The XSAVE feature set supports the saving and restoring of xstate components.
XSAVE feature has been used for process context switching. XSAVE components
include x87 state for FP execution environment, SSE state, AVX state and so on.
In order to ensure that XSAVE works correctly, add XSAVE most basic test for
XSAVE architecture functionality.
This patch tests "FP, SSE(XMM), AVX2(YMM), AVX512_OPMASK/AVX512_ZMM_Hi256/
AVX512_Hi16_ZMM and PKRU parts" xstates with following cases:
1. The contents of these xstates in the process should not change after the
signal handling.
2. The contents of these xstates in the child process should be the same as
the contents of the xstate in the parent process after the fork syscall.
3. The contents of xstates in the parent process should not change after
the context switch.
As stated in the ABI(Application Binary Interface) specification:
https://refspecs.linuxbase.org/elf/x86_64-abi-0.99.pdf
Xstate like XMM is not preserved across function calls, so fork() function
which provided from libc could not be used in the xsave test, and the libc
function is replaced with an inline function of the assembly code only.
To prevent GCC from generating any FP/SSE(XMM)/AVX/PKRU code by mistake, add
"-mno-sse -mno-mmx -mno-sse2 -mno-avx -mno-pku" compiler arguments. stdlib.h
can not be used because of the "-mno-sse" option.
Thanks Dave, Hansen for the above suggestion!
Thanks Chen Yu; Shuah Khan; Chatre Reinette and Tony Luck's comments!
Thanks to Bae, Chang Seok for a bunch of comments!
========
- Change from v12 to v13
- Improve the comments of CPUID.(EAX=0DH, ECX=0H):EBX.
- Change from v11 to v12
- Remove useless rbx register stuffing in assembly syscall functions.
(Zhang, Li)
- Change from v10 to v11
- Remove the small function like cpu_has_pkru(), get_xstate_size() and so
on. (Shuah Khan)
- Unify xfeature_num type to uint32_t.
- Change from v9 to v10
- Remove the small function if the function will be called once and there
is no good reason. (Shuah Khan)
- Change from v8 to v9
- Use function pointers to make it more structured. (Hansen, Dave)
- Improve the function name: xstate_tested -> xstate_in_test. (Chang S. Bae)
- Break this test up into two pieces: keep the xstate key test steps with
"-mno-sse" and no stdlib.h, keep others in xstate.c file. (Hansen, Dave)
- Use kselftest infrastructure for xstate.c file. (Hansen, Dave)
- Use instruction back to populate fp xstate buffer. (Hansen, Dave)
- Will skip the test if cpu could not support xsave. (Chang S. Bae)
- Use __cpuid_count() helper in kselftest.h. (Reinette, Chatre)
- Change from v7 to v8
Many thanks to Bae, Chang Seok for a bunch of comments as follow:
- Use the filling buffer way to prepare the xstate buffer, and use xrstor
instruction way to load the tested xstates.
- Remove useless dump_buffer, compare_buffer functions.
- Improve the struct of xstate_info.
- Added AVX512_ZMM_Hi256 and AVX512_Hi16_ZMM components in xstate test.
- Remove redundant xstate_info.xstate_mask, xstate_flag[], and
xfeature_test_mask, use xstate_info.mask instead.
- Check if xfeature is supported outside of fill_xstate_buf() , this change
is easier to read and understand.
- Remove useless wrpkru, only use filling all tested xstate buffer in
fill_xstates_buf().
- Improve a bunch of function names and variable names.
- Improve test steps flow for readability.
- Change from v6 to v7:
- Added the error number and error description of the reason for the
failure, thanks Shuah Khan's suggestion.
- Added a description of what these tests are doing in the head comments.
- Added changes update in the head comments.
- Added description of the purpose of the function. thanks Shuah Khan.
- Change from v5 to v6:
- In order to prevent GCC from generating any FP code by mistake,
"-mno-sse -mno-mmx -mno-sse2 -mno-avx -mno-pku" compiler parameter was
added, it's referred to the parameters for compiling the x86 kernel. Thanks
Dave Hansen's suggestion.
- Removed the use of "kselftest.h", because kselftest.h included <stdlib.h>,
and "stdlib.h" would use sse instructions in it's libc, and this *XSAVE*
test needed to be compiled without libc sse instructions(-mno-sse).
- Improved the description in commit header, thanks Chen Yu's suggestion.
- Becasue test code could not use buildin xsave64 in libc without sse, added
xsave function by instruction way.
- Every key test action would not use libc(like printf) except syscall until
it's failed or done. If it's failed, then it would print the failed reason.
- Used __cpuid_count() instead of native_cpuid(), becasue __cpuid_count()
was a macro definition function with one instruction in libc and did not
change xstate. Thanks Chatre Reinette, Shuah Khan.
https://lore.kernel.org/linux-sgx/8b7c98f4-f050-bc1c-5699-fa598ecc66a2@linu…
- Change from v4 to v5:
- Moved code files into tools/testing/selftests/x86.
- Delete xsave instruction test, becaue it's not related to kernel.
- Improved case description.
- Added AVX512 opmask change and related XSAVE content verification.
- Added PKRU part xstate test into instruction and signal handling test.
- Added XSAVE process swich test for FPU, AVX2, AVX512 opmask and PKRU part.
- Change from v3 to v4:
- Improve the comment in patch 1.
- Change from v2 to v3:
- Improve the description of patch 2 git log.
- Change from v1 to v2:
- Improve the cover-letter. Thanks Dave Hansen's suggestion.
Pengfei Xu (2):
selftests/x86/xstate: Add xstate signal handling test for XSAVE
feature
selftests/x86/xstate: Add xstate fork test for XSAVE feature
tools/testing/selftests/x86/.gitignore | 1 +
tools/testing/selftests/x86/Makefile | 11 +-
tools/testing/selftests/x86/xstate.c | 214 +++++++++++++++++
tools/testing/selftests/x86/xstate.h | 228 +++++++++++++++++++
tools/testing/selftests/x86/xstate_helpers.c | 209 +++++++++++++++++
tools/testing/selftests/x86/xstate_helpers.h | 9 +
6 files changed, 670 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/x86/xstate.c
create mode 100644 tools/testing/selftests/x86/xstate.h
create mode 100644 tools/testing/selftests/x86/xstate_helpers.c
create mode 100644 tools/testing/selftests/x86/xstate_helpers.h
--
2.31.1
Remove the repeated word "and" in comments.
Signed-off-by: Shaomin Deng <dengshaomin(a)cdjrlc.com>
---
tools/testing/selftests/core/close_range_test.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/core/close_range_test.c b/tools/testing/selftests/core/close_range_test.c
index 749239930ca8..4db5ec73d016 100644
--- a/tools/testing/selftests/core/close_range_test.c
+++ b/tools/testing/selftests/core/close_range_test.c
@@ -476,7 +476,7 @@ TEST(close_range_cloexec_unshare_syzbot)
/*
* Create a huge gap in the fd table. When we now call
- * CLOSE_RANGE_UNSHARE with a shared fd table and and with ~0U as upper
+ * CLOSE_RANGE_UNSHARE with a shared fd table and with ~0U as upper
* bound the kernel will only copy up to fd1 file descriptors into the
* new fd table. If the kernel is buggy and doesn't handle
* CLOSE_RANGE_CLOEXEC correctly it will not have copied all file
--
2.35.1
Paul and myself got trapped a few times by not seeing the effects of
applying a patch to the nolibc source code until a "make clean" was
issued in the nolibc directory. It's particularly annoying when trying
to confirm that a proposed patch really solves a problem (or that
reverting it reintroduces the problem).
The reason for the sysroot not being rebuilt was that it can be quite
slow. But in fact it's only slow after a "make clean" issued at the
kernel's topdir, because it's the main "make headers" that can take a
tens of seconds; as long as "usr/include" still contains headers, the
"headers_install" phase is only a quick "rsync", and rebuilding the
whole nolibc sysroot takes a bit less than one second, which is perfectly
acceptable for a test, even more once the time lost caused by misleading
results if factored in.
This patch marks the sysroot target as phony and starts by clearing
the previous sysroot for the current architecture before reinstalling
it. Thanks to this, applying a patch to nolibc makes the effect
immediately visible to "make nolibc-test":
$ time make -j -C tools/testing/selftests/nolibc nolibc-test
make: Entering directory '/k/tools/testing/selftests/nolibc'
MKDIR sysroot/x86/include
make[1]: Entering directory '/k/tools/include/nolibc'
make[2]: Entering directory '/k'
make[2]: Leaving directory '/k'
make[2]: Entering directory '/k'
INSTALL /k/tools/testing/selftests/nolibc/sysroot/sysroot/include
make[2]: Leaving directory '/k'
make[1]: Leaving directory '/k/tools/include/nolibc'
CC nolibc-test
make: Leaving directory '/k/tools/testing/selftests/nolibc'
real 0m0.869s
user 0m0.716s
sys 0m0.149s
Cc: "Paul E. McKenney" <paulmck(a)kernel.org>
Link: https://lore.kernel.org/all/20221021155645.GK5600@paulmck-ThinkPad-P17-Gen-…
Signed-off-by: Willy Tarreau <w(a)1wt.eu>
---
tools/testing/selftests/nolibc/Makefile | 3 +++
1 file changed, 3 insertions(+)
diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 69ea659caca9..22f1e1d73fa8 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -95,6 +95,7 @@ all: run
sysroot: sysroot/$(ARCH)/include
sysroot/$(ARCH)/include:
+ $(Q)rm -rf sysroot/$(ARCH) sysroot/sysroot
$(QUIET_MKDIR)mkdir -p sysroot
$(Q)$(MAKE) -C ../../../include/nolibc ARCH=$(ARCH) OUTPUT=$(CURDIR)/sysroot/ headers_standalone
$(Q)mv sysroot/sysroot sysroot/$(ARCH)
@@ -133,3 +134,5 @@ clean:
$(Q)rm -rf initramfs
$(call QUIET_CLEAN, run.out)
$(Q)rm -rf run.out
+
+.PHONY: sysroot/$(ARCH)/include
--
2.35.3
From: Roberto Sassu <roberto.sassu(a)huawei.com>
include/linux/lsm_hooks.h reports the result of the LSM infrastructure to
the callers, not what LSMs should return to the LSM infrastructure.
Clarify that and add that returning 1 from the LSMs means calling
__vm_enough_memory() with cap_sys_admin set, 0 without.
Signed-off-by: Roberto Sassu <roberto.sassu(a)huawei.com>
---
include/linux/lsm_hooks.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 4ec80b96c22e..f40b82ca91e7 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1411,7 +1411,9 @@
* Check permissions for allocating a new virtual mapping.
* @mm contains the mm struct it is being added to.
* @pages contains the number of pages.
- * Return 0 if permission is granted.
+ * Return 0 if permission is granted by LSMs to the caller. LSMs should
+ * return 1 if __vm_enough_memory() should be called with
+ * cap_sys_admin set, 0 if not.
*
* @ismaclabel:
* Check if the extended attribute specified by @name
--
2.25.1