Commit 81d0bcf99009 ("drm/amdgpu: make display pinning more flexible (v2)")
allowed for newer ASICs to mix GTT and VRAM, this change also noted that
some older boards, such as Stoney and Carrizo do not support this.
It appears that at least one additional ASIC does not support this which
is Raven.
We observed this issue when migrating a device from a 5.4 to 6.6 kernel
and have confirmed that Raven also needs to be excluded from mixing GTT
and VRAM.
Fixes: 81d0bcf99009 ("drm/amdgpu: make display pinning more flexible (v2)")
Cc: Luben Tuikov <luben.tuikov(a)amd.com>
Cc: Christian König <christian.koenig(a)amd.com>
Cc: Alex Deucher <alexander.deucher(a)amd.com>
Cc: stable(a)vger.kernel.org # 6.1+
Tested-by: Thadeu Lima de Souza Cascardo <cascardo(a)igalia.com>
Signed-off-by: Brian Geffon <bgeffon(a)google.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 73403744331a..5d7f13e25b7c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -1545,7 +1545,8 @@ uint32_t amdgpu_bo_get_preferred_domain(struct amdgpu_device *adev,
uint32_t domain)
{
if ((domain == (AMDGPU_GEM_DOMAIN_VRAM | AMDGPU_GEM_DOMAIN_GTT)) &&
- ((adev->asic_type == CHIP_CARRIZO) || (adev->asic_type == CHIP_STONEY))) {
+ ((adev->asic_type == CHIP_CARRIZO) || (adev->asic_type == CHIP_STONEY) ||
+ (adev->asic_type == CHIP_RAVEN))) {
domain = AMDGPU_GEM_DOMAIN_VRAM;
if (adev->gmc.real_vram_size <= AMDGPU_SG_THRESHOLD)
domain = AMDGPU_GEM_DOMAIN_GTT;
--
2.50.0.727.gbf7dc18ff4-goog
When operating on struct vhost_net_ubuf_ref, the following execution
sequence is theoretically possible:
CPU0 is finalizing DMA operation CPU1 is doing VHOST_NET_SET_BACKEND
// &ubufs->refcount == 2
vhost_net_ubuf_put() vhost_net_ubuf_put_wait_and_free(oldubufs)
vhost_net_ubuf_put_and_wait()
vhost_net_ubuf_put()
int r = atomic_sub_return(1, &ubufs->refcount);
// r = 1
int r = atomic_sub_return(1, &ubufs->refcount);
// r = 0
wait_event(ubufs->wait, !atomic_read(&ubufs->refcount));
// no wait occurs here because condition is already true
kfree(ubufs);
if (unlikely(!r))
wake_up(&ubufs->wait); // use-after-free
This leads to use-after-free on ubufs access. This happens because CPU1
skips waiting for wake_up() when refcount is already zero.
To prevent that use a completion instead of wait_queue as the ubufs
notification mechanism. wait_for_completion() guarantees that there will
be complete() call prior to its return.
We also need to reinit completion in vhost_net_flush(), because
refcnt == 0 does not mean freeing in that case.
Cc: stable(a)vger.kernel.org
Fixes: 0ad8b480d6ee9 ("vhost: fix ref cnt checking deadlock")
Reported-by: Andrey Ryabinin <arbn(a)yandex-team.com>
Suggested-by: Andrey Smetanin <asmetanin(a)yandex-team.ru>
Suggested-by: Hillf Danton <hdanton(a)sina.com>
Tested-by: Lei Yang <leiyang(a)redhat.com> (v1)
Signed-off-by: Nikolay Kuratov <kniv(a)yandex-team.ru>
---
v2:
* move reinit_completion() into vhost_net_flush(), thanks
to Hillf Danton
* add Tested-by: Lei Yang
* check that usages of put_and_wait() are consistent across
LTS kernels
drivers/vhost/net.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 7cbfc7d718b3..69e1bfb9627e 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -94,7 +94,7 @@ struct vhost_net_ubuf_ref {
* >1: outstanding ubufs
*/
atomic_t refcount;
- wait_queue_head_t wait;
+ struct completion wait;
struct vhost_virtqueue *vq;
};
@@ -240,7 +240,7 @@ vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy)
if (!ubufs)
return ERR_PTR(-ENOMEM);
atomic_set(&ubufs->refcount, 1);
- init_waitqueue_head(&ubufs->wait);
+ init_completion(&ubufs->wait);
ubufs->vq = vq;
return ubufs;
}
@@ -249,14 +249,14 @@ static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs)
{
int r = atomic_sub_return(1, &ubufs->refcount);
if (unlikely(!r))
- wake_up(&ubufs->wait);
+ complete_all(&ubufs->wait);
return r;
}
static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs)
{
vhost_net_ubuf_put(ubufs);
- wait_event(ubufs->wait, !atomic_read(&ubufs->refcount));
+ wait_for_completion(&ubufs->wait);
}
static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs)
@@ -1381,6 +1381,7 @@ static void vhost_net_flush(struct vhost_net *n)
mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
n->tx_flush = false;
atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1);
+ reinit_completion(&n->vqs[VHOST_NET_VQ_TX].ubufs->wait);
mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex);
}
}
--
2.34.1
Starting with Rust 1.91.0 (expected 2025-10-30), `rustdoc` has improved
some false negatives around intra-doc links [1], and it found a broken
intra-doc link we currently have:
error: unresolved link to `include/linux/device/faux.h`
--> rust/kernel/faux.rs:7:17
|
7 | //! C header: [`include/linux/device/faux.h`]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ no item named `include/linux/device/faux.h` in scope
|
= help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
= note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(rustdoc::broken_intra_doc_links)]`
Our `srctree/` C header links are not intra-doc links, thus they need
the link destination.
Thus fix it.
Cc: stable(a)vger.kernel.org
Link: https://github.com/rust-lang/rust/pull/132748 [1]
Fixes: 78418f300d39 ("rust/kernel: Add faux device bindings")
Signed-off-by: Miguel Ojeda <ojeda(a)kernel.org>
---
It may have been in 1.90, but the beta branch does not have it, and the
rollup PR says 1.91, unlike the PR itself, so I picked 1.91. It happened
just after the version bump to 1.91, so it may have to do with that.
rust/kernel/faux.rs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/rust/kernel/faux.rs b/rust/kernel/faux.rs
index 7a906099993f..7fe2dd197e37 100644
--- a/rust/kernel/faux.rs
+++ b/rust/kernel/faux.rs
@@ -4,7 +4,7 @@
//!
//! This module provides bindings for working with faux devices in kernel modules.
//!
-//! C header: [`include/linux/device/faux.h`]
+//! C header: [`include/linux/device/faux.h`](srctree/include/linux/device/faux.h)
use crate::{bindings, device, error::code::*, prelude::*};
use core::ptr::{addr_of_mut, null, null_mut, NonNull};
base-commit: d2eedaa3909be9102d648a4a0a50ccf64f96c54f
--
2.50.1
The hwprobe vDSO data for some keys, like MISALIGNED_VECTOR_PERF,
is determined by an asynchronous kthread. This can create a race
condition where the kthread finishes after the vDSO data has
already been populated, causing userspace to read stale values.
To fix this race, a new 'ready' flag is added to the vDSO data,
initialized to 'false' during late_initcall. This flag is checked
by both the vDSO's user-space code and the riscv_hwprobe syscall.
The syscall serves as a one-time gate, using a completion to wait
for any pending probes before populating the data and setting the
flag to 'true', thus ensuring userspace reads fresh values on its
first request.
Reported-by: Tsukasa OI <research_trasio(a)irq.a4lg.com>
Closes: https://lore.kernel.org/linux-riscv/760d637b-b13b-4518-b6bf-883d55d44e7f@ir…
Fixes: e7c9d66e313b ("RISC-V: Report vector unaligned access speed hwprobe")
Cc: Palmer Dabbelt <palmer(a)dabbelt.com>
Cc: Alexandre Ghiti <alexghiti(a)rivosinc.com>
Cc: Olof Johansson <olof(a)lixom.net>
Cc: stable(a)vger.kernel.org
Co-developed-by: Palmer Dabbelt <palmer(a)dabbelt.com>
Signed-off-by: Jingwei Wang <wangjingwei(a)iscas.ac.cn>
---
Changes in v6:
- Based on Palmer's feedback, reworked the synchronization to be on-demand,
deferring the wait until the first hwprobe syscall via a 'ready' flag.
This avoids the boot-time regression from v5's approach.
Changes in v5:
- Reworked the synchronization logic to a robust "sentinel-count"
pattern based on feedback from Alexandre.
- Fixed a "multiple definition" linker error for nommu builds by changing
the header-file stub functions to `static inline`, as pointed out by Olof.
- Updated the commit message to better explain the rationale for moving
the vDSO initialization to `late_initcall`.
Changes in v4:
- Reworked the synchronization mechanism based on feedback from Palmer
and Alexandre.
- Instead of a post-hoc refresh, this version introduces a robust
completion-based framework using an atomic counter to ensure async
probes are finished before populating the vDSO.
- Moved the vdso data initialization to a late_initcall to avoid
impacting boot time.
Changes in v3:
- Retained existing blank line.
Changes in v2:
- Addressed feedback from Yixun's regarding #ifdef CONFIG_MMU usage.
- Updated commit message to provide a high-level summary.
- Added Fixes tag for commit e7c9d66e313b.
v1: https://lore.kernel.org/linux-riscv/20250521052754.185231-1-wangjingwei@isc…
arch/riscv/include/asm/hwprobe.h | 8 ++-
arch/riscv/include/asm/vdso/arch_data.h | 6 ++
arch/riscv/kernel/sys_hwprobe.c | 71 ++++++++++++++++++----
arch/riscv/kernel/unaligned_access_speed.c | 9 ++-
arch/riscv/kernel/vdso/hwprobe.c | 2 +-
5 files changed, 79 insertions(+), 17 deletions(-)
diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h
index 7fe0a379474ae2c6..3b2888126e659ea1 100644
--- a/arch/riscv/include/asm/hwprobe.h
+++ b/arch/riscv/include/asm/hwprobe.h
@@ -40,5 +40,11 @@ static inline bool riscv_hwprobe_pair_cmp(struct riscv_hwprobe *pair,
return pair->value == other_pair->value;
}
-
+#ifdef CONFIG_MMU
+void riscv_hwprobe_register_async_probe(void);
+void riscv_hwprobe_complete_async_probe(void);
+#else
+static inline void riscv_hwprobe_register_async_probe(void) {}
+static inline void riscv_hwprobe_complete_async_probe(void) {}
+#endif
#endif
diff --git a/arch/riscv/include/asm/vdso/arch_data.h b/arch/riscv/include/asm/vdso/arch_data.h
index da57a3786f7a53c8..88b37af55175129b 100644
--- a/arch/riscv/include/asm/vdso/arch_data.h
+++ b/arch/riscv/include/asm/vdso/arch_data.h
@@ -12,6 +12,12 @@ struct vdso_arch_data {
/* Boolean indicating all CPUs have the same static hwprobe values. */
__u8 homogeneous_cpus;
+
+ /*
+ * A gate to check and see if the hwprobe data is actually ready, as
+ * probing is deferred to avoid boot slowdowns.
+ */
+ __u8 ready;
};
#endif /* __RISCV_ASM_VDSO_ARCH_DATA_H */
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index 0b170e18a2beba57..fecb6790fa88e96c 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -5,6 +5,8 @@
* more details.
*/
#include <linux/syscalls.h>
+#include <linux/completion.h>
+#include <linux/atomic.h>
#include <asm/cacheflush.h>
#include <asm/cpufeature.h>
#include <asm/hwprobe.h>
@@ -452,28 +454,36 @@ static int hwprobe_get_cpus(struct riscv_hwprobe __user *pairs,
return 0;
}
-static int do_riscv_hwprobe(struct riscv_hwprobe __user *pairs,
- size_t pair_count, size_t cpusetsize,
- unsigned long __user *cpus_user,
- unsigned int flags)
-{
- if (flags & RISCV_HWPROBE_WHICH_CPUS)
- return hwprobe_get_cpus(pairs, pair_count, cpusetsize,
- cpus_user, flags);
+#ifdef CONFIG_MMU
- return hwprobe_get_values(pairs, pair_count, cpusetsize,
- cpus_user, flags);
+static DECLARE_COMPLETION(boot_probes_done);
+static atomic_t pending_boot_probes = ATOMIC_INIT(1);
+
+void riscv_hwprobe_register_async_probe(void)
+{
+ atomic_inc(&pending_boot_probes);
}
-#ifdef CONFIG_MMU
+void riscv_hwprobe_complete_async_probe(void)
+{
+ if (atomic_dec_and_test(&pending_boot_probes))
+ complete(&boot_probes_done);
+}
-static int __init init_hwprobe_vdso_data(void)
+static int complete_hwprobe_vdso_data(void)
{
struct vdso_arch_data *avd = vdso_k_arch_data;
u64 id_bitsmash = 0;
struct riscv_hwprobe pair;
int key;
+ /* We've probably already produced these values. */
+ if (likely(avd->ready))
+ return 0;
+
+ if (unlikely(!atomic_dec_and_test(&pending_boot_probes)))
+ wait_for_completion(&boot_probes_done);
+
/*
* Initialize vDSO data with the answers for the "all CPUs" case, to
* save a syscall in the common case.
@@ -501,13 +511,48 @@ static int __init init_hwprobe_vdso_data(void)
* vDSO should defer to the kernel for exotic cpu masks.
*/
avd->homogeneous_cpus = id_bitsmash != 0 && id_bitsmash != -1;
+
+ /*
+ * Make sure all the VDSO values are visible before we look at them.
+ * This pairs with the implicit "no speculativly visible accesses"
+ * barrier in the VDSO hwprobe code.
+ */
+ smp_wmb();
+ avd->ready = true;
+ return 0;
+}
+
+static int __init init_hwprobe_vdso_data(void)
+{
+ struct vdso_arch_data *avd = vdso_k_arch_data;
+
+ /*
+ * Prevent the vDSO cached values from being used, as they're not ready
+ * yet.
+ */
+ avd->ready = false;
return 0;
}
-arch_initcall_sync(init_hwprobe_vdso_data);
+late_initcall(init_hwprobe_vdso_data);
#endif /* CONFIG_MMU */
+static int do_riscv_hwprobe(struct riscv_hwprobe __user *pairs,
+ size_t pair_count, size_t cpusetsize,
+ unsigned long __user *cpus_user,
+ unsigned int flags)
+{
+ complete_hwprobe_vdso_data();
+
+ if (flags & RISCV_HWPROBE_WHICH_CPUS)
+ return hwprobe_get_cpus(pairs, pair_count, cpusetsize,
+ cpus_user, flags);
+
+ return hwprobe_get_values(pairs, pair_count, cpusetsize,
+ cpus_user, flags);
+}
+
SYSCALL_DEFINE5(riscv_hwprobe, struct riscv_hwprobe __user *, pairs,
size_t, pair_count, size_t, cpusetsize, unsigned long __user *,
cpus, unsigned int, flags)
diff --git a/arch/riscv/kernel/unaligned_access_speed.c b/arch/riscv/kernel/unaligned_access_speed.c
index ae2068425fbcd207..4b8ad2673b0f7470 100644
--- a/arch/riscv/kernel/unaligned_access_speed.c
+++ b/arch/riscv/kernel/unaligned_access_speed.c
@@ -379,6 +379,7 @@ static void check_vector_unaligned_access(struct work_struct *work __always_unus
static int __init vec_check_unaligned_access_speed_all_cpus(void *unused __always_unused)
{
schedule_on_each_cpu(check_vector_unaligned_access);
+ riscv_hwprobe_complete_async_probe();
return 0;
}
@@ -473,8 +474,12 @@ static int __init check_unaligned_access_all_cpus(void)
per_cpu(vector_misaligned_access, cpu) = unaligned_vector_speed_param;
} else if (!check_vector_unaligned_access_emulated_all_cpus() &&
IS_ENABLED(CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS)) {
- kthread_run(vec_check_unaligned_access_speed_all_cpus,
- NULL, "vec_check_unaligned_access_speed_all_cpus");
+ riscv_hwprobe_register_async_probe();
+ if (IS_ERR(kthread_run(vec_check_unaligned_access_speed_all_cpus,
+ NULL, "vec_check_unaligned_access_speed_all_cpus"))) {
+ pr_warn("Failed to create vec_unalign_check kthread\n");
+ riscv_hwprobe_complete_async_probe();
+ }
}
/*
diff --git a/arch/riscv/kernel/vdso/hwprobe.c b/arch/riscv/kernel/vdso/hwprobe.c
index 2ddeba6c68dda09b..bf77b4c1d2d8e803 100644
--- a/arch/riscv/kernel/vdso/hwprobe.c
+++ b/arch/riscv/kernel/vdso/hwprobe.c
@@ -27,7 +27,7 @@ static int riscv_vdso_get_values(struct riscv_hwprobe *pairs, size_t pair_count,
* homogeneous, then this function can handle requests for arbitrary
* masks.
*/
- if ((flags != 0) || (!all_cpus && !avd->homogeneous_cpus))
+ if ((flags != 0) || (!all_cpus && !avd->homogeneous_cpus) || unlikely(!avd->ready))
return riscv_hwprobe(pairs, pair_count, cpusetsize, cpus, flags);
/* This is something we can handle, fill out the pairs. */
--
2.50.1
The error path in adfs_fplus_read() prints an error message via
adfs_error() but incorrectly returns success (0) to the caller.
This occurs because the 'ret' variable remains set to 0 from the earlier
successful call to adfs_fplus_validate_tail().
Fix by setting 'ret = -EIO' before jumping to the error exit.
This issue was detected by smatch static analysis:
warning: fs/adfs/dir_fplus.c:146: adfs_fplus_read() warn: missing error
code 'ret'.
Fixes: d79288b4f61b ("fs/adfs: bigdir: calculate and validate directory checkbyte")
Cc: stable(a)vger.kernel.org
Signed-off-by: Zhen Ni <zhen.ni(a)easystack.cn>
---
Changes in v2:
- Add tags of 'Fixes' and 'Cc' in commit message
- Added error description and the corresponding fix in commit message
---
fs/adfs/dir_fplus.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/adfs/dir_fplus.c b/fs/adfs/dir_fplus.c
index 4a15924014da..4334279409b2 100644
--- a/fs/adfs/dir_fplus.c
+++ b/fs/adfs/dir_fplus.c
@@ -143,6 +143,7 @@ static int adfs_fplus_read(struct super_block *sb, u32 indaddr,
if (adfs_fplus_checkbyte(dir) != t->bigdircheckbyte) {
adfs_error(sb, "dir %06x checkbyte mismatch\n", indaddr);
+ ret = -EIO;
goto out;
}
--
2.20.1
Pentium 4's which are INTEL_P4_PRESCOTT (model 0x03) and later have
a constant TSC. This was correctly captured until commit fadb6f569b10
("x86/cpu/intel: Limit the non-architectural constant_tsc model checks").
In that commit, an error was introduced while selecting the last P4
model (0x06) as the upper bound. Model 0x06 was transposed to
INTEL_P4_WILLAMETTE, which is just plain wrong. That was presumably a
simple typo, probably just copying and pasting the wrong P4 model.
Fix the constant TSC logic to cover all later P4 models. End at
INTEL_P4_CEDARMILL which accurately corresponds to the last P4 model.
Fixes: fadb6f569b10 ("x86/cpu/intel: Limit the non-architectural constant_tsc model checks")
Cc: <stable(a)vger.kernel.org> # v6.15
Signed-off-by: Suchit Karunakaran <suchitkarunakaran(a)gmail.com>
Changes since v3:
- Refined changelog
Changes since v2:
- Improve commit message
Changes since v1:
- Fix incorrect logic
---
arch/x86/kernel/cpu/intel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 076eaa41b8c8..6f5bd5dbc249 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -262,7 +262,7 @@ static void early_init_intel(struct cpuinfo_x86 *c)
if (c->x86_power & (1 << 8)) {
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
- } else if ((c->x86_vfm >= INTEL_P4_PRESCOTT && c->x86_vfm <= INTEL_P4_WILLAMETTE) ||
+ } else if ((c->x86_vfm >= INTEL_P4_PRESCOTT && c->x86_vfm <= INTEL_P4_CEDARMILL) ||
(c->x86_vfm >= INTEL_CORE_YONAH && c->x86_vfm <= INTEL_IVYBRIDGE)) {
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
}
--
2.50.1
From: Quang Le <quanglex97(a)gmail.com>
When packet_set_ring() releases po->bind_lock, another thread can
run packet_notifier() and process an NETDEV_UP event.
This race and the fix are both similar to that of commit 15fe076edea7
("net/packet: fix a race in packet_bind() and packet_notifier()").
There too the packet_notifier NETDEV_UP event managed to run while a
po->bind_lock critical section had to be temporarily released. And
the fix was similarly to temporarily set po->num to zero to keep
the socket unhooked until the lock is retaken.
The po->bind_lock in packet_set_ring and packet_notifier precede the
introduction of git history.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable(a)vger.kernel.org
Signed-off-by: Quang Le <quanglex97(a)gmail.com>
Signed-off-by: Willem de Bruijn <willemb(a)google.com>
---
v1->v2:
- fix author attribution (From: at the top)
v1: https://lore.kernel.org/netdev/20250731175132.2592130-1-willemdebruijn.kern…
---
net/packet/af_packet.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index bc438d0d96a7..a7017d7f0927 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -4573,10 +4573,10 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
spin_lock(&po->bind_lock);
was_running = packet_sock_flag(po, PACKET_SOCK_RUNNING);
num = po->num;
- if (was_running) {
- WRITE_ONCE(po->num, 0);
+ WRITE_ONCE(po->num, 0);
+ if (was_running)
__unregister_prot_hook(sk, false);
- }
+
spin_unlock(&po->bind_lock);
synchronize_net();
@@ -4608,10 +4608,10 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
mutex_unlock(&po->pg_vec_lock);
spin_lock(&po->bind_lock);
- if (was_running) {
- WRITE_ONCE(po->num, num);
+ WRITE_ONCE(po->num, num);
+ if (was_running)
register_prot_hook(sk);
- }
+
spin_unlock(&po->bind_lock);
if (pg_vec && (po->tp_version > TPACKET_V2)) {
/* Because we don't support block-based V3 on tx-ring */
--
2.50.1.565.gc32cd1483b-goog
During the integration of the RTL8239 POE chip + its frontend MCU, it was
noticed that multi-byte operations were basically broken in the current
driver.
Tests using SMBus Block Writes showed that the data (after the Wr + Ack
marker) was mixed up on the wire. At first glance, it looked like an
endianness problem. But for transfers were the number of count + data bytes
was not divisible by 4, the last bytes were not looking like an endianness
problem because they were were in the wrong order but not for example 0 -
which would be the case for an endianness problem with 32 bit registers. At
the end, it turned out to be a the way how i2c_write tried to add the bytes
to the send registers.
Each 32 bit register was used similar to a shift register - shifting the
various bytes up the register while the next one is added to the least
significant byte. But the I2C controller expects the first byte of the
tranmission in the least significant byte of the first register. And the
last byte (assuming it is a 16 byte transfer) in the most significant byte
of the fourth register.
While doing these tests, it was also observed that the count byte was
missing from the SMBus Block Writes. The driver just removed them from the
data->block (from the I2C subsystem). But the I2C controller DOES NOT
automatically add this byte - for example by using the configured
transmission length.
The RTL8239 MCU is not actually an SMBus compliant device. Instead, it
expects I2C Block Reads + I2C Block Writes. But according to the already
identified bugs in the driver, it was clear that the I2C controller can
simply be modified to not send the count byte for I2C_SMBUS_I2C_BLOCK_DATA.
The receive part, just needs to write the content of the receive buffer to
the correct position in data->block.
While the on-wire formwat was now correct, reads were still not possible
against the MCU (for the RTL8239 POE chip). It was always timing out
because the 2ms were not enough for sending the read request and then
receiving the 12 byte answer.
These changes were originally submitted to OpenWrt. But there are plans to
migrate OpenWrt to the upstream Linux driver. As result, the pull request
was stopped and the changes were redone against this driver.
For reasons of transparency: The work on I2C_SMBUS_I2C_BLOCK_DATA support
for the RTL8239-MCU was done on RTL931xx. All problem were therefore
detected with the patches from Jonas Jelonek [1] and not the vanilla Linux
driver. But looking through the code, it seems like these are NOT
regressions introduced by the RTL931x patchset.
[1] https://patchwork.ozlabs.org/project/linux-i2c/cover/20250727114800.3046-1-…
Signed-off-by: Sven Eckelmann <sven(a)narfation.org>
---
Changes in v2:
- add the missing transfer width and read length increase for the SMBus
Write/Read
- Link to v1: https://lore.kernel.org/r/20250802-i2c-rtl9300-multi-byte-v1-0-5f687e0098e2…
---
Harshal Gohel (2):
i2c: rtl9300: Fix multi-byte I2C write
i2c: rtl9300: Implement I2C block read and write
Sven Eckelmann (2):
i2c: rtl9300: Increase timeout for transfer polling
i2c: rtl9300: Add missing count byte for SMBus Block Ops
drivers/i2c/busses/i2c-rtl9300.c | 43 +++++++++++++++++++++++++++++++++-------
1 file changed, 36 insertions(+), 7 deletions(-)
---
base-commit: b9ddaa95fd283bce7041550ddbbe7e764c477110
change-id: 20250802-i2c-rtl9300-multi-byte-edaa1fb0872c
Best regards,
--
Sven Eckelmann <sven(a)narfation.org>
During the integration of the RTL8239 POE chip + its frontend MCU, it was
noticed that multi-byte operations were basically broken in the current
driver.
Tests using SMBus Block Writes showed that the data (after the Wr + Ack
marker) was mixed up on the wire. At first glance, it looked like an
endianness problem. But for transfers were the number of count + data bytes
was not divisible by 4, the last bytes were not looking like an endianness
problem because they were were in the wrong order but not for example 0 -
which would be the case for an endianness problem with 32 bit registers. At
the end, it turned out to be a the way how i2c_write tried to add the bytes
to the send registers.
Each 32 bit register was used similar to a shift register - shifting the
various bytes up the register while the next one is added to the least
significant byte. But the I2C controller expects the first byte of the
tranmission in the least significant byte of the first register. And the
last byte (assuming it is a 16 byte transfer) in the most significant byte
of the fourth register.
While doing these tests, it was also observed that the count byte was
missing from the SMBus Block Writes. The driver just removed them from the
data->block (from the I2C subsystem). But the I2C controller DOES NOT
automatically add this byte - for example by using the configured
transmission length.
The RTL8239 MCU is not actually an SMBus compliant device. Instead, it
expects I2C Block Reads + I2C Block Writes. But according to the already
identified bugs in the driver, it was clear that the I2C controller can
simply be modified to not send the count byte for I2C_SMBUS_I2C_BLOCK_DATA.
The receive part, just needs to write the content of the receive buffer to
the correct position in data->block.
While the on-wire formwat was now correct, reads were still not possible
against the MCU (for the RTL8239 POE chip). It was always timing out
because the 2ms were not enough for sending the read request and then
receiving the 12 byte answer.
These changes were originally submitted to OpenWrt. But there are plans to
migrate OpenWrt to the upstream Linux driver. As result, the pull request
was stopped and the changes were redone against this driver.
For reasons of transparency: The work on I2C_SMBUS_I2C_BLOCK_DATA support
for the RTL8239-MCU was done on RTL931xx. All problem were therefore
detected with the patches from Jonas Jelonek [1] and not the vanilla Linux
driver. But looking through the code, it seems like these are NOT
regressions introduced by the RTL931x patchset.
I've picked up Alex Guo's patch [2] to reduce conflicts between pending
fixes.
[1] https://patchwork.ozlabs.org/project/linux-i2c/cover/20250727114800.3046-1-…
[2] https://lore.kernel.org/r/20250615235248.529019-1-alexguo1023@gmail.com
Signed-off-by: Sven Eckelmann <sven(a)narfation.org>
---
Changes in v3:
- integrated patch
https://lore.kernel.org/r/20250615235248.529019-1-alexguo1023@gmail.com
to avoid conflicts in the I2C_SMBUS_BLOCK_DATA code
- added Fixes and stable(a)vger.kernel.org to Alex Guo's patch
- added Chris Packham's Reviewed-by/Acked-by
- Link to v2: https://lore.kernel.org/r/20250803-i2c-rtl9300-multi-byte-v2-0-9b7b759fe2b6…
Changes in v2:
- add the missing transfer width and read length increase for the SMBus
Write/Read
- Link to v1: https://lore.kernel.org/r/20250802-i2c-rtl9300-multi-byte-v1-0-5f687e0098e2…
---
Alex Guo (1):
i2c: rtl9300: Fix out-of-bounds bug in rtl9300_i2c_smbus_xfer
Harshal Gohel (2):
i2c: rtl9300: Fix multi-byte I2C write
i2c: rtl9300: Implement I2C block read and write
Sven Eckelmann (2):
i2c: rtl9300: Increase timeout for transfer polling
i2c: rtl9300: Add missing count byte for SMBus Block Ops
drivers/i2c/busses/i2c-rtl9300.c | 51 ++++++++++++++++++++++++++++++++++------
1 file changed, 44 insertions(+), 7 deletions(-)
---
base-commit: 0ae982df67760cd08affa935c0fe86c8a9311797
change-id: 20250802-i2c-rtl9300-multi-byte-edaa1fb0872c
Best regards,
--
Sven Eckelmann <sven(a)narfation.org>
With a timeout of only 1 second, my rx 5700XT fails to initialize,
so this increases the timeout to 2s.
Closes https://gitlab.freedesktop.org/drm/amd/-/issues/3697
Signed-off-by: Xaver Hugl <xaver.hugl(a)kde.org>
Cc: stable(a)vger.kernel.org
---
drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
index 6d34eac0539d..ae6908b57d78 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
@@ -275,7 +275,7 @@ static int amdgpu_discovery_read_binary_from_mem(struct amdgpu_device *adev,
int i, ret = 0;
if (!amdgpu_sriov_vf(adev)) {
- /* It can take up to a second for IFWI init to complete on some dGPUs,
+ /* It can take up to two seconds for IFWI init to complete on some dGPUs,
* but generally it should be in the 60-100ms range. Normally this starts
* as soon as the device gets power so by the time the OS loads this has long
* completed. However, when a card is hotplugged via e.g., USB4, we need to
@@ -283,7 +283,7 @@ static int amdgpu_discovery_read_binary_from_mem(struct amdgpu_device *adev,
* continue.
*/
- for (i = 0; i < 1000; i++) {
+ for (i = 0; i < 2000; i++) {
msg = RREG32(mmMP0_SMN_C2PMSG_33);
if (msg & 0x80000000)
break;
--
2.50.1
Ensure that epoll instances can never form a graph deeper than
EP_MAX_NESTS+1 links.
Currently, ep_loop_check_proc() ensures that the graph is loop-free and
does some recursion depth checks, but those recursion depth checks don't
limit the depth of the resulting tree for two reasons:
- They don't look upwards in the tree.
- If there are multiple downwards paths of different lengths, only one of
the paths is actually considered for the depth check since commit
28d82dc1c4ed ("epoll: limit paths").
Essentially, the current recursion depth check in ep_loop_check_proc() just
serves to prevent it from recursing too deeply while checking for loops.
A more thorough check is done in reverse_path_check() after the new graph
edge has already been created; this checks, among other things, that no
paths going upwards from any non-epoll file with a length of more than 5
edges exist. However, this check does not apply to non-epoll files.
As a result, it is possible to recurse to a depth of at least roughly 500,
tested on v6.15. (I am unsure if deeper recursion is possible; and this may
have changed with commit 8c44dac8add7 ("eventpoll: Fix priority inversion
problem").)
To fix it:
1. In ep_loop_check_proc(), note the subtree depth of each visited node,
and use subtree depths for the total depth calculation even when a subtree
has already been visited.
2. Add ep_get_upwards_depth_proc() for similarly determining the maximum
depth of an upwards walk.
3. In ep_loop_check(), use these values to limit the total path length
between epoll nodes to EP_MAX_NESTS edges.
Fixes: 22bacca48a17 ("epoll: prevent creating circular epoll structures")
Cc: stable(a)vger.kernel.org
Signed-off-by: Jann Horn <jannh(a)google.com>
---
fs/eventpoll.c | 60 ++++++++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 46 insertions(+), 14 deletions(-)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index d4dbffdedd08..44648cc09250 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -218,6 +218,7 @@ struct eventpoll {
/* used to optimize loop detection check */
u64 gen;
struct hlist_head refs;
+ u8 loop_check_depth;
/*
* usage count, used together with epitem->dying to
@@ -2142,23 +2143,24 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
}
/**
- * ep_loop_check_proc - verify that adding an epoll file inside another
- * epoll structure does not violate the constraints, in
- * terms of closed loops, or too deep chains (which can
- * result in excessive stack usage).
+ * ep_loop_check_proc - verify that adding an epoll file @ep inside another
+ * epoll file does not create closed loops, and
+ * determine the depth of the subtree starting at @ep
*
* @ep: the &struct eventpoll to be currently checked.
* @depth: Current depth of the path being checked.
*
- * Return: %zero if adding the epoll @file inside current epoll
- * structure @ep does not violate the constraints, or %-1 otherwise.
+ * Return: depth of the subtree, or INT_MAX if we found a loop or went too deep.
*/
static int ep_loop_check_proc(struct eventpoll *ep, int depth)
{
- int error = 0;
+ int result = 0;
struct rb_node *rbp;
struct epitem *epi;
+ if (ep->gen == loop_check_gen)
+ return ep->loop_check_depth;
+
mutex_lock_nested(&ep->mtx, depth + 1);
ep->gen = loop_check_gen;
for (rbp = rb_first_cached(&ep->rbr); rbp; rbp = rb_next(rbp)) {
@@ -2166,13 +2168,11 @@ static int ep_loop_check_proc(struct eventpoll *ep, int depth)
if (unlikely(is_file_epoll(epi->ffd.file))) {
struct eventpoll *ep_tovisit;
ep_tovisit = epi->ffd.file->private_data;
- if (ep_tovisit->gen == loop_check_gen)
- continue;
if (ep_tovisit == inserting_into || depth > EP_MAX_NESTS)
- error = -1;
+ result = INT_MAX;
else
- error = ep_loop_check_proc(ep_tovisit, depth + 1);
- if (error != 0)
+ result = max(result, ep_loop_check_proc(ep_tovisit, depth + 1) + 1);
+ if (result > EP_MAX_NESTS)
break;
} else {
/*
@@ -2186,9 +2186,27 @@ static int ep_loop_check_proc(struct eventpoll *ep, int depth)
list_file(epi->ffd.file);
}
}
+ ep->loop_check_depth = result;
mutex_unlock(&ep->mtx);
- return error;
+ return result;
+}
+
+/**
+ * ep_get_upwards_depth_proc - determine depth of @ep when traversed upwards
+ */
+static int ep_get_upwards_depth_proc(struct eventpoll *ep, int depth)
+{
+ int result = 0;
+ struct epitem *epi;
+
+ if (ep->gen == loop_check_gen)
+ return ep->loop_check_depth;
+ hlist_for_each_entry_rcu(epi, &ep->refs, fllink)
+ result = max(result, ep_get_upwards_depth_proc(epi->ep, depth + 1) + 1);
+ ep->gen = loop_check_gen;
+ ep->loop_check_depth = result;
+ return result;
}
/**
@@ -2204,8 +2222,22 @@ static int ep_loop_check_proc(struct eventpoll *ep, int depth)
*/
static int ep_loop_check(struct eventpoll *ep, struct eventpoll *to)
{
+ int depth, upwards_depth;
+
inserting_into = ep;
- return ep_loop_check_proc(to, 0);
+ /*
+ * Check how deep down we can get from @to, and whether it is possible
+ * to loop up to @ep.
+ */
+ depth = ep_loop_check_proc(to, 0);
+ if (depth > EP_MAX_NESTS)
+ return -1;
+ /* Check how far up we can go from @ep. */
+ rcu_read_lock();
+ upwards_depth = ep_get_upwards_depth_proc(ep, 0);
+ rcu_read_unlock();
+
+ return (depth+1+upwards_depth > EP_MAX_NESTS) ? -1 : 0;
}
static void clear_tfile_check_list(void)
---
base-commit: 0ff41df1cb268fc69e703a08a57ee14ae967d0ca
change-id: 20250711-epoll-recursion-fix-fb0e336b2aeb
--
Jann Horn <jannh(a)google.com>
From: Su Hui <suhui(a)nfschina.com>
[ Upstream commit 7919407eca2ef562fa6c98c41cfdf6f6cdd69d92 ]
When encounters some errors like these:
xhci_hcd 0000:4a:00.2: xHCI dying or halted, can't queue_command
xhci_hcd 0000:4a:00.2: FIXME: allocate a command ring segment
usb usb5-port6: couldn't allocate usb_device
It's hard to know whether xhc_state is dying or halted. So it's better
to print xhc_state's value which can help locate the resaon of the bug.
Signed-off-by: Su Hui <suhui(a)nfschina.com>
Link: https://lore.kernel.org/r/20250725060117.1773770-1-suhui@nfschina.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
LLM Generated explanations, may be completely bogus:
**Backport Status: YES**
This commit is suitable for backporting to stable kernel trees for the
following reasons:
1. **Enhanced Debugging for Real-World Issues**: The commit improves
debugging of USB xHCI host controller failures by printing the actual
`xhc_state` value when `queue_command` fails. The commit message
shows real error messages users encounter ("xHCI dying or halted,
can't queue_command"), demonstrating this is a real-world debugging
problem.
2. **Minimal and Safe Change**: The change is extremely small and safe -
it only modifies a debug print statement from:
```c
xhci_dbg(xhci, "xHCI dying or halted, can't queue_command\n");
```
to:
```c
xhci_dbg(xhci, "xHCI dying or halted, can't queue_command. state:
0x%x\n", xhci->xhc_state);
```
3. **No Functional Changes**: This is a pure diagnostic improvement. It
doesn't change any logic, control flow, or data structures. It only
adds the state value (0x%x format) to an existing debug message.
4. **Important for Troubleshooting**: The xHCI driver is critical for
USB functionality, and when it fails with "dying or halted" states,
knowing the exact state helps diagnose whether:
- `XHCI_STATE_DYING` (0x1) - controller is dying
- `XHCI_STATE_HALTED` (0x2) - controller is halted
- Both states (0x3) - controller has both flags set
This distinction is valuable for debugging hardware issues, driver
bugs, or system problems.
5. **Zero Risk of Regression**: Adding a parameter to a debug print
statement has no risk of introducing regressions. The worst case is
the debug message prints the state value.
6. **Follows Stable Rules**: This meets stable kernel criteria as it:
- Fixes a real debugging limitation
- Is obviously correct
- Has been tested (signed-off and accepted by Greg KH)
- Is small (single line change)
- Doesn't add new features, just improves existing diagnostics
The commit helps system administrators and developers diagnose USB
issues more effectively by providing the actual state value rather than
just saying "dying or halted", making it a valuable debugging
enhancement for stable kernels.
drivers/usb/host/xhci-ring.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 44352df58c9e..c6d89b51c678 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -4454,7 +4454,8 @@ static int queue_command(struct xhci_hcd *xhci, struct xhci_command *cmd,
if ((xhci->xhc_state & XHCI_STATE_DYING) ||
(xhci->xhc_state & XHCI_STATE_HALTED)) {
- xhci_dbg(xhci, "xHCI dying or halted, can't queue_command\n");
+ xhci_dbg(xhci, "xHCI dying or halted, can't queue_command. state: 0x%x\n",
+ xhci->xhc_state);
return -ESHUTDOWN;
}
--
2.39.5
On systems using the hash MMU, there is a software SLB preload cache that
mirrors the entries loaded into the hardware SLB buffer. This preload
cache is subject to periodic eviction — typically after every 256 context
switches — to remove old entry.
To optimize performance, the kernel skips switch_mmu_context() in
switch_mm_irqs_off() when the prev and next mm_struct are the same.
However, on hash MMU systems, this can lead to inconsistencies between
the hardware SLB and the software preload cache.
If an SLB entry for a process is evicted from the software cache on one
CPU, and the same process later runs on another CPU without executing
switch_mmu_context(), the hardware SLB may retain stale entries. If the
kernel then attempts to reload that entry, it can trigger an SLB
multi-hit error.
The following timeline shows how stale SLB entries are created and can
cause a multi-hit error when a process moves between CPUs without a
MMU context switch.
CPU 0 CPU 1
----- -----
Process P
exec swapper/1
load_elf_binary
begin_new_exc
activate_mm
switch_mm_irqs_off
switch_mmu_context
switch_slb
/*
* This invalidates all
* the entries in the HW
* and setup the new HW
* SLB entries as per the
* preload cache.
*/
context_switch
sched_migrate_task migrates process P to cpu-1
Process swapper/0 context switch (to process P)
(uses mm_struct of Process P) switch_mm_irqs_off()
switch_slb
load_slb++
/*
* load_slb becomes 0 here
* and we evict an entry from
* the preload cache with
* preload_age(). We still
* keep HW SLB and preload
* cache in sync, that is
* because all HW SLB entries
* anyways gets evicted in
* switch_slb during SLBIA.
* We then only add those
* entries back in HW SLB,
* which are currently
* present in preload_cache
* (after eviction).
*/
load_elf_binary continues...
setup_new_exec()
slb_setup_new_exec()
sched_switch event
sched_migrate_task migrates
process P to cpu-0
context_switch from swapper/0 to Process P
switch_mm_irqs_off()
/*
* Since both prev and next mm struct are same we don't call
* switch_mmu_context(). This will cause the HW SLB and SW preload
* cache to go out of sync in preload_new_slb_context. Because there
* was an SLB entry which was evicted from both HW and preload cache
* on cpu-1. Now later in preload_new_slb_context(), when we will try
* to add the same preload entry again, we will add this to the SW
* preload cache and then will add it to the HW SLB. Since on cpu-0
* this entry was never invalidated, hence adding this entry to the HW
* SLB will cause a SLB multi-hit error.
*/
load_elf_binary continues...
START_THREAD
start_thread
preload_new_slb_context
/*
* This tries to add a new EA to preload cache which was earlier
* evicted from both cpu-1 HW SLB and preload cache. This caused the
* HW SLB of cpu-0 to go out of sync with the SW preload cache. The
* reason for this was, that when we context switched back on CPU-0,
* we should have ideally called switch_mmu_context() which will
* bring the HW SLB entries on CPU-0 in sync with SW preload cache
* entries by setting up the mmu context properly. But we didn't do
* that since the prev mm_struct running on cpu-0 was same as the
* next mm_struct (which is true for swapper / kernel threads). So
* now when we try to add this new entry into the HW SLB of cpu-0,
* we hit a SLB multi-hit error.
*/
WARNING: CPU: 0 PID: 1810970 at arch/powerpc/mm/book3s64/slb.c:62
assert_slb_presence+0x2c/0x50(48 results) 02:47:29 [20157/42149]
Modules linked in:
CPU: 0 UID: 0 PID: 1810970 Comm: dd Not tainted 6.16.0-rc3-dirty #12
VOLUNTARY
Hardware name: IBM pSeries (emulated by qemu) POWER8 (architected)
0x4d0200 0xf000004 of:SLOF,HEAD hv:linux,kvm pSeries
NIP: c00000000015426c LR: c0000000001543b4 CTR: 0000000000000000
REGS: c0000000497c77e0 TRAP: 0700 Not tainted (6.16.0-rc3-dirty)
MSR: 8000000002823033 <SF,VEC,VSX,FP,ME,IR,DR,RI,LE> CR: 28888482 XER: 00000000
CFAR: c0000000001543b0 IRQMASK: 3
<...>
NIP [c00000000015426c] assert_slb_presence+0x2c/0x50
LR [c0000000001543b4] slb_insert_entry+0x124/0x390
Call Trace:
0x7fffceb5ffff (unreliable)
preload_new_slb_context+0x100/0x1a0
start_thread+0x26c/0x420
load_elf_binary+0x1b04/0x1c40
bprm_execve+0x358/0x680
do_execveat_common+0x1f8/0x240
sys_execve+0x58/0x70
system_call_exception+0x114/0x300
system_call_common+0x160/0x2c4
To fix this issue, we add a code change to always switch the MMU context on
hash MMU if the SLB preload cache has aged. With this change, the
SLB multi-hit error no longer occurs.
cc: Christophe Leroy <christophe.leroy(a)csgroup.eu>
cc: Ritesh Harjani (IBM) <ritesh.list(a)gmail.com>
cc: Michael Ellerman <mpe(a)ellerman.id.au>
cc: Nicholas Piggin <npiggin(a)gmail.com>
Fixes: 5434ae74629a ("powerpc/64s/hash: Add a SLB preload cache")
cc: stable(a)vger.kernel.org
Suggested-by: Ritesh Harjani (IBM) <ritesh.list(a)gmail.com>
Signed-off-by: Donet Tom <donettom(a)linux.ibm.com>
---
v1 -> v2 : Changed commit message and added a comment in
switch_mm_irqs_off()
v1 - https://lore.kernel.org/all/20250731161027.966196-1-donettom@linux.ibm.com/
---
arch/powerpc/mm/book3s64/slb.c | 2 +-
arch/powerpc/mm/mmu_context.c | 7 +++++--
2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/mm/book3s64/slb.c b/arch/powerpc/mm/book3s64/slb.c
index 6b783552403c..08daac3f978c 100644
--- a/arch/powerpc/mm/book3s64/slb.c
+++ b/arch/powerpc/mm/book3s64/slb.c
@@ -509,7 +509,7 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
* SLB preload cache.
*/
tsk->thread.load_slb++;
- if (!tsk->thread.load_slb) {
+ if (tsk->thread.load_slb == U8_MAX) {
unsigned long pc = KSTK_EIP(tsk);
preload_age(ti);
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index 3e3af29b4523..95455d787288 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -83,8 +83,11 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
/* Some subarchs need to track the PGD elsewhere */
switch_mm_pgdir(tsk, next);
- /* Nothing else to do if we aren't actually switching */
- if (prev == next)
+ /*
+ * Nothing else to do if we aren't actually switching and
+ * the preload slb cache has not aged
+ */
+ if ((prev == next) && (tsk->thread.load_slb != U8_MAX))
return;
/*
--
2.50.1
Testing has shown that reading multiple registers at once (for 10 bit
adc values) does not work. Set the use_single_read regmap_config flag
to make regmap split these for is.
This should fix temperature opregion accesses done by
drivers/acpi/pmic/intel_pmic_chtdc_ti.c and is also necessary for
the upcoming drivers for the ADC and battery MFD cells.
Fixes: 6bac0606fdba ("mfd: Add support for Cherry Trail Dollar Cove TI PMIC")
Cc: stable(a)vger.kernel.org
Reviewed-by: Andy Shevchenko <andy(a)kernel.org>
Signed-off-by: Hans de Goede <hansg(a)kernel.org>
---
Changes in v2:
- Update comment to: "The hardware does not support reading multiple
registers at once"
---
drivers/mfd/intel_soc_pmic_chtdc_ti.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/mfd/intel_soc_pmic_chtdc_ti.c b/drivers/mfd/intel_soc_pmic_chtdc_ti.c
index 4c1a68c9f575..6daf33e07ea0 100644
--- a/drivers/mfd/intel_soc_pmic_chtdc_ti.c
+++ b/drivers/mfd/intel_soc_pmic_chtdc_ti.c
@@ -82,6 +82,8 @@ static const struct regmap_config chtdc_ti_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = 0xff,
+ /* The hardware does not support reading multiple registers at once */
+ .use_single_read = true,
};
static const struct regmap_irq chtdc_ti_irqs[] = {
--
2.49.0
Testing has shown that reading multiple registers at once (for 10 bit
adc values) does not work. Set the use_single_read regmap_config flag
to make regmap split these for is.
This should fix temperature opregion accesses done by
drivers/acpi/pmic/intel_pmic_chtdc_ti.c and is also necessary for
the upcoming drivers for the ADC and battery MFD cells.
Fixes: 6bac0606fdba ("mfd: Add support for Cherry Trail Dollar Cove TI PMIC")
Cc: stable(a)vger.kernel.org
Signed-off-by: Hans de Goede <hansg(a)kernel.org>
---
drivers/mfd/intel_soc_pmic_chtdc_ti.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/mfd/intel_soc_pmic_chtdc_ti.c b/drivers/mfd/intel_soc_pmic_chtdc_ti.c
index 4c1a68c9f575..a23bda8ddae8 100644
--- a/drivers/mfd/intel_soc_pmic_chtdc_ti.c
+++ b/drivers/mfd/intel_soc_pmic_chtdc_ti.c
@@ -82,6 +82,8 @@ static const struct regmap_config chtdc_ti_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = 0xff,
+ /* Reading multiple registers at once is not supported */
+ .use_single_read = true,
};
static const struct regmap_irq chtdc_ti_irqs[] = {
--
2.49.0
From: Su Hui <suhui(a)nfschina.com>
[ Upstream commit 7919407eca2ef562fa6c98c41cfdf6f6cdd69d92 ]
When encounters some errors like these:
xhci_hcd 0000:4a:00.2: xHCI dying or halted, can't queue_command
xhci_hcd 0000:4a:00.2: FIXME: allocate a command ring segment
usb usb5-port6: couldn't allocate usb_device
It's hard to know whether xhc_state is dying or halted. So it's better
to print xhc_state's value which can help locate the resaon of the bug.
Signed-off-by: Su Hui <suhui(a)nfschina.com>
Link: https://lore.kernel.org/r/20250725060117.1773770-1-suhui@nfschina.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
LLM Generated explanations, may be completely bogus:
**Backport Status: YES**
This commit is suitable for backporting to stable kernel trees for the
following reasons:
1. **Enhanced Debugging for Real-World Issues**: The commit improves
debugging of USB xHCI host controller failures by printing the actual
`xhc_state` value when `queue_command` fails. The commit message
shows real error messages users encounter ("xHCI dying or halted,
can't queue_command"), demonstrating this is a real-world debugging
problem.
2. **Minimal and Safe Change**: The change is extremely small and safe -
it only modifies a debug print statement from:
```c
xhci_dbg(xhci, "xHCI dying or halted, can't queue_command\n");
```
to:
```c
xhci_dbg(xhci, "xHCI dying or halted, can't queue_command. state:
0x%x\n", xhci->xhc_state);
```
3. **No Functional Changes**: This is a pure diagnostic improvement. It
doesn't change any logic, control flow, or data structures. It only
adds the state value (0x%x format) to an existing debug message.
4. **Important for Troubleshooting**: The xHCI driver is critical for
USB functionality, and when it fails with "dying or halted" states,
knowing the exact state helps diagnose whether:
- `XHCI_STATE_DYING` (0x1) - controller is dying
- `XHCI_STATE_HALTED` (0x2) - controller is halted
- Both states (0x3) - controller has both flags set
This distinction is valuable for debugging hardware issues, driver
bugs, or system problems.
5. **Zero Risk of Regression**: Adding a parameter to a debug print
statement has no risk of introducing regressions. The worst case is
the debug message prints the state value.
6. **Follows Stable Rules**: This meets stable kernel criteria as it:
- Fixes a real debugging limitation
- Is obviously correct
- Has been tested (signed-off and accepted by Greg KH)
- Is small (single line change)
- Doesn't add new features, just improves existing diagnostics
The commit helps system administrators and developers diagnose USB
issues more effectively by providing the actual state value rather than
just saying "dying or halted", making it a valuable debugging
enhancement for stable kernels.
drivers/usb/host/xhci-ring.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index b720e04ce7d8..8be033f1877d 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -4337,7 +4337,8 @@ static int queue_command(struct xhci_hcd *xhci, struct xhci_command *cmd,
if ((xhci->xhc_state & XHCI_STATE_DYING) ||
(xhci->xhc_state & XHCI_STATE_HALTED)) {
- xhci_dbg(xhci, "xHCI dying or halted, can't queue_command\n");
+ xhci_dbg(xhci, "xHCI dying or halted, can't queue_command. state: 0x%x\n",
+ xhci->xhc_state);
return -ESHUTDOWN;
}
--
2.39.5
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✅ Cost Efficiency: 40%+ clients reduce logistics/QC costs through our integrated service model (ISO 9001:2015 certified).
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pnv_irq_domain_alloc() allocates interrupts at parent's interrupt
domain. If it fails in the progress, all allocated interrupts are
freed.
The number of successfully allocated interrupts so far is stored
"i". However, "i - 1" interrupts are freed. This is broken:
- One interrupt is not be freed
- If "i" is zero, "i - 1" wraps around
Correct the number of freed interrupts to "i".
Fixes: 0fcfe2247e75 ("powerpc/powernv/pci: Add MSI domains")
Signed-off-by: Nam Cao <namcao(a)linutronix.de>
Cc: stable(a)vger.kernel.org
---
arch/powerpc/platforms/powernv/pci-ioda.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index d8ccf2c9b98a..0166bf39ce1e 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1854,7 +1854,7 @@ static int pnv_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
return 0;
out:
- irq_domain_free_irqs_parent(domain, virq, i - 1);
+ irq_domain_free_irqs_parent(domain, virq, i);
msi_bitmap_free_hwirqs(&phb->msi_bmp, hwirq, nr_irqs);
return ret;
}
--
2.39.5
pseries_irq_domain_alloc() allocates interrupts at parent's interrupt
domain. If it fails in the progress, all allocated interrupts are
freed.
The number of successfully allocated interrupts so far is stored
"i". However, "i - 1" interrupts are freed. This is broken:
- One interrupt is not be freed
- If "i" is zero, "i - 1" wraps around
Correct the number of freed interrupts to 'i'.
Fixes: a5f3d2c17b07 ("powerpc/pseries/pci: Add MSI domains")
Signed-off-by: Nam Cao <namcao(a)linutronix.de>
Cc: stable(a)vger.kernel.org
---
arch/powerpc/platforms/pseries/msi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
index ee1c8c6898a3..9dc294de631f 100644
--- a/arch/powerpc/platforms/pseries/msi.c
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -593,7 +593,7 @@ static int pseries_irq_domain_alloc(struct irq_domain *domain, unsigned int virq
out:
/* TODO: handle RTAS cleanup in ->msi_finish() ? */
- irq_domain_free_irqs_parent(domain, virq, i - 1);
+ irq_domain_free_irqs_parent(domain, virq, i);
return ret;
}
--
2.39.5
This driver, for the time being, assumes that the kernel page size is 4kB,
so it fails on loong64 and aarch64 with 16kB pages, and ppc64el with 64kB
pages.
Signed-off-by: Simon Richter <Simon.Richter(a)hogyros.de>
Cc: stable(a)vger.kernel.org
---
drivers/gpu/drm/xe/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/gpu/drm/xe/Kconfig b/drivers/gpu/drm/xe/Kconfig
index 2bb2bc052120..714d5702dfd7 100644
--- a/drivers/gpu/drm/xe/Kconfig
+++ b/drivers/gpu/drm/xe/Kconfig
@@ -5,6 +5,7 @@ config DRM_XE
depends on KUNIT || !KUNIT
depends on INTEL_VSEC || !INTEL_VSEC
depends on X86_PLATFORM_DEVICES || !(X86 && ACPI)
+ depends on PAGE_SIZE_4KB || COMPILE_TEST || BROKEN
select INTERVAL_TREE
# we need shmfs for the swappable backing store, and in particular
# the shmem_readpage() which depends upon tmpfs
--
2.47.2
replace_fd() returns either a negative error number or the number of the
new file descriptor. The current code misinterprets any positive file
descriptor number as an error.
Only check for negative error numbers, so that __receive_sock() is called
correctly for valid file descriptors.
Fixes: 173817151b15 ("fs: Expand __receive_fd() to accept existing fd")
Fixes: 42eb0d54c08a ("fs: split receive_fd_replace from __receive_fd")
Cc: stable(a)vger.kernel.org
Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>
---
Untested, it stuck out while reading the code.
---
fs/file.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/file.c b/fs/file.c
index 6d2275c3be9c6967d16c75d1b6521f9b58980926..56c3a045121d8f43a54cf05e6ce1962f896339ac 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -1387,7 +1387,7 @@ int receive_fd_replace(int new_fd, struct file *file, unsigned int o_flags)
if (error)
return error;
error = replace_fd(new_fd, file, o_flags);
- if (error)
+ if (error < 0)
return error;
__receive_sock(file);
return new_fd;
---
base-commit: 89748acdf226fd1a8775ff6fa2703f8412b286c8
change-id: 20250801-fix-receive_fd_replace-7fdd5ce6532d
Best regards,
--
Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>
The ring buffer size varies across VMBus channels. The size of sysfs
node for the ring buffer is currently hardcoded to 4 MB. Userspace
clients either use fstat() or hardcode this size for doing mmap().
To address this, make the sysfs node size dynamic to reflect the
actual ring buffer size for each channel. This will ensure that
fstat() on ring sysfs node always returns the correct size of
ring buffer.
This is a backport of the upstream commit
65995e97a1ca ("Drivers: hv: Make the sysfs node size for the ring buffer dynamic")
with modifications, as the original patch has missing dependencies on
kernel v6.12.x. The structure "struct attribute_group" does not have
bin_size field in v6.12.x kernel so the logic of configuring size of
sysfs node for ring buffer has been moved to
vmbus_chan_bin_attr_is_visible().
Original change was not a fix, but it needs to be backported to fix size
related discrepancy caused by the commit mentioned in Fixes tag.
Fixes: bf1299797c3c ("uio_hv_generic: Align ring size to system page")
Cc: <stable(a)vger.kernel.org> # 6.12.x
Signed-off-by: Naman Jain <namjain(a)linux.microsoft.com>
---
This change won't apply on older kernels currently due to missing
dependencies. I will take care of them after this goes in.
I did not retain any Reviewed-by or Tested-by tags, since the code has
changed completely, while the functionality remains same.
Requesting Michael, Dexuan, Wei to please review again.
---
drivers/hv/vmbus_drv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 1f519e925f06..616e63fb2f15 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1810,7 +1810,6 @@ static struct bin_attribute chan_attr_ring_buffer = {
.name = "ring",
.mode = 0600,
},
- .size = 2 * SZ_2M,
.mmap = hv_mmap_ring_buffer_wrapper,
};
static struct attribute *vmbus_chan_attrs[] = {
@@ -1866,6 +1865,7 @@ static umode_t vmbus_chan_bin_attr_is_visible(struct kobject *kobj,
/* Hide ring attribute if channel's ring_sysfs_visible is set to false */
if (attr == &chan_attr_ring_buffer && !channel->ring_sysfs_visible)
return 0;
+ attr->size = channel->ringbuffer_pagecount << PAGE_SHIFT;
return attr->attr.mode;
}
--
2.34.1