[ I should really have CC'd the selftests maintainer and mailing list.
Adding them in Cc to patch 0/5 to bring this series to their attention. ]
----- On Jan 17, 2022, at 3:39 PM, Mathieu Desnoyers mathieu.desnoyers(a)efficios.com wrote:
> glibc-2.35 will be released on 2022-02-01. It introduces a user-space ABI
> based on the thread pointer to access a reserved area of the TCB.
>
> The rseq selftests originally expected the rseq thread data to sit in a
> __rseq_abi TLS variable.
>
> Considering that the rseq ABI only allows a single rseq registration per
> thread, both cannot actively coexist in a process.
>
> Adapt the selftests librseq implementation to become compatible with
> glibc-2.35. Keep a fallback implementation based on TLS available when
> an older glibc is detected.
>
> Feedback is welcome,
>
> Thanks,
>
> Mathieu
>
> Mathieu Desnoyers (5):
> selftests/rseq: Remove useless assignment to cpu variable
> selftests/rseq: Remove volatile from __rseq_abi
> selftests/rseq: Introduce rseq_get_abi() helper
> selftests/rseq: Introduce thread pointer getters
> selftests/rseq: Uplift rseq selftests for compatibility with
> glibc-2.35
>
> tools/testing/selftests/rseq/Makefile | 2 +-
> tools/testing/selftests/rseq/param_test.c | 4 +-
> tools/testing/selftests/rseq/rseq-arm.h | 32 ++--
> tools/testing/selftests/rseq/rseq-arm64.h | 32 ++--
> .../rseq/rseq-generic-thread-pointer.h | 25 +++
> tools/testing/selftests/rseq/rseq-mips.h | 32 ++--
> .../selftests/rseq/rseq-ppc-thread-pointer.h | 30 ++++
> tools/testing/selftests/rseq/rseq-ppc.h | 32 ++--
> tools/testing/selftests/rseq/rseq-s390.h | 24 +--
> .../selftests/rseq/rseq-thread-pointer.h | 19 +++
> .../selftests/rseq/rseq-x86-thread-pointer.h | 40 +++++
> tools/testing/selftests/rseq/rseq-x86.h | 30 ++--
> tools/testing/selftests/rseq/rseq.c | 161 +++++++++---------
> tools/testing/selftests/rseq/rseq.h | 24 ++-
> 14 files changed, 302 insertions(+), 185 deletions(-)
> create mode 100644 tools/testing/selftests/rseq/rseq-generic-thread-pointer.h
> create mode 100644 tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h
> create mode 100644 tools/testing/selftests/rseq/rseq-thread-pointer.h
> create mode 100644 tools/testing/selftests/rseq/rseq-x86-thread-pointer.h
>
> --
> 2.17.1
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
From: Thadeu Lima de Souza Cascardo <cascardo(a)canonical.com>
[ Upstream commit 3c42e9542050d49610077e083c7c3f5fd5e26820 ]
A mis-match between reported and actual mitigation is not restricted to the
Vulnerable case. The guest might also report the mitigation as "Software
count cache flush" and the host will still mitigate with branch cache
disabled.
So, instead of skipping depending on the detected mitigation, simply skip
whenever the detected miss_percent is the expected one for a fully
mitigated system, that is, above 95%.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo(a)canonical.com>
Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au>
Link: https://lore.kernel.org/r/20211207130557.40566-1-cascardo@canonical.com
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/powerpc/security/spectre_v2.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/powerpc/security/spectre_v2.c b/tools/testing/selftests/powerpc/security/spectre_v2.c
index adc2b7294e5fd..83647b8277e7d 100644
--- a/tools/testing/selftests/powerpc/security/spectre_v2.c
+++ b/tools/testing/selftests/powerpc/security/spectre_v2.c
@@ -193,7 +193,7 @@ int spectre_v2_test(void)
* We are not vulnerable and reporting otherwise, so
* missing such a mismatch is safe.
*/
- if (state == VULNERABLE)
+ if (miss_percent > 95)
return 4;
return 1;
--
2.34.1
From: Thadeu Lima de Souza Cascardo <cascardo(a)canonical.com>
[ Upstream commit 3c42e9542050d49610077e083c7c3f5fd5e26820 ]
A mis-match between reported and actual mitigation is not restricted to the
Vulnerable case. The guest might also report the mitigation as "Software
count cache flush" and the host will still mitigate with branch cache
disabled.
So, instead of skipping depending on the detected mitigation, simply skip
whenever the detected miss_percent is the expected one for a fully
mitigated system, that is, above 95%.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo(a)canonical.com>
Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au>
Link: https://lore.kernel.org/r/20211207130557.40566-1-cascardo@canonical.com
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/powerpc/security/spectre_v2.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/powerpc/security/spectre_v2.c b/tools/testing/selftests/powerpc/security/spectre_v2.c
index adc2b7294e5fd..83647b8277e7d 100644
--- a/tools/testing/selftests/powerpc/security/spectre_v2.c
+++ b/tools/testing/selftests/powerpc/security/spectre_v2.c
@@ -193,7 +193,7 @@ int spectre_v2_test(void)
* We are not vulnerable and reporting otherwise, so
* missing such a mismatch is safe.
*/
- if (state == VULNERABLE)
+ if (miss_percent > 95)
return 4;
return 1;
--
2.34.1
From: Thadeu Lima de Souza Cascardo <cascardo(a)canonical.com>
[ Upstream commit 3c42e9542050d49610077e083c7c3f5fd5e26820 ]
A mis-match between reported and actual mitigation is not restricted to the
Vulnerable case. The guest might also report the mitigation as "Software
count cache flush" and the host will still mitigate with branch cache
disabled.
So, instead of skipping depending on the detected mitigation, simply skip
whenever the detected miss_percent is the expected one for a fully
mitigated system, that is, above 95%.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo(a)canonical.com>
Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au>
Link: https://lore.kernel.org/r/20211207130557.40566-1-cascardo@canonical.com
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
tools/testing/selftests/powerpc/security/spectre_v2.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/powerpc/security/spectre_v2.c b/tools/testing/selftests/powerpc/security/spectre_v2.c
index adc2b7294e5fd..83647b8277e7d 100644
--- a/tools/testing/selftests/powerpc/security/spectre_v2.c
+++ b/tools/testing/selftests/powerpc/security/spectre_v2.c
@@ -193,7 +193,7 @@ int spectre_v2_test(void)
* We are not vulnerable and reporting otherwise, so
* missing such a mismatch is safe.
*/
- if (state == VULNERABLE)
+ if (miss_percent > 95)
return 4;
return 1;
--
2.34.1