* Re: [PATCH v3 15/16] userfaultfd.2: Add read-write protect mode
From: Mike Rapoport @ 2026-05-23 10:37 UTC (permalink / raw)
To: Kiryl Shutsemau
Cc: akpm, peterx, david, ljs, surenb, vbabka, Liam.Howlett, ziy,
corbet, skhan, seanjc, pbonzini, jthoughton, aarcange, sj,
usama.arif, linux-mm, linux-kernel, linux-doc, linux-kselftest,
kvm, kernel-team, linux-man, alx, Kiryl Shutsemau (Meta)
In-Reply-To: <20260522133857.552279-16-kirill@shutemov.name>
On Fri, May 22, 2026 at 02:38:56PM +0100, Kiryl Shutsemau wrote:
> From: "Kiryl Shutsemau (Meta)" <kas@kernel.org>
>
> Read-write protect mode (UFFDIO_REGISTER_MODE_RWP) is supported starting
> from Linux 7.2. It traps every access -- read or write -- to a present
> page within a registered range. The matching UAPI consists of:
>
> - UFFDIO_REGISTER_MODE_RWP registration-mode bit
> - UFFD_FEATURE_RWP capability bit
> - UFFD_FEATURE_RWP_ASYNC async (in-kernel) fault resolution
> - UFFDIO_RWPROTECT install / remove RWP on a range
> - UFFDIO_SET_MODE runtime sync/async toggle
> - UFFD_PAGEFAULT_FLAG_RWP new pagefault.flags bit
>
> Document the new registration-mode entry, the "Userfaultfd read-write
> protect mode" section, the new pagefault flag, and a VERSIONS line.
>
> Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
> ---
> man2/userfaultfd.2 | 147 ++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 146 insertions(+), 1 deletion(-)
This doesn't apply to the current man-pages tree
https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git
and reading raw groff hurts eyes too much.
What linux-man tree did you use to generate those?
--
Sincerely yours,
Mike.
^ permalink raw reply
* Re: [PATCH v3 14/16] Documentation/userfaultfd: document RWP working set tracking
From: Mike Rapoport @ 2026-05-23 10:30 UTC (permalink / raw)
To: Kiryl Shutsemau
Cc: akpm, peterx, david, ljs, surenb, vbabka, Liam.Howlett, ziy,
corbet, skhan, seanjc, pbonzini, jthoughton, aarcange, sj,
usama.arif, linux-mm, linux-kernel, linux-doc, linux-kselftest,
kvm, kernel-team, linux-man, alx, Kiryl Shutsemau (Meta)
In-Reply-To: <20260522133857.552279-15-kirill@shutemov.name>
On Fri, May 22, 2026 at 02:38:55PM +0100, Kiryl Shutsemau wrote:
> From: "Kiryl Shutsemau (Meta)" <kas@kernel.org>
>
> Add an admin-guide section covering UFFDIO_REGISTER_MODE_RWP:
>
> - sync and async fault models;
> - UFFDIO_RWPROTECT semantics;
> - UFFD_FEATURE_RWP_ASYNC;
> - UFFDIO_SET_MODE runtime mode flips.
>
> It also covers typical VMM working-set-tracking workflow from detection
> loop through sync-mode eviction and back to async.
>
> Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
> Assisted-by: Claude:claude-opus-4-6
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
with some nits below
> ---
> Documentation/admin-guide/mm/userfaultfd.rst | 226 ++++++++++++++++++-
> 1 file changed, 220 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/admin-guide/mm/userfaultfd.rst b/Documentation/admin-guide/mm/userfaultfd.rst
> index 1e533639fd50..cb5d0e0c9fff 100644
> --- a/Documentation/admin-guide/mm/userfaultfd.rst
> +++ b/Documentation/admin-guide/mm/userfaultfd.rst
...
> The user app can collect the "written/dirty" status by looking up the
> -uffd-wp bit for the pages being interested in /proc/pagemap.
> +uffd bit for the pages being interested in /proc/pagemap.
It's pre-existing, but "being interested" sounds weird to me
Maybe let's change "being interested" to "of interest" or "the app is
interested in".
> -The page will not be under track of uffd-wp async mode until the page is
> +The page will not be under track of userfaultfd-wp async mode until the page is
Here as well I'd s/will not be under track of/will not be tracked by/
> explicitly write-protected by ``ioctl(UFFDIO_WRITEPROTECT)`` with the mode
> flag ``UFFDIO_WRITEPROTECT_MODE_WP`` set. Trying to resolve a page fault
> that was tracked by async mode userfaultfd-wp is invalid.
> @@ -307,6 +307,220 @@ transparent to the guest, we want that same address range to act as if it was
> still poisoned, even though it's on a new physical host which ostensibly
> doesn't have a memory error in the exact same spot.
>
> +Read-Write Protection
> +---------------------
...
> +**Setup:**
> +
> +1. Open a userfaultfd and enable ``UFFD_FEATURE_RWP`` via ``UFFDIO_API``.
> + Optionally request ``UFFD_FEATURE_RWP_ASYNC`` as well — it requires
> + ``UFFD_FEATURE_RWP`` to be set in the same ``UFFDIO_API`` call.
> +
> +2. Register the guest memory range with ``UFFDIO_REGISTER_MODE_RWP``
> + (and ``UFFDIO_REGISTER_MODE_MISSING`` if evicted pages will need to be
> + fetched back from storage).
I'd make it
2. Register the guest memory range with ``UFFDIO_REGISTER_MODE_RWP``.
Add ``UFFDIO_REGISTER_MODE_MISSING`` if evicted pages will need to be
fetched back from storage.
--
Sincerely yours,
Mike.
^ permalink raw reply
* Re: [PATCH v3 13/16] selftests/mm: add userfaultfd RWP tests
From: Mike Rapoport @ 2026-05-23 10:07 UTC (permalink / raw)
To: Kiryl Shutsemau
Cc: akpm, peterx, david, ljs, surenb, vbabka, Liam.Howlett, ziy,
corbet, skhan, seanjc, pbonzini, jthoughton, aarcange, sj,
usama.arif, linux-mm, linux-kernel, linux-doc, linux-kselftest,
kvm, kernel-team, linux-man, alx, Kiryl Shutsemau (Meta)
In-Reply-To: <20260522133857.552279-14-kirill@shutemov.name>
On Fri, May 22, 2026 at 02:38:54PM +0100, Kiryl Shutsemau wrote:
> From: "Kiryl Shutsemau (Meta)" <kas@kernel.org>
>
> Coverage for UFFDIO_REGISTER_MODE_RWP and UFFDIO_RWPROTECT:
>
> rwp-async async mode — touch pages, verify permissions are
> auto-restored without a message
> rwp-sync sync mode — access blocks, handler resolves via
> UFFDIO_RWPROTECT
> rwp-pagemap PAGEMAP_SCAN reports still-cold pages via
> inverted PAGE_IS_ACCESSED
> rwp-mprotect RWP survives mprotect(PROT_NONE) ->
> mprotect(PROT_READ|PROT_WRITE) round-trip
> rwp-gup GUP walks through a protnone RWP PTE (pipe
> write/read drives the GUP path)
> rwp-async-toggle UFFDIO_SET_MODE flips between sync and async
> without re-registering
> rwp-close closing the uffd restores page permissions
> rwp-fork RWP survives fork() with EVENT_FORK; child's
> PTEs keep the uffd bit
> rwp-fork-pin RWP survives fork() on an RO-longterm-pinned
> anon page (forces copy_present_page()); child
> read auto-resolves and clears the bit, proving
> PAGE_NONE was in place
> rwp-wp-exclusive register with MODE_WP|MODE_RWP returns -EINVAL
>
> All tests run against anon, shmem, shmem-private, hugetlb, and
> hugetlb-private memory, except rwp-fork-pin which is anon-only —
> copy_present_page() is the private-anon pinned-exclusive fork path.
>
> Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
> Assisted-by: Claude:claude-opus-4-6
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---
> tools/testing/selftests/mm/uffd-unit-tests.c | 766 +++++++++++++++++++
> 1 file changed, 766 insertions(+)
--
Sincerely yours,
Mike.
^ permalink raw reply
* Re: [PATCH v3 05/16] mm: add MM_CP_UFFD_RWP change_protection() flag
From: Mike Rapoport @ 2026-05-23 10:03 UTC (permalink / raw)
To: Kiryl Shutsemau
Cc: akpm, peterx, david, ljs, surenb, vbabka, Liam.Howlett, ziy,
corbet, skhan, seanjc, pbonzini, jthoughton, aarcange, sj,
usama.arif, linux-mm, linux-kernel, linux-doc, linux-kselftest,
kvm, kernel-team, linux-man, alx, Kiryl Shutsemau (Meta)
In-Reply-To: <20260522133857.552279-6-kirill@shutemov.name>
On Fri, May 22, 2026 at 02:38:46PM +0100, Kiryl Shutsemau wrote:
> From: "Kiryl Shutsemau (Meta)" <kas@kernel.org>
>
> Preparatory patch. Add the change_protection() primitive that
> userfaultfd RWP will use.
>
> An RWP-protected PTE is PAGE_NONE with the uffd PTE bit set. The
> PROT_NONE half makes the CPU fault on any access; the uffd bit
> distinguishes an RWP fault from a plain mprotect(PROT_NONE) or NUMA
> hinting fault. MM_CP_UFFD_WP and MM_CP_UFFD_RWP share the same PTE
> bit, so the two cannot be used together on the same range.
>
> Two new change_protection() flags:
>
> MM_CP_UFFD_RWP install PAGE_NONE and set the uffd bit
> MM_CP_UFFD_RWP_RESOLVE restore vma->vm_page_prot, clear the uffd bit
>
> Both are wired through change_pte_range(), change_huge_pmd(), and
> hugetlb_change_protection() so anon, shmem, THP, and hugetlb all
> share the same semantics.
>
> Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
> Assisted-by: Claude:claude-opus-4-6
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
> ---
> include/linux/mm.h | 5 ++++
> include/linux/userfaultfd_k.h | 1 -
> mm/huge_memory.c | 30 +++++++++++++----------
> mm/hugetlb.c | 25 ++++++++++++++-----
> mm/mprotect.c | 46 +++++++++++++++++++++++++++--------
> 5 files changed, 77 insertions(+), 30 deletions(-)
--
Sincerely yours,
Mike.
^ permalink raw reply
* [PATCH 2/2] docs/zh_TW: update DAMON usage sysfs documentation
From: Doehyun Baek @ 2026-05-23 9:44 UTC (permalink / raw)
To: Alex Shi, Yanteng Si, Hu Haowen
Cc: Dongliang Mu, Jonathan Corbet, Shuah Khan, SeongJae Park,
linux-doc, linux-kernel, damon, Doehyun Baek
In-Reply-To: <20260523094420.741003-1-doehyunbaek@gmail.com>
The DAMON usage documentation translation is missing recent sysfs
interface updates that are already documented in the English version,
including refresh_ms, addr_unit, obsolete_target, goal_tuner, nid, and
max_nr_snapshots.
Update the Traditional Chinese translation for those stale sysfs entries.
Signed-off-by: Doehyun Baek <doehyunbaek@gmail.com>
---
.../zh_TW/admin-guide/mm/damon/usage.rst | 56 +++++++++++++------
1 file changed, 40 insertions(+), 16 deletions(-)
diff --git a/Documentation/translations/zh_TW/admin-guide/mm/damon/usage.rst b/Documentation/translations/zh_TW/admin-guide/mm/damon/usage.rst
index d3fd4f850793..debe455723af 100644
--- a/Documentation/translations/zh_TW/admin-guide/mm/damon/usage.rst
+++ b/Documentation/translations/zh_TW/admin-guide/mm/damon/usage.rst
@@ -15,6 +15,10 @@
DAMON 爲不同的用戶提供了下面這些接口。
+- *專用DAMON模塊。*
+ :ref:`這 <damon_modules_special_purpose>` 是爲構建、發佈或管理帶有專用DAMON用法的內
+ 核的用戶準備的。使用它，用戶可以在構建、啓動或運行時以簡單的方式爲給定目的使用DAMON的主要
+ 功能。
- *DAMON用戶空間工具。*
`這 <https://github.com/damonitor/damo>`_ 爲有這特權的人， 如系統管理員，希望有一個剛好
可以工作的人性化界面。
@@ -55,14 +59,14 @@ DAMON sysfs接口的文件層次結構如下圖所示。在下圖中，父子關
/sys/kernel/mm/damon/admin
│ kdamonds/nr_kdamonds
- │ │ 0/state,pid
+ │ │ 0/state,pid,refresh_ms
│ │ │ contexts/nr_contexts
- │ │ │ │ 0/operations
+ │ │ │ │ 0/operations,addr_unit
│ │ │ │ │ monitoring_attrs/
│ │ │ │ │ │ intervals/sample_us,aggr_us,update_us
│ │ │ │ │ │ nr_regions/min,max
│ │ │ │ │ targets/nr_targets
- │ │ │ │ │ │ 0/pid_target
+ │ │ │ │ │ │ 0/pid_target,obsolete_target
│ │ │ │ │ │ │ regions/nr_regions
│ │ │ │ │ │ │ │ 0/start,end
│ │ │ │ │ │ │ │ ...
@@ -73,10 +77,12 @@ DAMON sysfs接口的文件層次結構如下圖所示。在下圖中，父子關
│ │ │ │ │ │ │ │ sz/min,max
│ │ │ │ │ │ │ │ nr_accesses/min,max
│ │ │ │ │ │ │ │ age/min,max
- │ │ │ │ │ │ │ quotas/ms,bytes,reset_interval_ms
+ │ │ │ │ │ │ │ quotas/ms,bytes,reset_interval_ms,goal_tuner
│ │ │ │ │ │ │ │ weights/sz_permil,nr_accesses_permil,age_permil
+ │ │ │ │ │ │ │ │ goals/nr_goals
+ │ │ │ │ │ │ │ │ │ 0/target_metric,target_value,current_value,nid
│ │ │ │ │ │ │ watermarks/metric,interval_us,high,mid,low
- │ │ │ │ │ │ │ stats/nr_tried,sz_tried,nr_applied,sz_applied,qt_exceeds
+ │ │ │ │ │ │ │ stats/nr_tried,sz_tried,nr_applied,sz_applied,qt_exceeds,nr_snapshots,max_nr_snapshots
│ │ │ │ │ │ │ tried_regions/
│ │ │ │ │ │ │ │ 0/start,end,nr_accesses,age
│ │ │ │ │ │ │ │ ...
@@ -104,7 +110,8 @@ kdamonds/
kdamonds/<N>/
-------------
-在每個kdamond目錄中，存在兩個文件（``state`` 和 ``pid`` ）和一個目錄( ``contexts`` )。
+在每個kdamond目錄中，存在三個文件（``state``、``pid`` 和 ``refresh_ms``）和一個目錄
+(``contexts``)。
讀取 ``state`` 時，如果kdamond當前正在運行，則返回 ``on`` ，如果沒有運行則返回 ``off`` 。
寫入 ``on`` 或 ``off`` 使kdamond處於狀態。向 ``state`` 文件寫 ``update_schemes_stats`` ，
@@ -117,6 +124,10 @@ kdamonds/<N>/
如果狀態爲 ``on``，讀取 ``pid`` 顯示kdamond線程的pid。
+用戶可以要求內核通過 ``refresh_ms`` 文件週期性地更新顯示自動調優參數和DAMOS統計信息的文件。
+向該文件寫入希望的更新時間間隔（毫秒）。如果間隔爲零，則禁用週期性更新。讀取該文件會顯示當前
+設置的時間間隔。
+
``contexts`` 目錄包含控制這個kdamond要執行的監測上下文的文件。
kdamonds/<N>/contexts/
@@ -129,8 +140,8 @@ kdamonds/<N>/contexts/
contexts/<N>/
-------------
-在每個上下文目錄中，存在一個文件(``operations``)和三個目錄(``monitoring_attrs``,
-``targets``, 和 ``schemes``)。
+在每個上下文目錄中，存在兩個文件（``operations`` 和 ``addr_unit``）和三個目錄
+（``monitoring_attrs``、``targets`` 和 ``schemes``）。
DAMON支持多種類型的監測操作，包括對虛擬地址空間和物理地址空間的監測。你可以通過向文件
中寫入以下關鍵詞之一，並從文件中讀取，來設置和獲取DAMON將爲上下文使用何種類型的監測操作。
@@ -138,6 +149,8 @@ DAMON支持多種類型的監測操作，包括對虛擬地址空間和物理地
- vaddr: 監測特定進程的虛擬地址空間
- paddr: 監視系統的物理地址空間
+``addr_unit`` 文件用於設置和獲取操作集的 :ref:`地址單位 <damon_design_addr_unit>` 參數。
+
contexts/<N>/monitoring_attrs/
------------------------------
@@ -161,11 +174,15 @@ contexts/<N>/targets/
targets/<N>/
------------
-在每個目標目錄中，存在一個文件(``pid_target``)和一個目錄(``regions``)。
+在每個目標目錄中，存在兩個文件（``pid_target`` 和 ``obsolete_target``）和一個目錄
+（``regions``）。
如果你把 ``vaddr`` 寫到 ``contexts/<N>/operations`` 中，每個目標應該是一個進程。你
可以通過將進程的pid寫到 ``pid_target`` 文件中來指定DAMON的進程。
+用戶可以向 ``obsolete_target`` 文件寫入非零值並提交它（向 ``state`` 文件寫入 ``commit``），
+從目標數組中間選擇性地刪除目標。
+
targets/<N>/regions
-------------------
@@ -239,14 +256,20 @@ schemes/<N>/quotas/
當預計超過配額限制時，DAMON會根據 ``目標訪問模式`` 的大小、訪問頻率和年齡，對找到的內存區域
進行優先排序。爲了進行個性化的優先排序，用戶可以爲這三個屬性設置權重。
-在 ``quotas`` 目錄下，存在三個文件（``ms``, ``bytes``, ``reset_interval_ms``）和一個
-目錄(``weights``)，其中有三個文件(``sz_permil``, ``nr_accesses_permil``, 和
-``age_permil``)。
+在 ``quotas`` 目錄下，存在四個文件（``ms``、``bytes``、``reset_interval_ms`` 和
+``goal_tuner``）和兩個目錄（``weights`` 和 ``goals``）。
你可以設置以毫秒爲單位的 ``時間配額`` ，以字節爲單位的 ``大小配額`` ，以及以毫秒爲單位的 ``重
置間隔`` ，分別向這三個文件寫入數值。你還可以通過向 ``weights`` 目錄下的三個文件寫入數值來設
置大小、訪問頻率和年齡的優先權，單位爲千分之一。
+你可以通過向 ``goal_tuner`` 文件寫入算法名稱，設置要使用的基於目標的有效配額自動調優算法。
+讀取該文件會返回當前選定的調優器算法。
+
+``goals`` 目錄用於設置自動配額調優目標。每個目標目錄包含 ``target_metric``、
+``target_value``、``current_value`` 和 ``nid`` 文件。用戶可以讀寫這些文件來設置和獲取配額
+自動調優目標的參數。
+
schemes/<N>/watermarks/
-----------------------
@@ -271,10 +294,11 @@ schemes/<N>/stats/
DAMON統計每個方案被嘗試應用的區域的總數量和字節數，每個方案被成功應用的區域的兩個數字，以及
超過配額限制的總數量。這些統計數據可用於在線分析或調整方案。
-可以通過讀取 ``stats`` 目錄下的文件(``nr_tried``, ``sz_tried``, ``nr_applied``,
-``sz_applied``, 和 ``qt_exceeds``)）分別檢索這些統計數據。這些文件不是實時更新的，所以
-你應該要求DAMON sysfs接口通過在相關的 ``kdamonds/<N>/state`` 文件中寫入一個特殊的關鍵字
-``update_schemes_stats`` 來更新統計信息的文件內容。
+可以通過讀取 ``stats`` 目錄下的文件（``nr_tried``、``sz_tried``、``nr_applied``、
+``sz_applied``、``qt_exceeds``、``nr_snapshots`` 和 ``max_nr_snapshots``）分別檢索這些
+統計數據。這些文件默認不是實時更新的。你應該要求DAMON sysfs接口通過 ``refresh_ms`` 週期性地
+更新這些文件，或者通過在相關的 ``kdamonds/<N>/state`` 文件中寫入一個特殊的關鍵字
+``update_schemes_stats`` 來執行一次性更新。
schemes/<N>/tried_regions/
--------------------------
--
2.43.0
^ permalink raw reply related
* [PATCH 1/2] docs/zh_CN: update DAMON usage sysfs documentation
From: Doehyun Baek @ 2026-05-23 9:44 UTC (permalink / raw)
To: Alex Shi, Yanteng Si, Hu Haowen
Cc: Dongliang Mu, Jonathan Corbet, Shuah Khan, SeongJae Park,
linux-doc, linux-kernel, damon, Doehyun Baek
In-Reply-To: <20260523094420.741003-1-doehyunbaek@gmail.com>
The DAMON usage documentation translation is missing recent sysfs
interface updates that are already documented in the English version,
including refresh_ms, addr_unit, obsolete_target, goal_tuner, nid, and
max_nr_snapshots.
Update the Simplified Chinese translation for those stale sysfs entries.
Signed-off-by: Doehyun Baek <doehyunbaek@gmail.com>
---
.../zh_CN/admin-guide/mm/damon/usage.rst | 56 +++++++++++++------
1 file changed, 40 insertions(+), 16 deletions(-)
diff --git a/Documentation/translations/zh_CN/admin-guide/mm/damon/usage.rst b/Documentation/translations/zh_CN/admin-guide/mm/damon/usage.rst
index 9d7cb51be493..3fbfa9df9935 100644
--- a/Documentation/translations/zh_CN/admin-guide/mm/damon/usage.rst
+++ b/Documentation/translations/zh_CN/admin-guide/mm/damon/usage.rst
@@ -15,6 +15,10 @@
DAMON 为不同的用户提供了下面这些接口。
+- *专用DAMON模块。*
+ :ref:`这 <damon_modules_special_purpose>` 是为构建、发布或管理带有专用DAMON用法的内
+ 核的用户准备的。使用它，用户可以在构建、启动或运行时以简单的方式为给定目的使用DAMON的主要
+ 功能。
- *DAMON用户空间工具。*
`这 <https://github.com/damonitor/damo>`_ 为有这特权的人， 如系统管理员，希望有一个刚好
可以工作的人性化界面。
@@ -55,14 +59,14 @@ DAMON sysfs接口的文件层次结构如下图所示。在下图中，父子关
/sys/kernel/mm/damon/admin
│ kdamonds/nr_kdamonds
- │ │ 0/state,pid
+ │ │ 0/state,pid,refresh_ms
│ │ │ contexts/nr_contexts
- │ │ │ │ 0/operations
+ │ │ │ │ 0/operations,addr_unit
│ │ │ │ │ monitoring_attrs/
│ │ │ │ │ │ intervals/sample_us,aggr_us,update_us
│ │ │ │ │ │ nr_regions/min,max
│ │ │ │ │ targets/nr_targets
- │ │ │ │ │ │ 0/pid_target
+ │ │ │ │ │ │ 0/pid_target,obsolete_target
│ │ │ │ │ │ │ regions/nr_regions
│ │ │ │ │ │ │ │ 0/start,end
│ │ │ │ │ │ │ │ ...
@@ -73,10 +77,12 @@ DAMON sysfs接口的文件层次结构如下图所示。在下图中，父子关
│ │ │ │ │ │ │ │ sz/min,max
│ │ │ │ │ │ │ │ nr_accesses/min,max
│ │ │ │ │ │ │ │ age/min,max
- │ │ │ │ │ │ │ quotas/ms,bytes,reset_interval_ms
+ │ │ │ │ │ │ │ quotas/ms,bytes,reset_interval_ms,goal_tuner
│ │ │ │ │ │ │ │ weights/sz_permil,nr_accesses_permil,age_permil
+ │ │ │ │ │ │ │ │ goals/nr_goals
+ │ │ │ │ │ │ │ │ │ 0/target_metric,target_value,current_value,nid
│ │ │ │ │ │ │ watermarks/metric,interval_us,high,mid,low
- │ │ │ │ │ │ │ stats/nr_tried,sz_tried,nr_applied,sz_applied,qt_exceeds
+ │ │ │ │ │ │ │ stats/nr_tried,sz_tried,nr_applied,sz_applied,qt_exceeds,nr_snapshots,max_nr_snapshots
│ │ │ │ │ │ │ tried_regions/
│ │ │ │ │ │ │ │ 0/start,end,nr_accesses,age
│ │ │ │ │ │ │ │ ...
@@ -104,7 +110,8 @@ kdamonds/
kdamonds/<N>/
-------------
-在每个kdamond目录中，存在两个文件（``state`` 和 ``pid`` ）和一个目录( ``contexts`` )。
+在每个kdamond目录中，存在三个文件（``state``、``pid`` 和 ``refresh_ms``）和一个目录
+(``contexts``)。
读取 ``state`` 时，如果kdamond当前正在运行，则返回 ``on`` ，如果没有运行则返回 ``off`` 。
写入 ``on`` 或 ``off`` 使kdamond处于状态。向 ``state`` 文件写 ``update_schemes_stats`` ，
@@ -117,6 +124,10 @@ kdamonds/<N>/
如果状态为 ``on``，读取 ``pid`` 显示kdamond线程的pid。
+用户可以要求内核通过 ``refresh_ms`` 文件周期性地更新显示自动调优参数和DAMOS统计信息的文件。
+向该文件写入希望的更新时间间隔（毫秒）。如果间隔为零，则禁用周期性更新。读取该文件会显示当前
+设置的时间间隔。
+
``contexts`` 目录包含控制这个kdamond要执行的监测上下文的文件。
kdamonds/<N>/contexts/
@@ -129,8 +140,8 @@ kdamonds/<N>/contexts/
contexts/<N>/
-------------
-在每个上下文目录中，存在一个文件(``operations``)和三个目录(``monitoring_attrs``,
-``targets``, 和 ``schemes``)。
+在每个上下文目录中，存在两个文件（``operations`` 和 ``addr_unit``）和三个目录
+（``monitoring_attrs``、``targets`` 和 ``schemes``）。
DAMON支持多种类型的监测操作，包括对虚拟地址空间和物理地址空间的监测。你可以通过向文件
中写入以下关键词之一，并从文件中读取，来设置和获取DAMON将为上下文使用何种类型的监测操作。
@@ -138,6 +149,8 @@ DAMON支持多种类型的监测操作，包括对虚拟地址空间和物理地
- vaddr: 监测特定进程的虚拟地址空间
- paddr: 监视系统的物理地址空间
+``addr_unit`` 文件用于设置和获取操作集的 :ref:`地址单位 <damon_design_addr_unit>` 参数。
+
contexts/<N>/monitoring_attrs/
------------------------------
@@ -161,11 +174,15 @@ contexts/<N>/targets/
targets/<N>/
------------
-在每个目标目录中，存在一个文件(``pid_target``)和一个目录(``regions``)。
+在每个目标目录中，存在两个文件（``pid_target`` 和 ``obsolete_target``）和一个目录
+（``regions``）。
如果你把 ``vaddr`` 写到 ``contexts/<N>/operations`` 中，每个目标应该是一个进程。你
可以通过将进程的pid写到 ``pid_target`` 文件中来指定DAMON的进程。
+用户可以向 ``obsolete_target`` 文件写入非零值并提交它（向 ``state`` 文件写入 ``commit``），
+从目标数组中间选择性地删除目标。
+
targets/<N>/regions
-------------------
@@ -239,14 +256,20 @@ schemes/<N>/quotas/
当预计超过配额限制时，DAMON会根据 ``目标访问模式`` 的大小、访问频率和年龄，对找到的内存区域
进行优先排序。为了进行个性化的优先排序，用户可以为这三个属性设置权重。
-在 ``quotas`` 目录下，存在三个文件（``ms``, ``bytes``, ``reset_interval_ms``）和一个
-目录(``weights``)，其中有三个文件(``sz_permil``, ``nr_accesses_permil``, 和
-``age_permil``)。
+在 ``quotas`` 目录下，存在四个文件（``ms``、``bytes``、``reset_interval_ms`` 和
+``goal_tuner``）和两个目录（``weights`` 和 ``goals``）。
你可以设置以毫秒为单位的 ``时间配额`` ，以字节为单位的 ``大小配额`` ，以及以毫秒为单位的 ``重
置间隔`` ，分别向这三个文件写入数值。你还可以通过向 ``weights`` 目录下的三个文件写入数值来设
置大小、访问频率和年龄的优先权，单位为千分之一。
+你可以通过向 ``goal_tuner`` 文件写入算法名称，设置要使用的基于目标的有效配额自动调优算法。
+读取该文件会返回当前选定的调优器算法。
+
+``goals`` 目录用于设置自动配额调优目标。每个目标目录包含 ``target_metric``、
+``target_value``、``current_value`` 和 ``nid`` 文件。用户可以读写这些文件来设置和获取配额
+自动调优目标的参数。
+
schemes/<N>/watermarks/
-----------------------
@@ -271,10 +294,11 @@ schemes/<N>/stats/
DAMON统计每个方案被尝试应用的区域的总数量和字节数，每个方案被成功应用的区域的两个数字，以及
超过配额限制的总数量。这些统计数据可用于在线分析或调整方案。
-可以通过读取 ``stats`` 目录下的文件(``nr_tried``, ``sz_tried``, ``nr_applied``,
-``sz_applied``, 和 ``qt_exceeds``)）分别检索这些统计数据。这些文件不是实时更新的，所以
-你应该要求DAMON sysfs接口通过在相关的 ``kdamonds/<N>/state`` 文件中写入一个特殊的关键字
-``update_schemes_stats`` 来更新统计信息的文件内容。
+可以通过读取 ``stats`` 目录下的文件（``nr_tried``、``sz_tried``、``nr_applied``、
+``sz_applied``、``qt_exceeds``、``nr_snapshots`` 和 ``max_nr_snapshots``）分别检索这些
+统计数据。这些文件默认不是实时更新的。你应该要求DAMON sysfs接口通过 ``refresh_ms`` 周期性地
+更新这些文件，或者通过在相关的 ``kdamonds/<N>/state`` 文件中写入一个特殊的关键字
+``update_schemes_stats`` 来执行一次性更新。
schemes/<N>/tried_regions/
--------------------------
--
2.43.0
^ permalink raw reply related
* [PATCH 0/2] docs/zh: update DAMON usage sysfs documentation
From: Doehyun Baek @ 2026-05-23 9:44 UTC (permalink / raw)
To: Alex Shi, Yanteng Si, Hu Haowen
Cc: Dongliang Mu, Jonathan Corbet, Shuah Khan, SeongJae Park,
linux-doc, linux-kernel, damon, Doehyun Baek
Hi,
The Simplified and Traditional Chinese DAMON usage translations are
missing selected updates that are already documented in the English file.
As a result, parts of the translated sysfs hierarchy and descriptions are
stale, and the translations also lack the newer introduction of DAMON's
special-purpose modules.
The gaps correspond to the following English documentation commits:
commit a7bb1e754559 ("Docs/admin-guide/mm/damon/usage: document 'nid' file")
commit e85e965bdbec ("Docs/admin-guide/mm/damon/usage: document refresh_ms file")
commit e0c725455fd5 ("Docs/admin-guide/mm/damon/usage: document addr_unit file")
commit e06469cdf1fd ("Docs/admin-guide/mm/damon/usage: document obsolete_target file")
commit 2584dd7496c5 ("Docs/admin-guide/mm/damon/usage: update for max_nr_snapshots")
commit 652fd06d20da ("Docs/admin-guide/mm/damon/usage: update stats update process for refresh_ms")
commit e7df7a0bfc90 ("Docs/admin-guide/mm/damon/usage: introduce DAMON modules at the beginning")
commit d9cfe515d36e ("Docs/admin-guide/mm/damon/usage: document goal_tuner sysfs file")
Update both translations only for those stale DAMON usage entries,
including refresh_ms, addr_unit, obsolete_target, goal_tuner, nid, and
max_nr_snapshots.
Doehyun Baek (2):
docs/zh_CN: update DAMON usage sysfs documentation
docs/zh_TW: update DAMON usage sysfs documentation
.../zh_CN/admin-guide/mm/damon/usage.rst | 56 +++++++++++++------
.../zh_TW/admin-guide/mm/damon/usage.rst | 56 +++++++++++++------
2 files changed, 80 insertions(+), 32 deletions(-)
base-commit: 79bd2dded182b1d458b18e62684b7f82ffc682e5
--
2.43.0
^ permalink raw reply
* [PATCH v2 24/24] dyndbg: improve section names
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
change __dyndbg to __dyndbg_descs
change __dyndbg_classes to __dyndbg_class_maps
this sets up for adding __dyndbg_class_users
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
include/asm-generic/dyndbg.lds.h | 14 +++++++-------
include/linux/dynamic_debug.h | 4 ++--
kernel/module/main.c | 2 +-
lib/dynamic_debug.c | 24 ++++++++++++------------
4 files changed, 22 insertions(+), 22 deletions(-)
diff --git a/include/asm-generic/dyndbg.lds.h b/include/asm-generic/dyndbg.lds.h
index 9d8951bef688..ec661f9f3793 100644
--- a/include/asm-generic/dyndbg.lds.h
+++ b/include/asm-generic/dyndbg.lds.h
@@ -3,16 +3,16 @@
#define __ASM_GENERIC_DYNDBG_LDS_H
#include <asm-generic/bounded_sections.lds.h>
-#define DYNDBG_SECTIONS() \
- BOUNDED_SECTION_BY(__dyndbg, ___dyndbg) \
- BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes)
+#define DYNDBG_SECTIONS() \
+ BOUNDED_SECTION_BY(__dyndbg_descs, ___dyndbg_descs) \
+ BOUNDED_SECTION_BY(__dyndbg_class_maps, ___dyndbg_class_maps)
#define MOD_DYNDBG_SECTIONS() \
- __dyndbg 0 : ALIGN(8) { \
- KEEP(*(__dyndbg)) \
+ __dyndbg_descs 0 : ALIGN(8) { \
+ KEEP(*(__dyndbg_descs)) \
} \
- __dyndbg_classes 0 : ALIGN(8) { \
- KEEP(*(__dyndbg_classes)) \
+ __dyndbg_class_maps 0 : ALIGN(8) { \
+ KEEP(*(__dyndbg_class_maps)) \
}
#endif /* __ASM_GENERIC_DYNDBG_LDS_H */
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index fe73aa27b350..206337af71e9 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -128,7 +128,7 @@ struct _ddebug_class_param {
#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \
static const char *_var##_classnames[] = { __VA_ARGS__ }; \
static struct _ddebug_class_map __aligned(8) __used \
- __section("__dyndbg_classes") _var = { \
+ __section("__dyndbg_class_maps") _var = { \
.mod = THIS_MODULE, \
.mod_name = KBUILD_MODNAME, \
.base = _base, \
@@ -168,7 +168,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
#define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt) \
static struct _ddebug __aligned(8) \
- __section("__dyndbg") name = { \
+ __section("__dyndbg_descs") name = { \
.modname = KBUILD_MODNAME, \
.function = __func__, \
.filename = __FILE__, \
diff --git a/kernel/module/main.c b/kernel/module/main.c
index c2b6e70f2e77..bd7899a91755 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2774,7 +2774,7 @@ static int find_module_sections(struct module *mod, struct load_info *info)
pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
#ifdef CONFIG_DYNAMIC_DEBUG_CORE
- mod->dyndbg_info.descs.start = section_objs(info, "__dyndbg_descriptors",
+ mod->dyndbg_info.descs.start = section_objs(info, "__dyndbg_descs",
sizeof(*mod->dyndbg_info.descs.start),
&mod->dyndbg_info.descs.len);
mod->dyndbg_info.maps.start = section_objs(info, "__dyndbg_class_maps",
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index b877f4c6d778..ce70cfee50c5 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -40,10 +40,10 @@
#include <rdma/ib_verbs.h>
-extern struct _ddebug __start___dyndbg[];
-extern struct _ddebug __stop___dyndbg[];
-extern struct _ddebug_class_map __start___dyndbg_classes[];
-extern struct _ddebug_class_map __stop___dyndbg_classes[];
+extern struct _ddebug __start___dyndbg_descs[];
+extern struct _ddebug __stop___dyndbg_descs[];
+extern struct _ddebug_class_map __start___dyndbg_class_maps[];
+extern struct _ddebug_class_map __stop___dyndbg_class_maps[];
struct ddebug_table {
struct list_head link;
@@ -1379,10 +1379,10 @@ static int __init dynamic_debug_init(void)
char *cmdline;
struct _ddebug_info di = {
- .descs.start = __start___dyndbg,
- .maps.start = __start___dyndbg_classes,
- .descs.len = __stop___dyndbg - __start___dyndbg,
- .maps.len = __stop___dyndbg_classes - __start___dyndbg_classes,
+ .descs.start = __start___dyndbg_descs,
+ .maps.start = __start___dyndbg_class_maps,
+ .descs.len = __stop___dyndbg_descs - __start___dyndbg_descs,
+ .maps.len = __stop___dyndbg_class_maps - __start___dyndbg_class_maps,
};
#ifdef CONFIG_MODULES
@@ -1393,7 +1393,7 @@ static int __init dynamic_debug_init(void)
}
#endif /* CONFIG_MODULES */
- if (&__start___dyndbg == &__stop___dyndbg) {
+ if (&__start___dyndbg_descs == &__stop___dyndbg_descs) {
if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
return 1;
@@ -1403,11 +1403,11 @@ static int __init dynamic_debug_init(void)
return 0;
}
- iter = iter_mod_start = __start___dyndbg;
+ iter = iter_mod_start = __start___dyndbg_descs;
modname = iter->modname;
i = mod_sites = mod_ct = 0;
- for (; iter < __stop___dyndbg; iter++, i++, mod_sites++) {
+ for (; iter < __stop___dyndbg_descs; iter++, i++, mod_sites++) {
if (strcmp(modname, iter->modname)) {
mod_ct++;
@@ -1431,7 +1431,7 @@ static int __init dynamic_debug_init(void)
goto out_err;
ddebug_init_success = 1;
- vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg section\n",
+ vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg_descs section\n",
i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),
(int)((i * sizeof(struct _ddebug)) >> 10));
--
2.54.0
^ permalink raw reply related
* [PATCH v2 23/24] dyndbg: change __dynamic_func_call_cls* macros into expressions
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
The Xe driver's XE_IOCTL_DBG macro calls drm_dbg() from inside an if
(expression). This breaks when CONFIG_DRM_USE_DYNAMIC_DEBUG=y because
the invoked macro has a do-while-0 wrapper, and is not an expression.
if (cond && (drm_dbg("expr-form"),1)) {
... do some more stuff
}
Fix for this usage by changing __dynamic_func_call_cls{,_no_desc}
macros into expressions, by replacing the do-while-0s with a ({ })
wrapper. In the common usage, the trailing ';' converts the
expression into a statement.
drm_dbg("statement form");
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2:
fix statement-expressions to return 0 (not void) like their respective fallbacks
1. Add 0; to __dynamic_func_call_cls
2. Add 0; to __dynamic_func_call_cls_no_desc
3. Convert the disabled fallback of dynamic_hex_dump from do { ... } while(0) to ({ ... 0; })
move RvB after SoB
---
include/linux/dynamic_debug.h | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 11ec40f488f3..fe73aa27b350 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -224,24 +224,26 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
* (|_cls): adds in _DPRINT_CLASS_DFLT as needed
* (|_no_desc): former gets callsite descriptor as 1st arg (for prdbgs)
*/
-#define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \
+#define __dynamic_func_call_cls(id, cls, fmt, func, ...) ({ \
DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
if (DYNAMIC_DEBUG_BRANCH(id)) { \
func(&id, ##__VA_ARGS__); \
__dynamic_dump_stack(id); \
} \
-} while (0)
+ 0; /* match no_printk return value */ \
+})
#define __dynamic_func_call(id, fmt, func, ...) \
__dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt, \
func, ##__VA_ARGS__)
-#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do { \
+#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) ({ \
DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
if (DYNAMIC_DEBUG_BRANCH(id)) { \
func(__VA_ARGS__); \
__dynamic_dump_stack(id); \
} \
-} while (0)
+ 0; /* match no_printk return value */ \
+})
#define __dynamic_func_call_no_desc(id, fmt, func, ...) \
__dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT, \
fmt, func, ##__VA_ARGS__)
@@ -321,10 +323,12 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
dev_no_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__)
#define dynamic_hex_dump(prefix_str, prefix_type, rowsize, \
groupsize, buf, len, ascii) \
- do { if (0) \
+({ \
+ if (0) \
print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, \
- rowsize, groupsize, buf, len, ascii); \
- } while (0)
+ rowsize, groupsize, buf, len, ascii); \
+ 0; \
+})
#endif /* CONFIG_DYNAMIC_DEBUG || (CONFIG_DYNAMIC_DEBUG_CORE && DYNAMIC_DEBUG_MODULE) */
--
2.54.0
^ permalink raw reply related
* [PATCH v2 22/24] selftests-dyndbg: add a dynamic_debug run_tests target
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Łukasz Bartosik, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
Add a selftest script for dynamic-debug. The config requires
CONFIG_TEST_DYNAMIC_DEBUG=m and CONFIG_TEST_DYNAMIC_DEBUG_SUBMOD=m,
which tacitly requires either CONFIG_DYNAMIC_DEBUG=y or
CONFIG_DYNAMIC_DEBUG_CORE=y
ATM this has just basic_tests(), which modify pr_debug() flags in the
builtin params module. This means they're available to manipulate and
observe the effects in "cat control".
This is backported from another feature branch; the support-fns (thx
Lukas) have unused features at the moment, they'll get used shortly.
The script enables simple virtme-ng testing:
[jimc@gandalf b0-ftrace]$ vrun_t
virtme-ng 1.32+115.g07b109d
doing: vng --name v6.14-rc4-60-gd5f48427de0c \
--user root -v -p 4 -a dynamic_debug.verbose=3 V=1 \
-- ../tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
virtme: waiting for virtiofsd to start
..
And add dynamic_debug to TARGETS, so `make run_tests` sees it properly
For the impatient, set TARGETS explicitly:
[root@v6 selftests]# make TARGETS=dynamic_debug run_tests
make[1]: Nothing to be done for 'all'.
TAP version 13
1..1
# timeout set to 45
# selftests: dynamic_debug: dyndbg_selftest.sh
# # BASIC_TESTS 95.422122] dyndbg: query 0: 0"=_" mod:*
...
NOTES
check KCONFIG_CONFIG to avoid silly fails
Several tests are dependent upon config choices. Lets avoid failing
where that is noise.
The KCONFIG_CONFIG var exists to convey the config-file around. If
the var names a file, read it and extract the relevant CONFIG items,
and use them to skip the dependent tests, thus avoiding the fails that
would follow, and the disruption to whatever CI is running these
selftests.
If the envar doesn't name a config-file, ".config" is assumed.
CONFIG_DYNAMIC_DEBUG=y:
basic-tests() and comma-terminator-tests() test for the presence of
the builtin pr_debugs in module/main.c, which I deemed stable and
therefore safe to count. That said, the test fails if only
CONFIG_DYNAMIC_DEBUG_CORE=y is set. It could be rewritten to test
against test-dynamic-debug.ko, but that just trades one config
dependence for another.
Co-developed-by: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2:
drop commit-msg mention of yet-to-be-submitted tests
move RvB after SoB
script fixups per sashiko review
1. CONFIG_DYNAMIC_DEBUG=y is set correctly.
2. All subshell captures $( ( ... ) 2>&1 ) are fixed.
3. All echo variables are safely quoted to prevent word-splitting.
4. Standardized on modern /sys/kernel/tracing/ paths.
5. exit $exp_exit_code correctly propagates failure status.
---
MAINTAINERS | 1 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/dynamic_debug/Makefile | 9 +
tools/testing/selftests/dynamic_debug/config | 8 +
.../selftests/dynamic_debug/dyndbg_selftest.sh | 257 +++++++++++++++++++++
5 files changed, 276 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index e87bfe2e9e62..3f1c7dd278d4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9083,6 +9083,7 @@ F: include/asm-generic/dyndbg.lds.h
F: include/linux/dynamic_debug.h
F: lib/dynamic_debug.c
F: lib/test_dynamic_debug.c
+F: tools/testing/selftests/dynamic_debug/*
DYNAMIC INTERRUPT MODERATION
M: Tal Gilboa <talgi@nvidia.com>
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index 6e59b8f63e41..17c4ddbcee89 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -27,6 +27,7 @@ TARGETS += drivers/net/team
TARGETS += drivers/net/virtio_net
TARGETS += drivers/platform/x86/intel/ifs
TARGETS += dt
+TARGETS += dynamic_debug
TARGETS += efivarfs
TARGETS += exec
TARGETS += fchmodat2
diff --git a/tools/testing/selftests/dynamic_debug/Makefile b/tools/testing/selftests/dynamic_debug/Makefile
new file mode 100644
index 000000000000..6d06fa7f1040
--- /dev/null
+++ b/tools/testing/selftests/dynamic_debug/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# borrowed from Makefile for user memory selftests
+
+# No binaries, but make sure arg-less "make" doesn't trigger "run_tests"
+all:
+
+TEST_PROGS := dyndbg_selftest.sh
+
+include ../lib.mk
diff --git a/tools/testing/selftests/dynamic_debug/config b/tools/testing/selftests/dynamic_debug/config
new file mode 100644
index 000000000000..ec478b17873d
--- /dev/null
+++ b/tools/testing/selftests/dynamic_debug/config
@@ -0,0 +1,8 @@
+
+# basic tests ref the builtin params module
+CONFIG_DYNAMIC_DEBUG=y
+
+# more testing is possible with these,
+# but insisting on them here skips testing entirely for such configs
+# CONFIG_TEST_DYNAMIC_DEBUG=m
+# CONFIG_TEST_DYNAMIC_DEBUG_SUBMOD=m
diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
new file mode 100755
index 000000000000..01c035fe8c9a
--- /dev/null
+++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
@@ -0,0 +1,257 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-only
+
+V=${V:=0} # invoke as V=1 $0 for global verbose
+RED="\033[0;31m"
+GREEN="\033[0;32m"
+YELLOW="\033[0;33m"
+BLUE="\033[0;34m"
+MAGENTA="\033[0;35m"
+CYAN="\033[0;36m"
+NC="\033[0;0m"
+error_msg=""
+
+[ -e /proc/dynamic_debug/control ] || {
+ echo -e "${RED}: this test requires CONFIG_DYNAMIC_DEBUG=y ${NC}"
+ exit 0 # nothing to test here, no good reason to fail.
+}
+
+# need info to avoid failures due to untestable configs
+
+[ -f "$KCONFIG_CONFIG" ] || KCONFIG_CONFIG=".config"
+if [ -f "$KCONFIG_CONFIG" ]; then
+ echo "# consulting KCONFIG_CONFIG: $KCONFIG_CONFIG"
+ grep -q "CONFIG_DYNAMIC_DEBUG=y" $KCONFIG_CONFIG ; LACK_DD_BUILTIN=$?
+ grep -q "CONFIG_TEST_DYNAMIC_DEBUG=m" $KCONFIG_CONFIG ; LACK_TMOD=$?
+ grep -q "CONFIG_TEST_DYNAMIC_DEBUG_SUBMOD=m" $KCONFIG_CONFIG ; LACK_TMOD_SUBMOD=$?
+ if [ $V -eq 1 ]; then
+ echo LACK_DD_BUILTIN: $LACK_DD_BUILTIN
+ echo LACK_TMOD: $LACK_TMOD
+ echo LACK_TMOD_SUBMOD: $LACK_TMOD_SUBMOD
+ fi
+else
+ LACK_DD_BUILTIN=0
+ LACK_TMOD=0
+ LACK_TMOD_SUBMOD=0
+fi
+
+function vx () {
+ echo "$1" > /sys/module/dynamic_debug/parameters/verbose
+}
+
+function ddgrep () {
+ grep "$1" /proc/dynamic_debug/control
+}
+
+function doprints () {
+ cat /sys/module/test_dynamic_debug/parameters/do_prints
+}
+
+function ddcmd () {
+ exp_exit_code=0
+ num_args=$#
+ if [ "${@:$#}" = "pass" ]; then
+ num_args=$#-1
+ elif [ "${@:$#}" = "fail" ]; then
+ num_args=$#-1
+ exp_exit_code=1
+ fi
+ args=${@:1:$num_args}
+ output=$( (echo "$args" > /proc/dynamic_debug/control) 2>&1)
+ exit_code=$?
+ error_msg=$(echo "$output" | cut -d ":" -f 5 | sed -e 's/^[[:space:]]*//')
+ handle_exit_code $BASH_LINENO $FUNCNAME $exit_code $exp_exit_code
+}
+
+function handle_exit_code() {
+ local exp_exit_code=0
+ [ $# == 4 ] && exp_exit_code=$4
+ if [ $3 -ne $exp_exit_code ]; then
+ echo -e "${RED}: $BASH_SOURCE:$1 $2() expected to exit with code $exp_exit_code"
+ [ $3 == 1 ] && echo "Error: '$error_msg'"
+ exit $exp_exit_code
+ fi
+}
+
+# $1 - pattern to match, pattern in $1 is enclosed by spaces for a match ""\s$1\s"
+# $2 - number of times the pattern passed in $1 is expected to match
+# $3 - optional can be set either to "-r" or "-v"
+# "-r" means relaxed matching in this case pattern provided in $1 is passed
+# as is without enclosing it with spaces
+# "-v" prints matching lines
+# $4 - optional when $3 is set to "-r" then $4 can be used to pass "-v"
+function check_match_ct {
+ pattern="\s$1\s"
+ exp_cnt=0
+
+ [ "$3" == "-r" ] && pattern="$1"
+ let cnt=$(ddgrep "$pattern" | wc -l)
+ if [ $V -eq 1 ] || [ "$3" == "-v" ] || [ "$4" == "-v" ]; then
+ echo -ne "${BLUE}" && ddgrep $pattern && echo -ne "${NC}"
+ fi
+ [ $# -gt 1 ] && exp_cnt=$2
+ if [ $cnt -ne $exp_cnt ]; then
+ echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO check failed expected $exp_cnt on $1, got $cnt"
+ exit
+ else
+ echo ": $cnt matches on $1"
+ fi
+}
+
+# $1 - trace instance name
+# #2 - if > 0 then directory is expected to exist, if <= 0 then otherwise
+# $3 - "-v" for verbose
+function check_trace_instance_dir {
+ if [ -e /sys/kernel/tracing/instances/$1 ]; then
+ if [ "$3" == "-v" ] ; then
+ echo "ls -l /sys/kernel/tracing/instances/$1: "
+ ls -l /sys/kernel/tracing/instances/$1
+ fi
+ if [ $2 -le 0 ]; then
+ echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO error trace instance \
+ '/sys/kernel/tracing/instances/$1' does exist"
+ exit
+ fi
+ else
+ if [ $2 -gt 0 ]; then
+ echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO error trace instance \
+ '/sys/kernel/tracing/instances/$1' does not exist"
+ exit
+ fi
+ fi
+}
+
+function tmark {
+ echo $* > /sys/kernel/tracing/trace_marker
+}
+
+# $1 - trace instance name
+# $2 - line number
+# $3 - if > 0 then the instance is expected to be opened, otherwise
+# the instance is expected to be closed
+function check_trace_instance {
+ output=$(tail -n9 /proc/dynamic_debug/control | grep ": Opened trace instances" \
+ | xargs -n1 | grep $1)
+ if [ "$output" != $1 ] && [ $3 -gt 0 ]; then
+ echo -e "${RED}: $BASH_SOURCE:$2 trace instance $1 is not opened"
+ exit
+ fi
+ if [ "$output" == $1 ] && [ $3 -le 0 ]; then
+ echo -e "${RED}: $BASH_SOURCE:$2 trace instance $1 is not closed"
+ exit
+ fi
+}
+
+function is_trace_instance_opened {
+ check_trace_instance $1 $BASH_LINENO 1
+}
+
+function is_trace_instance_closed {
+ check_trace_instance $1 $BASH_LINENO 0
+}
+
+# $1 - trace instance directory to delete
+# $2 - if > 0 then directory is expected to be deleted successfully, if <= 0 then otherwise
+function del_trace_instance_dir() {
+ exp_exit_code=1
+ [ $2 -gt 0 ] && exp_exit_code=0
+ output=$( (rmdir /sys/kernel/tracing/instances/$1) 2>&1)
+ exit_code=$?
+ error_msg=$(echo "$output" | cut -d ":" -f 3 | sed -e 's/^[[:space:]]*//')
+ handle_exit_code $BASH_LINENO $FUNCNAME $exit_code $exp_exit_code
+}
+
+function error_log_ref {
+ # to show what I got
+ : echo "# error-log-ref: $1"
+ : echo cat \$2
+}
+
+function ifrmmod {
+ lsmod | grep $1 2>&1>/dev/null && rmmod $1
+}
+
+# $1 - text to search for
+function search_trace() {
+ search_trace_name 0 1 $1
+}
+
+# $1 - trace instance name, 0 for global event trace
+# $2 - line number counting from the bottom
+# $3 - text to search for
+function search_trace_name() {
+ if [ "$1" = "0" ]; then
+ buf=$(cat /sys/kernel/tracing/trace)
+ line=$(tail -$2 /sys/kernel/tracing/trace | head -1 | sed -e 's/^[[:space:]]*//')
+ else
+ buf=$(cat /sys/kernel/tracing/instances/$1/trace)
+ line=$(tail -$2 /sys/kernel/tracing/instances/$1/trace | head -1 | \
+ sed -e 's/^[[:space:]]*//')
+ fi
+ if [ $2 = 0 ]; then
+ # whole-buf check
+ output=$(echo "$buf" | grep "$3")
+ else
+ output=$(echo "$line" | grep "$3")
+ fi
+ if [ "$output" = "" ]; then
+ echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO search for '$3' failed \
+ in line '$line' or '$buf'"
+ exit
+ fi
+ if [ $V = 1 ]; then
+ echo -e "${MAGENTA}: search_trace_name in $1 found: \n$output \nin:${BLUE} $buf ${NC}"
+ fi
+}
+
+# $1 - error message to check
+function check_err_msg() {
+ if [ "$error_msg" != "$1" ]; then
+ echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO error message '$error_msg' \
+ does not match with '$1'"
+ exit
+ fi
+}
+
+function basic_tests {
+ echo -e "${GREEN}# BASIC_TESTS ${NC}"
+ if [ $LACK_DD_BUILTIN -eq 1 ]; then
+ echo "SKIP"
+ return
+ fi
+ ddcmd =_ # zero everything
+ check_match_ct =p 0
+
+ # module params are builtin to handle boot args
+ check_match_ct '\[params\]' 4 -r
+ ddcmd module params +mpf
+ check_match_ct =pmf 4
+
+ # multi-cmd input, newline separated, with embedded comments
+ cat <<"EOF" > /proc/dynamic_debug/control
+ module params =_ # clear params
+ module params +mf # set flags
+ module params func parse_args +sl # other flags
+EOF
+ check_match_ct =mf 3
+ check_match_ct =mfsl 1
+ ddcmd =_
+}
+
+tests_list=(
+ basic_tests
+)
+
+# Run tests
+
+ifrmmod test_dynamic_debug_submod
+ifrmmod test_dynamic_debug
+
+for test in "${tests_list[@]}"
+do
+ $test
+ echo ""
+done
+echo -en "${GREEN}# Done on: "
+date
+echo -en "${NC}"
--
2.54.0
^ permalink raw reply related
* [PATCH v2 21/24] dyndbg: hoist classmap-filter-by-modname up to ddebug_add_module
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
The body of ddebug_attach_module_classes() is just a code-block that
finds the contiguous subrange of classmaps matching on modname, and
saves it into the ddebug_table's info record.
Implement this block in a macro to accommodate different component
vectors in the "box" (as named in the for_subvec macro). We will
reuse this macro shortly.
And hoist its invocation out of ddebug_attach_module_classes() up into
ddebug_add_module(). This moves the filtering step up closer to
dynamic_debug_init(), which already segments the builtin pr_debug
descriptors on their mod_name boundaries.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2:
move RvB after SoB
finish hoist - drop old fn - ddebug_attach_module_classes
the v1 rev left the old ddebug_attach_module_classes in place, but it
is completely redundant now, since it already lost the list-linking
job it was doing.
It was being cut out later in the patchset (in the unsent API
adaptation phase), but for cleaner review, lets excise it now.
OLD all-in-1-series (pre split into reviewable chunks)
v10?- reordered params to match kdoc
v12- refactor/rename: s/dd_mark_vector_subrange/dd_set_module_subrange/
1. Renamed the macro from dd_mark_vector_subrange to
dd_set_module_subrange to better reflect its purpose of narrowing a
vector to a module-specific subrange.
2. Simplified the arguments by removing the redundant _dst, as the _di
pointer already provides access to the target _ddebug_info struct.
3. Refactored for Clarity: Instead of overwriting the struct's start
pointer while the for_subvec loop is using it to iterate, I
introduced a temporary __start variable. This avoids the "subtle"
side effect and makes the logic easier to follow.
4. Updated Documentation: Improved the comment block to explicitly
state that the macro scans for the first match and counts
contiguous elements.
---
lib/dynamic_debug.c | 65 +++++++++++++++++++++++++++--------------------------
1 file changed, 33 insertions(+), 32 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 4a9b9bc9efc5..b877f4c6d778 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -162,8 +162,8 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
}
static struct _ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
- const char *class_string,
- int *class_id)
+ const char *class_string,
+ int *class_id)
{
struct _ddebug_class_map *map;
int i, idx;
@@ -1166,34 +1166,34 @@ static const struct proc_ops proc_fops = {
.proc_write = ddebug_proc_write
};
-static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
-{
- struct _ddebug_class_map *cm;
- int i, nc = 0;
-
- /*
- * Find this module's classmaps in a subrange/wholerange of
- * the builtin/modular classmap vector/section. Save the start
- * and length of the subrange at its edges.
- */
- for_subvec(i, cm, di, maps) {
- if (!strcmp(cm->mod_name, dt->info.mod_name)) {
- if (!nc) {
- v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
- i, cm->mod_name, cm->base, cm->length, cm->map_type);
- dt->info.maps.start = cm;
- }
- nc++;
- } else if (nc) {
- /* end of matching classmaps */
- break;
- }
- }
- if (nc) {
- dt->info.maps.len = nc;
- vpr_info("module:%s attached %d classes\n", dt->info.mod_name, nc);
- }
-}
+/*
+ * Narrow a _ddebug_info's vector (@_vec) to the contiguous subrange
+ * of elements where ->mod_name matches @__di->mod_name.
+ *
+ * This scans the @_di->_vec for the first element matching the module
+ * name, and counts contiguous matches to define the subrange.
+ *
+ * @_i: caller-provided index var
+ * @_sp: cursor into @_vec
+ * @_di: pointer to the struct _ddebug_info to be narrowed
+ * @_vec: name of the vector member (must have .start and .len)
+ */
+#define dd_set_module_subrange(_i, _sp, _di, _vec) ({ \
+ struct _ddebug_info *__di = (_di); \
+ typeof(__di->_vec.start) __start = NULL; \
+ int __nc = 0; \
+ for_subvec(_i, _sp, __di, _vec) { \
+ if (!strcmp((_sp)->mod_name, __di->mod_name)) { \
+ if (!__nc++) \
+ __start = (_sp); \
+ } else if (__nc) { \
+ break; /* end of consecutive matches */ \
+ } \
+ } \
+ if (__nc) \
+ __di->_vec.start = __start; \
+ __di->_vec.len = __nc; \
+})
/*
* Allocate a new ddebug_table for the given module
@@ -1202,6 +1202,8 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
static int ddebug_add_module(struct _ddebug_info *di)
{
struct ddebug_table *dt;
+ struct _ddebug_class_map *cm;
+ int i;
if (!di->descs.len)
return 0;
@@ -1223,8 +1225,7 @@ static int ddebug_add_module(struct _ddebug_info *di)
INIT_LIST_HEAD(&dt->link);
- if (di->maps.len)
- ddebug_attach_module_classes(dt, di);
+ dd_set_module_subrange(i, cm, &dt->info, maps);
mutex_lock(&ddebug_lock);
list_add_tail(&dt->link, &ddebug_tables);
--
2.54.0
^ permalink raw reply related
* [PATCH v2 20/24] dyndbg: move mod_name down from struct ddebug_table to _ddebug_info
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
struct _ddebug_info already has most of dyndbg's info for a module;
push debug_table.mod_name down into it, finishing the encapsulation.
This allows refactoring several callchains, passing &_ddebug_info
instead of &ddebug_table, and hoisting the "&dt->info" deref up
instead of repeating it thru the callchans
ddebug_table contains a _ddebug_info member, so its users keep access
to mod_name, just now with "->info." added in.
In static ddebug_add_module(&di), reinforce the cursor-model by
dropping the modname arg, and setting di->mod_name at each caller.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: move RvB after SoB
old-v12
. moved up 1 position in series, ahead of hoist...
---
include/linux/dynamic_debug.h | 1 +
lib/dynamic_debug.c | 50 ++++++++++++++++++++++---------------------
2 files changed, 27 insertions(+), 24 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 001bc84eadca..11ec40f488f3 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -97,6 +97,7 @@ struct _ddebug_class_maps {
};
struct _ddebug_info {
+ const char *mod_name;
struct _ddebug_descs descs;
struct _ddebug_class_maps maps;
};
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 169b94ff6f8e..4a9b9bc9efc5 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -47,7 +47,6 @@ extern struct _ddebug_class_map __stop___dyndbg_classes[];
struct ddebug_table {
struct list_head link;
- const char *mod_name;
struct _ddebug_info info;
};
@@ -246,10 +245,11 @@ static int ddebug_change(const struct ddebug_query *query,
/* search for matching ddebugs */
mutex_lock(&ddebug_lock);
list_for_each_entry(dt, &ddebug_tables, link) {
+ struct _ddebug_info *di = &dt->info;
/* match against the module name */
if (query->module &&
- !match_wildcard(query->module, dt->mod_name))
+ !match_wildcard(query->module, di->mod_name))
continue;
if (query->class_string) {
@@ -261,8 +261,8 @@ static int ddebug_change(const struct ddebug_query *query,
valid_class = _DPRINTK_CLASS_DFLT;
}
- for (i = 0; i < dt->info.descs.len; i++) {
- struct _ddebug *dp = &dt->info.descs.start[i];
+ for (i = 0; i < di->descs.len; i++) {
+ struct _ddebug *dp = &di->descs.start[i];
if (!ddebug_match_desc(query, dp, valid_class))
continue;
@@ -282,7 +282,7 @@ static int ddebug_change(const struct ddebug_query *query,
#endif
v4pr_info("changed %s:%d [%s]%s %s => %s\n",
trim_prefix(dp->filename), dp->lineno,
- dt->mod_name, dp->function,
+ di->mod_name, dp->function,
ddebug_describe_flags(dp->flags, &fbuf),
ddebug_describe_flags(newflags, &nbuf));
dp->flags = newflags;
@@ -1077,12 +1077,12 @@ static bool ddebug_class_in_range(const int class_id, const struct _ddebug_class
class_id < map->base + map->length);
}
-static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp)
+static const char *ddebug_class_name(struct _ddebug_info *di, struct _ddebug *dp)
{
struct _ddebug_class_map *map;
int i;
- for_subvec(i, map, &dt->info, maps)
+ for_subvec(i, map, di, maps)
if (ddebug_class_in_range(dp->class_id, map))
return map->class_names[dp->class_id - map->base];
@@ -1110,13 +1110,13 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
seq_printf(m, "%s:%u [%s]%s =%s \"",
trim_prefix(dp->filename), dp->lineno,
- iter->table->mod_name, dp->function,
+ iter->table->info.mod_name, dp->function,
ddebug_describe_flags(dp->flags, &flags));
seq_escape_str(m, dp->format, ESCAPE_SPACE, "\t\r\n\"");
seq_putc(m, '"');
if (dp->class_id != _DPRINTK_CLASS_DFLT) {
- class = ddebug_class_name(iter->table, dp);
+ class = ddebug_class_name(&iter->table->info, dp);
if (class)
seq_printf(m, " class:%s", class);
else
@@ -1177,7 +1177,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
* and length of the subrange at its edges.
*/
for_subvec(i, cm, di, maps) {
- if (!strcmp(cm->mod_name, dt->mod_name)) {
+ if (!strcmp(cm->mod_name, dt->info.mod_name)) {
if (!nc) {
v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
i, cm->mod_name, cm->base, cm->length, cm->map_type);
@@ -1191,7 +1191,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
}
if (nc) {
dt->info.maps.len = nc;
- vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
+ vpr_info("module:%s attached %d classes\n", dt->info.mod_name, nc);
}
}
@@ -1199,27 +1199,26 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
* Allocate a new ddebug_table for the given module
* and add it to the global list.
*/
-static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
+static int ddebug_add_module(struct _ddebug_info *di)
{
struct ddebug_table *dt;
if (!di->descs.len)
return 0;
- v3pr_info("add-module: %s %d sites\n", modname, di->descs.len);
+ v3pr_info("add-module: %s %d sites\n", di->mod_name, di->descs.len);
dt = kzalloc_obj(*dt);
if (dt == NULL) {
- pr_err("error adding module: %s\n", modname);
+ pr_err("error adding module: %s\n", di->mod_name);
return -ENOMEM;
}
/*
- * For built-in modules, name lives in .rodata and is
- * immortal. For loaded modules, name points at the name[]
- * member of struct module, which lives at least as long as
- * this struct ddebug_table.
+ * For built-in modules, name (as supplied in di by its
+ * callers) lives in .rodata and is immortal. For loaded
+ * modules, name points at the name[] member of struct module,
+ * which lives at least as long as this struct ddebug_table.
*/
- dt->mod_name = modname;
dt->info = *di;
INIT_LIST_HEAD(&dt->link);
@@ -1231,7 +1230,7 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
list_add_tail(&dt->link, &ddebug_tables);
mutex_unlock(&ddebug_lock);
- vpr_info("%3u debug prints in module %s\n", di->descs.len, modname);
+ vpr_info("%3u debug prints in module %s\n", di->descs.len, di->mod_name);
return 0;
}
@@ -1294,7 +1293,7 @@ static int ddebug_remove_module(const char *mod_name)
mutex_lock(&ddebug_lock);
list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
- if (dt->mod_name == mod_name) {
+ if (dt->info.mod_name == mod_name) {
ddebug_table_free(dt);
ret = 0;
break;
@@ -1314,7 +1313,8 @@ static int ddebug_module_notify(struct notifier_block *self, unsigned long val,
switch (val) {
case MODULE_STATE_COMING:
- ret = ddebug_add_module(&mod->dyndbg_info, mod->name);
+ mod->dyndbg_info.mod_name = mod->name;
+ ret = ddebug_add_module(&mod->dyndbg_info);
if (ret)
WARN(1, "Failed to allocate memory: dyndbg may not work properly.\n");
break;
@@ -1412,7 +1412,8 @@ static int __init dynamic_debug_init(void)
mod_ct++;
di.descs.len = mod_sites;
di.descs.start = iter_mod_start;
- ret = ddebug_add_module(&di, modname);
+ di.mod_name = modname;
+ ret = ddebug_add_module(&di);
if (ret)
goto out_err;
@@ -1423,7 +1424,8 @@ static int __init dynamic_debug_init(void)
}
di.descs.len = mod_sites;
di.descs.start = iter_mod_start;
- ret = ddebug_add_module(&di, modname);
+ di.mod_name = modname;
+ ret = ddebug_add_module(&di);
if (ret)
goto out_err;
--
2.54.0
^ permalink raw reply related
* [PATCH v2 19/24] dyndbg,module: make proper substructs in _ddebug_info
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
recompose struct _ddebug_info, inserting proper sub-structs.
The struct _ddebug_info has 2 pairs of _vec, num_##_vec fields, for
descs and classes respectively. for_subvec() makes walking these
vectors less cumbersome, now lets move those field pairs into their
own "vec" structs: _ddebug_descs & _ddebug_class_maps, and re-compose
struct _ddebug_info to contain them cleanly. This also lets us get
rid of for_subvec()'s num_##_vec paste-up.
Also recompose struct ddebug_table to contain a _ddebug_info. This
reinforces its use as a cursor into relevant data for a builtin
module, and access to the full _ddebug state for modules.
NOTES:
Fixup names: Normalize all struct names to "struct _ddebug_*"
eliminating the minor/stupid variations created in classmaps-v1.
Invariant: These vectors ref a contiguous subrange of __section memory
in builtin/DATA or in loadable modules via mod->dyndbg_info; with
guaranteed life-time for us.
struct module contains a _ddebug_info field and module/main.c sets it
up, so that gets adjusted rather obviously.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2:
Move RvB after SoB
In structs _ddebug_descs & _ddebug_class_maps, change int length to unsigned int
No use of <0 vals is contemplated.
---
include/linux/dynamic_debug.h | 36 ++++++++++-----
kernel/module/main.c | 12 ++---
lib/dynamic_debug.c | 104 +++++++++++++++++++++---------------------
lib/test_dynamic_debug.c | 2 +-
4 files changed, 83 insertions(+), 71 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index a84dcc127e5a..001bc84eadca 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -72,8 +72,8 @@ enum ddebug_class_map_type {
*/
};
-struct ddebug_class_map {
- struct module *mod;
+struct _ddebug_class_map {
+ struct module *mod; /* NULL for builtins */
const char *mod_name; /* needed for builtins */
const char **class_names;
const int length;
@@ -81,21 +81,33 @@ struct ddebug_class_map {
enum ddebug_class_map_type map_type;
};
-/* encapsulate linker provided built-in (or module) dyndbg data */
+/*
+ * @_ddebug_info: gathers module/builtin dyndbg_* __sections together.
+ * For builtins, it is used as a cursor, with the inner structs
+ * marking sub-vectors of the builtin __sections in DATA.
+ */
+struct _ddebug_descs {
+ struct _ddebug *start;
+ unsigned int len;
+};
+
+struct _ddebug_class_maps {
+ struct _ddebug_class_map *start;
+ unsigned int len;
+};
+
struct _ddebug_info {
- struct _ddebug *descs;
- struct ddebug_class_map *classes;
- unsigned int num_descs;
- unsigned int num_classes;
+ struct _ddebug_descs descs;
+ struct _ddebug_class_maps maps;
};
-struct ddebug_class_param {
+struct _ddebug_class_param {
union {
u64 *bits;
u64 *lvl;
};
char flags[8];
- const struct ddebug_class_map *map;
+ const struct _ddebug_class_map *map;
};
/*
@@ -114,7 +126,7 @@ struct ddebug_class_param {
*/
#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \
static const char *_var##_classnames[] = { __VA_ARGS__ }; \
- static struct ddebug_class_map __aligned(8) __used \
+ static struct _ddebug_class_map __aligned(8) __used \
__section("__dyndbg_classes") _var = { \
.mod = THIS_MODULE, \
.mod_name = KBUILD_MODNAME, \
@@ -242,7 +254,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
* macro.
*/
#define _dynamic_func_call_cls(cls, fmt, func, ...) \
- __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
+ __dynamic_func_call_cls(__UNIQUE_ID(_ddebug), cls, fmt, func, ##__VA_ARGS__)
#define _dynamic_func_call(fmt, func, ...) \
_dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__)
@@ -252,7 +264,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
* with precisely the macro's varargs.
*/
#define _dynamic_func_call_cls_no_desc(cls, fmt, func, ...) \
- __dynamic_func_call_cls_no_desc(__UNIQUE_ID(ddebug), cls, fmt, \
+ __dynamic_func_call_cls_no_desc(__UNIQUE_ID(_ddebug), cls, fmt, \
func, ##__VA_ARGS__)
#define _dynamic_func_call_no_desc(fmt, func, ...) \
_dynamic_func_call_cls_no_desc(_DPRINTK_CLASS_DFLT, fmt, \
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 46dd8d25a605..c2b6e70f2e77 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2774,12 +2774,12 @@ static int find_module_sections(struct module *mod, struct load_info *info)
pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
#ifdef CONFIG_DYNAMIC_DEBUG_CORE
- mod->dyndbg_info.descs = section_objs(info, "__dyndbg",
- sizeof(*mod->dyndbg_info.descs),
- &mod->dyndbg_info.num_descs);
- mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
- sizeof(*mod->dyndbg_info.classes),
- &mod->dyndbg_info.num_classes);
+ mod->dyndbg_info.descs.start = section_objs(info, "__dyndbg_descriptors",
+ sizeof(*mod->dyndbg_info.descs.start),
+ &mod->dyndbg_info.descs.len);
+ mod->dyndbg_info.maps.start = section_objs(info, "__dyndbg_class_maps",
+ sizeof(*mod->dyndbg_info.maps.start),
+ &mod->dyndbg_info.maps.len);
#endif
return 0;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 580aa258f902..169b94ff6f8e 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -42,15 +42,13 @@
extern struct _ddebug __start___dyndbg[];
extern struct _ddebug __stop___dyndbg[];
-extern struct ddebug_class_map __start___dyndbg_classes[];
-extern struct ddebug_class_map __stop___dyndbg_classes[];
+extern struct _ddebug_class_map __start___dyndbg_classes[];
+extern struct _ddebug_class_map __stop___dyndbg_classes[];
struct ddebug_table {
struct list_head link;
const char *mod_name;
- struct _ddebug *ddebugs;
- struct ddebug_class_map *classes;
- unsigned int num_ddebugs, num_classes;
+ struct _ddebug_info info;
};
struct ddebug_query {
@@ -137,11 +135,11 @@ do { \
* @_i: caller provided counter.
* @_sp: cursor into _vec, to examine each item.
* @_box: ptr to a struct containing @_vec member
- * @_vec: name of a member in @_box
+ * @_vec: name of a vector member in @_box
*/
#define for_subvec(_i, _sp, _box, _vec) \
- for ((_i) = 0, (_sp) = (_box)->_vec; \
- (_i) < (_box)->num_##_vec; \
+ for ((_i) = 0, (_sp) = (_box)->_vec.start; \
+ (_i) < (_box)->_vec.len; \
(_i)++, (_sp)++) /* { block } */
static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
@@ -164,14 +162,14 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
query->first_lineno, query->last_lineno, query->class_string);
}
-static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
+static struct _ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
const char *class_string,
int *class_id)
{
- struct ddebug_class_map *map;
+ struct _ddebug_class_map *map;
int i, idx;
- for_subvec(i, map, dt, classes) {
+ for_subvec(i, map, &dt->info, maps) {
idx = match_string(map->class_names, map->length, class_string);
if (idx >= 0) {
*class_id = idx + map->base;
@@ -242,7 +240,7 @@ static int ddebug_change(const struct ddebug_query *query,
unsigned int newflags;
unsigned int nfound = 0;
struct flagsbuf fbuf, nbuf;
- struct ddebug_class_map *map = NULL;
+ struct _ddebug_class_map *map = NULL;
int valid_class;
/* search for matching ddebugs */
@@ -263,8 +261,8 @@ static int ddebug_change(const struct ddebug_query *query,
valid_class = _DPRINTK_CLASS_DFLT;
}
- for (i = 0; i < dt->num_ddebugs; i++) {
- struct _ddebug *dp = &dt->ddebugs[i];
+ for (i = 0; i < dt->info.descs.len; i++) {
+ struct _ddebug *dp = &dt->info.descs.start[i];
if (!ddebug_match_desc(query, dp, valid_class))
continue;
@@ -623,13 +621,13 @@ static int ddebug_exec_queries(char *query, const char *modname)
}
/* apply a new class-param setting */
-static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
+static int ddebug_apply_class_bitmap(const struct _ddebug_class_param *dcp,
const u64 *new_bits, const u64 old_bits,
const char *query_modname)
{
#define QUERY_SIZE 128
char query[QUERY_SIZE];
- const struct ddebug_class_map *map = dcp->map;
+ const struct _ddebug_class_map *map = dcp->map;
int matches = 0;
int bi, ct;
@@ -681,8 +679,8 @@ static int param_set_dyndbg_module_classes(const char *instr,
const struct kernel_param *kp,
const char *mod_name)
{
- const struct ddebug_class_param *dcp = kp->arg;
- const struct ddebug_class_map *map = dcp->map;
+ const struct _ddebug_class_param *dcp = kp->arg;
+ const struct _ddebug_class_map *map = dcp->map;
u64 inrep, new_bits, old_bits;
int rc, totct = 0;
@@ -756,8 +754,8 @@ EXPORT_SYMBOL(param_set_dyndbg_classes);
*/
int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
{
- const struct ddebug_class_param *dcp = kp->arg;
- const struct ddebug_class_map *map = dcp->map;
+ const struct _ddebug_class_param *dcp = kp->arg;
+ const struct _ddebug_class_map *map = dcp->map;
switch (map->map_type) {
case DD_CLASS_TYPE_DISJOINT_BITS:
@@ -1004,8 +1002,8 @@ static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
}
iter->table = list_entry(ddebug_tables.next,
struct ddebug_table, link);
- iter->idx = iter->table->num_ddebugs;
- return &iter->table->ddebugs[--iter->idx];
+ iter->idx = iter->table->info.descs.len;
+ return &iter->table->info.descs.start[--iter->idx];
}
/*
@@ -1026,10 +1024,10 @@ static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
}
iter->table = list_entry(iter->table->link.next,
struct ddebug_table, link);
- iter->idx = iter->table->num_ddebugs;
+ iter->idx = iter->table->info.descs.len;
--iter->idx;
}
- return &iter->table->ddebugs[iter->idx];
+ return &iter->table->info.descs.start[iter->idx];
}
/*
@@ -1073,16 +1071,19 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
return dp;
}
-#define class_in_range(class_id, map) \
- (class_id >= map->base && class_id < map->base + map->length)
+static bool ddebug_class_in_range(const int class_id, const struct _ddebug_class_map *map)
+{
+ return (class_id >= map->base &&
+ class_id < map->base + map->length);
+}
-static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
+static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp)
{
- struct ddebug_class_map *map = iter->table->classes;
- int i, nc = iter->table->num_classes;
+ struct _ddebug_class_map *map;
+ int i;
- for (i = 0; i < nc; i++, map++)
- if (class_in_range(dp->class_id, map))
+ for_subvec(i, map, &dt->info, maps)
+ if (ddebug_class_in_range(dp->class_id, map))
return map->class_names[dp->class_id - map->base];
return NULL;
@@ -1115,7 +1116,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
seq_putc(m, '"');
if (dp->class_id != _DPRINTK_CLASS_DFLT) {
- class = ddebug_class_name(iter, dp);
+ class = ddebug_class_name(iter->table, dp);
if (class)
seq_printf(m, " class:%s", class);
else
@@ -1167,7 +1168,7 @@ static const struct proc_ops proc_fops = {
static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
{
- struct ddebug_class_map *cm;
+ struct _ddebug_class_map *cm;
int i, nc = 0;
/*
@@ -1175,12 +1176,12 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
* the builtin/modular classmap vector/section. Save the start
* and length of the subrange at its edges.
*/
- for_subvec(i, cm, di, classes) {
+ for_subvec(i, cm, di, maps) {
if (!strcmp(cm->mod_name, dt->mod_name)) {
if (!nc) {
v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
i, cm->mod_name, cm->base, cm->length, cm->map_type);
- dt->classes = cm;
+ dt->info.maps.start = cm;
}
nc++;
} else if (nc) {
@@ -1189,7 +1190,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
}
}
if (nc) {
- dt->num_classes = nc;
+ dt->info.maps.len = nc;
vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
}
}
@@ -1202,10 +1203,10 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
{
struct ddebug_table *dt;
- if (!di->num_descs)
+ if (!di->descs.len)
return 0;
- v3pr_info("add-module: %s %d sites\n", modname, di->num_descs);
+ v3pr_info("add-module: %s %d sites\n", modname, di->descs.len);
dt = kzalloc_obj(*dt);
if (dt == NULL) {
@@ -1219,19 +1220,18 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
* this struct ddebug_table.
*/
dt->mod_name = modname;
- dt->ddebugs = di->descs;
- dt->num_ddebugs = di->num_descs;
+ dt->info = *di;
INIT_LIST_HEAD(&dt->link);
- if (di->classes && di->num_classes)
+ if (di->maps.len)
ddebug_attach_module_classes(dt, di);
mutex_lock(&ddebug_lock);
list_add_tail(&dt->link, &ddebug_tables);
mutex_unlock(&ddebug_lock);
- vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
+ vpr_info("%3u debug prints in module %s\n", di->descs.len, modname);
return 0;
}
@@ -1378,10 +1378,10 @@ static int __init dynamic_debug_init(void)
char *cmdline;
struct _ddebug_info di = {
- .descs = __start___dyndbg,
- .classes = __start___dyndbg_classes,
- .num_descs = __stop___dyndbg - __start___dyndbg,
- .num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
+ .descs.start = __start___dyndbg,
+ .maps.start = __start___dyndbg_classes,
+ .descs.len = __stop___dyndbg - __start___dyndbg,
+ .maps.len = __stop___dyndbg_classes - __start___dyndbg_classes,
};
#ifdef CONFIG_MODULES
@@ -1410,8 +1410,8 @@ static int __init dynamic_debug_init(void)
if (strcmp(modname, iter->modname)) {
mod_ct++;
- di.num_descs = mod_sites;
- di.descs = iter_mod_start;
+ di.descs.len = mod_sites;
+ di.descs.start = iter_mod_start;
ret = ddebug_add_module(&di, modname);
if (ret)
goto out_err;
@@ -1421,8 +1421,8 @@ static int __init dynamic_debug_init(void)
iter_mod_start = iter;
}
}
- di.num_descs = mod_sites;
- di.descs = iter_mod_start;
+ di.descs.len = mod_sites;
+ di.descs.start = iter_mod_start;
ret = ddebug_add_module(&di, modname);
if (ret)
goto out_err;
@@ -1432,8 +1432,8 @@ static int __init dynamic_debug_init(void)
i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),
(int)((i * sizeof(struct _ddebug)) >> 10));
- if (di.num_classes)
- v2pr_info(" %d builtin ddebug class-maps\n", di.num_classes);
+ if (di.maps.len)
+ v2pr_info(" %d builtin ddebug class-maps\n", di.maps.len);
/* now that ddebug tables are loaded, process all boot args
* again to find and activate queries given in dyndbg params.
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index c049580d2152..e6b2422ca671 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -41,7 +41,7 @@ module_param_cb(do_prints, ¶m_ops_do_prints, NULL, 0600);
*/
#define DD_SYS_WRAP(_model, _flags) \
static u64 bits_##_model; \
- static struct ddebug_class_param _flags##_model = { \
+ static struct _ddebug_class_param _flags##_model = { \
.bits = &bits_##_model, \
.flags = #_flags, \
.map = &map_##_model, \
--
2.54.0
^ permalink raw reply related
* [PATCH v2 18/24] dyndbg: Upgrade class param storage to u64 for 64-bit classmaps
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
Currently, `struct ddebug_class_param` uses `unsigned long` pointers
to store the state of `bits` and `lvl`. On 32-bit architectures, this
limits the bit-vector to 32 bits, which truncates 64-bit classmaps
(such as the one needed by `__drm_debug`).
To guarantee support for 64-bit debug categories across all
architectures, upgrade the internal storage types in `struct
_ddebug_class_param` to `u64`. This inherently makes both union
members the same size while safely avoiding truncation.
This includes:
- Changing union members `bits` and `lvl` to `u64 *`.
- Using `kstrtou64()` for sysfs input parsing.
- Replacing array-based `test_bit()` operations with safe `u64` scalar
bitwise logic (`!!(val & (1ULL << bi))`).
- adjusting lib/test_dynamic_debug.c too
Not yet done:
- Updating `drm_print`'s `__drm_debug` to `u64` and configuring the
associated module parameter as `ullong`.
- Fixing an unused variable warning in `__drm_printfn_dbg`.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
v2:
patch was "make bits & lvl same size"
but that size was unsigned long, only 32 bits on i386 etc
use u64 for all bits, and %llu %llx
---
include/linux/dynamic_debug.h | 4 ++--
lib/dynamic_debug.c | 34 ++++++++++++++++++----------------
lib/test_dynamic_debug.c | 2 +-
3 files changed, 21 insertions(+), 19 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 0a137a586510..a84dcc127e5a 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -91,8 +91,8 @@ struct _ddebug_info {
struct ddebug_class_param {
union {
- unsigned long *bits;
- unsigned int *lvl;
+ u64 *bits;
+ u64 *lvl;
};
char flags[8];
const struct ddebug_class_map *map;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index e9481ef21825..580aa258f902 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -624,8 +624,7 @@ static int ddebug_exec_queries(char *query, const char *modname)
/* apply a new class-param setting */
static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
- const unsigned long *new_bits,
- const unsigned long old_bits,
+ const u64 *new_bits, const u64 old_bits,
const char *query_modname)
{
#define QUERY_SIZE 128
@@ -635,24 +634,27 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
int bi, ct;
if (*new_bits != old_bits)
- v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+ v2pr_info("apply bitmap: 0x%llx to: 0x%llx for %s\n", *new_bits,
old_bits, query_modname ?: "'*'");
for (bi = 0; bi < map->length; bi++) {
- if (test_bit(bi, new_bits) == test_bit(bi, &old_bits))
+ bool new_b = !!(*new_bits & (1ULL << bi));
+ bool old_b = !!(old_bits & (1ULL << bi));
+
+ if (new_b == old_b)
continue;
snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
- test_bit(bi, new_bits) ? '+' : '-', dcp->flags);
+ new_b ? '+' : '-', dcp->flags);
ct = ddebug_exec_queries(query, query_modname);
matches += ct;
- v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
+ v2pr_info("bit_%d: %d matches on class: %s -> 0x%llx\n", bi,
ct, map->class_names[bi], *new_bits);
}
if (*new_bits != old_bits)
- v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+ v2pr_info("applied bitmap: 0x%llx to: 0x%llx for %s\n", *new_bits,
old_bits, query_modname ?: "'*'");
return matches;
@@ -661,7 +663,7 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
/* stub to later conditionally add "$module." prefix where not already done */
#define KP_NAME(kp) kp->name
-#define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
+#define CLASSMAP_BITMASK(width) ((1ULL << (width)) - 1)
/**
* param_set_dyndbg_classes - class FOO >control
@@ -681,10 +683,10 @@ static int param_set_dyndbg_module_classes(const char *instr,
{
const struct ddebug_class_param *dcp = kp->arg;
const struct ddebug_class_map *map = dcp->map;
- unsigned long inrep, new_bits, old_bits;
+ u64 inrep, new_bits, old_bits;
int rc, totct = 0;
- rc = kstrtoul(instr, 0, &inrep);
+ rc = kstrtou64(instr, 0, &inrep);
if (rc) {
int len = strcspn(instr, "\n");
pr_err("expecting numeric input, not: %.*s > %s\n",
@@ -696,24 +698,24 @@ static int param_set_dyndbg_module_classes(const char *instr,
case DD_CLASS_TYPE_DISJOINT_BITS:
/* expect bits. mask and warn if too many */
if (inrep & ~CLASSMAP_BITMASK(map->length)) {
- pr_warn("%s: input: 0x%lx exceeds mask: 0x%lx, masking\n",
+ pr_warn("%s: input: 0x%llx exceeds mask: 0x%llx, masking\n",
KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
inrep &= CLASSMAP_BITMASK(map->length);
}
- v2pr_info("bits:0x%lx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp));
+ v2pr_info("bits:0x%llx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp));
totct += ddebug_apply_class_bitmap(dcp, &inrep, *dcp->bits, mod_name);
*dcp->bits = inrep;
break;
case DD_CLASS_TYPE_LEVEL_NUM:
/* input is bitpos, of highest verbosity to be enabled */
if (inrep > map->length) {
- pr_warn("%s: level:%ld exceeds max:%d, clamping\n",
+ pr_warn("%s: level:%llu exceeds max:%d, clamping\n",
KP_NAME(kp), inrep, map->length);
inrep = map->length;
}
old_bits = CLASSMAP_BITMASK(*dcp->lvl);
new_bits = CLASSMAP_BITMASK(inrep);
- v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
+ v2pr_info("lvl:%llu bits:0x%llx > %s\n", inrep, new_bits, KP_NAME(kp));
totct += ddebug_apply_class_bitmap(dcp, &new_bits, old_bits, mod_name);
*dcp->lvl = inrep;
break;
@@ -759,9 +761,9 @@ int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
switch (map->map_type) {
case DD_CLASS_TYPE_DISJOINT_BITS:
- return scnprintf(buffer, PAGE_SIZE, "0x%lx\n", *dcp->bits);
+ return scnprintf(buffer, PAGE_SIZE, "0x%llx\n", *dcp->bits);
case DD_CLASS_TYPE_LEVEL_NUM:
- return scnprintf(buffer, PAGE_SIZE, "%d\n", *dcp->lvl);
+ return scnprintf(buffer, PAGE_SIZE, "%llu\n", *dcp->lvl);
default:
return -1;
}
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 74d183ebf3e0..c049580d2152 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -40,7 +40,7 @@ module_param_cb(do_prints, ¶m_ops_do_prints, NULL, 0600);
* - tie together sysname, mapname, bitsname, flagsname
*/
#define DD_SYS_WRAP(_model, _flags) \
- static unsigned long bits_##_model; \
+ static u64 bits_##_model; \
static struct ddebug_class_param _flags##_model = { \
.bits = &bits_##_model, \
.flags = #_flags, \
--
2.54.0
^ permalink raw reply related
* [PATCH v2 17/24] dyndbg: macrofy a 2-index for-loop pattern
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
dynamic-debug currently has 2 __sections (__dyndbg, __dyndb_classes),
struct _ddebug_info keeps track of them both, with 2 members each:
_vec and _vec#_len.
We need to loop over these sections, with index and record pointer,
making ref to both _vec and _vec_len. This is already fiddly and
error-prone, and will get worse as we add a 3rd section.
Lets instead embed/abstract the fiddly-ness in the `for_subvec()`
macro, and avoid repeating it going forward.
This is a for-loop macro expander, so it syntactically expects to
precede either a single statement or a { block } of them, and the
usual typeof or do-while-0 tricks are unavailable to fix the
multiple-expansion warning.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: move RvB after SoB
---
lib/dynamic_debug.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 7f03b331d185..e9481ef21825 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -130,6 +130,20 @@ do { \
#define v3pr_info(fmt, ...) vnpr_info(3, fmt, ##__VA_ARGS__)
#define v4pr_info(fmt, ...) vnpr_info(4, fmt, ##__VA_ARGS__)
+/*
+ * simplify a repeated for-loop pattern walking N steps in a T _vec
+ * member inside a struct _box. It expects int i and T *_sp to be
+ * declared in the caller.
+ * @_i: caller provided counter.
+ * @_sp: cursor into _vec, to examine each item.
+ * @_box: ptr to a struct containing @_vec member
+ * @_vec: name of a member in @_box
+ */
+#define for_subvec(_i, _sp, _box, _vec) \
+ for ((_i) = 0, (_sp) = (_box)->_vec; \
+ (_i) < (_box)->num_##_vec; \
+ (_i)++, (_sp)++) /* { block } */
+
static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
{
/* trim any trailing newlines */
@@ -157,7 +171,7 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
struct ddebug_class_map *map;
int i, idx;
- for (map = dt->classes, i = 0; i < dt->num_classes; i++, map++) {
+ for_subvec(i, map, dt, classes) {
idx = match_string(map->class_names, map->length, class_string);
if (idx >= 0) {
*class_id = idx + map->base;
@@ -1159,8 +1173,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
* the builtin/modular classmap vector/section. Save the start
* and length of the subrange at its edges.
*/
- for (cm = di->classes, i = 0; i < di->num_classes; i++, cm++) {
-
+ for_subvec(i, cm, di, classes) {
if (!strcmp(cm->mod_name, dt->mod_name)) {
if (!nc) {
v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
--
2.54.0
^ permalink raw reply related
* [PATCH v2 16/24] dyndbg: replace classmap list with an array-slice
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
Classmaps are stored in an elf section/array, but currently are
individually list-linked onto dyndbg's per-module ddebug_table for
operation. This is unnecessary.
Just like dyndbg's descriptors, classes are packed in compile order;
so even with many builtin modules employing multiple classmaps, each
modules' maps are packed contiguously, and can be treated as a
array-start-address & array-length.
So this drops the whole list building operation done in
ddebug_attach_module_classes(), and removes the list-head members of
the classmap structs. The "select-by-modname" condition is reused to
find the start,end of the subrange of classmaps belonging to the module.
NOTES:
There are multiple modules named "main" but thats an artifact of how
KBUILD_MODNAME gets its value, and none of those repeats are
contiguous. The legacy code segmenting the builtin descriptors
depends upon this, we are "reusing" that dependency.
The "filter-by-modname" on classmaps should really be done in
ddebug_add_module(1); ie closer to dynamic_debug_init(2), which
already splits up pr-debug descriptors into subranges by modname, then
calls (1) on each. (2) knows nothing of classmaps currently, and
doesn't need to.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: RvB after SoB
---
include/linux/dynamic_debug.h | 1 -
lib/dynamic_debug.c | 65 +++++++++++++++++++++++--------------------
2 files changed, 35 insertions(+), 31 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index e724f6b93663..0a137a586510 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -73,7 +73,6 @@ enum ddebug_class_map_type {
};
struct ddebug_class_map {
- struct list_head link;
struct module *mod;
const char *mod_name; /* needed for builtins */
const char **class_names;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index d4cce0f4f197..7f03b331d185 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -46,10 +46,11 @@ extern struct ddebug_class_map __start___dyndbg_classes[];
extern struct ddebug_class_map __stop___dyndbg_classes[];
struct ddebug_table {
- struct list_head link, maps;
+ struct list_head link;
const char *mod_name;
- unsigned int num_ddebugs;
struct _ddebug *ddebugs;
+ struct ddebug_class_map *classes;
+ unsigned int num_ddebugs, num_classes;
};
struct ddebug_query {
@@ -150,12 +151,13 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
}
static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
- const char *class_string, int *class_id)
+ const char *class_string,
+ int *class_id)
{
struct ddebug_class_map *map;
- int idx;
+ int i, idx;
- list_for_each_entry(map, &dt->maps, link) {
+ for (map = dt->classes, i = 0; i < dt->num_classes; i++, map++) {
idx = match_string(map->class_names, map->length, class_string);
if (idx >= 0) {
*class_id = idx + map->base;
@@ -166,7 +168,6 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
return NULL;
}
-#define __outvar /* filled by callee */
/*
* Search the tables for _ddebug's which match the given `query' and
* apply the `flags' and `mask' to them. Returns number of matching
@@ -228,7 +229,7 @@ static int ddebug_change(const struct ddebug_query *query,
unsigned int nfound = 0;
struct flagsbuf fbuf, nbuf;
struct ddebug_class_map *map = NULL;
- int __outvar valid_class;
+ int valid_class;
/* search for matching ddebugs */
mutex_lock(&ddebug_lock);
@@ -1061,9 +1062,10 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
{
- struct ddebug_class_map *map;
+ struct ddebug_class_map *map = iter->table->classes;
+ int i, nc = iter->table->num_classes;
- list_for_each_entry(map, &iter->table->maps, link)
+ for (i = 0; i < nc; i++, map++)
if (class_in_range(dp->class_id, map))
return map->class_names[dp->class_id - map->base];
@@ -1147,30 +1149,34 @@ static const struct proc_ops proc_fops = {
.proc_write = ddebug_proc_write
};
-static void ddebug_attach_module_classes(struct ddebug_table *dt,
- struct ddebug_class_map *classes,
- int num_classes)
+static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
{
struct ddebug_class_map *cm;
- int i, j, ct = 0;
+ int i, nc = 0;
- for (cm = classes, i = 0; i < num_classes; i++, cm++) {
+ /*
+ * Find this module's classmaps in a subrange/wholerange of
+ * the builtin/modular classmap vector/section. Save the start
+ * and length of the subrange at its edges.
+ */
+ for (cm = di->classes, i = 0; i < di->num_classes; i++, cm++) {
if (!strcmp(cm->mod_name, dt->mod_name)) {
-
- v2pr_info("class[%d]: module:%s base:%d len:%d ty:%d\n", i,
- cm->mod_name, cm->base, cm->length, cm->map_type);
-
- for (j = 0; j < cm->length; j++)
- v3pr_info(" %d: %d %s\n", j + cm->base, j,
- cm->class_names[j]);
-
- list_add(&cm->link, &dt->maps);
- ct++;
+ if (!nc) {
+ v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
+ i, cm->mod_name, cm->base, cm->length, cm->map_type);
+ dt->classes = cm;
+ }
+ nc++;
+ } else if (nc) {
+ /* end of matching classmaps */
+ break;
}
}
- if (ct)
- vpr_info("module:%s attached %d classes\n", dt->mod_name, ct);
+ if (nc) {
+ dt->num_classes = nc;
+ vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
+ }
}
/*
@@ -1202,10 +1208,9 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
dt->num_ddebugs = di->num_descs;
INIT_LIST_HEAD(&dt->link);
- INIT_LIST_HEAD(&dt->maps);
if (di->classes && di->num_classes)
- ddebug_attach_module_classes(dt, di->classes, di->num_classes);
+ ddebug_attach_module_classes(dt, di);
mutex_lock(&ddebug_lock);
list_add_tail(&dt->link, &ddebug_tables);
@@ -1318,8 +1323,8 @@ static void ddebug_remove_all_tables(void)
mutex_lock(&ddebug_lock);
while (!list_empty(&ddebug_tables)) {
struct ddebug_table *dt = list_entry(ddebug_tables.next,
- struct ddebug_table,
- link);
+ struct ddebug_table,
+ link);
ddebug_table_free(dt);
}
mutex_unlock(&ddebug_lock);
--
2.54.0
^ permalink raw reply related
* [PATCH v2 15/24] dyndbg: tighten fn-sig of ddebug_apply_class_bitmap
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
old_bits arg is currently a pointer to the input bits, but this could
allow inadvertent changes to the input by the fn. Disallow this.
And constify new_bits while here.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: move RvB after SoB
---
lib/dynamic_debug.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index ce069459aafc..d4cce0f4f197 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -609,7 +609,8 @@ static int ddebug_exec_queries(char *query, const char *modname)
/* apply a new class-param setting */
static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
- unsigned long *new_bits, unsigned long *old_bits,
+ const unsigned long *new_bits,
+ const unsigned long old_bits,
const char *query_modname)
{
#define QUERY_SIZE 128
@@ -618,12 +619,12 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
int matches = 0;
int bi, ct;
- if (*new_bits != *old_bits)
+ if (*new_bits != old_bits)
v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
- *old_bits, query_modname ?: "'*'");
+ old_bits, query_modname ?: "'*'");
for (bi = 0; bi < map->length; bi++) {
- if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
+ if (test_bit(bi, new_bits) == test_bit(bi, &old_bits))
continue;
snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
@@ -635,9 +636,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
ct, map->class_names[bi], *new_bits);
}
- if (*new_bits != *old_bits)
+ if (*new_bits != old_bits)
v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
- *old_bits, query_modname ?: "'*'");
+ old_bits, query_modname ?: "'*'");
return matches;
}
@@ -685,7 +686,7 @@ static int param_set_dyndbg_module_classes(const char *instr,
inrep &= CLASSMAP_BITMASK(map->length);
}
v2pr_info("bits:0x%lx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp));
- totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits, mod_name);
+ totct += ddebug_apply_class_bitmap(dcp, &inrep, *dcp->bits, mod_name);
*dcp->bits = inrep;
break;
case DD_CLASS_TYPE_LEVEL_NUM:
@@ -698,7 +699,7 @@ static int param_set_dyndbg_module_classes(const char *instr,
old_bits = CLASSMAP_BITMASK(*dcp->lvl);
new_bits = CLASSMAP_BITMASK(inrep);
v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
- totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, mod_name);
+ totct += ddebug_apply_class_bitmap(dcp, &new_bits, old_bits, mod_name);
*dcp->lvl = inrep;
break;
default:
--
2.54.0
^ permalink raw reply related
* [PATCH v2 14/24] dyndbg: refactor param_set_dyndbg_classes and below
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
Refactor callchain below param_set_dyndbg_classes(1) to allow mod-name
specific settings. Split (1) into upper/lower fns, adding modname
param to lower, and passing NULL in from upper. Below that, add the
same param to ddebug_apply_class_bitmap(), and pass it thru to
_ddebug_queries(), replacing NULL with the param.
This allows the callchain to update the classmap in just one module,
vs just all as currently done. While the sysfs param is unlikely to
ever update just one module, the callchain will be used for modprobe
handling, which should update only that just-probed module.
In ddebug_apply_class_bitmap(), also check for actual changes to the
bits before announcing them, to declutter logs.
No functional change.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: move RvB after SoB
---
lib/dynamic_debug.c | 51 +++++++++++++++++++++++++++++++++++++++------------
1 file changed, 39 insertions(+), 12 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index dfed3725aa44..ce069459aafc 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -607,9 +607,10 @@ static int ddebug_exec_queries(char *query, const char *modname)
return nfound;
}
-/* apply a new bitmap to the sys-knob's current bit-state */
+/* apply a new class-param setting */
static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
- unsigned long *new_bits, unsigned long *old_bits)
+ unsigned long *new_bits, unsigned long *old_bits,
+ const char *query_modname)
{
#define QUERY_SIZE 128
char query[QUERY_SIZE];
@@ -617,7 +618,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
int matches = 0;
int bi, ct;
- v2pr_info("apply: 0x%lx to: 0x%lx\n", *new_bits, *old_bits);
+ if (*new_bits != *old_bits)
+ v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+ *old_bits, query_modname ?: "'*'");
for (bi = 0; bi < map->length; bi++) {
if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
@@ -626,12 +629,16 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
test_bit(bi, new_bits) ? '+' : '-', dcp->flags);
- ct = ddebug_exec_queries(query, NULL);
+ ct = ddebug_exec_queries(query, query_modname);
matches += ct;
v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
ct, map->class_names[bi], *new_bits);
}
+ if (*new_bits != *old_bits)
+ v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+ *old_bits, query_modname ?: "'*'");
+
return matches;
}
@@ -644,6 +651,7 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
* param_set_dyndbg_classes - class FOO >control
* @instr: string echo>d to sysfs, input depends on map_type
* @kp: kp->arg has state: bits/lvl, map, map_type
+ * @mod_name: module name or null for all modules with the classes
*
* Enable/disable prdbgs by their class, as given in the arguments to
* DECLARE_DYNDBG_CLASSMAP. For LEVEL map-types, enforce relative
@@ -651,7 +659,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
*
* Returns: 0 or <0 if error.
*/
-int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
+static int param_set_dyndbg_module_classes(const char *instr,
+ const struct kernel_param *kp,
+ const char *mod_name)
{
const struct ddebug_class_param *dcp = kp->arg;
const struct ddebug_class_map *map = dcp->map;
@@ -674,8 +684,8 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
inrep &= CLASSMAP_BITMASK(map->length);
}
- v2pr_info("bits:%lx > %s\n", inrep, KP_NAME(kp));
- totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits);
+ v2pr_info("bits:0x%lx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp));
+ totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits, mod_name);
*dcp->bits = inrep;
break;
case DD_CLASS_TYPE_LEVEL_NUM:
@@ -688,7 +698,7 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
old_bits = CLASSMAP_BITMASK(*dcp->lvl);
new_bits = CLASSMAP_BITMASK(inrep);
v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
- totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits);
+ totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, mod_name);
*dcp->lvl = inrep;
break;
default:
@@ -698,16 +708,33 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
vpr_info("%s: total matches: %d\n", KP_NAME(kp), totct);
return 0;
}
+
+/**
+ * param_set_dyndbg_classes - classmap kparam setter
+ * @instr: string echo>d to sysfs, input depends on map_type
+ * @kp: kp->arg has state: bits/lvl, map, map_type
+ *
+ * enable/disable all class'd pr_debugs in the classmap. For LEVEL
+ * map-types, enforce * relative levels by bitpos.
+ *
+ * Returns: 0 or <0 if error.
+ */
+int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
+{
+ return param_set_dyndbg_module_classes(instr, kp, NULL);
+}
EXPORT_SYMBOL(param_set_dyndbg_classes);
/**
- * param_get_dyndbg_classes - classes reader
+ * param_get_dyndbg_classes - classmap kparam getter
* @buffer: string description of controlled bits -> classes
* @kp: kp->arg has state: bits, map
*
- * Reads last written state, underlying prdbg state may have been
- * altered by direct >control. Displays 0x for DISJOINT, 0-N for
- * LEVEL Returns: #chars written or <0 on error
+ * Reads last written state, underlying pr_debug states may have been
+ * altered by direct >control. Displays 0x for DISJOINT classmap
+ * types, 0-N for LEVEL types.
+ *
+ * Returns: ct of chars written or <0 on error
*/
int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
{
--
2.54.0
^ permalink raw reply related
* [PATCH v2 13/24] dyndbg: reduce verbose/debug clutter
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
currently, for verbose=3, these are logged (blank lines for clarity):
dyndbg: query 0: "class DRM_UT_CORE +p" mod:*
dyndbg: split into words: "class" "DRM_UT_CORE" "+p"
dyndbg: op='+'
dyndbg: flags=0x1
dyndbg: *flagsp=0x1 *maskp=0xffffffff
dyndbg: parsed: func="" file="" module="" format="" lineno=0-0 class=...
dyndbg: no matches for query
dyndbg: no-match: func="" file="" module="" format="" lineno=0-0 class=...
dyndbg: processed 1 queries, with 0 matches, 0 errs
That is excessive, so this patch:
- shrinks 3 lines of 2nd stanza to single line
- drops 1st 2 lines of 3rd stanza
3rd line is like 1st, with result, not procedure.
2nd line is just status, retold in 4th, with more info.
New output:
dyndbg: query 0: "class DRM_UT_CORE +p"
dyndbg: split into words: "class" "DRM_UT_CORE" "+p"
dyndbg: op='+' flags=0x1 maskp=0xffffffff
dyndbg: processed 1 queries, with 0 matches, 0 errs
Also drop several verbose=3 messages in ddebug_add_module
When modprobing a module, dyndbg currently logs/says "add-module", and
then "skipping" if the module has no prdbgs. Instead just check 1st
and return quietly.
no functional change
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2:
RvB after SoB
trivial change to verbose-debug output line to output the actual
"module" keyword rather than "mod:", and do so only when the module is
constrained by the callchain (ie as part of a modprobe).
was: query X: "(keyword value)* [+-=]flags" mod:*
now: query X: "(keyword value)* [+-=]flags"
or query X: module FOO "keyword value)* [+-=]flags"
IOW, adjust output to reflect the input grammar more closely.
---
lib/dynamic_debug.c | 24 ++++++++----------------
1 file changed, 8 insertions(+), 16 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 6d9dbeb68ae8..dfed3725aa44 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -277,9 +277,6 @@ static int ddebug_change(const struct ddebug_query *query,
}
mutex_unlock(&ddebug_lock);
- if (!nfound && verbose)
- pr_info("no matches for query\n");
-
return nfound;
}
@@ -512,7 +509,6 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
pr_err("bad flag-op %c, at start of %s\n", *str, str);
return -EINVAL;
}
- v3pr_info("op='%c'\n", op);
for (; *str ; ++str) {
for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
@@ -526,7 +522,6 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
return -EINVAL;
}
}
- v3pr_info("flags=0x%x\n", modifiers->flags);
/* calculate final flags, mask based upon op */
switch (op) {
@@ -542,7 +537,7 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
modifiers->flags = 0;
break;
}
- v3pr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
+ v3pr_info("op='%c' flags=0x%x maskp=0x%x\n", op, modifiers->flags, modifiers->mask);
return 0;
}
@@ -552,7 +547,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
struct flag_settings modifiers = {};
struct ddebug_query query = {};
#define MAXWORDS 9
- int nwords, nfound;
+ int nwords;
char *words[MAXWORDS];
nwords = ddebug_tokenize(query_string, words, MAXWORDS);
@@ -570,10 +565,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
return -EINVAL;
}
/* actually go and implement the change */
- nfound = ddebug_change(&query, &modifiers);
- vpr_info_dq(&query, nfound ? "applied" : "no-match");
-
- return nfound;
+ return ddebug_change(&query, &modifiers);
}
/* handle multiple queries in query string, continue on error, return
@@ -594,7 +586,8 @@ static int ddebug_exec_queries(char *query, const char *modname)
if (!query || !*query || *query == '#')
continue;
- vpr_info("query %d: \"%s\" mod:%s\n", i, query, modname ?: "*");
+ vpr_info("query %d: %s%s \"%s\"\n", i,
+ modname ? "module " : "", modname ?: "", query);
rc = ddebug_exec_query(query, modname);
if (rc < 0) {
@@ -1160,11 +1153,10 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
{
struct ddebug_table *dt;
- v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs);
- if (!di->num_descs) {
- v3pr_info(" skip %s\n", modname);
+ if (!di->num_descs)
return 0;
- }
+
+ v3pr_info("add-module: %s %d sites\n", modname, di->num_descs);
dt = kzalloc_obj(*dt);
if (dt == NULL) {
--
2.54.0
^ permalink raw reply related
* [PATCH v2 12/24] dyndbg: drop NUM_TYPE_ARGS
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
ARRAY_SIZE works here, since array decl is complete.
no functional change
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2: include linux/array_size.h, correct commit subject
review after sob
---
include/linux/dynamic_debug.h | 4 +---
lib/dynamic_debug.c | 1 +
2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index aa45dcf36a44..e724f6b93663 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -121,11 +121,9 @@ struct ddebug_class_param {
.mod_name = KBUILD_MODNAME, \
.base = _base, \
.map_type = _maptype, \
- .length = NUM_TYPE_ARGS(char*, __VA_ARGS__), \
+ .length = ARRAY_SIZE(_var##_classnames), \
.class_names = _var##_classnames, \
}
-#define NUM_TYPE_ARGS(eltype, ...) \
- (sizeof((eltype[]) {__VA_ARGS__}) / sizeof(eltype))
extern __printf(2, 3)
void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 0377d9f8dcd1..6d9dbeb68ae8 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -13,6 +13,7 @@
#define pr_fmt(fmt) "dyndbg: " fmt
+#include <linux/array_size.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
--
2.54.0
^ permalink raw reply related
* [PATCH v2 11/24] dyndbg-API: remove DD_CLASS_TYPE_(DISJOINT|LEVEL)_NAMES and code
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
Remove the DD_CLASS_TYPE_*_NAMES classmap types and code.
These 2 classmap types accept class names at the PARAM interface, for
example:
echo +DRM_UT_CORE,-DRM_UT_KMS > /sys/module/drm/parameters/debug_names
The code works, but its only used by test-dynamic-debug, and wasn't
asked for by anyone else, so reduce LOC & test-surface; simplify things.
Also rename enum class_map_type to enum ddebug_class_map_type.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
v2:
move RvB after SoB
respect const instr in param_set_dyndbg_module_classes, return -EINVAL on classtype err.
---
include/linux/dynamic_debug.h | 23 +++-------
lib/dynamic_debug.c | 99 +++----------------------------------------
lib/test_dynamic_debug.c | 26 ------------
3 files changed, 12 insertions(+), 136 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index a10adac8e8f0..aa45dcf36a44 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -59,27 +59,16 @@ struct _ddebug {
#endif
} __attribute__((aligned(8)));
-enum class_map_type {
+enum ddebug_class_map_type {
DD_CLASS_TYPE_DISJOINT_BITS,
/**
- * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, one per bit.
- * expecting hex input. Built for drm.debug, basis for other types.
+ * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, mapped to bits[0..N].
+ * Expects hex input. Built for drm.debug, basis for other types.
*/
DD_CLASS_TYPE_LEVEL_NUM,
/**
- * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N.
- * N turns on just bits N-1 .. 0, so N=0 turns all bits off.
- */
- DD_CLASS_TYPE_DISJOINT_NAMES,
- /**
- * DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES,
- * classes are independent, like _DISJOINT_BITS.
- */
- DD_CLASS_TYPE_LEVEL_NAMES,
- /**
- * DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES,
- * intended for names like: INFO,DEBUG,TRACE, with a module prefix
- * avoid EMERG,ALERT,CRIT,ERR,WARNING: they're not debug
+ * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0..N.
+ * Input N turns on bits 0..N-1
*/
};
@@ -90,7 +79,7 @@ struct ddebug_class_map {
const char **class_names;
const int length;
const int base; /* index of 1st .class_id, allows split/shared space */
- enum class_map_type map_type;
+ enum ddebug_class_map_type map_type;
};
/* encapsulate linker provided built-in (or module) dyndbg data */
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index a9caf84ddb22..0377d9f8dcd1 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -646,76 +646,6 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
#define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
-/* accept comma-separated-list of [+-] classnames */
-static int param_set_dyndbg_classnames(const char *instr, const struct kernel_param *kp)
-{
- const struct ddebug_class_param *dcp = kp->arg;
- const struct ddebug_class_map *map = dcp->map;
- unsigned long curr_bits, old_bits;
- char *cl_str, *p, *tmp;
- int cls_id, totct = 0;
- bool wanted;
-
- cl_str = tmp = kstrdup_and_replace(instr, '\n', '\0', GFP_KERNEL);
- if (!tmp)
- return -ENOMEM;
-
- /* start with previously set state-bits, then modify */
- curr_bits = old_bits = *dcp->bits;
- vpr_info("\"%s\" > %s:0x%lx\n", cl_str, KP_NAME(kp), curr_bits);
-
- for (; cl_str; cl_str = p) {
- p = strchr(cl_str, ',');
- if (p)
- *p++ = '\0';
-
- if (*cl_str == '-') {
- wanted = false;
- cl_str++;
- } else {
- wanted = true;
- if (*cl_str == '+')
- cl_str++;
- }
- cls_id = match_string(map->class_names, map->length, cl_str);
- if (cls_id < 0) {
- pr_err("%s unknown to %s\n", cl_str, KP_NAME(kp));
- continue;
- }
-
- /* have one or more valid class_ids of one *_NAMES type */
- switch (map->map_type) {
- case DD_CLASS_TYPE_DISJOINT_NAMES:
- /* the +/- pertains to a single bit */
- if (test_bit(cls_id, &curr_bits) == wanted) {
- v3pr_info("no change on %s\n", cl_str);
- continue;
- }
- curr_bits ^= BIT(cls_id);
- totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits);
- *dcp->bits = curr_bits;
- v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
- map->class_names[cls_id]);
- break;
- case DD_CLASS_TYPE_LEVEL_NAMES:
- /* cls_id = N in 0..max. wanted +/- determines N or N-1 */
- old_bits = CLASSMAP_BITMASK(*dcp->lvl);
- curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
-
- totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits);
- *dcp->lvl = (cls_id + (wanted ? 1 : 0));
- v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
- map->class_names[cls_id], old_bits, curr_bits);
- break;
- default:
- pr_err("illegal map-type value %d\n", map->map_type);
- }
- }
- kfree(tmp);
- vpr_info("total matches: %d\n", totct);
- return 0;
-}
-
/**
* param_set_dyndbg_classes - class FOO >control
* @instr: string echo>d to sysfs, input depends on map_type
@@ -734,28 +664,14 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
unsigned long inrep, new_bits, old_bits;
int rc, totct = 0;
- switch (map->map_type) {
-
- case DD_CLASS_TYPE_DISJOINT_NAMES:
- case DD_CLASS_TYPE_LEVEL_NAMES:
- /* handle [+-]classnames list separately, we are done here */
- return param_set_dyndbg_classnames(instr, kp);
-
- case DD_CLASS_TYPE_DISJOINT_BITS:
- case DD_CLASS_TYPE_LEVEL_NUM:
- /* numeric input, accept and fall-thru */
- rc = kstrtoul(instr, 0, &inrep);
- if (rc) {
- pr_err("expecting numeric input: %s > %s\n", instr, KP_NAME(kp));
- return -EINVAL;
- }
- break;
- default:
- pr_err("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
+ rc = kstrtoul(instr, 0, &inrep);
+ if (rc) {
+ int len = strcspn(instr, "\n");
+ pr_err("expecting numeric input, not: %.*s > %s\n",
+ len, instr, KP_NAME(kp));
return -EINVAL;
}
- /* only _BITS,_NUM (numeric) map-types get here */
switch (map->map_type) {
case DD_CLASS_TYPE_DISJOINT_BITS:
/* expect bits. mask and warn if too many */
@@ -783,6 +699,7 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
break;
default:
pr_warn("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
+ return -EINVAL;
}
vpr_info("%s: total matches: %d\n", KP_NAME(kp), totct);
return 0;
@@ -804,12 +721,8 @@ int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
const struct ddebug_class_map *map = dcp->map;
switch (map->map_type) {
-
- case DD_CLASS_TYPE_DISJOINT_NAMES:
case DD_CLASS_TYPE_DISJOINT_BITS:
return scnprintf(buffer, PAGE_SIZE, "0x%lx\n", *dcp->bits);
-
- case DD_CLASS_TYPE_LEVEL_NAMES:
case DD_CLASS_TYPE_LEVEL_NUM:
return scnprintf(buffer, PAGE_SIZE, "%d\n", *dcp->lvl);
default:
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 77c2a669b6af..74d183ebf3e0 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -74,13 +74,6 @@ DECLARE_DYNDBG_CLASSMAP(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS, 0,
DD_SYS_WRAP(disjoint_bits, p);
DD_SYS_WRAP(disjoint_bits, T);
-/* symbolic input, independent bits */
-enum cat_disjoint_names { LOW = 11, MID, HI };
-DECLARE_DYNDBG_CLASSMAP(map_disjoint_names, DD_CLASS_TYPE_DISJOINT_NAMES, 10,
- "LOW", "MID", "HI");
-DD_SYS_WRAP(disjoint_names, p);
-DD_SYS_WRAP(disjoint_names, T);
-
/* numeric verbosity, V2 > V1 related */
enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 };
DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
@@ -88,13 +81,6 @@ DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
DD_SYS_WRAP(level_num, p);
DD_SYS_WRAP(level_num, T);
-/* symbolic verbosity */
-enum cat_level_names { L0 = 22, L1, L2, L3, L4, L5, L6, L7 };
-DECLARE_DYNDBG_CLASSMAP(map_level_names, DD_CLASS_TYPE_LEVEL_NAMES, 22,
- "L0", "L1", "L2", "L3", "L4", "L5", "L6", "L7");
-DD_SYS_WRAP(level_names, p);
-DD_SYS_WRAP(level_names, T);
-
/* stand-in for all pr_debug etc */
#define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n")
@@ -102,10 +88,6 @@ static void do_cats(void)
{
pr_debug("doing categories\n");
- prdbg(LOW);
- prdbg(MID);
- prdbg(HI);
-
prdbg(D2_CORE);
prdbg(D2_DRIVER);
prdbg(D2_KMS);
@@ -129,14 +111,6 @@ static void do_levels(void)
prdbg(V5);
prdbg(V6);
prdbg(V7);
-
- prdbg(L1);
- prdbg(L2);
- prdbg(L3);
- prdbg(L4);
- prdbg(L5);
- prdbg(L6);
- prdbg(L7);
}
static void do_prints(void)
--
2.54.0
^ permalink raw reply related
* [PATCH v2 09/24] dyndbg: add stub macro for DECLARE_DYNDBG_CLASSMAP
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
Add the stub macro for !DYNAMIC_DEBUG builds, after moving the
original macro-defn down under the big ifdef. Do it now so future
changes have a cleaner starting point.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
include/linux/dynamic_debug.h | 43 ++++++++++++++++++++++---------------------
1 file changed, 22 insertions(+), 21 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 05743900a116..a10adac8e8f0 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -93,27 +93,6 @@ struct ddebug_class_map {
enum class_map_type map_type;
};
-/**
- * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
- * @_var: a struct ddebug_class_map, passed to module_param_cb
- * @_type: enum class_map_type, chooses bits/verbose, numeric/symbolic
- * @_base: offset of 1st class-name. splits .class_id space
- * @classes: class-names used to control class'd prdbgs
- */
-#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \
- static const char *_var##_classnames[] = { __VA_ARGS__ }; \
- static struct ddebug_class_map __aligned(8) __used \
- __section("__dyndbg_classes") _var = { \
- .mod = THIS_MODULE, \
- .mod_name = KBUILD_MODNAME, \
- .base = _base, \
- .map_type = _maptype, \
- .length = NUM_TYPE_ARGS(char*, __VA_ARGS__), \
- .class_names = _var##_classnames, \
- }
-#define NUM_TYPE_ARGS(eltype, ...) \
- (sizeof((eltype[]){__VA_ARGS__}) / sizeof(eltype))
-
/* encapsulate linker provided built-in (or module) dyndbg data */
struct _ddebug_info {
struct _ddebug *descs;
@@ -138,6 +117,27 @@ struct ddebug_class_param {
#if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
+/**
+ * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
+ * @_var: a struct ddebug_class_map, passed to module_param_cb
+ * @_type: enum class_map_type, chooses bits/verbose, numeric/symbolic
+ * @_base: offset of 1st class-name. splits .class_id space
+ * @classes: class-names used to control class'd prdbgs
+ */
+#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \
+ static const char *_var##_classnames[] = { __VA_ARGS__ }; \
+ static struct ddebug_class_map __aligned(8) __used \
+ __section("__dyndbg_classes") _var = { \
+ .mod = THIS_MODULE, \
+ .mod_name = KBUILD_MODNAME, \
+ .base = _base, \
+ .map_type = _maptype, \
+ .length = NUM_TYPE_ARGS(char*, __VA_ARGS__), \
+ .class_names = _var##_classnames, \
+ }
+#define NUM_TYPE_ARGS(eltype, ...) \
+ (sizeof((eltype[]) {__VA_ARGS__}) / sizeof(eltype))
+
extern __printf(2, 3)
void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
@@ -314,6 +314,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)
#define DYNAMIC_DEBUG_BRANCH(descriptor) false
+#define DECLARE_DYNDBG_CLASSMAP(...)
#define dynamic_pr_debug(fmt, ...) \
no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
--
2.54.0
^ permalink raw reply related
* [PATCH v2 10/24] dyndbg: reword "class unknown," to "class:_UNKNOWN_"
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
When a dyndbg classname is unknown to a kernel module, the callsite is
un-addressable via >control queries.
The control-file displays this condition as "class unknown,"
currently. That spelling is sub-optimal/too-generic, so change it to
"class:_UNKNOWN_" to loudly announce the erroneous situation, and to
make it uniquely greppable.
NB: while this might be seen as a user-visible change, this shouldn't
disqualify the change:
a- it reports classmap coding error condition, which should be
detected before review.
b- SHOUTING the error makes it uniquely greppable.
c- the classmap feature is marked BROKEN for its only current user.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
lib/dynamic_debug.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 6b1e983cfedc..a9caf84ddb22 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -1166,7 +1166,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
if (class)
seq_printf(m, " class:%s", class);
else
- seq_printf(m, " class unknown, _id:%d", dp->class_id);
+ seq_printf(m, " class:_UNKNOWN_ _id:%d", dp->class_id);
}
seq_putc(m, '\n');
--
2.54.0
^ permalink raw reply related
* [PATCH v2 08/24] dyndbg: factor ddebug_match_desc out from ddebug_change
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie, Louis Chauvet
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
ddebug_change() is a big (~100 lines) function with a nested for loop.
The outer loop walks the per-module ddebug_tables list, and does
module stuff: it filters on a query's "module FOO*" and "class BAR",
failures here skip the entire inner loop.
The inner loop (60 lines) scans a module's descriptors. It starts
with a long block of filters on function, line, format, and the
validated "BAR" class (or the legacy/_DPRINTK_CLASS_DFLT).
These filters "continue" past pr_debugs that don't match the query
criteria, before it falls through the code below that counts matches,
then adjusts the flags and static-keys. This is unnecessarily hard to
think about.
So move the per-descriptor filter-block into a boolean function:
ddebug_match_desc(desc), and change each "continue" to "return false".
This puts a clear interface in place, so any future changes are either
inside, outside, or across this interface.
also fix checkpatch complaints about spaces and braces.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
lib/dynamic_debug.c | 83 ++++++++++++++++++++++++++++++-----------------------
1 file changed, 47 insertions(+), 36 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 18a71a9108d3..6b1e983cfedc 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -172,6 +172,52 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
* callsites, normally the same as number of changes. If verbose,
* logs the changes. Takes ddebug_lock.
*/
+static bool ddebug_match_desc(const struct ddebug_query *query,
+ struct _ddebug *dp,
+ int valid_class)
+{
+ /* match site against query-class */
+ if (dp->class_id != valid_class)
+ return false;
+
+ /* match against the source filename */
+ if (query->filename &&
+ !match_wildcard(query->filename, dp->filename) &&
+ !match_wildcard(query->filename,
+ kbasename(dp->filename)) &&
+ !match_wildcard(query->filename,
+ trim_prefix(dp->filename)))
+ return false;
+
+ /* match against the function */
+ if (query->function &&
+ !match_wildcard(query->function, dp->function))
+ return false;
+
+ /* match against the format */
+ if (query->format) {
+ if (*query->format == '^') {
+ char *p;
+ /* anchored search. match must be at beginning */
+ p = strstr(dp->format, query->format + 1);
+ if (p != dp->format)
+ return false;
+ } else if (!strstr(dp->format, query->format)) {
+ return false;
+ }
+ }
+
+ /* match against the line number range */
+ if (query->first_lineno &&
+ dp->lineno < query->first_lineno)
+ return false;
+ if (query->last_lineno &&
+ dp->lineno > query->last_lineno)
+ return false;
+
+ return true;
+}
+
static int ddebug_change(const struct ddebug_query *query,
struct flag_settings *modifiers)
{
@@ -204,42 +250,7 @@ static int ddebug_change(const struct ddebug_query *query,
for (i = 0; i < dt->num_ddebugs; i++) {
struct _ddebug *dp = &dt->ddebugs[i];
- /* match site against query-class */
- if (dp->class_id != valid_class)
- continue;
-
- /* match against the source filename */
- if (query->filename &&
- !match_wildcard(query->filename, dp->filename) &&
- !match_wildcard(query->filename,
- kbasename(dp->filename)) &&
- !match_wildcard(query->filename,
- trim_prefix(dp->filename)))
- continue;
-
- /* match against the function */
- if (query->function &&
- !match_wildcard(query->function, dp->function))
- continue;
-
- /* match against the format */
- if (query->format) {
- if (*query->format == '^') {
- char *p;
- /* anchored search. match must be at beginning */
- p = strstr(dp->format, query->format+1);
- if (p != dp->format)
- continue;
- } else if (!strstr(dp->format, query->format))
- continue;
- }
-
- /* match against the line number range */
- if (query->first_lineno &&
- dp->lineno < query->first_lineno)
- continue;
- if (query->last_lineno &&
- dp->lineno > query->last_lineno)
+ if (!ddebug_match_desc(query, dp, valid_class))
continue;
nfound++;
--
2.54.0
^ permalink raw reply related
* [PATCH v2 07/24] dyndbg.lds.S: fix lost dyndbg sections in modules
From: Jim Cromie @ 2026-05-23 7:14 UTC (permalink / raw)
To: Jonathan Corbet, Shuah Khan, Arnd Bergmann, Jason Baron,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Andrew Morton, Shuah Khan
Cc: linux-doc, linux-kernel, linux-arch, linux-modules,
linux-kselftest, Jim Cromie
In-Reply-To: <20260523-dd-maint-2-v2-0-b937312aa083@gmail.com>
With CONFIG_DRM_USE_DYNAMIC_DEBUG=y, several build configs had
problems with __dyndbg* sections getting lost in drm drivers. Fix
this by following the model demonstrated in codetag.lds.h.
Introduce include/asm-generic/dyndbg.lds.h, to bundle dynamic-debug's
multiple sections together, into 2 macros:
vmlinux.lds.h DATA_DATA: move the 2 BOUNDED_SECTION_BY(__dyndbg*)
calls into dyndbg.lds.h DYNDBG_SECTIONS(). vmlinux.lds.h now includes
the new file and calls the new macro.
MOD_DYNDBG_SECTIONS keeps the 2 sections by name, aligns them and sets
the output address to 0 when the sections are empty.
dyndbg.lds.h includes (reuses) bounded-section.lds.h
scripts/module.lds.S: now calls MOD_DYNDBG_SECTIONS right before the
CODETAG macro (consistent with their placements in vmlinux.lds.h), and
also includes dyndbg.lds.h
This isolates vmlinux.lds.h from further __dyndbg section additions.
CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
---
v3: move #includes to top, drop extra ALIGN(8) in DYNDBG_SECTIONS, add RvBy
v2: Address linker script review feedback for relocatable modules.
MOD_DYNDBG_SECTIONS() used the BOUNDED_SECTION_BY() macro, which
proved problematic for kernel modules for two reasons:
1. Unwanted Empty Sections:
BOUNDED_SECTION_BY() automatically generates `__start` and `__stop`
symbols. When applied to `MOD_DYNDBG_SECTIONS()`, the linker assumes
the sections are populated due to the symbol definitions, forcing an
empty `__dyndbg` and `__dyndbg_classes` output section in every
compiled module, even those without dynamic debug configuration.
Since the module loader uses `section_objs()` to locate data via
ELF headers instead of relying on `__start`/`__stop` symbols, these
assignments are completely unnecessary.
2. Non-zero Output Addresses:
During relocatable linking (e.g., `ld.bfd -r`), omitting an explicit
base address causes the section to inherit the current location
counter. This results in non-zero sh_addr values in `.ko` files,
which is confusing, degrades compressibility, and can cause issues
with external tools parsing the ELF.
Fix both issues by dropping `BOUNDED_SECTION_BY()` in favor of a simple
`KEEP(*(...))` constraint and explicitly defining the sections with a `0`
base address: `__dyndbg 0 : ALIGN(8) { ... }`.
fixup-inc-vml
---
MAINTAINERS | 1 +
include/asm-generic/dyndbg.lds.h | 18 ++++++++++++++++++
include/asm-generic/vmlinux.lds.h | 6 ++----
scripts/module.lds.S | 2 ++
4 files changed, 23 insertions(+), 4 deletions(-)
diff --git a/MAINTAINERS b/MAINTAINERS
index c2c6d79275c6..e87bfe2e9e62 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9079,6 +9079,7 @@ DYNAMIC DEBUG
M: Jason Baron <jbaron@akamai.com>
M: Jim Cromie <jim.cromie@gmail.com>
S: Maintained
+F: include/asm-generic/dyndbg.lds.h
F: include/linux/dynamic_debug.h
F: lib/dynamic_debug.c
F: lib/test_dynamic_debug.c
diff --git a/include/asm-generic/dyndbg.lds.h b/include/asm-generic/dyndbg.lds.h
new file mode 100644
index 000000000000..9d8951bef688
--- /dev/null
+++ b/include/asm-generic/dyndbg.lds.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_GENERIC_DYNDBG_LDS_H
+#define __ASM_GENERIC_DYNDBG_LDS_H
+
+#include <asm-generic/bounded_sections.lds.h>
+#define DYNDBG_SECTIONS() \
+ BOUNDED_SECTION_BY(__dyndbg, ___dyndbg) \
+ BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes)
+
+#define MOD_DYNDBG_SECTIONS() \
+ __dyndbg 0 : ALIGN(8) { \
+ KEEP(*(__dyndbg)) \
+ } \
+ __dyndbg_classes 0 : ALIGN(8) { \
+ KEEP(*(__dyndbg_classes)) \
+ }
+
+#endif /* __ASM_GENERIC_DYNDBG_LDS_H */
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 0e4677b71d16..f2ec36a35809 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -52,6 +52,7 @@
#include <asm-generic/bounded_sections.lds.h>
#include <asm-generic/codetag.lds.h>
+#include <asm-generic/dyndbg.lds.h>
#ifndef LOAD_OFFSET
#define LOAD_OFFSET 0
@@ -344,10 +345,7 @@
*(.data..do_once) \
STRUCT_ALIGN(); \
*(__tracepoints) \
- /* implement dynamic printk debug */ \
- . = ALIGN(8); \
- BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes) \
- BOUNDED_SECTION_BY(__dyndbg, ___dyndbg) \
+ DYNDBG_SECTIONS() \
CODETAG_SECTIONS() \
LIKELY_PROFILE() \
BRANCH_PROFILE() \
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index b62683061d79..2e62dc5bd5d4 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -10,6 +10,7 @@
#endif
#include <asm-generic/codetag.lds.h>
+#include <asm-generic/dyndbg.lds.h>
SECTIONS {
/DISCARD/ : {
@@ -61,6 +62,7 @@ SECTIONS {
*(.rodata..L*)
}
+ MOD_DYNDBG_SECTIONS()
MOD_SEPARATE_CODETAG_SECTIONS()
}
--
2.54.0
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