This is a note to let you know that I've just added the patch titled
iio: adc: ad7192: fix channel select
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
From 21d7241faf406e8aee3ce348451cc362d5db6a02 Mon Sep 17 00:00:00 2001
From: Markus Burri <markus.burri(a)mt.com>
Date: Fri, 24 Jan 2025 16:07:03 +0100
Subject: iio: adc: ad7192: fix channel select
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Channel configuration doesn't work as expected.
For FIELD_PREP the bit mask is needed and not the bit number.
Fixes: 874bbd1219c7 ("iio: adc: ad7192: Use bitfield access macros")
Signed-off-by: Markus Burri <markus.burri(a)mt.com>
Reviewed-by: Nuno Sá <nuno.sa(a)analog.com>
Link: https://patch.msgid.link/20250124150703.97848-1-markus.burri@mt.com
Cc: <Stable(a)vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron(a)huawei.com>
---
drivers/iio/adc/ad7192.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
index e96a5ae92375..cfaf8f7e0a07 100644
--- a/drivers/iio/adc/ad7192.c
+++ b/drivers/iio/adc/ad7192.c
@@ -1084,7 +1084,7 @@ static int ad7192_update_scan_mode(struct iio_dev *indio_dev, const unsigned lon
conf &= ~AD7192_CONF_CHAN_MASK;
for_each_set_bit(i, scan_mask, 8)
- conf |= FIELD_PREP(AD7192_CONF_CHAN_MASK, i);
+ conf |= FIELD_PREP(AD7192_CONF_CHAN_MASK, BIT(i));
ret = ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, conf);
if (ret < 0)
--
2.48.1
Hi all,
I ran into a small memory leak while working on the BPF selftests suite
on the bpf-next tree. It leads to an oom-kill after thousands of iterations
in the qemu environment provided by tools/testing/selftests/bpf/vmtest.sh.
To reproduce the issue from the net-next tree:
$ git remote add bpf-next https://github.com/kernel-patches/bpf
$ git fetch bpf-next
$ git cherry-pick 723f1b9ce332^..edb996fae276
$ tools/testing/selftests/bpf/vmtest.sh -i -s "bash -c 'for i in {1..8192}; do ./test_progs -t xdp_veth_redirect; done'"
[... coffee break ...]
[ XXXX.YYYYYY] sh invoked oom-killer: gfp_mask=0x440dc0(GFP_KERNEL_ACCOUNT|__GFP_COMP|__GFP_ZERO), order=0, oom_score_adj=0
[...]
[ XXXX.YYYYYY] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/,task=bash,pid=116,uid=0
[ XXXX.YYYYYY] Out of memory: Killed process 116 (bash) total-vm:6816kB, anon-rss:2816kB, file-rss:240kB, shmem-rss:0kB, UID:0 pgtables:48kB oom_score_adj:0
Signed-off-by: Bastien Curutchet (eBPF Foundation) <bastien.curutchet(a)bootlin.com>
---
Bastien Curutchet (eBPF Foundation) (2):
rtnetlink: Fix rtnl_net_cmp_locks() when DEBUG is off
rtnetlink: Release nets when leaving rtnl_setlink()
net/core/rtnetlink.c | 4 ++++
1 file changed, 4 insertions(+)
---
base-commit: 5d332c1ad3226c0a31653dbf2391bd332e157625
change-id: 20250211-rtnetlink_leak-8b12ca5c83f3
Best regards,
--
Bastien Curutchet (eBPF Foundation) <bastien.curutchet(a)bootlin.com>
When update_mmu_cache_range() is called by update_mmu_cache(), the vmf
parameter is NULL, which will cause a NULL pointer dereference issue in
adjust_pte():
Unable to handle kernel NULL pointer dereference at virtual address 00000030 when read
Hardware name: Atmel AT91SAM9
PC is at update_mmu_cache_range+0x1e0/0x278
LR is at pte_offset_map_rw_nolock+0x18/0x2c
Call trace:
update_mmu_cache_range from remove_migration_pte+0x29c/0x2ec
remove_migration_pte from rmap_walk_file+0xcc/0x130
rmap_walk_file from remove_migration_ptes+0x90/0xa4
remove_migration_ptes from migrate_pages_batch+0x6d4/0x858
migrate_pages_batch from migrate_pages+0x188/0x488
migrate_pages from compact_zone+0x56c/0x954
compact_zone from compact_node+0x90/0xf0
compact_node from kcompactd+0x1d4/0x204
kcompactd from kthread+0x120/0x12c
kthread from ret_from_fork+0x14/0x38
Exception stack(0xc0d8bfb0 to 0xc0d8bff8)
To fix it, do not rely on whether 'ptl' is equal to decide whether to hold
the pte lock, but decide it by whether CONFIG_SPLIT_PTE_PTLOCKS is
enabled. In addition, if two vmas map to the same PTE page, there is no
need to hold the pte lock again, otherwise a deadlock will occur. Just add
the need_lock parameter to let adjust_pte() know this information.
Reported-by: Ezra Buehler <ezra(a)easyb.ch>
Closes: https://lore.kernel.org/lkml/CAM1KZSmZ2T_riHvay+7cKEFxoPgeVpHkVFTzVVEQ1BO0c…
Fixes: fc9c45b71f43 ("arm: adjust_pte() use pte_offset_map_rw_nolock()")
Cc: stable(a)vger.kernel.org
Signed-off-by: Qi Zheng <zhengqi.arch(a)bytedance.com>
---
arch/arm/mm/fault-armv.c | 40 ++++++++++++++++++++++++++++------------
1 file changed, 28 insertions(+), 12 deletions(-)
diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c
index 2bec87c3327d2..3627bf0957c75 100644
--- a/arch/arm/mm/fault-armv.c
+++ b/arch/arm/mm/fault-armv.c
@@ -62,7 +62,7 @@ static int do_adjust_pte(struct vm_area_struct *vma, unsigned long address,
}
static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
- unsigned long pfn, struct vm_fault *vmf)
+ unsigned long pfn, bool need_lock)
{
spinlock_t *ptl;
pgd_t *pgd;
@@ -99,12 +99,11 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
if (!pte)
return 0;
- /*
- * If we are using split PTE locks, then we need to take the page
- * lock here. Otherwise we are using shared mm->page_table_lock
- * which is already locked, thus cannot take it.
- */
- if (ptl != vmf->ptl) {
+ if (need_lock) {
+ /*
+ * Use nested version here to indicate that we are already
+ * holding one similar spinlock.
+ */
spin_lock_nested(ptl, SINGLE_DEPTH_NESTING);
if (unlikely(!pmd_same(pmdval, pmdp_get_lockless(pmd)))) {
pte_unmap_unlock(pte, ptl);
@@ -114,7 +113,7 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
ret = do_adjust_pte(vma, address, pfn, pte);
- if (ptl != vmf->ptl)
+ if (need_lock)
spin_unlock(ptl);
pte_unmap(pte);
@@ -123,16 +122,17 @@ static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
static void
make_coherent(struct address_space *mapping, struct vm_area_struct *vma,
- unsigned long addr, pte_t *ptep, unsigned long pfn,
- struct vm_fault *vmf)
+ unsigned long addr, pte_t *ptep, unsigned long pfn)
{
struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *mpnt;
unsigned long offset;
+ unsigned long start;
pgoff_t pgoff;
int aliases = 0;
pgoff = vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT);
+ start = ALIGN_DOWN(addr, PMD_SIZE);
/*
* If we have any shared mappings that are in the same mm
@@ -141,6 +141,14 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma,
*/
flush_dcache_mmap_lock(mapping);
vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
+ unsigned long mpnt_addr;
+ /*
+ * If we are using split PTE locks, then we need to take the pte
+ * lock. Otherwise we are using shared mm->page_table_lock which
+ * is already locked, thus cannot take it.
+ */
+ bool need_lock = IS_ENABLED(CONFIG_SPLIT_PTE_PTLOCKS);
+
/*
* If this VMA is not in our MM, we can ignore it.
* Note that we intentionally mask out the VMA
@@ -151,7 +159,15 @@ make_coherent(struct address_space *mapping, struct vm_area_struct *vma,
if (!(mpnt->vm_flags & VM_MAYSHARE))
continue;
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
- aliases += adjust_pte(mpnt, mpnt->vm_start + offset, pfn, vmf);
+ mpnt_addr = mpnt->vm_start + offset;
+ /*
+ * If mpnt_addr and addr are mapped to the same PTE page, there
+ * is no need to hold the pte lock again, otherwise a deadlock
+ * will occur.
+ */
+ if (mpnt_addr >= start && mpnt_addr - start < PMD_SIZE)
+ need_lock = false;
+ aliases += adjust_pte(mpnt, mpnt_addr, pfn, need_lock);
}
flush_dcache_mmap_unlock(mapping);
if (aliases)
@@ -194,7 +210,7 @@ void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma,
__flush_dcache_folio(mapping, folio);
if (mapping) {
if (cache_is_vivt())
- make_coherent(mapping, vma, addr, ptep, pfn, vmf);
+ make_coherent(mapping, vma, addr, ptep, pfn);
else if (vma->vm_flags & VM_EXEC)
__flush_icache_all();
}
--
2.20.1
Since the new_metric and last_hop_metric variables can reach
the MAX_METRIC(0xffffffff) value, an integer overflow may occur
when multiplying them by 10/9. It can lead to incorrect behavior.
Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with SVACE.
Fixes: a8d418d9ac25 ("mac80211: mesh: only switch path when new metric is at least 10% better")
Cc: stable(a)vger.kernel.org
Signed-off-by: Ilia Gavrilov <Ilia.Gavrilov(a)infotecs.ru>
---
v2:
- Remove 64-bit arithmetic according to https://lore.kernel.org/all/a6bd38c58f2f7685eac53844f2336432503c328e.camel@…
- Replace multiplication by 10/9 with a function that compares metrics by adding 10% without integer overflow
v3:
- Fix a typo (persent->percent)
v4:
- Simplify the is_metric_better() function
- Remove 'inline', add a comment
net/mac80211/mesh_hwmp.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index 4e9546e998b6..c94a9c7ca960 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -367,6 +367,12 @@ u32 airtime_link_metric_get(struct ieee80211_local *local,
return (u32)result;
}
+/* Check that the first metric is at least 10% better than the second one */
+static bool is_metric_better(u32 x, u32 y)
+{
+ return (x < y) && (x < (y - x / 10));
+}
+
/**
* hwmp_route_info_get - Update routing info to originator and transmitter
*
@@ -458,8 +464,8 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
(mpath->sn == orig_sn &&
(rcu_access_pointer(mpath->next_hop) !=
sta ?
- mult_frac(new_metric, 10, 9) :
- new_metric) >= mpath->metric)) {
+ !is_metric_better(new_metric, mpath->metric) :
+ new_metric >= mpath->metric))) {
process = false;
fresh_info = false;
}
@@ -533,8 +539,8 @@ static u32 hwmp_route_info_get(struct ieee80211_sub_if_data *sdata,
if ((mpath->flags & MESH_PATH_FIXED) ||
((mpath->flags & MESH_PATH_ACTIVE) &&
((rcu_access_pointer(mpath->next_hop) != sta ?
- mult_frac(last_hop_metric, 10, 9) :
- last_hop_metric) > mpath->metric)))
+ !is_metric_better(last_hop_metric, mpath->metric) :
+ last_hop_metric > mpath->metric))))
fresh_info = false;
} else {
mpath = mesh_path_add(sdata, ta);
--
2.39.5
The function drm_syncobj_fence_get() may return NULL if the syncobj
has no fence. In eb_fences_add(), this return value is not checked,
leading to a potential NULL pointer dereference in
i915_request_await_dma_fence().
This patch adds a check for the return value of drm_syncobj_fence_get
and returns an error if it is NULL, preventing the NULL pointer
dereference.
Fixes: 544460c33821 ("drm/i915: Multi-BB execbuf")
Cc: stable(a)vger.kernel.org # 5.16+
Signed-off-by: Wentao Liang <vulab(a)iscas.ac.cn>
---
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index f151640c1d13..7da65535feb9 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -3252,6 +3252,12 @@ eb_fences_add(struct i915_execbuffer *eb, struct i915_request *rq,
struct dma_fence *fence;
fence = drm_syncobj_fence_get(eb->gem_context->syncobj);
+ if (!fence) {
+ drm_dbg(&eb->i915->drm,
+ "Syncobj handle has no fence\n");
+ return ERR_PTR(-EINVAL);
+ }
+
err = i915_request_await_dma_fence(rq, fence);
dma_fence_put(fence);
if (err)
--
2.42.0.windows.2
The patch titled
Subject: arm: pgtable: fix NULL pointer dereference issue
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
arm-pgtable-fix-null-pointer-dereference-issue.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Qi Zheng <zhengqi.arch(a)bytedance.com>
Subject: arm: pgtable: fix NULL pointer dereference issue
Date: Wed, 12 Feb 2025 14:40:02 +0800
When update_mmu_cache_range() is called by update_mmu_cache(), the vmf
parameter is NULL, which will cause a NULL pointer dereference issue in
adjust_pte():
Unable to handle kernel NULL pointer dereference at virtual address 00000030 when read
Hardware name: Atmel AT91SAM9
PC is at update_mmu_cache_range+0x1e0/0x278
LR is at pte_offset_map_rw_nolock+0x18/0x2c
Call trace:
update_mmu_cache_range from remove_migration_pte+0x29c/0x2ec
remove_migration_pte from rmap_walk_file+0xcc/0x130
rmap_walk_file from remove_migration_ptes+0x90/0xa4
remove_migration_ptes from migrate_pages_batch+0x6d4/0x858
migrate_pages_batch from migrate_pages+0x188/0x488
migrate_pages from compact_zone+0x56c/0x954
compact_zone from compact_node+0x90/0xf0
compact_node from kcompactd+0x1d4/0x204
kcompactd from kthread+0x120/0x12c
kthread from ret_from_fork+0x14/0x38
Exception stack(0xc0d8bfb0 to 0xc0d8bff8)
To fix it, do not rely on whether 'ptl' is equal to decide whether to hold
the pte lock, but decide it by whether CONFIG_SPLIT_PTE_PTLOCKS is
enabled. In addition, if two vmas map to the same PTE page, there is no
need to hold the pte lock again, otherwise a deadlock will occur. Just add
the need_lock parameter to let adjust_pte() know this information.
Link: https://lkml.kernel.org/r/20250212064002.55598-1-zhengqi.arch@bytedance.com
Fixes: fc9c45b71f43 ("arm: adjust_pte() use pte_offset_map_rw_nolock()")
Signed-off-by: Qi Zheng <zhengqi.arch(a)bytedance.com>
Reported-by: Ezra Buehler <ezra(a)easyb.ch>
Closes: https://lore.kernel.org/lkml/CAM1KZSmZ2T_riHvay+7cKEFxoPgeVpHkVFTzVVEQ1BO0c…
Cc: David Hildenbrand <david(a)redhat.com>
Cc: Hugh Dickins <hughd(a)google.com>
Cc: Muchun Song <muchun.song(a)linux.dev>
Cc: Russell King <linux(a)armlinux.org.uk>
Cc: Ryan Roberts <ryan.roberts(a)arm.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
arch/arm/mm/fault-armv.c | 40 +++++++++++++++++++++++++------------
1 file changed, 28 insertions(+), 12 deletions(-)
--- a/arch/arm/mm/fault-armv.c~arm-pgtable-fix-null-pointer-dereference-issue
+++ a/arch/arm/mm/fault-armv.c
@@ -62,7 +62,7 @@ static int do_adjust_pte(struct vm_area_
}
static int adjust_pte(struct vm_area_struct *vma, unsigned long address,
- unsigned long pfn, struct vm_fault *vmf)
+ unsigned long pfn, bool need_lock)
{
spinlock_t *ptl;
pgd_t *pgd;
@@ -99,12 +99,11 @@ again:
if (!pte)
return 0;
- /*
- * If we are using split PTE locks, then we need to take the page
- * lock here. Otherwise we are using shared mm->page_table_lock
- * which is already locked, thus cannot take it.
- */
- if (ptl != vmf->ptl) {
+ if (need_lock) {
+ /*
+ * Use nested version here to indicate that we are already
+ * holding one similar spinlock.
+ */
spin_lock_nested(ptl, SINGLE_DEPTH_NESTING);
if (unlikely(!pmd_same(pmdval, pmdp_get_lockless(pmd)))) {
pte_unmap_unlock(pte, ptl);
@@ -114,7 +113,7 @@ again:
ret = do_adjust_pte(vma, address, pfn, pte);
- if (ptl != vmf->ptl)
+ if (need_lock)
spin_unlock(ptl);
pte_unmap(pte);
@@ -123,16 +122,17 @@ again:
static void
make_coherent(struct address_space *mapping, struct vm_area_struct *vma,
- unsigned long addr, pte_t *ptep, unsigned long pfn,
- struct vm_fault *vmf)
+ unsigned long addr, pte_t *ptep, unsigned long pfn)
{
struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *mpnt;
unsigned long offset;
+ unsigned long start;
pgoff_t pgoff;
int aliases = 0;
pgoff = vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT);
+ start = ALIGN_DOWN(addr, PMD_SIZE);
/*
* If we have any shared mappings that are in the same mm
@@ -141,6 +141,14 @@ make_coherent(struct address_space *mapp
*/
flush_dcache_mmap_lock(mapping);
vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
+ unsigned long mpnt_addr;
+ /*
+ * If we are using split PTE locks, then we need to take the pte
+ * lock. Otherwise we are using shared mm->page_table_lock which
+ * is already locked, thus cannot take it.
+ */
+ bool need_lock = IS_ENABLED(CONFIG_SPLIT_PTE_PTLOCKS);
+
/*
* If this VMA is not in our MM, we can ignore it.
* Note that we intentionally mask out the VMA
@@ -151,7 +159,15 @@ make_coherent(struct address_space *mapp
if (!(mpnt->vm_flags & VM_MAYSHARE))
continue;
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
- aliases += adjust_pte(mpnt, mpnt->vm_start + offset, pfn, vmf);
+ mpnt_addr = mpnt->vm_start + offset;
+ /*
+ * If mpnt_addr and addr are mapped to the same PTE page, there
+ * is no need to hold the pte lock again, otherwise a deadlock
+ * will occur.
+ */
+ if (mpnt_addr >= start && mpnt_addr - start < PMD_SIZE)
+ need_lock = false;
+ aliases += adjust_pte(mpnt, mpnt_addr, pfn, need_lock);
}
flush_dcache_mmap_unlock(mapping);
if (aliases)
@@ -194,7 +210,7 @@ void update_mmu_cache_range(struct vm_fa
__flush_dcache_folio(mapping, folio);
if (mapping) {
if (cache_is_vivt())
- make_coherent(mapping, vma, addr, ptep, pfn, vmf);
+ make_coherent(mapping, vma, addr, ptep, pfn);
else if (vma->vm_flags & VM_EXEC)
__flush_icache_all();
}
_
Patches currently in -mm which might be from zhengqi.arch(a)bytedance.com are
mm-pgtable-fix-incorrect-reclaim-of-non-empty-pte-pages.patch
arm-pgtable-fix-null-pointer-dereference-issue.patch
UNCRD is recruiting eligible candidates for the post listed below:
Human Resources Officer
Economic Affairs Officer
Logistics Officer
Environmental Affairs Officer
Administrative Officer
Chief Nurse
Finance and Budget Officer
Information Management Officer
Property Management Officer
Project Manager Engineer
Pharmacist
Research Officer
Medical Officer
Programme Officer
Training Officer
Engineer
Full Listing in the attached PDF.
HOW TO APPLY
Interested and qualified applicants should send their detailed Resumes/Cvs to recruit(a)uncrd.org as soon as possible.
Each applicant must bear in mind that submission of incomplete or inaccurate applications may render that applicant ineligible for consideration. Candidates under serious consideration for selection will be subjected to a reference-checking process to verify the information provided in the application.
Goodluck,
New Recruitment.
The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x a9ab6591b45258b79af1cb66112fd9f83c8855da
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025021018-attire-arrange-51d4@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a9ab6591b45258b79af1cb66112fd9f83c8855da Mon Sep 17 00:00:00 2001
From: Lucas De Marchi <lucas.demarchi(a)intel.com>
Date: Thu, 23 Jan 2025 12:22:03 -0800
Subject: [PATCH] drm/xe: Fix and re-enable xe_print_blob_ascii85()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Commit 70fb86a85dc9 ("drm/xe: Revert some changes that break a mesa
debug tool") partially reverted some changes to workaround breakage
caused to mesa tools. However, in doing so it also broke fetching the
GuC log via debugfs since xe_print_blob_ascii85() simply bails out.
The fix is to avoid the extra newlines: the devcoredump interface is
line-oriented and adding random newlines in the middle breaks it. If a
tool is able to parse it by looking at the data and checking for chars
that are out of the ascii85 space, it can still do so. A format change
that breaks the line-oriented output on devcoredump however needs better
coordination with existing tools.
v2: Add suffix description comment
v3: Reword explanation of xe_print_blob_ascii85() calling drm_puts()
in a loop
Reviewed-by: José Roberto de Souza <jose.souza(a)intel.com>
Cc: John Harrison <John.C.Harrison(a)Intel.com>
Cc: Julia Filipchuk <julia.filipchuk(a)intel.com>
Cc: José Roberto de Souza <jose.souza(a)intel.com>
Cc: stable(a)vger.kernel.org
Fixes: 70fb86a85dc9 ("drm/xe: Revert some changes that break a mesa debug tool")
Fixes: ec1455ce7e35 ("drm/xe/devcoredump: Add ASCII85 dump helper function")
Link: https://patchwork.freedesktop.org/patch/msgid/20250123202307.95103-2-jose.s…
Signed-off-by: Lucas De Marchi <lucas.demarchi(a)intel.com>
(cherry picked from commit 2c95bbf5002776117a69caed3b31c10bf7341bec)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi(a)intel.com>
diff --git a/drivers/gpu/drm/xe/xe_devcoredump.c b/drivers/gpu/drm/xe/xe_devcoredump.c
index a7946a76777e..39fe485d2085 100644
--- a/drivers/gpu/drm/xe/xe_devcoredump.c
+++ b/drivers/gpu/drm/xe/xe_devcoredump.c
@@ -391,42 +391,34 @@ int xe_devcoredump_init(struct xe_device *xe)
/**
* xe_print_blob_ascii85 - print a BLOB to some useful location in ASCII85
*
- * The output is split to multiple lines because some print targets, e.g. dmesg
- * cannot handle arbitrarily long lines. Note also that printing to dmesg in
- * piece-meal fashion is not possible, each separate call to drm_puts() has a
- * line-feed automatically added! Therefore, the entire output line must be
- * constructed in a local buffer first, then printed in one atomic output call.
+ * The output is split into multiple calls to drm_puts() because some print
+ * targets, e.g. dmesg, cannot handle arbitrarily long lines. These targets may
+ * add newlines, as is the case with dmesg: each drm_puts() call creates a
+ * separate line.
*
* There is also a scheduler yield call to prevent the 'task has been stuck for
* 120s' kernel hang check feature from firing when printing to a slow target
* such as dmesg over a serial port.
*
- * TODO: Add compression prior to the ASCII85 encoding to shrink huge buffers down.
- *
* @p: the printer object to output to
* @prefix: optional prefix to add to output string
+ * @suffix: optional suffix to add at the end. 0 disables it and is
+ * not added to the output, which is useful when using multiple calls
+ * to dump data to @p
* @blob: the Binary Large OBject to dump out
* @offset: offset in bytes to skip from the front of the BLOB, must be a multiple of sizeof(u32)
* @size: the size in bytes of the BLOB, must be a multiple of sizeof(u32)
*/
-void xe_print_blob_ascii85(struct drm_printer *p, const char *prefix,
+void xe_print_blob_ascii85(struct drm_printer *p, const char *prefix, char suffix,
const void *blob, size_t offset, size_t size)
{
const u32 *blob32 = (const u32 *)blob;
char buff[ASCII85_BUFSZ], *line_buff;
size_t line_pos = 0;
- /*
- * Splitting blobs across multiple lines is not compatible with the mesa
- * debug decoder tool. Note that even dropping the explicit '\n' below
- * doesn't help because the GuC log is so big some underlying implementation
- * still splits the lines at 512K characters. So just bail completely for
- * the moment.
- */
- return;
-
#define DMESG_MAX_LINE_LEN 800
-#define MIN_SPACE (ASCII85_BUFSZ + 2) /* 85 + "\n\0" */
+ /* Always leave space for the suffix char and the \0 */
+#define MIN_SPACE (ASCII85_BUFSZ + 2) /* 85 + "<suffix>\0" */
if (size & 3)
drm_printf(p, "Size not word aligned: %zu", size);
@@ -458,7 +450,6 @@ void xe_print_blob_ascii85(struct drm_printer *p, const char *prefix,
line_pos += strlen(line_buff + line_pos);
if ((line_pos + MIN_SPACE) >= DMESG_MAX_LINE_LEN) {
- line_buff[line_pos++] = '\n';
line_buff[line_pos++] = 0;
drm_puts(p, line_buff);
@@ -470,10 +461,11 @@ void xe_print_blob_ascii85(struct drm_printer *p, const char *prefix,
}
}
- if (line_pos) {
- line_buff[line_pos++] = '\n';
- line_buff[line_pos++] = 0;
+ if (suffix)
+ line_buff[line_pos++] = suffix;
+ if (line_pos) {
+ line_buff[line_pos++] = 0;
drm_puts(p, line_buff);
}
diff --git a/drivers/gpu/drm/xe/xe_devcoredump.h b/drivers/gpu/drm/xe/xe_devcoredump.h
index 6a17e6d60102..5391a80a4d1b 100644
--- a/drivers/gpu/drm/xe/xe_devcoredump.h
+++ b/drivers/gpu/drm/xe/xe_devcoredump.h
@@ -29,7 +29,7 @@ static inline int xe_devcoredump_init(struct xe_device *xe)
}
#endif
-void xe_print_blob_ascii85(struct drm_printer *p, const char *prefix,
+void xe_print_blob_ascii85(struct drm_printer *p, const char *prefix, char suffix,
const void *blob, size_t offset, size_t size);
#endif
diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
index 8b65c5e959cc..50c8076b5158 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.c
+++ b/drivers/gpu/drm/xe/xe_guc_ct.c
@@ -1724,7 +1724,8 @@ void xe_guc_ct_snapshot_print(struct xe_guc_ct_snapshot *snapshot,
snapshot->g2h_outstanding);
if (snapshot->ctb)
- xe_print_blob_ascii85(p, "CTB data", snapshot->ctb, 0, snapshot->ctb_size);
+ xe_print_blob_ascii85(p, "CTB data", '\n',
+ snapshot->ctb, 0, snapshot->ctb_size);
} else {
drm_puts(p, "CT disabled\n");
}
diff --git a/drivers/gpu/drm/xe/xe_guc_log.c b/drivers/gpu/drm/xe/xe_guc_log.c
index df4cfb698cdb..2baa4d95571f 100644
--- a/drivers/gpu/drm/xe/xe_guc_log.c
+++ b/drivers/gpu/drm/xe/xe_guc_log.c
@@ -211,8 +211,10 @@ void xe_guc_log_snapshot_print(struct xe_guc_log_snapshot *snapshot, struct drm_
remain = snapshot->size;
for (i = 0; i < snapshot->num_chunks; i++) {
size_t size = min(GUC_LOG_CHUNK_SIZE, remain);
+ const char *prefix = i ? NULL : "Log data";
+ char suffix = i == snapshot->num_chunks - 1 ? '\n' : 0;
- xe_print_blob_ascii85(p, i ? NULL : "Log data", snapshot->copy[i], 0, size);
+ xe_print_blob_ascii85(p, prefix, suffix, snapshot->copy[i], 0, size);
remain -= size;
}
}