The patch below does not apply to the 6.12-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-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x 7498159226772d66f150dd406be462d75964a366
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025072102-theorize-single-3700@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7498159226772d66f150dd406be462d75964a366 Mon Sep 17 00:00:00 2001
From: Miguel Ojeda <ojeda(a)kernel.org>
Date: Sat, 12 Jul 2025 18:01:03 +0200
Subject: [PATCH] rust: use `#[used(compiler)]` to fix build and `modpost` with
Rust >= 1.89.0
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Starting with Rust 1.89.0 (expected 2025-08-07), the Rust compiler fails
to build the `rusttest` target due to undefined references such as:
kernel...-cgu.0:(.text....+0x116): undefined reference to
`rust_helper_kunit_get_current_test'
Moreover, tooling like `modpost` gets confused:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/gpu/drm/nova/nova.o
ERROR: modpost: missing MODULE_LICENSE() in drivers/gpu/nova-core/nova_core.o
The reason behind both issues is that the Rust compiler will now [1]
treat `#[used]` as `#[used(linker)]` instead of `#[used(compiler)]`
for our targets. This means that the retain section flag (`R`,
`SHF_GNU_RETAIN`) will be used and that they will be marked as `unique`
too, with different IDs. In turn, that means we end up with undefined
references that did not get discarded in `rusttest` and that multiple
`.modinfo` sections are generated, which confuse tooling like `modpost`
because they only expect one.
Thus start using `#[used(compiler)]` to keep the previous behavior
and to be explicit about what we want. Sadly, it is an unstable feature
(`used_with_arg`) [2] -- we will talk to upstream Rust about it. The good
news is that it has been available for a long time (Rust >= 1.60) [3].
The changes should also be fine for previous Rust versions, since they
behave the same way as before [4].
Alternatively, we could use `#[no_mangle]` or `#[export_name = ...]`
since those still behave like `#[used(compiler)]`, but of course it is
not really what we want to express, and it requires other changes to
avoid symbol conflicts.
Cc: David Wood <david(a)davidtw.co>
Cc: Wesley Wiser <wwiser(a)gmail.com>
Cc: stable(a)vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/140872 [1]
Link: https://github.com/rust-lang/rust/issues/93798 [2]
Link: https://github.com/rust-lang/rust/pull/91504 [3]
Link: https://godbolt.org/z/sxzWTMfzW [4]
Reviewed-by: Alice Ryhl <aliceryhl(a)google.com>
Acked-by: Björn Roy Baron <bjorn3_gh(a)protonmail.com>
Link: https://lore.kernel.org/r/20250712160103.1244945-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda(a)kernel.org>
diff --git a/rust/Makefile b/rust/Makefile
index 27dec7904c3a..115b63b7d1e3 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -194,6 +194,7 @@ quiet_cmd_rustdoc_test = RUSTDOC T $<
RUST_MODFILE=test.rs \
OBJTREE=$(abspath $(objtree)) \
$(RUSTDOC) --test $(rust_common_flags) \
+ -Zcrate-attr='feature(used_with_arg)' \
@$(objtree)/include/generated/rustc_cfg \
$(rustc_target_flags) $(rustdoc_test_target_flags) \
$(rustdoc_test_quiet) \
diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs
index 2494c96e105f..4fe621f35716 100644
--- a/rust/kernel/firmware.rs
+++ b/rust/kernel/firmware.rs
@@ -202,7 +202,7 @@ macro_rules! module_firmware {
};
#[link_section = ".modinfo"]
- #[used]
+ #[used(compiler)]
static __MODULE_FIRMWARE: [u8; $($builder)*::create(__MODULE_FIRMWARE_PREFIX)
.build_length()] = $($builder)*::create(__MODULE_FIRMWARE_PREFIX).build();
};
diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs
index 4b8cdcb21e77..b9e65905e121 100644
--- a/rust/kernel/kunit.rs
+++ b/rust/kernel/kunit.rs
@@ -302,7 +302,7 @@ macro_rules! kunit_unsafe_test_suite {
is_init: false,
};
- #[used]
+ #[used(compiler)]
#[allow(unused_unsafe)]
#[cfg_attr(not(target_os = "macos"), link_section = ".kunit_test_suites")]
static mut KUNIT_TEST_SUITE_ENTRY: *const ::kernel::bindings::kunit_suite =
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 6b4774b2b1c3..e13d6ed88fa6 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -34,6 +34,9 @@
// Expected to become stable.
#![feature(arbitrary_self_types)]
//
+// To be determined.
+#![feature(used_with_arg)]
+//
// `feature(derive_coerce_pointee)` is expected to become stable. Before Rust
// 1.84.0, it did not exist, so enable the predecessor features.
#![cfg_attr(CONFIG_RUSTC_HAS_COERCE_POINTEE, feature(derive_coerce_pointee))]
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index 2ddd2eeb2852..75efc6eeeafc 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -57,7 +57,7 @@ fn emit_base(&mut self, field: &str, content: &str, builtin: bool) {
{cfg}
#[doc(hidden)]
#[cfg_attr(not(target_os = \"macos\"), link_section = \".modinfo\")]
- #[used]
+ #[used(compiler)]
pub static __{module}_{counter}: [u8; {length}] = *{string};
",
cfg = if builtin {
@@ -249,7 +249,7 @@ mod __module_init {{
// key or a new section. For the moment, keep it simple.
#[cfg(MODULE)]
#[doc(hidden)]
- #[used]
+ #[used(compiler)]
static __IS_RUST_MODULE: () = ();
static mut __MOD: ::core::mem::MaybeUninit<{type_}> =
@@ -273,7 +273,7 @@ mod __module_init {{
#[cfg(MODULE)]
#[doc(hidden)]
- #[used]
+ #[used(compiler)]
#[link_section = \".init.data\"]
static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module;
@@ -293,7 +293,7 @@ mod __module_init {{
#[cfg(MODULE)]
#[doc(hidden)]
- #[used]
+ #[used(compiler)]
#[link_section = \".exit.data\"]
static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module;
@@ -303,7 +303,7 @@ mod __module_init {{
#[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
#[doc(hidden)]
#[link_section = \"{initcall_section}\"]
- #[used]
+ #[used(compiler)]
pub static __{ident}_initcall: extern \"C\" fn() ->
::kernel::ffi::c_int = __{ident}_init;
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index a6461ea411f7..ba71b27aa363 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -312,10 +312,11 @@ $(obj)/%.lst: $(obj)/%.c FORCE
# - Stable since Rust 1.82.0: `feature(asm_const)`, `feature(raw_ref_op)`.
# - Stable since Rust 1.87.0: `feature(asm_goto)`.
# - Expected to become stable: `feature(arbitrary_self_types)`.
+# - To be determined: `feature(used_with_arg)`.
#
# Please see https://github.com/Rust-for-Linux/linux/issues/2 for details on
# the unstable features in use.
-rust_allowed_features := asm_const,asm_goto,arbitrary_self_types,lint_reasons,raw_ref_op
+rust_allowed_features := asm_const,asm_goto,arbitrary_self_types,lint_reasons,raw_ref_op,used_with_arg
# `--out-dir` is required to avoid temporaries being created by `rustc` in the
# current working directory, which may be not accessible in the out-of-tree
The patch below does not apply to the 5.4-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-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x d66e1e90b16055d2f0ee76e5384e3f119c3c2773
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071202-cycling-woof-6cf6@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d66e1e90b16055d2f0ee76e5384e3f119c3c2773 Mon Sep 17 00:00:00 2001
From: Yazen Ghannam <yazen.ghannam(a)amd.com>
Date: Tue, 24 Jun 2025 14:15:58 +0000
Subject: [PATCH] x86/mce/amd: Add default names for MCA banks and blocks
Ensure that sysfs init doesn't fail for new/unrecognized bank types or if
a bank has additional blocks available.
Most MCA banks have a single thresholding block, so the block takes the same
name as the bank.
Unified Memory Controllers (UMCs) are a special case where there are two
blocks and each has a unique name.
However, the microarchitecture allows for five blocks. Any new MCA bank types
with more than one block will be missing names for the extra blocks. The MCE
sysfs will fail to initialize in this case.
Fixes: 87a6d4091bd7 ("x86/mce/AMD: Update sysfs bank names for SMCA systems")
Signed-off-by: Yazen Ghannam <yazen.ghannam(a)amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp(a)alien8.de>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/20250624-wip-mca-updates-v4-3-236dd74f645f@amd.com
diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 9d852c3b2cb5..6820ebce5d46 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -1113,13 +1113,20 @@ static const char *get_name(unsigned int cpu, unsigned int bank, struct threshol
}
bank_type = smca_get_bank_type(cpu, bank);
- if (bank_type >= N_SMCA_BANK_TYPES)
- return NULL;
if (b && (bank_type == SMCA_UMC || bank_type == SMCA_UMC_V2)) {
if (b->block < ARRAY_SIZE(smca_umc_block_names))
return smca_umc_block_names[b->block];
- return NULL;
+ }
+
+ if (b && b->block) {
+ snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN, "th_block_%u", b->block);
+ return buf_mcatype;
+ }
+
+ if (bank_type >= N_SMCA_BANK_TYPES) {
+ snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN, "th_bank_%u", bank);
+ return buf_mcatype;
}
if (per_cpu(smca_bank_counts, cpu)[bank_type] == 1)
The patch below does not apply to the 5.10-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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x d66e1e90b16055d2f0ee76e5384e3f119c3c2773
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071201-coping-motto-1a12@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d66e1e90b16055d2f0ee76e5384e3f119c3c2773 Mon Sep 17 00:00:00 2001
From: Yazen Ghannam <yazen.ghannam(a)amd.com>
Date: Tue, 24 Jun 2025 14:15:58 +0000
Subject: [PATCH] x86/mce/amd: Add default names for MCA banks and blocks
Ensure that sysfs init doesn't fail for new/unrecognized bank types or if
a bank has additional blocks available.
Most MCA banks have a single thresholding block, so the block takes the same
name as the bank.
Unified Memory Controllers (UMCs) are a special case where there are two
blocks and each has a unique name.
However, the microarchitecture allows for five blocks. Any new MCA bank types
with more than one block will be missing names for the extra blocks. The MCE
sysfs will fail to initialize in this case.
Fixes: 87a6d4091bd7 ("x86/mce/AMD: Update sysfs bank names for SMCA systems")
Signed-off-by: Yazen Ghannam <yazen.ghannam(a)amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp(a)alien8.de>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/20250624-wip-mca-updates-v4-3-236dd74f645f@amd.com
diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 9d852c3b2cb5..6820ebce5d46 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -1113,13 +1113,20 @@ static const char *get_name(unsigned int cpu, unsigned int bank, struct threshol
}
bank_type = smca_get_bank_type(cpu, bank);
- if (bank_type >= N_SMCA_BANK_TYPES)
- return NULL;
if (b && (bank_type == SMCA_UMC || bank_type == SMCA_UMC_V2)) {
if (b->block < ARRAY_SIZE(smca_umc_block_names))
return smca_umc_block_names[b->block];
- return NULL;
+ }
+
+ if (b && b->block) {
+ snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN, "th_block_%u", b->block);
+ return buf_mcatype;
+ }
+
+ if (bank_type >= N_SMCA_BANK_TYPES) {
+ snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN, "th_bank_%u", bank);
+ return buf_mcatype;
}
if (per_cpu(smca_bank_counts, cpu)[bank_type] == 1)
The patch below does not apply to the 5.15-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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x d66e1e90b16055d2f0ee76e5384e3f119c3c2773
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071200-cone-ogle-b45b@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d66e1e90b16055d2f0ee76e5384e3f119c3c2773 Mon Sep 17 00:00:00 2001
From: Yazen Ghannam <yazen.ghannam(a)amd.com>
Date: Tue, 24 Jun 2025 14:15:58 +0000
Subject: [PATCH] x86/mce/amd: Add default names for MCA banks and blocks
Ensure that sysfs init doesn't fail for new/unrecognized bank types or if
a bank has additional blocks available.
Most MCA banks have a single thresholding block, so the block takes the same
name as the bank.
Unified Memory Controllers (UMCs) are a special case where there are two
blocks and each has a unique name.
However, the microarchitecture allows for five blocks. Any new MCA bank types
with more than one block will be missing names for the extra blocks. The MCE
sysfs will fail to initialize in this case.
Fixes: 87a6d4091bd7 ("x86/mce/AMD: Update sysfs bank names for SMCA systems")
Signed-off-by: Yazen Ghannam <yazen.ghannam(a)amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp(a)alien8.de>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/20250624-wip-mca-updates-v4-3-236dd74f645f@amd.com
diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 9d852c3b2cb5..6820ebce5d46 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -1113,13 +1113,20 @@ static const char *get_name(unsigned int cpu, unsigned int bank, struct threshol
}
bank_type = smca_get_bank_type(cpu, bank);
- if (bank_type >= N_SMCA_BANK_TYPES)
- return NULL;
if (b && (bank_type == SMCA_UMC || bank_type == SMCA_UMC_V2)) {
if (b->block < ARRAY_SIZE(smca_umc_block_names))
return smca_umc_block_names[b->block];
- return NULL;
+ }
+
+ if (b && b->block) {
+ snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN, "th_block_%u", b->block);
+ return buf_mcatype;
+ }
+
+ if (bank_type >= N_SMCA_BANK_TYPES) {
+ snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN, "th_bank_%u", bank);
+ return buf_mcatype;
}
if (per_cpu(smca_bank_counts, cpu)[bank_type] == 1)
The blocking notifier is registered in cros_ec_register(); however, it
isn't unregistered in cros_ec_unregister().
Fix it.
Fixes: 42cd0ab476e2 ("platform/chrome: cros_ec: Query EC protocol version if EC transitions between RO/RW")
Cc: stable(a)vger.kernel.org
Signed-off-by: Tzung-Bi Shih <tzungbi(a)kernel.org>
---
This is separated from a series (https://lore.kernel.org/chrome-platform/20250721044456.2736300-3-tzungbi@ke…).
While I'm still figuring out/testing the series, it'd be better to send the
fix earlier (to catch up the upcoming merge window for example).
drivers/platform/chrome/cros_ec.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
index 110771a8645e..fd58781a2fb7 100644
--- a/drivers/platform/chrome/cros_ec.c
+++ b/drivers/platform/chrome/cros_ec.c
@@ -318,6 +318,9 @@ EXPORT_SYMBOL(cros_ec_register);
*/
void cros_ec_unregister(struct cros_ec_device *ec_dev)
{
+ if (ec_dev->mkbp_event_supported)
+ blocking_notifier_chain_unregister(&ec_dev->event_notifier,
+ &ec_dev->notifier_ready);
platform_device_unregister(ec_dev->pd);
platform_device_unregister(ec_dev->ec);
mutex_destroy(&ec_dev->lock);
--
2.50.0.727.gbf7dc18ff4-goog
When the PSLVERR_RESP_EN parameter is set to 1, the device generates
an error response if an attempt is made to read an empty RBR (Receive
Buffer Register) while the FIFO is enabled.
In serial8250_do_startup(), calling serial_port_out(port, UART_LCR,
UART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes
dw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter
function enables the FIFO via serial_out(p, UART_FCR, p->fcr).
Execution proceeds to the serial_port_in(port, UART_RX).
This satisfies the PSLVERR trigger condition.
When another CPU (e.g., using printk()) is accessing the UART (UART
is busy), the current CPU fails the check (value & ~UART_LCR_SPAR) ==
(lcr & ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter
dw8250_force_idle().
Put serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port->lock
to fix this issue.
Panic backtrace:
[ 0.442336] Oops - unknown exception [#1]
[ 0.442343] epc : dw8250_serial_in32+0x1e/0x4a
[ 0.442351] ra : serial8250_do_startup+0x2c8/0x88e
...
[ 0.442416] console_on_rootfs+0x26/0x70
Fixes: c49436b657d0 ("serial: 8250_dw: Improve unwritable LCR workaround")
Link: https://lore.kernel.org/all/84cydt5peu.fsf@jogness.linutronix.de/T/
Signed-off-by: Yunhui Cui <cuiyunhui(a)bytedance.com>
Reviewed-by: John Ogness <john.ogness(a)linutronix.de>
Cc: stable(a)vger.kernel.org
---
drivers/tty/serial/8250/8250_port.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 7eddcab318b4b..2da9db960d09f 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2269,9 +2269,9 @@ static void serial8250_initialize(struct uart_port *port)
{
unsigned long flags;
+ uart_port_lock_irqsave(port, &flags);
serial_port_out(port, UART_LCR, UART_LCR_WLEN8);
- uart_port_lock_irqsave(port, &flags);
serial8250_init_mctrl(port);
serial8250_iir_txen_test(port);
uart_port_unlock_irqrestore(port, flags);
--
2.39.5
The patch below does not apply to the 6.1-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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x d66e1e90b16055d2f0ee76e5384e3f119c3c2773
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071200-bath-copartner-6a91@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From d66e1e90b16055d2f0ee76e5384e3f119c3c2773 Mon Sep 17 00:00:00 2001
From: Yazen Ghannam <yazen.ghannam(a)amd.com>
Date: Tue, 24 Jun 2025 14:15:58 +0000
Subject: [PATCH] x86/mce/amd: Add default names for MCA banks and blocks
Ensure that sysfs init doesn't fail for new/unrecognized bank types or if
a bank has additional blocks available.
Most MCA banks have a single thresholding block, so the block takes the same
name as the bank.
Unified Memory Controllers (UMCs) are a special case where there are two
blocks and each has a unique name.
However, the microarchitecture allows for five blocks. Any new MCA bank types
with more than one block will be missing names for the extra blocks. The MCE
sysfs will fail to initialize in this case.
Fixes: 87a6d4091bd7 ("x86/mce/AMD: Update sysfs bank names for SMCA systems")
Signed-off-by: Yazen Ghannam <yazen.ghannam(a)amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp(a)alien8.de>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/20250624-wip-mca-updates-v4-3-236dd74f645f@amd.com
diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 9d852c3b2cb5..6820ebce5d46 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -1113,13 +1113,20 @@ static const char *get_name(unsigned int cpu, unsigned int bank, struct threshol
}
bank_type = smca_get_bank_type(cpu, bank);
- if (bank_type >= N_SMCA_BANK_TYPES)
- return NULL;
if (b && (bank_type == SMCA_UMC || bank_type == SMCA_UMC_V2)) {
if (b->block < ARRAY_SIZE(smca_umc_block_names))
return smca_umc_block_names[b->block];
- return NULL;
+ }
+
+ if (b && b->block) {
+ snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN, "th_block_%u", b->block);
+ return buf_mcatype;
+ }
+
+ if (bank_type >= N_SMCA_BANK_TYPES) {
+ snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN, "th_bank_%u", bank);
+ return buf_mcatype;
}
if (per_cpu(smca_bank_counts, cpu)[bank_type] == 1)
From: Arnd Bergmann <arnd(a)arndb.de>
[ Upstream commit 24171a5a4a952c26568ff0d2a0bc8c4708a95e1d ]
With large values of CONFIG_NR_CPUS, three Intel ethernet drivers fail to
compile like:
In function ‘i40e_free_q_vector’,
inlined from ‘i40e_vsi_alloc_q_vectors’ at drivers/net/ethernet/intel/i40e/i40e_main.c:12112:3:
571 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
include/linux/rcupdate.h:1084:17: note: in expansion of macro ‘BUILD_BUG_ON’
1084 | BUILD_BUG_ON(offsetof(typeof(*(ptr)), rhf) >= 4096); \
drivers/net/ethernet/intel/i40e/i40e_main.c:5113:9: note: in expansion of macro ‘kfree_rcu’
5113 | kfree_rcu(q_vector, rcu);
| ^~~~~~~~~
The problem is that the 'rcu' member in 'q_vector' is too far from the start
of the structure. Move this member before the CPU mask instead, in all three
drivers.
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
Acked-by: David S. Miller <davem(a)davemloft.net>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov(a)intel.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin(a)intel.com>
Tested-by: Sunitha Mekala <sunithax.d.mekala(a)intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen(a)intel.com>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
LLM Generated explanations, may be completely bogus:
**YES**
This commit should be backported to stable kernel trees for the
following reasons:
1. **Compilation Failure Fix**: This fixes a build-time compilation
failure that occurs with large values of CONFIG_NR_CPUS. The error
prevents the kernel from building successfully, which is a
significant issue for systems configured with high CPU counts.
2. **Root Cause**: The issue stems from the `kfree_rcu()` macro in
`include/linux/rcupdate.h:1084` which includes a
`BUILD_BUG_ON(offsetof(typeof(*(ptr)), rhf) >= 4096)` check. This
compile-time assertion ensures that the RCU head field is within the
first 4096 bytes of the structure.
3. **Simple and Safe Fix**: The fix is straightforward - it moves the
`struct rcu_head rcu` member earlier in the structure, placing it
before the `cpumask_t affinity_mask` member. This is a safe change
because:
- It only reorders structure members
- The RCU head doesn't need to be at any specific location
functionally
- Moving it earlier reduces the offset from the structure start
- No functional code changes are required
4. **Affects Multiple Drivers**: The issue affects three Intel ethernet
drivers (i40e, ixgbe, fm10k), all of which are fixed identically by
moving the rcu member earlier in their respective q_vector
structures.
5. **Configuration-Dependent Bug**: This bug only manifests with large
CONFIG_NR_CPUS values (likely >= 512 or higher), where the
`cpumask_t` type becomes large enough to push the rcu member beyond
the 4096-byte offset limit. Systems with high core counts are
becoming more common in production environments.
6. **No Risk of Regression**: The change is minimal and doesn't alter
any functionality. It's purely a structural reordering that maintains
all existing behavior while fixing the compilation issue.
7. **Meets Stable Criteria**: This fix clearly meets the stable kernel
criteria as it:
- Fixes a real bug (compilation failure)
- Is minimal and contained
- Has no risk of introducing new issues
- Affects users with legitimate configurations
The commit is an excellent candidate for stable backporting as it fixes
a real compilation issue that prevents kernel builds on systems with
large CPU counts, and the fix is trivial with no risk of regression.
drivers/net/ethernet/intel/fm10k/fm10k.h | 3 ++-
drivers/net/ethernet/intel/i40e/i40e.h | 2 +-
drivers/net/ethernet/intel/ixgbe/ixgbe.h | 3 ++-
3 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k.h b/drivers/net/ethernet/intel/fm10k/fm10k.h
index b14441944b4b2..db72e5e4acd36 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k.h
+++ b/drivers/net/ethernet/intel/fm10k/fm10k.h
@@ -189,13 +189,14 @@ struct fm10k_q_vector {
struct fm10k_ring_container rx, tx;
struct napi_struct napi;
+ struct rcu_head rcu; /* to avoid race with update stats on free */
+
cpumask_t affinity_mask;
char name[IFNAMSIZ + 9];
#ifdef CONFIG_DEBUG_FS
struct dentry *dbg_q_vector;
#endif /* CONFIG_DEBUG_FS */
- struct rcu_head rcu; /* to avoid race with update stats on free */
/* for dynamic allocation of rings associated with this q_vector */
struct fm10k_ring ring[0] ____cacheline_internodealigned_in_smp;
diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 4c8c31692e9e0..edb5e408c980f 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -864,6 +864,7 @@ struct i40e_q_vector {
u16 reg_idx; /* register index of the interrupt */
struct napi_struct napi;
+ struct rcu_head rcu; /* to avoid race with update stats on free */
struct i40e_ring_container rx;
struct i40e_ring_container tx;
@@ -874,7 +875,6 @@ struct i40e_q_vector {
cpumask_t affinity_mask;
struct irq_affinity_notify affinity_notify;
- struct rcu_head rcu; /* to avoid race with update stats on free */
char name[I40E_INT_NAME_STR_LEN];
bool arm_wb_state;
} ____cacheline_internodealigned_in_smp;
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
index 0142ca226bf50..0f9a1fce0dee9 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h
@@ -458,9 +458,10 @@ struct ixgbe_q_vector {
struct ixgbe_ring_container rx, tx;
struct napi_struct napi;
+ struct rcu_head rcu; /* to avoid race with update stats on free */
+
cpumask_t affinity_mask;
int numa_node;
- struct rcu_head rcu; /* to avoid race with update stats on free */
char name[IFNAMSIZ + 9];
/* for dynamic allocation of rings associated with this q_vector */
--
2.39.5