Slimbus devices can be allocated dynamically upon reception of
report-present messages.
Make sure to drop the reference taken when looking up already registered
devices.
Note that this requires taking an extra reference in case the device has
not yet been registered and has to be allocated.
Fixes: 46a2bb5a7f7e ("slimbus: core: Add slim controllers support")
Cc: stable(a)vger.kernel.org # 4.16
Signed-off-by: Johan Hovold <johan(a)kernel.org>
---
drivers/slimbus/core.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/slimbus/core.c b/drivers/slimbus/core.c
index 9f85c4280171..b4ab9a5d44b3 100644
--- a/drivers/slimbus/core.c
+++ b/drivers/slimbus/core.c
@@ -379,6 +379,8 @@ struct slim_device *slim_get_device(struct slim_controller *ctrl,
sbdev = slim_alloc_device(ctrl, e_addr, NULL);
if (!sbdev)
return ERR_PTR(-ENOMEM);
+
+ get_device(&sbdev->dev);
}
return sbdev;
@@ -505,6 +507,7 @@ int slim_device_report_present(struct slim_controller *ctrl,
ret = slim_device_alloc_laddr(sbdev, true);
}
+ put_device(&sbdev->dev);
out_put_rpm:
pm_runtime_mark_last_busy(ctrl->dev);
pm_runtime_put_autosuspend(ctrl->dev);
--
2.51.2
The current UFS clocks does not align with their respective names,
causing the ref_clk to be set to an incorrect frequency as below,
which results in command timeouts.
ufshcd-qcom 1d84000.ufshc: invalid ref_clk setting = 300000000
This commit fixes the issue by properly reordering the UFS clocks to
match their names.
Fixes: ea172f61f4fd ("arm64: dts: qcom: qcs615: Fix up UFS clocks")
Cc: stable(a)vger.kernel.org
Signed-off-by: Pradeep P V K <pradeep.pragallapati(a)oss.qualcomm.com>
---
arch/arm64/boot/dts/qcom/talos.dtsi | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/boot/dts/qcom/talos.dtsi b/arch/arm64/boot/dts/qcom/talos.dtsi
index d1dbfa3bd81c..95d26e313622 100644
--- a/arch/arm64/boot/dts/qcom/talos.dtsi
+++ b/arch/arm64/boot/dts/qcom/talos.dtsi
@@ -1399,10 +1399,10 @@
<&gcc GCC_AGGRE_UFS_PHY_AXI_CLK>,
<&gcc GCC_UFS_PHY_AHB_CLK>,
<&gcc GCC_UFS_PHY_UNIPRO_CORE_CLK>,
- <&gcc GCC_UFS_PHY_ICE_CORE_CLK>,
<&rpmhcc RPMH_CXO_CLK>,
<&gcc GCC_UFS_PHY_TX_SYMBOL_0_CLK>,
- <&gcc GCC_UFS_PHY_RX_SYMBOL_0_CLK>;
+ <&gcc GCC_UFS_PHY_RX_SYMBOL_0_CLK>,
+ <&gcc GCC_UFS_PHY_ICE_CORE_CLK>;
clock-names = "core_clk",
"bus_aggr_clk",
"iface_clk",
--
2.17.1
# TL;DR
previous discussion: https://lore.kernel.org/linux-mm/20250921232709.1608699-1-harry.yoo@oracle.…
A "bad pmd" error occurs due to race condition between
change_prot_numa() and THP migration. The mainline kernel does not have
this bug as commit 670ddd8cdc fixes the race condition. 6.1.y, 5.15.y,
5.10.y, 5.4.y are affected by this bug.
Fixing this in -stable kernels is tricky because pte_map_offset_lock()
has different semantics in pre-6.5 and post-6.5 kernels. I am trying to
backport the same mechanism we have in the mainline kernel.
# Testing
I verified that the bug described below is not reproduced anymore
(on a downstream kernel) after applying this patch series. It used to
trigger in few days of intensive numa balancing testing, but it survived
2 weeks with this applied.
# Bug Description
It was reported that a bad pmd is seen when automatic NUMA
balancing is marking page table entries as prot_numa:
[2437548.196018] mm/pgtable-generic.c:50: bad pmd 00000000af22fc02(dffffffe71fbfe02)
[2437548.235022] Call Trace:
[2437548.238234] <TASK>
[2437548.241060] dump_stack_lvl+0x46/0x61
[2437548.245689] panic+0x106/0x2e5
[2437548.249497] pmd_clear_bad+0x3c/0x3c
[2437548.253967] change_pmd_range.isra.0+0x34d/0x3a7
[2437548.259537] change_p4d_range+0x156/0x20e
[2437548.264392] change_protection_range+0x116/0x1a9
[2437548.269976] change_prot_numa+0x15/0x37
[2437548.274774] task_numa_work+0x1b8/0x302
[2437548.279512] task_work_run+0x62/0x95
[2437548.283882] exit_to_user_mode_loop+0x1a4/0x1a9
[2437548.289277] exit_to_user_mode_prepare+0xf4/0xfc
[2437548.294751] ? sysvec_apic_timer_interrupt+0x34/0x81
[2437548.300677] irqentry_exit_to_user_mode+0x5/0x25
[2437548.306153] asm_sysvec_apic_timer_interrupt+0x16/0x1b
This is due to a race condition between change_prot_numa() and
THP migration because the kernel doesn't check is_swap_pmd() and
pmd_trans_huge() atomically:
change_prot_numa() THP migration
======================================================================
- change_pmd_range()
-> is_swap_pmd() returns false,
meaning it's not a PMD migration
entry.
- do_huge_pmd_numa_page()
-> migrate_misplaced_page() sets
migration entries for the THP.
- change_pmd_range()
-> pmd_none_or_clear_bad_unless_trans_huge()
-> pmd_none() and pmd_trans_huge() returns false
- pmd_none_or_clear_bad_unless_trans_huge()
-> pmd_bad() returns true for the migration entry!
The upstream commit 670ddd8cdcbd ("mm/mprotect: delete
pmd_none_or_clear_bad_unless_trans_huge()") closes this race condition
by checking is_swap_pmd() and pmd_trans_huge() atomically.
# Backporting note
commit a79390f5d6a7 ("mm/mprotect: use long for page accountings and retval")
is backported to return an error code (negative value) in
change_pte_range().
Unlike the mainline, pte_offset_map_lock() does not check if the pmd
entry is a migration entry or a hugepage; acquires PTL unconditionally
instead of returning failure. Therefore, it is necessary to keep the
!is_swap_pmd() && !pmd_trans_huge() && !pmd_devmap() checks in
change_pmd_range() before acquiring the PTL.
After acquiring the lock, open-code the semantics of
pte_offset_map_lock() in the mainline kernel; change_pte_range() fails
if the pmd value has changed. This requires adding pmd_old parameter
(pmd_t value that is read before calling the function) to
change_pte_range().
Hugh Dickins (1):
mm/mprotect: delete pmd_none_or_clear_bad_unless_trans_huge()
Peter Xu (1):
mm/mprotect: use long for page accountings and retval
include/linux/hugetlb.h | 4 +-
include/linux/mm.h | 2 +-
mm/hugetlb.c | 4 +-
mm/mempolicy.c | 2 +-
mm/mprotect.c | 121 ++++++++++++++++++----------------------
5 files changed, 59 insertions(+), 74 deletions(-)
--
2.43.0
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 0d6c356dd6547adac2b06b461528e3573f52d953
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112033-overstep-denim-0e6a@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0d6c356dd6547adac2b06b461528e3573f52d953 Mon Sep 17 00:00:00 2001
From: "Isaac J. Manjarres" <isaacmanjarres(a)google.com>
Date: Tue, 28 Oct 2025 12:10:12 -0700
Subject: [PATCH] mm/mm_init: fix hash table order logging in
alloc_large_system_hash()
When emitting the order of the allocation for a hash table,
alloc_large_system_hash() unconditionally subtracts PAGE_SHIFT from log
base 2 of the allocation size. This is not correct if the allocation size
is smaller than a page, and yields a negative value for the order as seen
below:
TCP established hash table entries: 32 (order: -4, 256 bytes, linear) TCP
bind hash table entries: 32 (order: -2, 1024 bytes, linear)
Use get_order() to compute the order when emitting the hash table
information to correctly handle cases where the allocation size is smaller
than a page:
TCP established hash table entries: 32 (order: 0, 256 bytes, linear) TCP
bind hash table entries: 32 (order: 0, 1024 bytes, linear)
Link: https://lkml.kernel.org/r/20251028191020.413002-1-isaacmanjarres@google.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Isaac J. Manjarres <isaacmanjarres(a)google.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org>
Reviewed-by: David Hildenbrand <david(a)redhat.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 3db2dea7db4c..7712d887b696 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -2469,7 +2469,7 @@ void *__init alloc_large_system_hash(const char *tablename,
panic("Failed to allocate %s hash table\n", tablename);
pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
- tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size,
+ tablename, 1UL << log2qty, get_order(size), size,
virt ? (huge ? "vmalloc hugepage" : "vmalloc") : "linear");
if (_hash_shift)