply-To: <87v81txjb7.ffs@tglx>
On Fri, Jun 28, 2024 at 03:56:12PM +0200, Thomas Gleixner wrote:
> Jason!
>
> On Thu, Jun 20 2024 at 14:18, Jason A. Donenfeld wrote:
> > On Wed, Jun 19, 2024 at 07:13:26PM -0700, Aleksa Sarai wrote:
> >> Then again, I guess since libc is planned to be the primary user,
> >> creating a new syscall in a decade if necessary is probably not that big
> >> of an issue.
> >
> > I'm not sure going the whole big struct thing is really necessary, and
> > for an additional reason: this is only meant to be used with the vDSO
> > function, which is also coupled with the kernel. It doesn't return
> > information that's made to be used (or allowed to be used) anywhere
> > else. So both the vdso code and the syscall code are part of the same
> > basic thing that will evolve together. So I'm not convinced extensible
> > struct really makes sense for this, as neat as it is.
> >
> > If there's wide consensus that it's desirable, in contrast to what I'm
> > saying, I'm not vehemently opposed to it and could do it, but it just
> > seems like massive overkill and not at all necessary. Things are
> > intentionally as simple and straightforward as can be.
>
> Right, but the problem is that this is a syscall, so people are free to
> explore it even without the vdso part. Now when you want to change it
> later then you are caught in the no-regression trap.
>
> So making it extensible with backwards compability in place (add the
> unused flag field and check for 0) will allow you to expand without
> breaking users.
Okay, so it sounds like you're also in camp-struct. I guess let's do it
then. This opens up a few questions, but I think we can get them sorted.
Right now this version of the patch has this signature:
void *vgetrandom_alloc(unsigned int *num, unsigned int *size_per_each,
unsigned long addr, unsigned int flags);
The semantics are currently:
- [in] unsigned int num - desired number of states
- [in] unsigned long addr - reserved, nothing
- [in] unsigned int flags - reserved, nothing
- [out] unsigned int num - actual number of states
- [out] unsigned int size_per_each - size of each state
- [out] void* return value - the allocated thing
Following Aleksa's suggestion, we keep the `[out] void* return value` as
a return value, but move all the other into a struct:
void *vgetrandom_alloc(struct vgetrandom_args *arg, size_t size);
So now the struct can become:
struct vgetrandom_args {
[in] u64 flags;
[in/out] u32 num;
[out] u32 size_per_each;
}
Alternatively, this now opens the possibility to incorporate Eric's
suggestion of also returning the number of allocated bytes, which is
perhaps definitely to deal with, but I didn't do because I wanted
symmetry in the argument list. So doing that, now we have:
struct vgetrandom_args {
[in] u64 flags;
[in/out] u32 num;
[out] u32 size_per_each;
[out] u64 bytes_allocated;
}
Does that seem reasonable? There's a little bit of mixing of ins and
outs within the struct, and the return value is still a return value,
rather than a `[out] void *ret` inside of the struct. But maybe that's
fine. Also I used u32 there for the two smaller arguments, but maybe
that's silly and we should go straight to u64?
Anyway, how does that look to you?
Jason
^ permalink raw reply
* Re: [PATCH v18 5/5] x86: vdso: Wire up getrandom() vDSO implementation
From: Thomas Gleixner @ 2024-06-28 13:57 UTC (permalink / raw)
To: Jason A. Donenfeld, linux-kernel, patches
Cc: Jason A. Donenfeld, linux-crypto, linux-api, x86,
Greg Kroah-Hartman, Adhemerval Zanella Netto, Carlos O'Donell,
Florian Weimer, Arnd Bergmann, Jann Horn, Christian Brauner,
David Hildenbrand, Samuel Neves
In-Reply-To: <20240620005339.1273434-6-Jason@zx2c4.com>
On Thu, Jun 20 2024 at 02:53, Jason A. Donenfeld wrote:
> Hook up the generic vDSO implementation to the x86 vDSO data page. Since
> the existing vDSO infrastructure is heavily based on the timekeeping
> functionality, which works over arrays of bases, a new macro is
> introduced for vvars that are not arrays.
>
> The vDSO function requires a ChaCha20 implementation that does not write
> to the stack, yet can still do an entire ChaCha20 permutation, so
> provide this using SSE2, since this is userland code that must work on
> all x86-64 processors. There's a simple test for this code as well.
>
> Reviewed-by: Samuel Neves <sneves@dei.uc.pt> # for vgetrandom-chacha.S
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
^ permalink raw reply
* Re: [PATCH v18 4/5] random: introduce generic vDSO getrandom() implementation
From: Thomas Gleixner @ 2024-06-28 13:57 UTC (permalink / raw)
To: Jason A. Donenfeld, linux-kernel, patches
Cc: Jason A. Donenfeld, linux-crypto, linux-api, x86,
Greg Kroah-Hartman, Adhemerval Zanella Netto, Carlos O'Donell,
Florian Weimer, Arnd Bergmann, Jann Horn, Christian Brauner,
David Hildenbrand
In-Reply-To: <20240620005339.1273434-5-Jason@zx2c4.com>
On Thu, Jun 20 2024 at 02:53, Jason A. Donenfeld wrote:
> return grnd_ctx.fn(buf, len, flags, state, grnd_allocator.size_per_each);
> }
>
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
^ permalink raw reply
* Re: [PATCH v18 2/5] random: add vgetrandom_alloc() syscall
From: Thomas Gleixner @ 2024-06-28 13:56 UTC (permalink / raw)
To: Jason A. Donenfeld, Aleksa Sarai
Cc: linux-kernel, patches, linux-crypto, linux-api, x86,
Greg Kroah-Hartman, Adhemerval Zanella Netto, Carlos O'Donell,
Florian Weimer, Arnd Bergmann, Jann Horn, Christian Brauner,
David Hildenbrand
In-Reply-To: <ZnQeCRjgNXEAQjEo@zx2c4.com>
Jason!
On Thu, Jun 20 2024 at 14:18, Jason A. Donenfeld wrote:
> On Wed, Jun 19, 2024 at 07:13:26PM -0700, Aleksa Sarai wrote:
>> Then again, I guess since libc is planned to be the primary user,
>> creating a new syscall in a decade if necessary is probably not that big
>> of an issue.
>
> I'm not sure going the whole big struct thing is really necessary, and
> for an additional reason: this is only meant to be used with the vDSO
> function, which is also coupled with the kernel. It doesn't return
> information that's made to be used (or allowed to be used) anywhere
> else. So both the vdso code and the syscall code are part of the same
> basic thing that will evolve together. So I'm not convinced extensible
> struct really makes sense for this, as neat as it is.
>
> If there's wide consensus that it's desirable, in contrast to what I'm
> saying, I'm not vehemently opposed to it and could do it, but it just
> seems like massive overkill and not at all necessary. Things are
> intentionally as simple and straightforward as can be.
Right, but the problem is that this is a syscall, so people are free to
explore it even without the vdso part. Now when you want to change it
later then you are caught in the no-regression trap.
So making it extensible with backwards compability in place (add the
unused flag field and check for 0) will allow you to expand without
breaking users.
Thanks,
tglx
^ permalink raw reply
* [PATCH v3] platform/x86: asus-wmi: support the disable camera LED on F10 of Zenbook 2023
From: Devin Bayer @ 2024-06-28 8:46 UTC (permalink / raw)
To: corentin.chary, luke
Cc: hdegoede, platform-driver-x86, linux-kernel, linux-api,
ilpo.jarvinen, Devin Bayer
Adds a sysfs entry for the LED on F10 above the crossed out camera icon on 2023 Zenbooks.
v3
- add docs for WMI devices
- remove duplicate #define
v2
- Changed name from `platform::camera` to `asus::camera`
- Separated patch from patchset
v1
- https://lore.kernel.org/platform-driver-x86/20240620082223.20178-1-dev@doubly.so/
Signed-off-by: Devin Bayer <dev@doubly.so>
---
drivers/platform/x86/asus-wmi.c | 35 ++++++++++++++++++++++
include/linux/platform_data/x86/asus-wmi.h | 4 +++
2 files changed, 39 insertions(+)
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 3f07bbf809ef..4a9ad8b313e6 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -227,6 +227,7 @@ struct asus_wmi {
struct led_classdev lightbar_led;
int lightbar_led_wk;
struct led_classdev micmute_led;
+ struct led_classdev camera_led;
struct workqueue_struct *led_workqueue;
struct work_struct tpd_led_work;
struct work_struct wlan_led_work;
@@ -1533,6 +1534,27 @@ static int micmute_led_set(struct led_classdev *led_cdev,
return err < 0 ? err : 0;
}
+static enum led_brightness camera_led_get(struct led_classdev *led_cdev)
+{
+ struct asus_wmi *asus;
+ u32 result;
+
+ asus = container_of(led_cdev, struct asus_wmi, camera_led);
+ asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_CAMERA_LED, &result);
+
+ return result & ASUS_WMI_DSTS_BRIGHTNESS_MASK;
+}
+
+static int camera_led_set(struct led_classdev *led_cdev,
+ enum led_brightness brightness)
+{
+ int state = brightness != LED_OFF;
+ int err;
+
+ err = asus_wmi_set_devstate(ASUS_WMI_DEVID_CAMERA_LED, state, NULL);
+ return err < 0 ? err : 0;
+}
+
static void asus_wmi_led_exit(struct asus_wmi *asus)
{
led_classdev_unregister(&asus->kbd_led);
@@ -1540,6 +1562,7 @@ static void asus_wmi_led_exit(struct asus_wmi *asus)
led_classdev_unregister(&asus->wlan_led);
led_classdev_unregister(&asus->lightbar_led);
led_classdev_unregister(&asus->micmute_led);
+ led_classdev_unregister(&asus->camera_led);
if (asus->led_workqueue)
destroy_workqueue(asus->led_workqueue);
@@ -1631,6 +1654,18 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
goto error;
}
+ if (asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_CAMERA_LED)) {
+ asus->camera_led.name = "asus::camera";
+ asus->camera_led.max_brightness = 1;
+ asus->camera_led.brightness_get = camera_led_get;
+ asus->camera_led.brightness_set_blocking = camera_led_set;
+
+ rv = led_classdev_register(&asus->platform_device->dev,
+ &asus->camera_led);
+ if (rv)
+ goto error;
+ }
+
error:
if (rv)
asus_wmi_led_exit(asus);
diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
index ab1c7deff118..d020fcbbcfb7 100644
--- a/include/linux/platform_data/x86/asus-wmi.h
+++ b/include/linux/platform_data/x86/asus-wmi.h
@@ -51,6 +51,10 @@
#define ASUS_WMI_DEVID_LED6 0x00020016
#define ASUS_WMI_DEVID_MICMUTE_LED 0x00040017
+/* Disable Camera LED */
+#define ASUS_WMI_DEVID_CAMERA_LED_NEG 0x00060078 /* 0 = on (unused) */
+#define ASUS_WMI_DEVID_CAMERA_LED 0x00060079 /* 1 = on */
+
/* Backlight and Brightness */
#define ASUS_WMI_DEVID_ALS_ENABLE 0x00050001 /* Ambient Light Sensor */
#define ASUS_WMI_DEVID_BACKLIGHT 0x00050011
base-commit: 103a4e4a4351d3d5214c4f54fdf89f0f81b692ef
--
2.45.2
^ permalink raw reply related
* Re: [PATCH RFT v6 1/9] Documentation: userspace-api: Add shadow stack API documentation
From: Randy Dunlap @ 2024-06-25 22:31 UTC (permalink / raw)
To: Mark Brown, Rick P. Edgecombe, Deepak Gupta, Szabolcs Nagy,
H.J. Lu, Florian Weimer, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, Dave Hansen, x86, H. Peter Anvin, Peter Zijlstra,
Juri Lelli, Vincent Guittot, Dietmar Eggemann, Steven Rostedt,
Ben Segall, Mel Gorman, Daniel Bristot de Oliveira,
Valentin Schneider, Christian Brauner, Shuah Khan
Cc: linux-kernel, Catalin Marinas, Will Deacon, jannh,
linux-kselftest, linux-api, Kees Cook
In-Reply-To: <20240623-clone3-shadow-stack-v6-1-9ee7783b1fb9@kernel.org>
Hi,
On 6/23/24 4:23 AM, Mark Brown wrote:
> There are a number of architectures with shadow stack features which we are
> presenting to userspace with as consistent an API as we can (though there
> are some architecture specifics). Especially given that there are some
> important considerations for userspace code interacting directly with the
> feature let's provide some documentation covering the common aspects.
>
> Signed-off-by: Mark Brown <broonie@kernel.org>
> ---
> Documentation/userspace-api/index.rst | 1 +
> Documentation/userspace-api/shadow_stack.rst | 41 ++++++++++++++++++++++++++++
> 2 files changed, 42 insertions(+)
>
Fix run-on sentences...
> diff --git a/Documentation/userspace-api/shadow_stack.rst b/Documentation/userspace-api/shadow_stack.rst
> new file mode 100644
> index 000000000000..c576ad3d7ec1
> --- /dev/null
> +++ b/Documentation/userspace-api/shadow_stack.rst
> @@ -0,0 +1,41 @@
> +=============
> +Shadow Stacks
> +=============
> +
> +Introduction
> +============
> +
> +Several architectures have features which provide backward edge
> +control flow protection through a hardware maintained stack, only
> +writeable by userspace through very limited operations. This feature
> +is referred to as shadow stacks on Linux, on x86 it is part of Intel
Linux. On x86
> +Control Enforcement Technology (CET), on arm64 it is Guarded Control
(CET); on arm64
> +Stacks feature (FEAT_GCS) and for RISC-V it is the Zicfiss extension.
(FEAT_GCS); and for
> +It is expected that this feature will normally be managed by the
> +system dynamic linker and libc in ways broadly transparent to
> +application code, this document covers interfaces and considerations.
code. This document
> +
> +
> +Enabling
> +========
> +
> +Shadow stacks default to disabled when a userspace process is
> +executed, they can be enabled for the current thread with a syscall:
executed. They
> +
> + - For x86 the ARCH_SHSTK_ENABLE arch_prctl()
> +
> +It is expected that this will normally be done by the dynamic linker.
> +Any new threads created by a thread with shadow stacks enabled will
> +themselves have shadow stacks enabled.
> +
> +
> +Enablement considerations
> +=========================
> +
> +- Returning from the function that enables shadow stacks without first
> + disabling them will cause a shadow stack exception. This includes
> + any syscall wrapper or other library functions, the syscall will need
functions. The syscall
> + to be inlined.
> +- A lock feature allows userspace to prevent disabling of shadow stacks.
> +- Those that change the stack context like longjmp() or use of ucontext
> + changes on signal return will need support from libc.
>
--
~Randy
^ permalink raw reply
* Re: [PATCH v2] platform/x86: asus-wmi: support the disable camera LED on F10 of Zenbook 2023
From: Devin Bayer @ 2024-06-24 8:34 UTC (permalink / raw)
To: Ilpo Järvinen
Cc: corentin.chary, luke, Hans de Goede, platform-driver-x86, LKML,
linux-api
In-Reply-To: <a80c09f8-e932-722f-8c68-19a254d94633@linux.intel.com>
On 24/06/2024 10.17, Ilpo Järvinen wrote:
> On Fri, 21 Jun 2024, Devin Bayer wrote:
>
>> Adds a sysfs entry for the LED on F10 above the crossed out camera
>> icon on 2023 Zenbooks.
>
> Please wrap paragraphs at 72 characters.
OK.
>> --- a/include/linux/platform_data/x86/asus-wmi.h
>> +++ b/include/linux/platform_data/x86/asus-wmi.h
>> @@ -50,6 +50,8 @@
>> #define ASUS_WMI_DEVID_LED5 0x00020015
>> #define ASUS_WMI_DEVID_LED6 0x00020016
>> #define ASUS_WMI_DEVID_MICMUTE_LED 0x00040017
>> +#define ASUS_WMI_DEVID_CAMERA_LED_NEG 0x00060078
>
> This is not used?
No, it does the same as CAMERA_LED but the values are opposite. I
thought it would just be useful as documentation of the WMI functions.
Should I remove it?
>> +#define ASUS_WMI_DEVID_CAMERA_LED 0x00060079
>
> Why is ASUS_WMI_DEVID_CAMERA_LED added here and into the .c file?
That was a mistake, I used it for testing.
~ Dev
^ permalink raw reply
* Re: [PATCH v2] platform/x86: asus-wmi: support the disable camera LED on F10 of Zenbook 2023
From: Ilpo Järvinen @ 2024-06-24 8:17 UTC (permalink / raw)
To: Devin Bayer
Cc: corentin.chary, luke, Hans de Goede, platform-driver-x86, LKML,
linux-api
In-Reply-To: <20240621085745.233107-1-dev@doubly.so>
On Fri, 21 Jun 2024, Devin Bayer wrote:
> Adds a sysfs entry for the LED on F10 above the crossed out camera icon on 2023 Zenbooks.
Please wrap paragraphs at 72 characters.
>
> v2
> - Changed name from `platform::camera` to `asus::camera`
> - Separated patch from patchset
>
> v1
> - https://lore.kernel.org/platform-driver-x86/20240620082223.20178-1-dev@doubly.so/
>
> Signed-off-by: Devin Bayer <dev@doubly.so>
> ---
> drivers/platform/x86/asus-wmi.c | 36 ++++++++++++++++++++++
> include/linux/platform_data/x86/asus-wmi.h | 2 ++
> 2 files changed, 38 insertions(+)
>
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 3f07bbf809ef..20b7ed6a27b5 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -73,6 +73,7 @@ module_param(fnlock_default, bool, 0444);
> #define NOTIFY_LID_FLIP_ROG 0xbd
>
> #define ASUS_WMI_FNLOCK_BIOS_DISABLED BIT(0)
> +#define ASUS_WMI_DEVID_CAMERA_LED 0x00060079
> diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
> index ab1c7deff118..fb0b00f7d292 100644
> --- a/include/linux/platform_data/x86/asus-wmi.h
> +++ b/include/linux/platform_data/x86/asus-wmi.h
> @@ -50,6 +50,8 @@
> #define ASUS_WMI_DEVID_LED5 0x00020015
> #define ASUS_WMI_DEVID_LED6 0x00020016
> #define ASUS_WMI_DEVID_MICMUTE_LED 0x00040017
> +#define ASUS_WMI_DEVID_CAMERA_LED_NEG 0x00060078
This is not used?
> +#define ASUS_WMI_DEVID_CAMERA_LED 0x00060079
Why is ASUS_WMI_DEVID_CAMERA_LED added here and into the .c file?
--
i.
^ permalink raw reply
* Re: [PATCH v2] platform/x86: asus-wmi: support the disable camera LED on F10 of Zenbook 2023
From: Luke Jones @ 2024-06-23 23:55 UTC (permalink / raw)
To: Ilpo Järvinen
Cc: Devin Bayer, corentin.chary, Hans de Goede, platform-driver-x86,
LKML, linux-api
In-Reply-To: <22352c0a-a853-b28d-a36a-09cc502acb8b@linux.intel.com>
On Mon, 24 Jun 2024, at 4:57 AM, Ilpo Järvinen wrote:
> On Fri, 21 Jun 2024, Luke Jones wrote:
>
> > On Fri, 21 Jun 2024, at 8:57 PM, Devin Bayer wrote:
> > > Adds a sysfs entry for the LED on F10 above the crossed out camera icon on 2023 Zenbooks.
> > >
> > > v2
> > > - Changed name from `platform::camera` to `asus::camera`
> > > - Separated patch from patchset
> > >
> > > v1
> > > - https://lore.kernel.org/platform-driver-x86/20240620082223.20178-1-dev@doubly.so/
> > >
> > > Signed-off-by: Devin Bayer <dev@doubly.so>
> > > ---
> > > drivers/platform/x86/asus-wmi.c | 36 ++++++++++++++++++++++
> > > include/linux/platform_data/x86/asus-wmi.h | 2 ++
> > > 2 files changed, 38 insertions(+)
> > >
> > > diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> > > index 3f07bbf809ef..20b7ed6a27b5 100644
> > > --- a/drivers/platform/x86/asus-wmi.c
> > > +++ b/drivers/platform/x86/asus-wmi.c
> > > @@ -73,6 +73,7 @@ module_param(fnlock_default, bool, 0444);
> > > #define NOTIFY_LID_FLIP_ROG 0xbd
> > >
> > > #define ASUS_WMI_FNLOCK_BIOS_DISABLED BIT(0)
> > > +#define ASUS_WMI_DEVID_CAMERA_LED 0x00060079
> > >
> > > #define ASUS_MID_FAN_DESC "mid_fan"
> > > #define ASUS_GPU_FAN_DESC "gpu_fan"
> > > @@ -227,6 +228,7 @@ struct asus_wmi {
> > > struct led_classdev lightbar_led;
> > > int lightbar_led_wk;
> > > struct led_classdev micmute_led;
> > > + struct led_classdev camera_led;
> > > struct workqueue_struct *led_workqueue;
> > > struct work_struct tpd_led_work;
> > > struct work_struct wlan_led_work;
> > > @@ -1533,6 +1535,27 @@ static int micmute_led_set(struct led_classdev *led_cdev,
> > > return err < 0 ? err : 0;
> > > }
> > >
> > > +static enum led_brightness camera_led_get(struct led_classdev *led_cdev)
> > > +{
> > > + struct asus_wmi *asus;
> > > + u32 result;
> > > +
> > > + asus = container_of(led_cdev, struct asus_wmi, camera_led);
> > > + asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_CAMERA_LED, &result);
> > > +
> > > + return result & ASUS_WMI_DSTS_BRIGHTNESS_MASK;
> > > +}
> > > +
> > > +static int camera_led_set(struct led_classdev *led_cdev,
> > > + enum led_brightness brightness)
> > > +{
> > > + int state = brightness != LED_OFF;
> > > + int err;
> > > +
> > > + err = asus_wmi_set_devstate(ASUS_WMI_DEVID_CAMERA_LED, state, NULL);
> > > + return err < 0 ? err : 0;
> > > +}
> > > +
> > > static void asus_wmi_led_exit(struct asus_wmi *asus)
> > > {
> > > led_classdev_unregister(&asus->kbd_led);
> > > @@ -1540,6 +1563,7 @@ static void asus_wmi_led_exit(struct asus_wmi *asus)
> > > led_classdev_unregister(&asus->wlan_led);
> > > led_classdev_unregister(&asus->lightbar_led);
> > > led_classdev_unregister(&asus->micmute_led);
> > > + led_classdev_unregister(&asus->camera_led);
> > >
> > > if (asus->led_workqueue)
> > > destroy_workqueue(asus->led_workqueue);
> > > @@ -1631,6 +1655,18 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
> > > goto error;
> > > }
> > >
> > > + if (asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_CAMERA_LED)) {
> > > + asus->camera_led.name = "asus::camera";
> > > + asus->camera_led.max_brightness = 1;
> > > + asus->camera_led.brightness_get = camera_led_get;
> > > + asus->camera_led.brightness_set_blocking = camera_led_set;
> > > +
> > > + rv = led_classdev_register(&asus->platform_device->dev,
> > > + &asus->camera_led);
> > > + if (rv)
> > > + goto error;
> > > + }
> > > +
> > > error:
> > > if (rv)
> > > asus_wmi_led_exit(asus);
> > > diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
> > > index ab1c7deff118..fb0b00f7d292 100644
> > > --- a/include/linux/platform_data/x86/asus-wmi.h
> > > +++ b/include/linux/platform_data/x86/asus-wmi.h
> > > @@ -50,6 +50,8 @@
> > > #define ASUS_WMI_DEVID_LED5 0x00020015
> > > #define ASUS_WMI_DEVID_LED6 0x00020016
> > > #define ASUS_WMI_DEVID_MICMUTE_LED 0x00040017
> > > +#define ASUS_WMI_DEVID_CAMERA_LED_NEG 0x00060078
> > > +#define ASUS_WMI_DEVID_CAMERA_LED 0x00060079
> > >
> > > /* Backlight and Brightness */
> > > #define ASUS_WMI_DEVID_ALS_ENABLE 0x00050001 /* Ambient Light Sensor */
> > > --
> > > 2.45.2
> > >
> >
> > If Hans and Ilpo have no other comments regarding the written C code:
> >
> > Signed-off-by: Luke D. Jones <luke@ljones.dev>
>
> Luke,
>
> As I've seen you use S-o-b tag a few times like this, do you actually mean
> Reviewed-by: tag which tells you've looked through the change and think
> it's good/useful for the kernel?
>
> S-o-b relates to authorship of the code in the patch (and should be
> there right from the submission, not added like this).
I do. Yes. It's been a tough couple of months.
Reviewed-by: Luke D. Jones <luke@ljones.dev>
> --
> i.
>
>
^ permalink raw reply
* Re: [PATCH RFC] LSM, net: Add SO_PEERCONTEXT for peer LSM data
From: Paul Moore @ 2024-06-23 19:58 UTC (permalink / raw)
To: Casey Schaufler; +Cc: LSM List, netdev, linux-api, Linux kernel mailing list
In-Reply-To: <2cddc480-f911-44e3-b415-33e0cec2964c@schaufler-ca.com>
On Fri, Jun 21, 2024 at 6:00 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> On 6/21/2024 12:41 PM, Paul Moore wrote:
> > On Fri, Jun 21, 2024 at 12:06 PM Casey Schaufler <casey@schaufler-ca.com> wrote:
> >> On 6/20/2024 2:05 PM, Paul Moore wrote:
> >>> On May 13, 2024 Casey Schaufler <casey@schaufler-ca.com> wrote:
...
> > Unrelated to the above, it would also be good to datagram support as a
> > patch 2/2 thing in a future version of this patchset. Please be
> > careful not to carry over the mistakes we made with SCM_SECURITY (see
> > the GH discussion linked below).
>
> That's "in my queue". I didn't want to spend time on it until I got
> feedback on this one.
Fair enough, thanks.
--
paul-moore.com
^ permalink raw reply
* Re: [PATCH v2] platform/x86: asus-wmi: support the disable camera LED on F10 of Zenbook 2023
From: Ilpo Järvinen @ 2024-06-23 16:57 UTC (permalink / raw)
To: Luke Jones
Cc: Devin Bayer, corentin.chary, Hans de Goede, platform-driver-x86,
LKML, linux-api
In-Reply-To: <ab40d5d2-a14a-4cb2-b315-b4cb66654f9e@app.fastmail.com>
On Fri, 21 Jun 2024, Luke Jones wrote:
> On Fri, 21 Jun 2024, at 8:57 PM, Devin Bayer wrote:
> > Adds a sysfs entry for the LED on F10 above the crossed out camera icon on 2023 Zenbooks.
> >
> > v2
> > - Changed name from `platform::camera` to `asus::camera`
> > - Separated patch from patchset
> >
> > v1
> > - https://lore.kernel.org/platform-driver-x86/20240620082223.20178-1-dev@doubly.so/
> >
> > Signed-off-by: Devin Bayer <dev@doubly.so>
> > ---
> > drivers/platform/x86/asus-wmi.c | 36 ++++++++++++++++++++++
> > include/linux/platform_data/x86/asus-wmi.h | 2 ++
> > 2 files changed, 38 insertions(+)
> >
> > diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> > index 3f07bbf809ef..20b7ed6a27b5 100644
> > --- a/drivers/platform/x86/asus-wmi.c
> > +++ b/drivers/platform/x86/asus-wmi.c
> > @@ -73,6 +73,7 @@ module_param(fnlock_default, bool, 0444);
> > #define NOTIFY_LID_FLIP_ROG 0xbd
> >
> > #define ASUS_WMI_FNLOCK_BIOS_DISABLED BIT(0)
> > +#define ASUS_WMI_DEVID_CAMERA_LED 0x00060079
> >
> > #define ASUS_MID_FAN_DESC "mid_fan"
> > #define ASUS_GPU_FAN_DESC "gpu_fan"
> > @@ -227,6 +228,7 @@ struct asus_wmi {
> > struct led_classdev lightbar_led;
> > int lightbar_led_wk;
> > struct led_classdev micmute_led;
> > + struct led_classdev camera_led;
> > struct workqueue_struct *led_workqueue;
> > struct work_struct tpd_led_work;
> > struct work_struct wlan_led_work;
> > @@ -1533,6 +1535,27 @@ static int micmute_led_set(struct led_classdev *led_cdev,
> > return err < 0 ? err : 0;
> > }
> >
> > +static enum led_brightness camera_led_get(struct led_classdev *led_cdev)
> > +{
> > + struct asus_wmi *asus;
> > + u32 result;
> > +
> > + asus = container_of(led_cdev, struct asus_wmi, camera_led);
> > + asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_CAMERA_LED, &result);
> > +
> > + return result & ASUS_WMI_DSTS_BRIGHTNESS_MASK;
> > +}
> > +
> > +static int camera_led_set(struct led_classdev *led_cdev,
> > + enum led_brightness brightness)
> > +{
> > + int state = brightness != LED_OFF;
> > + int err;
> > +
> > + err = asus_wmi_set_devstate(ASUS_WMI_DEVID_CAMERA_LED, state, NULL);
> > + return err < 0 ? err : 0;
> > +}
> > +
> > static void asus_wmi_led_exit(struct asus_wmi *asus)
> > {
> > led_classdev_unregister(&asus->kbd_led);
> > @@ -1540,6 +1563,7 @@ static void asus_wmi_led_exit(struct asus_wmi *asus)
> > led_classdev_unregister(&asus->wlan_led);
> > led_classdev_unregister(&asus->lightbar_led);
> > led_classdev_unregister(&asus->micmute_led);
> > + led_classdev_unregister(&asus->camera_led);
> >
> > if (asus->led_workqueue)
> > destroy_workqueue(asus->led_workqueue);
> > @@ -1631,6 +1655,18 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
> > goto error;
> > }
> >
> > + if (asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_CAMERA_LED)) {
> > + asus->camera_led.name = "asus::camera";
> > + asus->camera_led.max_brightness = 1;
> > + asus->camera_led.brightness_get = camera_led_get;
> > + asus->camera_led.brightness_set_blocking = camera_led_set;
> > +
> > + rv = led_classdev_register(&asus->platform_device->dev,
> > + &asus->camera_led);
> > + if (rv)
> > + goto error;
> > + }
> > +
> > error:
> > if (rv)
> > asus_wmi_led_exit(asus);
> > diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
> > index ab1c7deff118..fb0b00f7d292 100644
> > --- a/include/linux/platform_data/x86/asus-wmi.h
> > +++ b/include/linux/platform_data/x86/asus-wmi.h
> > @@ -50,6 +50,8 @@
> > #define ASUS_WMI_DEVID_LED5 0x00020015
> > #define ASUS_WMI_DEVID_LED6 0x00020016
> > #define ASUS_WMI_DEVID_MICMUTE_LED 0x00040017
> > +#define ASUS_WMI_DEVID_CAMERA_LED_NEG 0x00060078
> > +#define ASUS_WMI_DEVID_CAMERA_LED 0x00060079
> >
> > /* Backlight and Brightness */
> > #define ASUS_WMI_DEVID_ALS_ENABLE 0x00050001 /* Ambient Light Sensor */
> > --
> > 2.45.2
> >
>
> If Hans and Ilpo have no other comments regarding the written C code:
>
> Signed-off-by: Luke D. Jones <luke@ljones.dev>
Luke,
As I've seen you use S-o-b tag a few times like this, do you actually mean
Reviewed-by: tag which tells you've looked through the change and think
it's good/useful for the kernel?
S-o-b relates to authorship of the code in the patch (and should be
there right from the submission, not added like this).
--
i.
^ permalink raw reply
* [PATCH RFT v6 9/9] selftests/clone3: Test shadow stack support
From: Mark Brown @ 2024-06-23 11:23 UTC (permalink / raw)
To: Rick P. Edgecombe, Deepak Gupta, Szabolcs Nagy, H.J. Lu,
Florian Weimer, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H. Peter Anvin, Peter Zijlstra, Juri Lelli,
Vincent Guittot, Dietmar Eggemann, Steven Rostedt, Ben Segall,
Mel Gorman, Daniel Bristot de Oliveira, Valentin Schneider,
Christian Brauner, Shuah Khan
Cc: linux-kernel, Catalin Marinas, Will Deacon, jannh, bsegall,
linux-kselftest, linux-api, Mark Brown, Kees Cook
In-Reply-To: <20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@kernel.org>
Add basic test coverage for specifying the shadow stack for a newly
created thread via clone3(), including coverage of the newly extended
argument structure. We check that a user specified shadow stack can be
provided, and that invalid combinations of parameters are rejected.
In order to facilitate testing on systems without userspace shadow stack
support we manually enable shadow stacks on startup, this is architecture
specific due to the use of an arch_prctl() on x86. Due to interactions with
potential userspace locking of features we actually detect support for
shadow stacks on the running system by attempting to allocate a shadow
stack page during initialisation using map_shadow_stack(), warning if this
succeeds when the enable failed.
In order to allow testing of user configured shadow stacks on
architectures with that feature we need to ensure that we do not return
from the function where the clone3() syscall is called in the child
process, doing so would trigger a shadow stack underflow. To do this we
use inline assembly rather than the standard syscall wrapper to call
clone3(). In order to avoid surprises we also use a syscall rather than
the libc exit() function., this should be overly cautious.
Signed-off-by: Mark Brown <broonie@kernel.org>
---
tools/testing/selftests/clone3/clone3.c | 135 +++++++++++++++++++++-
tools/testing/selftests/clone3/clone3_selftests.h | 38 ++++++
2 files changed, 172 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
index 26221661e9ae..696fbb6f9496 100644
--- a/tools/testing/selftests/clone3/clone3.c
+++ b/tools/testing/selftests/clone3/clone3.c
@@ -3,6 +3,7 @@
/* Based on Christian Brauner's clone3() example */
#define _GNU_SOURCE
+#include <asm/mman.h>
#include <errno.h>
#include <inttypes.h>
#include <linux/types.h>
@@ -11,6 +12,7 @@
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
+#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/un.h>
@@ -19,8 +21,12 @@
#include <sched.h>
#include "../kselftest.h"
+#include "../ksft_shstk.h"
#include "clone3_selftests.h"
+static bool shadow_stack_supported;
+static size_t max_supported_args_size;
+
enum test_mode {
CLONE3_ARGS_NO_TEST,
CLONE3_ARGS_ALL_0,
@@ -28,6 +34,10 @@ enum test_mode {
CLONE3_ARGS_INVAL_EXIT_SIGNAL_NEG,
CLONE3_ARGS_INVAL_EXIT_SIGNAL_CSIG,
CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
+ CLONE3_ARGS_SHADOW_STACK,
+ CLONE3_ARGS_SHADOW_STACK_NO_SIZE,
+ CLONE3_ARGS_SHADOW_STACK_NO_POINTER,
+ CLONE3_ARGS_SHADOW_STACK_NO_TOKEN,
};
typedef bool (*filter_function)(void);
@@ -44,6 +54,44 @@ struct test {
filter_function filter;
};
+
+/*
+ * We check for shadow stack support by attempting to use
+ * map_shadow_stack() since features may have been locked by the
+ * dynamic linker resulting in spurious errors when we attempt to
+ * enable on startup. We warn if the enable failed.
+ */
+static void test_shadow_stack_supported(void)
+{
+ long ret;
+
+ ret = syscall(__NR_map_shadow_stack, 0, getpagesize(), 0);
+ if (ret == -1) {
+ ksft_print_msg("map_shadow_stack() not supported\n");
+ } else if ((void *)ret == MAP_FAILED) {
+ ksft_print_msg("Failed to map shadow stack\n");
+ } else {
+ ksft_print_msg("Shadow stack supportd\n");
+ shadow_stack_supported = true;
+
+ if (!shadow_stack_enabled)
+ ksft_print_msg("Mapped but did not enable shadow stack\n");
+ }
+}
+
+static unsigned long long get_shadow_stack_page(unsigned long flags)
+{
+ unsigned long long page;
+
+ page = syscall(__NR_map_shadow_stack, 0, getpagesize(), flags);
+ if ((void *)page == MAP_FAILED) {
+ ksft_print_msg("map_shadow_stack() failed: %d\n", errno);
+ return 0;
+ }
+
+ return page;
+}
+
static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
{
struct __clone_args args = {
@@ -89,6 +137,21 @@ static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
case CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG:
args.exit_signal = 0x00000000000000f0ULL;
break;
+ case CLONE3_ARGS_SHADOW_STACK:
+ /* We need to specify a normal stack too to avoid corruption */
+ args.shadow_stack = get_shadow_stack_page(SHADOW_STACK_SET_TOKEN);
+ args.shadow_stack_size = getpagesize();
+ break;
+ case CLONE3_ARGS_SHADOW_STACK_NO_POINTER:
+ args.shadow_stack_size = getpagesize();
+ break;
+ case CLONE3_ARGS_SHADOW_STACK_NO_SIZE:
+ args.shadow_stack = get_shadow_stack_page(SHADOW_STACK_SET_TOKEN);
+ break;
+ case CLONE3_ARGS_SHADOW_STACK_NO_TOKEN:
+ args.shadow_stack = get_shadow_stack_page(0);
+ args.shadow_stack_size = getpagesize();
+ break;
}
memcpy(&args_ext.args, &args, sizeof(struct __clone_args));
@@ -102,7 +165,12 @@ static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
if (pid == 0) {
ksft_print_msg("I am the child, my PID is %d\n", getpid());
- _exit(EXIT_SUCCESS);
+ /*
+ * Use a raw syscall to ensure we don't get issues
+ * with manually specified shadow stack and exit handlers.
+ */
+ syscall(__NR_exit, EXIT_SUCCESS);
+ ksft_print_msg("CHILD FAILED TO EXIT PID is %d\n", getpid());
}
ksft_print_msg("I am the parent (%d). My child's pid is %d\n",
@@ -112,6 +180,7 @@ static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
ksft_print_msg("waitpid() returned %s\n", strerror(errno));
return -errno;
}
+ ksft_print_msg("WAITED\n");
if (WIFSIGNALED(status)) {
ksft_print_msg("Child exited with signal %d\n",
@@ -191,6 +260,26 @@ static bool no_timenamespace(void)
return true;
}
+static bool have_shadow_stack(void)
+{
+ if (shadow_stack_supported) {
+ ksft_print_msg("Shadow stack supported\n");
+ return true;
+ }
+
+ return false;
+}
+
+static bool no_shadow_stack(void)
+{
+ if (!shadow_stack_supported) {
+ ksft_print_msg("Shadow stack not supported\n");
+ return true;
+ }
+
+ return false;
+}
+
static size_t page_size_plus_8(void)
{
return getpagesize() + 8;
@@ -334,6 +423,47 @@ static const struct test tests[] = {
.expected = -EINVAL,
.test_mode = CLONE3_ARGS_NO_TEST,
},
+ {
+ .name = "Shadow stack on system with shadow stack",
+ .size = 0,
+ .expected = 0,
+ .e2big_valid = true,
+ .test_mode = CLONE3_ARGS_SHADOW_STACK,
+ .filter = no_shadow_stack,
+ },
+ {
+ .name = "Shadow stack with no pointer",
+ .size = 0,
+ .expected = -EINVAL,
+ .e2big_valid = true,
+ .test_mode = CLONE3_ARGS_SHADOW_STACK_NO_POINTER,
+ },
+ {
+ .name = "Shadow stack with no size",
+ .size = 0,
+ .expected = -EINVAL,
+ .e2big_valid = true,
+ .test_mode = CLONE3_ARGS_SHADOW_STACK_NO_SIZE,
+ .filter = no_shadow_stack,
+ },
+ {
+ .name = "Shadow stack with no token",
+ .flags = CLONE_VM,
+ .size = 0,
+ .expected = SIGSEGV,
+ .e2big_valid = true,
+ .test_mode = CLONE3_ARGS_SHADOW_STACK_NO_TOKEN,
+ .filter = no_shadow_stack,
+ },
+ {
+ .name = "Shadow stack on system without shadow stack",
+ .flags = CLONE_VM,
+ .size = 0,
+ .expected = -EINVAL,
+ .e2big_valid = true,
+ .test_mode = CLONE3_ARGS_SHADOW_STACK,
+ .filter = have_shadow_stack,
+ },
};
int main(int argc, char *argv[])
@@ -341,9 +471,12 @@ int main(int argc, char *argv[])
size_t size;
int i;
+ enable_shadow_stack();
+
ksft_print_header();
ksft_set_plan(ARRAY_SIZE(tests));
test_clone3_supported();
+ test_shadow_stack_supported();
for (i = 0; i < ARRAY_SIZE(tests); i++)
test_clone3(&tests[i]);
diff --git a/tools/testing/selftests/clone3/clone3_selftests.h b/tools/testing/selftests/clone3/clone3_selftests.h
index 39b5dcba663c..38d82934668a 100644
--- a/tools/testing/selftests/clone3/clone3_selftests.h
+++ b/tools/testing/selftests/clone3/clone3_selftests.h
@@ -31,12 +31,50 @@ struct __clone_args {
__aligned_u64 set_tid;
__aligned_u64 set_tid_size;
__aligned_u64 cgroup;
+#ifndef CLONE_ARGS_SIZE_VER2
+#define CLONE_ARGS_SIZE_VER2 88 /* sizeof third published struct */
+#endif
+ __aligned_u64 shadow_stack;
+ __aligned_u64 shadow_stack_size;
+#ifndef CLONE_ARGS_SIZE_VER3
+#define CLONE_ARGS_SIZE_VER3 104 /* sizeof fourth published struct */
+#endif
};
+/*
+ * For architectures with shadow stack support we need to be
+ * absolutely sure that the clone3() syscall will be inline and not a
+ * function call so we open code.
+ */
+#ifdef __x86_64__
+static pid_t __always_inline sys_clone3(struct __clone_args *args, size_t size)
+{
+ long ret;
+ register long _num __asm__ ("rax") = __NR_clone3;
+ register long _args __asm__ ("rdi") = (long)(args);
+ register long _size __asm__ ("rsi") = (long)(size);
+
+ __asm__ volatile (
+ "syscall\n"
+ : "=a"(ret)
+ : "r"(_args), "r"(_size),
+ "0"(_num)
+ : "rcx", "r11", "memory", "cc"
+ );
+
+ if (ret < 0) {
+ errno = -ret;
+ return -1;
+ }
+
+ return ret;
+}
+#else
static pid_t sys_clone3(struct __clone_args *args, size_t size)
{
return syscall(__NR_clone3, args, size);
}
+#endif
static inline void test_clone3_supported(void)
{
--
2.39.2
^ permalink raw reply related
* [PATCH RFT v6 8/9] selftests/clone3: Allow tests to flag if -E2BIG is a valid error code
From: Mark Brown @ 2024-06-23 11:23 UTC (permalink / raw)
To: Rick P. Edgecombe, Deepak Gupta, Szabolcs Nagy, H.J. Lu,
Florian Weimer, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H. Peter Anvin, Peter Zijlstra, Juri Lelli,
Vincent Guittot, Dietmar Eggemann, Steven Rostedt, Ben Segall,
Mel Gorman, Daniel Bristot de Oliveira, Valentin Schneider,
Christian Brauner, Shuah Khan
Cc: linux-kernel, Catalin Marinas, Will Deacon, jannh, bsegall,
linux-kselftest, linux-api, Mark Brown, Kees Cook
In-Reply-To: <20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@kernel.org>
The clone_args structure is extensible, with the syscall passing in the
length of the structure. Inside the kernel we use copy_struct_from_user()
to read the struct but this has the unfortunate side effect of silently
accepting some overrun in the structure size providing the extra data is
all zeros. This means that we can't discover the clone3() features that
the running kernel supports by simply probing with various struct sizes.
We need to check this for the benefit of test systems which run newer
kselftests on old kernels.
Add a flag which can be set on a test to indicate that clone3() may return
-E2BIG due to the use of newer struct versions. Currently no tests need
this but it will become an issue for testing clone3() support for shadow
stacks, the support for shadow stacks is already present on x86.
Signed-off-by: Mark Brown <broonie@kernel.org>
---
tools/testing/selftests/clone3/clone3.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
index 3b3a08e6a34d..26221661e9ae 100644
--- a/tools/testing/selftests/clone3/clone3.c
+++ b/tools/testing/selftests/clone3/clone3.c
@@ -39,6 +39,7 @@ struct test {
size_t size;
size_function size_function;
int expected;
+ bool e2big_valid;
enum test_mode test_mode;
filter_function filter;
};
@@ -153,6 +154,11 @@ static void test_clone3(const struct test *test)
ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n",
getpid(), ret, test->expected);
if (ret != test->expected) {
+ if (test->e2big_valid && ret == -E2BIG) {
+ ksft_print_msg("Test reported -E2BIG\n");
+ ksft_test_result_skip("%s\n", test->name);
+ return;
+ }
ksft_print_msg(
"[%d] Result (%d) is different than expected (%d)\n",
getpid(), ret, test->expected);
--
2.39.2
^ permalink raw reply related
* [PATCH RFT v6 7/9] selftests/clone3: Explicitly handle child exits due to signals
From: Mark Brown @ 2024-06-23 11:23 UTC (permalink / raw)
To: Rick P. Edgecombe, Deepak Gupta, Szabolcs Nagy, H.J. Lu,
Florian Weimer, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H. Peter Anvin, Peter Zijlstra, Juri Lelli,
Vincent Guittot, Dietmar Eggemann, Steven Rostedt, Ben Segall,
Mel Gorman, Daniel Bristot de Oliveira, Valentin Schneider,
Christian Brauner, Shuah Khan
Cc: linux-kernel, Catalin Marinas, Will Deacon, jannh, bsegall,
linux-kselftest, linux-api, Mark Brown, Kees Cook
In-Reply-To: <20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@kernel.org>
In order to improve diagnostics and allow tests to explicitly look for
signals check to see if the child exited due to a signal and if it did
print the code and return it as a positive value, distinct from the
negative errnos currently returned.
Signed-off-by: Mark Brown <broonie@kernel.org>
---
tools/testing/selftests/clone3/clone3.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
index e066b201fa64..3b3a08e6a34d 100644
--- a/tools/testing/selftests/clone3/clone3.c
+++ b/tools/testing/selftests/clone3/clone3.c
@@ -111,6 +111,13 @@ static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
ksft_print_msg("waitpid() returned %s\n", strerror(errno));
return -errno;
}
+
+ if (WIFSIGNALED(status)) {
+ ksft_print_msg("Child exited with signal %d\n",
+ WTERMSIG(status));
+ return WTERMSIG(status);
+ }
+
if (!WIFEXITED(status)) {
ksft_print_msg("Child did not exit normally, status 0x%x\n",
status);
--
2.39.2
^ permalink raw reply related
* [PATCH RFT v6 6/9] selftests/clone3: Factor more of main loop into test_clone3()
From: Mark Brown @ 2024-06-23 11:23 UTC (permalink / raw)
To: Rick P. Edgecombe, Deepak Gupta, Szabolcs Nagy, H.J. Lu,
Florian Weimer, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H. Peter Anvin, Peter Zijlstra, Juri Lelli,
Vincent Guittot, Dietmar Eggemann, Steven Rostedt, Ben Segall,
Mel Gorman, Daniel Bristot de Oliveira, Valentin Schneider,
Christian Brauner, Shuah Khan
Cc: linux-kernel, Catalin Marinas, Will Deacon, jannh, bsegall,
linux-kselftest, linux-api, Mark Brown, Kees Cook
In-Reply-To: <20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@kernel.org>
In order to make it easier to add more configuration for the tests and
more support for runtime detection of when tests can be run pass the
structure describing the tests into test_clone3() rather than picking
the arguments out of it and have that function do all the per-test work.
No functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
---
tools/testing/selftests/clone3/clone3.c | 77 ++++++++++++++++-----------------
1 file changed, 37 insertions(+), 40 deletions(-)
diff --git a/tools/testing/selftests/clone3/clone3.c b/tools/testing/selftests/clone3/clone3.c
index e61f07973ce5..e066b201fa64 100644
--- a/tools/testing/selftests/clone3/clone3.c
+++ b/tools/testing/selftests/clone3/clone3.c
@@ -30,6 +30,19 @@ enum test_mode {
CLONE3_ARGS_INVAL_EXIT_SIGNAL_NSIG,
};
+typedef bool (*filter_function)(void);
+typedef size_t (*size_function)(void);
+
+struct test {
+ const char *name;
+ uint64_t flags;
+ size_t size;
+ size_function size_function;
+ int expected;
+ enum test_mode test_mode;
+ filter_function filter;
+};
+
static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
{
struct __clone_args args = {
@@ -109,30 +122,40 @@ static int call_clone3(uint64_t flags, size_t size, enum test_mode test_mode)
return 0;
}
-static bool test_clone3(uint64_t flags, size_t size, int expected,
- enum test_mode test_mode)
+static void test_clone3(const struct test *test)
{
+ size_t size;
int ret;
+ if (test->filter && test->filter()) {
+ ksft_test_result_skip("%s\n", test->name);
+ return;
+ }
+
+ if (test->size_function)
+ size = test->size_function();
+ else
+ size = test->size;
+
+ ksft_print_msg("Running test '%s'\n", test->name);
+
ksft_print_msg(
"[%d] Trying clone3() with flags %#" PRIx64 " (size %zu)\n",
- getpid(), flags, size);
- ret = call_clone3(flags, size, test_mode);
+ getpid(), test->flags, size);
+ ret = call_clone3(test->flags, size, test->test_mode);
ksft_print_msg("[%d] clone3() with flags says: %d expected %d\n",
- getpid(), ret, expected);
- if (ret != expected) {
+ getpid(), ret, test->expected);
+ if (ret != test->expected) {
ksft_print_msg(
"[%d] Result (%d) is different than expected (%d)\n",
- getpid(), ret, expected);
- return false;
+ getpid(), ret, test->expected);
+ ksft_test_result_fail("%s\n", test->name);
+ return;
}
- return true;
+ ksft_test_result_pass("%s\n", test->name);
}
-typedef bool (*filter_function)(void);
-typedef size_t (*size_function)(void);
-
static bool not_root(void)
{
if (getuid() != 0) {
@@ -160,16 +183,6 @@ static size_t page_size_plus_8(void)
return getpagesize() + 8;
}
-struct test {
- const char *name;
- uint64_t flags;
- size_t size;
- size_function size_function;
- int expected;
- enum test_mode test_mode;
- filter_function filter;
-};
-
static const struct test tests[] = {
{
.name = "simple clone3()",
@@ -319,24 +332,8 @@ int main(int argc, char *argv[])
ksft_set_plan(ARRAY_SIZE(tests));
test_clone3_supported();
- for (i = 0; i < ARRAY_SIZE(tests); i++) {
- if (tests[i].filter && tests[i].filter()) {
- ksft_test_result_skip("%s\n", tests[i].name);
- continue;
- }
-
- if (tests[i].size_function)
- size = tests[i].size_function();
- else
- size = tests[i].size;
-
- ksft_print_msg("Running test '%s'\n", tests[i].name);
-
- ksft_test_result(test_clone3(tests[i].flags, size,
- tests[i].expected,
- tests[i].test_mode),
- "%s\n", tests[i].name);
- }
+ for (i = 0; i < ARRAY_SIZE(tests); i++)
+ test_clone3(&tests[i]);
ksft_finished();
}
--
2.39.2
^ permalink raw reply related
* [PATCH RFT v6 5/9] selftests/clone3: Remove redundant flushes of output streams
From: Mark Brown @ 2024-06-23 11:23 UTC (permalink / raw)
To: Rick P. Edgecombe, Deepak Gupta, Szabolcs Nagy, H.J. Lu,
Florian Weimer, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H. Peter Anvin, Peter Zijlstra, Juri Lelli,
Vincent Guittot, Dietmar Eggemann, Steven Rostedt, Ben Segall,
Mel Gorman, Daniel Bristot de Oliveira, Valentin Schneider,
Christian Brauner, Shuah Khan
Cc: linux-kernel, Catalin Marinas, Will Deacon, jannh, bsegall,
linux-kselftest, linux-api, Mark Brown, Kees Cook
In-Reply-To: <20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@kernel.org>
Since there were widespread issues with output not being flushed the
kselftest framework was modified to explicitly set the output streams
unbuffered in commit 58e2847ad2e6 ("selftests: line buffer test
program's stdout") so there is no need to explicitly flush in the clone3
tests.
Signed-off-by: Mark Brown <broonie@kernel.org>
---
tools/testing/selftests/clone3/clone3_selftests.h | 2 --
1 file changed, 2 deletions(-)
diff --git a/tools/testing/selftests/clone3/clone3_selftests.h b/tools/testing/selftests/clone3/clone3_selftests.h
index 3d2663fe50ba..39b5dcba663c 100644
--- a/tools/testing/selftests/clone3/clone3_selftests.h
+++ b/tools/testing/selftests/clone3/clone3_selftests.h
@@ -35,8 +35,6 @@ struct __clone_args {
static pid_t sys_clone3(struct __clone_args *args, size_t size)
{
- fflush(stdout);
- fflush(stderr);
return syscall(__NR_clone3, args, size);
}
--
2.39.2
^ permalink raw reply related
* [PATCH RFT v6 4/9] fork: Add shadow stack support to clone3()
From: Mark Brown @ 2024-06-23 11:23 UTC (permalink / raw)
To: Rick P. Edgecombe, Deepak Gupta, Szabolcs Nagy, H.J. Lu,
Florian Weimer, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H. Peter Anvin, Peter Zijlstra, Juri Lelli,
Vincent Guittot, Dietmar Eggemann, Steven Rostedt, Ben Segall,
Mel Gorman, Daniel Bristot de Oliveira, Valentin Schneider,
Christian Brauner, Shuah Khan
Cc: linux-kernel, Catalin Marinas, Will Deacon, jannh, bsegall,
linux-kselftest, linux-api, Mark Brown, Kees Cook
In-Reply-To: <20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@kernel.org>
Unlike with the normal stack there is no API for configuring the the shadow
stack for a new thread, instead the kernel will dynamically allocate a new
shadow stack with the same size as the normal stack. This appears to be due
to the shadow stack series having been in development since before the more
extensible clone3() was added rather than anything more deliberate.
Add parameters to clone3() specifying the location and size of a shadow
stack for the newly created process. If no shadow stack is specified
then the existing implicit allocation behaviour is maintained.
If a stack is specified then it is required to have an architecture
defined token placed on the stack, this will be consumed by the new
task. If the token is not provided then this will be reported as a
segmentation fault with si_code SEGV_CPERR, as a runtime shadow stack
protection error would be. This allows architectures to implement the
validation of the token in the child process context.
If the architecture does not support shadow stacks the shadow stack
parameters must be zero, architectures that do support the feature are
expected to enforce the same requirement on individual systems that lack
shadow stack support.
Update the existing x86 implementation to pay attention to the newly added
arguments, in order to maintain compatibility we use the existing behaviour
if no shadow stack is specified. Minimal validation is done of the supplied
parameters, detailed enforcement is left to when the thread is executed.
Since we are now using more fields from the kernel_clone_args we pass that
into the shadow stack code rather than individual fields.
At present this implementation does not consume the shadow stack token
atomically as would be desirable, it uses a separate read and write.
Signed-off-by: Mark Brown <broonie@kernel.org>
---
arch/x86/include/asm/shstk.h | 11 +++--
arch/x86/kernel/process.c | 2 +-
arch/x86/kernel/shstk.c | 104 +++++++++++++++++++++++++++++++++----------
include/linux/sched/task.h | 13 ++++++
include/uapi/linux/sched.h | 13 ++++--
kernel/fork.c | 76 ++++++++++++++++++++++++++-----
6 files changed, 176 insertions(+), 43 deletions(-)
diff --git a/arch/x86/include/asm/shstk.h b/arch/x86/include/asm/shstk.h
index 42fee8959df7..8be7b0a909c3 100644
--- a/arch/x86/include/asm/shstk.h
+++ b/arch/x86/include/asm/shstk.h
@@ -6,6 +6,7 @@
#include <linux/types.h>
struct task_struct;
+struct kernel_clone_args;
struct ksignal;
#ifdef CONFIG_X86_USER_SHADOW_STACK
@@ -16,8 +17,8 @@ struct thread_shstk {
long shstk_prctl(struct task_struct *task, int option, unsigned long arg2);
void reset_thread_features(void);
-unsigned long shstk_alloc_thread_stack(struct task_struct *p, unsigned long clone_flags,
- unsigned long stack_size);
+unsigned long shstk_alloc_thread_stack(struct task_struct *p,
+ const struct kernel_clone_args *args);
void shstk_free(struct task_struct *p);
int setup_signal_shadow_stack(struct ksignal *ksig);
int restore_signal_shadow_stack(void);
@@ -26,8 +27,10 @@ static inline long shstk_prctl(struct task_struct *task, int option,
unsigned long arg2) { return -EINVAL; }
static inline void reset_thread_features(void) {}
static inline unsigned long shstk_alloc_thread_stack(struct task_struct *p,
- unsigned long clone_flags,
- unsigned long stack_size) { return 0; }
+ const struct kernel_clone_args *args)
+{
+ return 0;
+}
static inline void shstk_free(struct task_struct *p) {}
static inline int setup_signal_shadow_stack(struct ksignal *ksig) { return 0; }
static inline int restore_signal_shadow_stack(void) { return 0; }
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index b8441147eb5e..f206e997f91d 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -207,7 +207,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
* is disabled, new_ssp will remain 0, and fpu_clone() will know not to
* update it.
*/
- new_ssp = shstk_alloc_thread_stack(p, clone_flags, args->stack_size);
+ new_ssp = shstk_alloc_thread_stack(p, args);
if (IS_ERR_VALUE(new_ssp))
return PTR_ERR((void *)new_ssp);
diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c
index 6f1e9883f074..953cc0893097 100644
--- a/arch/x86/kernel/shstk.c
+++ b/arch/x86/kernel/shstk.c
@@ -191,44 +191,102 @@ void reset_thread_features(void)
current->thread.features_locked = 0;
}
-unsigned long shstk_alloc_thread_stack(struct task_struct *tsk, unsigned long clone_flags,
- unsigned long stack_size)
+int arch_shstk_post_fork(struct task_struct *t, struct kernel_clone_args *args)
+{
+ /*
+ * SSP is aligned, so reserved bits and mode bit are a zero, just mark
+ * the token 64-bit.
+ */
+ struct mm_struct *mm;
+ unsigned long addr;
+ u64 expected;
+ u64 val;
+ int ret = -EINVAL;;
+
+ addr = args->shadow_stack + args->shadow_stack_size - sizeof(u64);
+ expected = (addr - SS_FRAME_SIZE) | BIT(0);
+
+ mm = get_task_mm(t);
+ if (!mm)
+ return -EFAULT;
+
+ /* This should really be an atomic cpmxchg. It is not. */
+ if (access_remote_vm(mm, addr, &val, sizeof(val),
+ FOLL_FORCE) != sizeof(val))
+ goto out;
+
+ if (val != expected)
+ goto out;
+ val = 0;
+ if (access_remote_vm(mm, addr, &val, sizeof(val),
+ FOLL_FORCE | FOLL_WRITE) != sizeof(val))
+ goto out;
+
+ ret = 0;
+
+out:
+ mmput(mm);
+ return ret;
+}
+
+unsigned long shstk_alloc_thread_stack(struct task_struct *tsk,
+ const struct kernel_clone_args *args)
{
struct thread_shstk *shstk = &tsk->thread.shstk;
+ unsigned long clone_flags = args->flags;
unsigned long addr, size;
/*
* If shadow stack is not enabled on the new thread, skip any
- * switch to a new shadow stack.
+ * implicit switch to a new shadow stack and reject attempts to
+ * explciitly specify one.
*/
- if (!features_enabled(ARCH_SHSTK_SHSTK))
- return 0;
+ if (!features_enabled(ARCH_SHSTK_SHSTK)) {
+ if (args->shadow_stack || args->shadow_stack_size)
+ return (unsigned long)ERR_PTR(-EINVAL);
- /*
- * For CLONE_VFORK the child will share the parents shadow stack.
- * Make sure to clear the internal tracking of the thread shadow
- * stack so the freeing logic run for child knows to leave it alone.
- */
- if (clone_flags & CLONE_VFORK) {
- shstk->base = 0;
- shstk->size = 0;
return 0;
}
/*
- * For !CLONE_VM the child will use a copy of the parents shadow
- * stack.
+ * If the user specified a shadow stack then do some basic
+ * validation and use it, otherwise fall back to a default
+ * shadow stack size if the clone_flags don't indicate an
+ * allocation is unneeded.
*/
- if (!(clone_flags & CLONE_VM))
- return 0;
+ if (args->shadow_stack) {
+ addr = args->shadow_stack;
+ size = args->shadow_stack_size;
+ } else {
+ /*
+ * For CLONE_VFORK the child will share the parents
+ * shadow stack. Make sure to clear the internal
+ * tracking of the thread shadow stack so the freeing
+ * logic run for child knows to leave it alone.
+ */
+ if (clone_flags & CLONE_VFORK) {
+ shstk->base = 0;
+ shstk->size = 0;
+ return 0;
+ }
- size = adjust_shstk_size(stack_size);
- addr = alloc_shstk(0, size, 0, false);
- if (IS_ERR_VALUE(addr))
- return addr;
+ /*
+ * For !CLONE_VM the child will use a copy of the
+ * parents shadow stack.
+ */
+ if (!(clone_flags & CLONE_VM))
+ return 0;
- shstk->base = addr;
- shstk->size = size;
+ size = args->stack_size;
+ size = adjust_shstk_size(size);
+ addr = alloc_shstk(0, size, 0, false);
+ if (IS_ERR_VALUE(addr))
+ return addr;
+
+ /* We allocated the shadow stack, we should deallocate it. */
+ shstk->base = addr;
+ shstk->size = size;
+ }
return addr + size;
}
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h
index d362aacf9f89..56b2013d7fe5 100644
--- a/include/linux/sched/task.h
+++ b/include/linux/sched/task.h
@@ -43,6 +43,8 @@ struct kernel_clone_args {
void *fn_arg;
struct cgroup *cgrp;
struct css_set *cset;
+ unsigned long shadow_stack;
+ unsigned long shadow_stack_size;
};
/*
@@ -230,4 +232,15 @@ static inline void task_unlock(struct task_struct *p)
DEFINE_GUARD(task_lock, struct task_struct *, task_lock(_T), task_unlock(_T))
+#ifdef CONFIG_ARCH_HAS_USER_SHADOW_STACK
+int arch_shstk_post_fork(struct task_struct *p,
+ struct kernel_clone_args *args);
+#else
+static inline int arch_shstk_post_fork(struct task_struct *p,
+ struct kernel_clone_args *args)
+{
+ return 0;
+}
+#endif
+
#endif /* _LINUX_SCHED_TASK_H */
diff --git a/include/uapi/linux/sched.h b/include/uapi/linux/sched.h
index 3bac0a8ceab2..8b7af52548fd 100644
--- a/include/uapi/linux/sched.h
+++ b/include/uapi/linux/sched.h
@@ -84,6 +84,10 @@
* kernel's limit of nested PID namespaces.
* @cgroup: If CLONE_INTO_CGROUP is specified set this to
* a file descriptor for the cgroup.
+ * @shadow_stack: Pointer to the memory allocated for the child
+ * shadow stack.
+ * @shadow_stack_size: Specify the size of the shadow stack for
+ * the child process.
*
* The structure is versioned by size and thus extensible.
* New struct members must go at the end of the struct and
@@ -101,12 +105,15 @@ struct clone_args {
__aligned_u64 set_tid;
__aligned_u64 set_tid_size;
__aligned_u64 cgroup;
+ __aligned_u64 shadow_stack;
+ __aligned_u64 shadow_stack_size;
};
#endif
-#define CLONE_ARGS_SIZE_VER0 64 /* sizeof first published struct */
-#define CLONE_ARGS_SIZE_VER1 80 /* sizeof second published struct */
-#define CLONE_ARGS_SIZE_VER2 88 /* sizeof third published struct */
+#define CLONE_ARGS_SIZE_VER0 64 /* sizeof first published struct */
+#define CLONE_ARGS_SIZE_VER1 80 /* sizeof second published struct */
+#define CLONE_ARGS_SIZE_VER2 88 /* sizeof third published struct */
+#define CLONE_ARGS_SIZE_VER3 104 /* sizeof fourth published struct */
/*
* Scheduling policies
diff --git a/kernel/fork.c b/kernel/fork.c
index 99076dbe27d8..d7c5769942f8 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -125,6 +125,11 @@
*/
#define MAX_THREADS FUTEX_TID_MASK
+/*
+ * Require that shadow stacks can store at least one element
+ */
+#define SHADOW_STACK_SIZE_MIN sizeof(void *)
+
/*
* Protected counters by write_lock_irq(&tasklist_lock)
*/
@@ -2745,6 +2750,19 @@ struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node)
return copy_process(NULL, 0, node, &args);
}
+static void shstk_post_fork(struct task_struct *p,
+ struct kernel_clone_args *args)
+{
+ if (!IS_ENABLED(CONFIG_ARCH_HAS_USER_SHADOW_STACK))
+ return;
+
+ if (!args->shadow_stack)
+ return;
+
+ if (arch_shstk_post_fork(p, args) != 0)
+ force_sig_fault_to_task(SIGSEGV, SEGV_CPERR, NULL, p);
+}
+
/*
* Ok, this is the main fork-routine.
*
@@ -2806,6 +2824,8 @@ pid_t kernel_clone(struct kernel_clone_args *args)
*/
trace_sched_process_fork(current, p);
+ shstk_post_fork(p, args);
+
pid = get_task_pid(p, PIDTYPE_PID);
nr = pid_vnr(pid);
@@ -2957,7 +2977,9 @@ noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
CLONE_ARGS_SIZE_VER1);
BUILD_BUG_ON(offsetofend(struct clone_args, cgroup) !=
CLONE_ARGS_SIZE_VER2);
- BUILD_BUG_ON(sizeof(struct clone_args) != CLONE_ARGS_SIZE_VER2);
+ BUILD_BUG_ON(offsetofend(struct clone_args, shadow_stack_size) !=
+ CLONE_ARGS_SIZE_VER3);
+ BUILD_BUG_ON(sizeof(struct clone_args) != CLONE_ARGS_SIZE_VER3);
if (unlikely(usize > PAGE_SIZE))
return -E2BIG;
@@ -2990,16 +3012,18 @@ noinline static int copy_clone_args_from_user(struct kernel_clone_args *kargs,
return -EINVAL;
*kargs = (struct kernel_clone_args){
- .flags = args.flags,
- .pidfd = u64_to_user_ptr(args.pidfd),
- .child_tid = u64_to_user_ptr(args.child_tid),
- .parent_tid = u64_to_user_ptr(args.parent_tid),
- .exit_signal = args.exit_signal,
- .stack = args.stack,
- .stack_size = args.stack_size,
- .tls = args.tls,
- .set_tid_size = args.set_tid_size,
- .cgroup = args.cgroup,
+ .flags = args.flags,
+ .pidfd = u64_to_user_ptr(args.pidfd),
+ .child_tid = u64_to_user_ptr(args.child_tid),
+ .parent_tid = u64_to_user_ptr(args.parent_tid),
+ .exit_signal = args.exit_signal,
+ .stack = args.stack,
+ .stack_size = args.stack_size,
+ .tls = args.tls,
+ .set_tid_size = args.set_tid_size,
+ .cgroup = args.cgroup,
+ .shadow_stack = args.shadow_stack,
+ .shadow_stack_size = args.shadow_stack_size,
};
if (args.set_tid &&
@@ -3040,6 +3064,34 @@ static inline bool clone3_stack_valid(struct kernel_clone_args *kargs)
return true;
}
+/**
+ * clone3_shadow_stack_valid - check and prepare shadow stack
+ * @kargs: kernel clone args
+ *
+ * Verify that shadow stacks are only enabled if supported.
+ */
+static inline bool clone3_shadow_stack_valid(struct kernel_clone_args *kargs)
+{
+ if (kargs->shadow_stack) {
+ if (!kargs->shadow_stack_size)
+ return false;
+
+ if (kargs->shadow_stack_size < SHADOW_STACK_SIZE_MIN)
+ return false;
+
+ if (kargs->shadow_stack_size > rlimit(RLIMIT_STACK))
+ return false;
+
+ /*
+ * The architecture must check support on the specific
+ * machine.
+ */
+ return IS_ENABLED(CONFIG_ARCH_HAS_USER_SHADOW_STACK);
+ } else {
+ return !kargs->shadow_stack_size;
+ }
+}
+
static bool clone3_args_valid(struct kernel_clone_args *kargs)
{
/* Verify that no unknown flags are passed along. */
@@ -3062,7 +3114,7 @@ static bool clone3_args_valid(struct kernel_clone_args *kargs)
kargs->exit_signal)
return false;
- if (!clone3_stack_valid(kargs))
+ if (!clone3_stack_valid(kargs) || !clone3_shadow_stack_valid(kargs))
return false;
return true;
--
2.39.2
^ permalink raw reply related
* [PATCH RFT v6 3/9] mm: Introduce ARCH_HAS_USER_SHADOW_STACK
From: Mark Brown @ 2024-06-23 11:23 UTC (permalink / raw)
To: Rick P. Edgecombe, Deepak Gupta, Szabolcs Nagy, H.J. Lu,
Florian Weimer, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H. Peter Anvin, Peter Zijlstra, Juri Lelli,
Vincent Guittot, Dietmar Eggemann, Steven Rostedt, Ben Segall,
Mel Gorman, Daniel Bristot de Oliveira, Valentin Schneider,
Christian Brauner, Shuah Khan
Cc: linux-kernel, Catalin Marinas, Will Deacon, jannh, bsegall,
linux-kselftest, linux-api, Mark Brown, Kees Cook,
David Hildenbrand
In-Reply-To: <20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@kernel.org>
Since multiple architectures have support for shadow stacks and we need to
select support for this feature in several places in the generic code
provide a generic config option that the architectures can select.
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Deepak Gupta <debug@rivosinc.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
arch/x86/Kconfig | 1 +
fs/proc/task_mmu.c | 2 +-
include/linux/mm.h | 2 +-
mm/Kconfig | 6 ++++++
4 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 1d7122a1883e..4a5e40d4c14e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1949,6 +1949,7 @@ config X86_USER_SHADOW_STACK
depends on AS_WRUSS
depends on X86_64
select ARCH_USES_HIGH_VMA_FLAGS
+ select ARCH_HAS_USER_SHADOW_STACK
select X86_CET
help
Shadow stack protection is a hardware feature that detects function
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f8d35f993fe5..1b56c1077507 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -704,7 +704,7 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
#ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
[ilog2(VM_UFFD_MINOR)] = "ui",
#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
-#ifdef CONFIG_X86_USER_SHADOW_STACK
+#ifdef CONFIG_ARCH_HAS_USER_SHADOW_STACK
[ilog2(VM_SHADOW_STACK)] = "ss",
#endif
};
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9849dfda44d4..5ec7bc355657 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -342,7 +342,7 @@ extern unsigned int kobjsize(const void *objp);
#endif
#endif /* CONFIG_ARCH_HAS_PKEYS */
-#ifdef CONFIG_X86_USER_SHADOW_STACK
+#ifdef CONFIG_ARCH_HAS_USER_SHADOW_STACK
/*
* VM_SHADOW_STACK should not be set with VM_SHARED because of lack of
* support core mm.
diff --git a/mm/Kconfig b/mm/Kconfig
index b4cb45255a54..45416916dec1 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1249,6 +1249,12 @@ config IOMMU_MM_DATA
config EXECMEM
bool
+config ARCH_HAS_USER_SHADOW_STACK
+ bool
+ help
+ The architecture has hardware support for userspace shadow call
+ stacks (eg, x87 CET, arm64 GCS or RISC-V Zicfiss).
+
source "mm/damon/Kconfig"
endmenu
--
2.39.2
^ permalink raw reply related
* [PATCH RFT v6 2/9] selftests: Provide helper header for shadow stack testing
From: Mark Brown @ 2024-06-23 11:23 UTC (permalink / raw)
To: Rick P. Edgecombe, Deepak Gupta, Szabolcs Nagy, H.J. Lu,
Florian Weimer, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86, H. Peter Anvin, Peter Zijlstra, Juri Lelli,
Vincent Guittot, Dietmar Eggemann, Steven Rostedt, Ben Segall,
Mel Gorman, Daniel Bristot de Oliveira, Valentin Schneider,
Christian Brauner, Shuah Khan
Cc: linux-kernel, Catalin Marinas, Will Deacon, jannh, bsegall,
linux-kselftest, linux-api, Mark Brown, Kees Cook
In-Reply-To: <20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@kernel.org>
While almost all users of shadow stacks should be relying on the dynamic
linker and libc to enable the feature there are several low level test
programs where it is useful to enable without any libc support, allowing
testing without full system enablement. This low level testing is helpful
during bringup of the support itself, and also in enabling coverage by
automated testing without needing all system components in the target root
filesystems to have enablement.
Provide a header with helpers for this purpose, intended for use only by
test programs directly exercising shadow stack interfaces.
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
tools/testing/selftests/ksft_shstk.h | 63 ++++++++++++++++++++++++++++++++++++
1 file changed, 63 insertions(+)
diff --git a/tools/testing/selftests/ksft_shstk.h b/tools/testing/selftests/ksft_shstk.h
new file mode 100644
index 000000000000..85d0747c1802
--- /dev/null
+++ b/tools/testing/selftests/ksft_shstk.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Helpers for shadow stack enablement, this is intended to only be
+ * used by low level test programs directly exercising interfaces for
+ * working with shadow stacks.
+ *
+ * Copyright (C) 2024 ARM Ltd.
+ */
+
+#ifndef __KSFT_SHSTK_H
+#define __KSFT_SHSTK_H
+
+#include <asm/mman.h>
+
+/* This is currently only defined for x86 */
+#ifndef SHADOW_STACK_SET_TOKEN
+#define SHADOW_STACK_SET_TOKEN (1ULL << 0)
+#endif
+
+static bool shadow_stack_enabled;
+
+#ifdef __x86_64__
+#define ARCH_SHSTK_ENABLE 0x5001
+#define ARCH_SHSTK_SHSTK (1ULL << 0)
+
+#define ARCH_PRCTL(arg1, arg2) \
+({ \
+ long _ret; \
+ register long _num asm("eax") = __NR_arch_prctl; \
+ register long _arg1 asm("rdi") = (long)(arg1); \
+ register long _arg2 asm("rsi") = (long)(arg2); \
+ \
+ asm volatile ( \
+ "syscall\n" \
+ : "=a"(_ret) \
+ : "r"(_arg1), "r"(_arg2), \
+ "0"(_num) \
+ : "rcx", "r11", "memory", "cc" \
+ ); \
+ _ret; \
+})
+
+#define ENABLE_SHADOW_STACK
+static inline __attribute__((always_inline)) void enable_shadow_stack(void)
+{
+ int ret = ARCH_PRCTL(ARCH_SHSTK_ENABLE, ARCH_SHSTK_SHSTK);
+ if (ret == 0)
+ shadow_stack_enabled = true;
+}
+
+#endif
+
+#ifndef __NR_map_shadow_stack
+#define __NR_map_shadow_stack 453
+#endif
+
+#ifndef ENABLE_SHADOW_STACK
+static inline void enable_shadow_stack(void) { }
+#endif
+
+#endif
+
+
--
2.39.2
^ permalink raw reply related
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