When turbo mode is unavailable on a Skylake-X system, executing the
command:
"echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo"
results in an unchecked MSR access error: WRMSR to 0x199
(attempted to write 0x0000000100001300).
This issue was reproduced on an OEM (Original Equipment Manufacturer)
system and is not a common problem across all Skylake-X systems.
This error occurs because the MSR 0x199 Turbo Engage Bit (bit 32) is set
when turbo mode is disabled. The issue arises when intel_pstate fails to
detect that turbo mode is disabled. Here intel_pstate relies on
MSR_IA32_MISC_ENABLE bit 38 to determine the status of turbo mode.
However, on this system, bit 38 is not set even when turbo mode is
disabled.
According to the Intel Software Developer's Manual (SDM), the BIOS sets
this bit during platform initialization to enable or disable
opportunistic processor performance operations. Logically, this bit
should be set in such cases. However, the SDM also specifies that "OS and
applications must use CPUID leaf 06H to detect processors with
opportunistic processor performance operations enabled."
Therefore, in addition to checking MSR_IA32_MISC_ENABLE bit 38, verify
that CPUID.06H:EAX[1] is 0 to accurately determine if turbo mode is
disabled.
Fixes: 4521e1a0ce17 ("cpufreq: intel_pstate: Reflect current no_turbo state correctly")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada(a)linux.intel.com>
Cc: stable(a)vger.kernel.org
---
drivers/cpufreq/intel_pstate.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index f41ed0b9e610..ba9bf06f1c77 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -598,6 +598,9 @@ static bool turbo_is_disabled(void)
{
u64 misc_en;
+ if (!cpu_feature_enabled(X86_FEATURE_IDA))
+ return true;
+
rdmsrl(MSR_IA32_MISC_ENABLE, misc_en);
return !!(misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE);
--
2.48.1
Fix a memory leak issue on netpoll and create a netconsole test that exposes
the problem, when run with kmemleak enabled.
This is a merge of two patches I've sent individually and are merged on
the same patchset[1][2].
Link: https://lore.kernel.org/all/20250904-netconsole_torture-v2-0-5775ed5dc366@d… [1]
Link: https://lore.kernel.org/all/20250902165426.6d6cd172@kernel.org/ [2]
Signed-off-by: Breno Leitao <leitao(a)debian.org>
---
Changes in v3:
- this patchset is a merge of the fix and the selftest together as
recommended by Jakub.
Changes in v2:
- Reuse the netconsole creation from lib_netcons.sh. Thus, refactoring
the create_dynamic_target() (Jakub)
- Move the "wait" to after all the messages has been sent.
- Link to v1: https://lore.kernel.org/r/20250902-netconsole_torture-v1-1-03c6066598e9@deb…
---
Breno Leitao (3):
netpoll: fix incorrect refcount handling causing incorrect cleanup
selftest: netcons: refactor target creation
selftest: netcons: create a torture test
net/core/netpoll.c | 7 +-
tools/testing/selftests/drivers/net/Makefile | 1 +
.../selftests/drivers/net/lib/sh/lib_netcons.sh | 30 +++--
.../selftests/drivers/net/netcons_torture.sh | 127 +++++++++++++++++++++
4 files changed, 152 insertions(+), 13 deletions(-)
---
base-commit: d69eb204c255c35abd9e8cb621484e8074c75eaa
change-id: 20250902-netconsole_torture-8fc23f0aca99
Best regards,
--
Breno Leitao <leitao(a)debian.org>
From: "Matthieu Baerts (NGI0)" <matttbe(a)kernel.org>
commit 68fc0f4b0d25692940cdc85c68e366cae63e1757 upstream.
A flush of the MPTCP endpoints should not affect the MPTCP limits. In
other words, 'ip mptcp endpoint flush' should not change 'ip mptcp
limits'.
But it was the case: the MPTCP_PM_ATTR_RCV_ADD_ADDRS (add_addr_accepted)
limit was reset by accident. Removing the reset of this counter during a
flush fixes this issue.
Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Cc: stable(a)vger.kernel.org
Reported-by: Thomas Dreibholz <dreibh(a)simula.no>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/579
Reviewed-by: Mat Martineau <martineau(a)kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
Link: https://patch.msgid.link/20250815-net-mptcp-misc-fixes-6-17-rc2-v1-2-521fe9…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
[adjusted patch by removing WRITE_ONCE to take into account the missing
commit 72603d207d59 ("mptcp: use WRITE_ONCE for the pernet *_max")]
Signed-off-by: Maximilian Heyne <mheyne(a)amazon.de>
---
For some reason only the corresponding selftest patch was backported and
it's now failing on 5.10 kernels. I tested that with this patch the
selftest is succeeding again.
---
net/mptcp/pm_netlink.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 32379fc706cac..c31a1dc69f835 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -869,7 +869,6 @@ static void __flush_addrs(struct pm_nl_pernet *pernet)
static void __reset_counters(struct pm_nl_pernet *pernet)
{
pernet->add_addr_signal_max = 0;
- pernet->add_addr_accept_max = 0;
pernet->local_addr_max = 0;
pernet->addrs = 0;
}
--
2.47.3
Amazon Web Services Development Center Germany GmbH
Tamara-Danz-Str. 13
10243 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597
From: Lance Yang <lance.yang(a)linux.dev>
The blocker tracking mechanism assumes that lock pointers are at least
4-byte aligned to use their lower bits for type encoding.
However, as reported by Eero Tamminen, some architectures like m68k
only guarantee 2-byte alignment of 32-bit values. This breaks the
assumption and causes two related WARN_ON_ONCE checks to trigger.
To fix this, the runtime checks are adjusted to silently ignore any lock
that is not 4-byte aligned, effectively disabling the feature in such
cases and avoiding the related warnings.
Thanks to Geert Uytterhoeven for bisecting!
Reported-by: Eero Tamminen <oak(a)helsinkinet.fi>
Closes: https://lore.kernel.org/lkml/CAMuHMdW7Ab13DdGs2acMQcix5ObJK0O2dG_Fxzr8_g58R…
Fixes: e711faaafbe5 ("hung_task: replace blocker_mutex with encoded blocker")
Cc: <stable(a)vger.kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org>
Signed-off-by: Lance Yang <lance.yang(a)linux.dev>
---
v1 -> v2:
- Pick RB from Masami - thanks!
- Update the changelog and comments
- https://lore.kernel.org/lkml/20250823050036.7748-1-lance.yang@linux.dev/
include/linux/hung_task.h | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/include/linux/hung_task.h b/include/linux/hung_task.h
index 34e615c76ca5..c4403eeb7144 100644
--- a/include/linux/hung_task.h
+++ b/include/linux/hung_task.h
@@ -20,6 +20,10 @@
* always zero. So we can use these bits to encode the specific blocking
* type.
*
+ * Note that on architectures where this is not guaranteed, or for any
+ * unaligned lock, this tracking mechanism is silently skipped for that
+ * lock.
+ *
* Type encoding:
* 00 - Blocked on mutex (BLOCKER_TYPE_MUTEX)
* 01 - Blocked on semaphore (BLOCKER_TYPE_SEM)
@@ -45,7 +49,7 @@ static inline void hung_task_set_blocker(void *lock, unsigned long type)
* If the lock pointer matches the BLOCKER_TYPE_MASK, return
* without writing anything.
*/
- if (WARN_ON_ONCE(lock_ptr & BLOCKER_TYPE_MASK))
+ if (lock_ptr & BLOCKER_TYPE_MASK)
return;
WRITE_ONCE(current->blocker, lock_ptr | type);
@@ -53,8 +57,6 @@ static inline void hung_task_set_blocker(void *lock, unsigned long type)
static inline void hung_task_clear_blocker(void)
{
- WARN_ON_ONCE(!READ_ONCE(current->blocker));
-
WRITE_ONCE(current->blocker, 0UL);
}
--
2.49.0
The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 51337a9a3a404fde0f5337662ffc7699793dfeb5
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025090600-revenue-discharge-a6c4@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 51337a9a3a404fde0f5337662ffc7699793dfeb5 Mon Sep 17 00:00:00 2001
From: Ada Couprie Diaz <ada.coupriediaz(a)arm.com>
Date: Thu, 21 Aug 2025 13:07:35 +0100
Subject: [PATCH] kasan: fix GCC mem-intrinsic prefix with sw tags
GCC doesn't support "hwasan-kernel-mem-intrinsic-prefix", only
"asan-kernel-mem-intrinsic-prefix"[0], while LLVM supports both. This is
already taken into account when checking
"CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX", but not in the KASAN Makefile
adding those parameters when "CONFIG_KASAN_SW_TAGS" is enabled.
Replace the version check with "CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX",
which already validates that mem-intrinsic prefix parameter can be used,
and choose the correct name depending on compiler.
GCC 13 and above trigger "CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX" which
prevents `mem{cpy,move,set}()` being redefined in "mm/kasan/shadow.c"
since commit 36be5cba99f6 ("kasan: treat meminstrinsic as builtins in
uninstrumented files"), as we expect the compiler to prefix those calls
with `__(hw)asan_` instead. But as the option passed to GCC has been
incorrect, the compiler has not been emitting those prefixes, effectively
never calling the instrumented versions of `mem{cpy,move,set}()` with
"CONFIG_KASAN_SW_TAGS" enabled.
If "CONFIG_FORTIFY_SOURCES" is enabled, this issue would be mitigated as
it redefines `mem{cpy,move,set}()` and properly aliases the
`__underlying_mem*()` that will be called to the instrumented versions.
Link: https://lkml.kernel.org/r/20250821120735.156244-1-ada.coupriediaz@arm.com
Link: https://gcc.gnu.org/onlinedocs/gcc-13.4.0/gcc/Optimize-Options.html [0]
Signed-off-by: Ada Couprie Diaz <ada.coupriediaz(a)arm.com>
Fixes: 36be5cba99f6 ("kasan: treat meminstrinsic as builtins in uninstrumented files")
Reviewed-by: Yeoreum Yun <yeoreum.yun(a)arm.com>
Cc: Alexander Potapenko <glider(a)google.com>
Cc: Andrey Konovalov <andreyknvl(a)gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com>
Cc: Dmitriy Vyukov <dvyukov(a)google.com>
Cc: Marco Elver <elver(a)google.com>
Cc: Marc Rutland <mark.rutland(a)arm.com>
Cc: Michael Ellerman <mpe(a)ellerman.id.au>
Cc: Nathan Chancellor <nathan(a)kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 693dbbebebba..0ba2aac3b8dc 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -86,10 +86,14 @@ kasan_params += hwasan-instrument-stack=$(stack_enable) \
hwasan-use-short-granules=0 \
hwasan-inline-all-checks=0
-# Instrument memcpy/memset/memmove calls by using instrumented __hwasan_mem*().
-ifeq ($(call clang-min-version, 150000)$(call gcc-min-version, 130000),y)
- kasan_params += hwasan-kernel-mem-intrinsic-prefix=1
-endif
+# Instrument memcpy/memset/memmove calls by using instrumented __(hw)asan_mem*().
+ifdef CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX
+ ifdef CONFIG_CC_IS_GCC
+ kasan_params += asan-kernel-mem-intrinsic-prefix=1
+ else
+ kasan_params += hwasan-kernel-mem-intrinsic-prefix=1
+ endif
+endif # CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX
endif # CONFIG_KASAN_SW_TAGS