* [PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user()
@ 2025-09-08 20:12 Thorsten Blum
2025-09-10 17:12 ` Jarkko Sakkinen
2025-09-21 9:59 ` kernel test robot
0 siblings, 2 replies; 5+ messages in thread
From: Thorsten Blum @ 2025-09-08 20:12 UTC (permalink / raw)
To: Jarkko Sakkinen, Dave Hansen, Thomas Gleixner, Ingo Molnar,
Borislav Petkov, x86, H. Peter Anvin
Cc: Thorsten Blum, linux-sgx, linux-kernel
Replace kmalloc() followed by copy_from_user() with memdup_user() to
improve and simplify sgx_ioc_enclave_create().
No functional changes intended.
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
arch/x86/kernel/cpu/sgx/ioctl.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
index 66f1efa16fbb..e99fc38f1273 100644
--- a/arch/x86/kernel/cpu/sgx/ioctl.c
+++ b/arch/x86/kernel/cpu/sgx/ioctl.c
@@ -164,15 +164,11 @@ static long sgx_ioc_enclave_create(struct sgx_encl *encl, void __user *arg)
if (copy_from_user(&create_arg, arg, sizeof(create_arg)))
return -EFAULT;
- secs = kmalloc(PAGE_SIZE, GFP_KERNEL);
- if (!secs)
- return -ENOMEM;
-
- if (copy_from_user(secs, (void __user *)create_arg.src, PAGE_SIZE))
- ret = -EFAULT;
- else
- ret = sgx_encl_create(encl, secs);
+ secs = memdup_user((void __user *)create_arg.src, PAGE_SIZE);
+ if (IS_ERR(secs))
+ return PTR_ERR(secs);
+ ret = sgx_encl_create(encl, secs);
kfree(secs);
return ret;
}
--
2.51.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user()
2025-09-08 20:12 [PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user() Thorsten Blum
@ 2025-09-10 17:12 ` Jarkko Sakkinen
2025-09-21 9:59 ` kernel test robot
1 sibling, 0 replies; 5+ messages in thread
From: Jarkko Sakkinen @ 2025-09-10 17:12 UTC (permalink / raw)
To: Thorsten Blum
Cc: Dave Hansen, Thomas Gleixner, Ingo Molnar, Borislav Petkov, x86,
H. Peter Anvin, linux-sgx, linux-kernel
On Mon, Sep 08, 2025 at 10:12:29PM +0200, Thorsten Blum wrote:
> Replace kmalloc() followed by copy_from_user() with memdup_user() to
> improve and simplify sgx_ioc_enclave_create().
>
> No functional changes intended.
>
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
> arch/x86/kernel/cpu/sgx/ioctl.c | 12 ++++--------
> 1 file changed, 4 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c
> index 66f1efa16fbb..e99fc38f1273 100644
> --- a/arch/x86/kernel/cpu/sgx/ioctl.c
> +++ b/arch/x86/kernel/cpu/sgx/ioctl.c
> @@ -164,15 +164,11 @@ static long sgx_ioc_enclave_create(struct sgx_encl *encl, void __user *arg)
> if (copy_from_user(&create_arg, arg, sizeof(create_arg)))
> return -EFAULT;
>
> - secs = kmalloc(PAGE_SIZE, GFP_KERNEL);
> - if (!secs)
> - return -ENOMEM;
> -
> - if (copy_from_user(secs, (void __user *)create_arg.src, PAGE_SIZE))
> - ret = -EFAULT;
> - else
> - ret = sgx_encl_create(encl, secs);
> + secs = memdup_user((void __user *)create_arg.src, PAGE_SIZE);
> + if (IS_ERR(secs))
> + return PTR_ERR(secs);
>
> + ret = sgx_encl_create(encl, secs);
> kfree(secs);
> return ret;
> }
> --
> 2.51.0
>
>
Agreed:
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
BR, Jarkko
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user()
2025-09-08 20:12 [PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user() Thorsten Blum
2025-09-10 17:12 ` Jarkko Sakkinen
@ 2025-09-21 9:59 ` kernel test robot
2025-09-22 13:18 ` Thorsten Blum
1 sibling, 1 reply; 5+ messages in thread
From: kernel test robot @ 2025-09-21 9:59 UTC (permalink / raw)
To: Thorsten Blum
Cc: oe-lkp, lkp, linux-sgx, Jarkko Sakkinen, Dave Hansen,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, x86,
H. Peter Anvin, Thorsten Blum, linux-kernel, oliver.sang
Hello,
kernel test robot noticed "kernel-selftests.sgx.test_sgx.enclave.tcs_entry.fail" on:
commit: c407010c166bcf30f9400bf0a4a4ec81c0149b81 ("[PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user()")
url: https://github.com/intel-lab-lkp/linux/commits/Thorsten-Blum/x86-sgx-Replace-kmalloc-copy_from_user-with-memdup_user/20250909-041627
base: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git ed16618c380c32c68c06186d0ccbb0d5e0586e59
patch link: https://lore.kernel.org/all/20250908201229.440105-2-thorsten.blum@linux.dev/
patch subject: [PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user()
in testcase: kernel-selftests
version: kernel-selftests-x86_64-79e8447ec662-1_20250914
with following parameters:
group: sgx
config: x86_64-rhel-9.4-kselftests
compiler: gcc-14
test machine: 16 threads 1 sockets Intel(R) Xeon(R) E-2278G CPU @ 3.40GHz (Coffee Lake-E) with 32G memory
(please refer to attached dmesg/kmsg for entire log/backtrace)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202509211747.1edb60f-lkp@intel.com
besides, we also observed below tests failed on this commit while passing
without this patch.
=========================================================================================
tbox_group/testcase/rootfs/kconfig/compiler/group:
lkp-cfl-e1/kernel-selftests/debian-13-x86_64-20250902.cgz/x86_64-rhel-9.4-kselftests/gcc-14/sgx
ed16618c380c32c6 c407010c166bcf30f9400bf0a4a
---------------- ---------------------------
fail:runs %reproduction fail:runs
| | |
:6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.clobbered_vdso.fail
:6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.clobbered_vdso_and_user_function.fail
:6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.pte_permissions.fail
:6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.tcs_entry.fail
:6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.unclobbered_vdso.fail
:6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.unclobbered_vdso_oversubscribed.fail
:6 100% 6:6 kernel-selftests.sgx.test_sgx.fail
# # RUN enclave.tcs_entry ...
# SGX_IOC_ENCLAVE_CREATE failed: Input/output error
# # main.c:231:tcs_entry:0x0000000000000000 0x0000000000002000 0x03
# # main.c:231:tcs_entry:0x0000000000002000 0x0000000000002000 0x05
# # main.c:231:tcs_entry:0x0000000000004000 0x0000000000007000 0x03
# # main.c:231:tcs_entry:0x000000000000b000 0x0000000000001000 0x03
# # main.c:246:tcs_entry:Failed to initialize the test enclave.
# # main.c:578:tcs_entry:Expected 0 (0) != setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata) (0)
# # tcs_entry: Test terminated by assertion
# # FAIL enclave.tcs_entry
# not ok 6 enclave.tcs_entry
The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20250921/202509211747.1edb60f-lkp@intel.com
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user()
2025-09-21 9:59 ` kernel test robot
@ 2025-09-22 13:18 ` Thorsten Blum
2025-09-25 15:37 ` Dave Hansen
0 siblings, 1 reply; 5+ messages in thread
From: Thorsten Blum @ 2025-09-22 13:18 UTC (permalink / raw)
To: kernel test robot
Cc: oe-lkp, lkp, linux-sgx, Jarkko Sakkinen, Dave Hansen,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, x86,
H. Peter Anvin, linux-kernel
On 21. Sep 2025, at 11:59, kernel test robot wrote:
>
> kernel test robot noticed "kernel-selftests.sgx.test_sgx.enclave.tcs_entry.fail" on:
>
> commit: c407010c166bcf30f9400bf0a4a4ec81c0149b81 ("[PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user()")
> url: https://github.com/intel-lab-lkp/linux/commits/Thorsten-Blum/x86-sgx-Replace-kmalloc-copy_from_user-with-memdup_user/20250909-041627
> base: https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git ed16618c380c32c68c06186d0ccbb0d5e0586e59
> patch link: https://lore.kernel.org/all/20250908201229.440105-2-thorsten.blum@linux.dev/
> patch subject: [PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user()
>
> in testcase: kernel-selftests
> version: kernel-selftests-x86_64-79e8447ec662-1_20250914
> with following parameters:
>
> group: sgx
>
>
>
> config: x86_64-rhel-9.4-kselftests
> compiler: gcc-14
> test machine: 16 threads 1 sockets Intel(R) Xeon(R) E-2278G CPU @ 3.40GHz (Coffee Lake-E) with 32G memory
>
> (please refer to attached dmesg/kmsg for entire log/backtrace)
>
>
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <oliver.sang@intel.com>
> | Closes: https://lore.kernel.org/oe-lkp/202509211747.1edb60f-lkp@intel.com
>
>
> besides, we also observed below tests failed on this commit while passing
> without this patch.
>
> =========================================================================================
> tbox_group/testcase/rootfs/kconfig/compiler/group:
> lkp-cfl-e1/kernel-selftests/debian-13-x86_64-20250902.cgz/x86_64-rhel-9.4-kselftests/gcc-14/sgx
>
> ed16618c380c32c6 c407010c166bcf30f9400bf0a4a
> ---------------- ---------------------------
> fail:runs %reproduction fail:runs
> | | |
> :6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.clobbered_vdso.fail
> :6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.clobbered_vdso_and_user_function.fail
> :6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.pte_permissions.fail
> :6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.tcs_entry.fail
> :6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.unclobbered_vdso.fail
> :6 100% 6:6 kernel-selftests.sgx.test_sgx.enclave.unclobbered_vdso_oversubscribed.fail
> :6 100% 6:6 kernel-selftests.sgx.test_sgx.fail
>
>
>
> # # RUN enclave.tcs_entry ...
> # SGX_IOC_ENCLAVE_CREATE failed: Input/output error
> # # main.c:231:tcs_entry:0x0000000000000000 0x0000000000002000 0x03
> # # main.c:231:tcs_entry:0x0000000000002000 0x0000000000002000 0x05
> # # main.c:231:tcs_entry:0x0000000000004000 0x0000000000007000 0x03
> # # main.c:231:tcs_entry:0x000000000000b000 0x0000000000001000 0x03
> # # main.c:246:tcs_entry:Failed to initialize the test enclave.
> # # main.c:578:tcs_entry:Expected 0 (0) != setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata) (0)
> # # tcs_entry: Test terminated by assertion
> # # FAIL enclave.tcs_entry
> # not ok 6 enclave.tcs_entry
>
>
>
> The kernel config and materials to reproduce are available at:
> https://download.01.org/0day-ci/archive/20250921/202509211747.1edb60f-lkp@intel.com
Can someone explain why this test is failing?
After some digging into SGX, I think it's the different allocators
kmalloc() vs. kmem_buckets_alloc_track_caller(), but I'm not exactly
sure why it fails.
Perhaps we should add a comment for anyone else trying to replace this?
Thanks,
Thorsten
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user()
2025-09-22 13:18 ` Thorsten Blum
@ 2025-09-25 15:37 ` Dave Hansen
0 siblings, 0 replies; 5+ messages in thread
From: Dave Hansen @ 2025-09-25 15:37 UTC (permalink / raw)
To: Thorsten Blum, kernel test robot
Cc: oe-lkp, lkp, linux-sgx, Jarkko Sakkinen, Dave Hansen,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, x86,
H. Peter Anvin, linux-kernel
On 9/22/25 06:18, Thorsten Blum wrote:
>> The kernel config and materials to reproduce are available at:
>> https://download.01.org/0day-ci/archive/20250921/202509211747.1edb60f-
>> lkp@intel.com
> Can someone explain why this test is failing?
>
> After some digging into SGX, I think it's the different allocators
> kmalloc() vs. kmem_buckets_alloc_track_caller(), but I'm not exactly
> sure why it fails.
>
> Perhaps we should add a comment for anyone else trying to replace this?
I can't fathom that this is an SGX problem. The SGX code is as dirt
simple as it gets:
secs = kmalloc(PAGE_SIZE, GFP_KERNEL);
There are literally thousands of those in the kernel.
memdup_user() look suspicious to me, though:
p = kmem_buckets_alloc_track_caller(...GFP_USER | __GFP_NOWARN);
That GFP_USER looks wrong. It shouldn't matter _much_ in practice, but
it's allocating kernel memory with GFP_USER.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2025-09-25 15:37 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-09-08 20:12 [PATCH] x86/sgx: Replace kmalloc() + copy_from_user() with memdup_user() Thorsten Blum
2025-09-10 17:12 ` Jarkko Sakkinen
2025-09-21 9:59 ` kernel test robot
2025-09-22 13:18 ` Thorsten Blum
2025-09-25 15:37 ` Dave Hansen
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox