The patch titled
Subject: rcu: dump vmalloc memory info safely
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
rcu-dump-vmalloc-memory-info-safely.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: Zqiang <qiang.zhang1211(a)gmail.com>
Subject: rcu: dump vmalloc memory info safely
Date: Mon, 4 Sep 2023 18:08:05 +0000
Currently, for double invoke call_rcu(), will dump rcu_head objects memory
info, if the objects is not allocated from the slab allocator, the
vmalloc_dump_obj() will be invoke and the vmap_area_lock spinlock need to
be held, since the call_rcu() can be invoked in interrupt context,
therefore, there is a possibility of spinlock deadlock scenarios.
And in Preempt-RT kernel, the rcutorture test also trigger the following
lockdep warning:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0
preempt_count: 1, expected: 0
RCU nest depth: 1, expected: 1
3 locks held by swapper/0/1:
#0: ffffffffb534ee80 (fullstop_mutex){+.+.}-{4:4}, at: torture_init_begin+0x24/0xa0
#1: ffffffffb5307940 (rcu_read_lock){....}-{1:3}, at: rcu_torture_init+0x1ec7/0x2370
#2: ffffffffb536af40 (vmap_area_lock){+.+.}-{3:3}, at: find_vmap_area+0x1f/0x70
irq event stamp: 565512
hardirqs last enabled at (565511): [<ffffffffb379b138>] __call_rcu_common+0x218/0x940
hardirqs last disabled at (565512): [<ffffffffb5804262>] rcu_torture_init+0x20b2/0x2370
softirqs last enabled at (399112): [<ffffffffb36b2586>] __local_bh_enable_ip+0x126/0x170
softirqs last disabled at (399106): [<ffffffffb43fef59>] inet_register_protosw+0x9/0x1d0
Preemption disabled at:
[<ffffffffb58040c3>] rcu_torture_init+0x1f13/0x2370
CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.5.0-rc4-rt2-yocto-preempt-rt+ #15
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x68/0xb0
dump_stack+0x14/0x20
__might_resched+0x1aa/0x280
? __pfx_rcu_torture_err_cb+0x10/0x10
rt_spin_lock+0x53/0x130
? find_vmap_area+0x1f/0x70
find_vmap_area+0x1f/0x70
vmalloc_dump_obj+0x20/0x60
mem_dump_obj+0x22/0x90
__call_rcu_common+0x5bf/0x940
? debug_smp_processor_id+0x1b/0x30
call_rcu_hurry+0x14/0x20
rcu_torture_init+0x1f82/0x2370
? __pfx_rcu_torture_leak_cb+0x10/0x10
? __pfx_rcu_torture_leak_cb+0x10/0x10
? __pfx_rcu_torture_init+0x10/0x10
do_one_initcall+0x6c/0x300
? debug_smp_processor_id+0x1b/0x30
kernel_init_freeable+0x2b9/0x540
? __pfx_kernel_init+0x10/0x10
kernel_init+0x1f/0x150
ret_from_fork+0x40/0x50
? __pfx_kernel_init+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
The previous patch fixes this by using the deadlock-safe best-effort
version of find_vm_area. However, in case of failure print the fact that
the pointer was a vmalloc pointer so that we print at least something.
Link: https://lkml.kernel.org/r/20230904180806.1002832-2-joel@joelfernandes.org
Fixes: 98f180837a89 ("mm: Make mem_dump_obj() handle vmalloc() memory")
Signed-off-by: Zqiang <qiang.zhang1211(a)gmail.com>
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
Reported-by: Zhen Lei <thunder.leizhen(a)huaweicloud.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy(a)infradead.org>
Cc: Paul E. McKenney <paulmck(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Cc: Uladzislau Rezki (Sony) <urezki(a)gmail.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/util.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/mm/util.c~rcu-dump-vmalloc-memory-info-safely
+++ a/mm/util.c
@@ -1071,7 +1071,9 @@ void mem_dump_obj(void *object)
if (vmalloc_dump_obj(object))
return;
- if (virt_addr_valid(object))
+ if (is_vmalloc_addr(object))
+ type = "vmalloc memory";
+ else if (virt_addr_valid(object))
type = "non-slab/vmalloc memory";
else if (object == NULL)
type = "NULL pointer";
_
Patches currently in -mm which might be from qiang.zhang1211(a)gmail.com are
rcu-dump-vmalloc-memory-info-safely.patch
The patch titled
Subject: mm/vmalloc: add a safer version of find_vm_area() for debug
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-vmalloc-add-a-safer-version-of-find_vm_area-for-debug.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: "Joel Fernandes (Google)" <joel(a)joelfernandes.org>
Subject: mm/vmalloc: add a safer version of find_vm_area() for debug
Date: Mon, 4 Sep 2023 18:08:04 +0000
It is unsafe to dump vmalloc area information when trying to do so from
some contexts. Add a safer trylock version of the same function to do a
best-effort VMA finding and use it from vmalloc_dump_obj().
[applied test robot feedback on unused function fix.]
[applied Uladzislau feedback on locking.]
Link: https://lkml.kernel.org/r/20230904180806.1002832-1-joel@joelfernandes.org
Fixes: 98f180837a89 ("mm: Make mem_dump_obj() handle vmalloc() memory")
Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
Reviewed-by: Uladzislau Rezki (Sony) <urezki(a)gmail.com>
Reported-by: Zhen Lei <thunder.leizhen(a)huaweicloud.com>
Cc: Paul E. McKenney <paulmck(a)kernel.org>
Cc: Zqiang <qiang.zhang1211(a)gmail.com>
Cc: <stable(a)vger.kernel.org>
Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/vmalloc.c | 26 ++++++++++++++++++++++----
1 file changed, 22 insertions(+), 4 deletions(-)
--- a/mm/vmalloc.c~mm-vmalloc-add-a-safer-version-of-find_vm_area-for-debug
+++ a/mm/vmalloc.c
@@ -4278,14 +4278,32 @@ void pcpu_free_vm_areas(struct vm_struct
#ifdef CONFIG_PRINTK
bool vmalloc_dump_obj(void *object)
{
- struct vm_struct *vm;
void *objp = (void *)PAGE_ALIGN((unsigned long)object);
+ const void *caller;
+ struct vm_struct *vm;
+ struct vmap_area *va;
+ unsigned long addr;
+ unsigned int nr_pages;
+
+ if (!spin_trylock(&vmap_area_lock))
+ return false;
+ va = __find_vmap_area((unsigned long)objp, &vmap_area_root);
+ if (!va) {
+ spin_unlock(&vmap_area_lock);
+ return false;
+ }
- vm = find_vm_area(objp);
- if (!vm)
+ vm = va->vm;
+ if (!vm) {
+ spin_unlock(&vmap_area_lock);
return false;
+ }
+ addr = (unsigned long)vm->addr;
+ caller = vm->caller;
+ nr_pages = vm->nr_pages;
+ spin_unlock(&vmap_area_lock);
pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
- vm->nr_pages, (unsigned long)vm->addr, vm->caller);
+ nr_pages, addr, caller);
return true;
}
#endif
_
Patches currently in -mm which might be from joel(a)joelfernandes.org are
mm-vmalloc-add-a-safer-version-of-find_vm_area-for-debug.patch
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 23e60c8daf5ec2ab1b731310761b668745fcf6ed
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2023090314-headroom-doorbell-3ac8@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
23e60c8daf5e ("usb: typec: tcpci: clear the fault status bit")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 23e60c8daf5ec2ab1b731310761b668745fcf6ed Mon Sep 17 00:00:00 2001
From: Marco Felsch <m.felsch(a)pengutronix.de>
Date: Wed, 16 Aug 2023 14:25:02 -0300
Subject: [PATCH] usb: typec: tcpci: clear the fault status bit
According the "USB Type-C Port Controller Interface Specification v2.0"
the TCPC sets the fault status register bit-7
(AllRegistersResetToDefault) once the registers have been reset to
their default values.
This triggers an alert(-irq) on PTN5110 devices albeit we do mask the
fault-irq, which may cause a kernel hang. Fix this generically by writing
a one to the corresponding bit-7.
Cc: stable(a)vger.kernel.org
Fixes: 74e656d6b055 ("staging: typec: Type-C Port Controller Interface driver (tcpci)")
Reported-by: "Angus Ainslie (Purism)" <angus(a)akkea.ca>
Closes: https://lore.kernel.org/all/20190508002749.14816-2-angus@akkea.ca/
Reported-by: Christian Bach <christian.bach(a)scs.ch>
Closes: https://lore.kernel.org/regressions/ZR0P278MB07737E5F1D48632897D51AC3EB329@…
Signed-off-by: Marco Felsch <m.felsch(a)pengutronix.de>
Signed-off-by: Fabio Estevam <festevam(a)denx.de>
Reviewed-by: Guenter Roeck <linux(a)roeck-us.net>
Link: https://lore.kernel.org/r/20230816172502.1155079-1-festevam@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c
index fc708c289a73..0ee3e6e29bb1 100644
--- a/drivers/usb/typec/tcpm/tcpci.c
+++ b/drivers/usb/typec/tcpm/tcpci.c
@@ -602,6 +602,10 @@ static int tcpci_init(struct tcpc_dev *tcpc)
if (time_after(jiffies, timeout))
return -ETIMEDOUT;
+ ret = tcpci_write16(tcpci, TCPC_FAULT_STATUS, TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT);
+ if (ret < 0)
+ return ret;
+
/* Handle vendor init */
if (tcpci->data->init) {
ret = tcpci->data->init(tcpci, tcpci->data);
diff --git a/include/linux/usb/tcpci.h b/include/linux/usb/tcpci.h
index 85e95a3251d3..83376473ac76 100644
--- a/include/linux/usb/tcpci.h
+++ b/include/linux/usb/tcpci.h
@@ -103,6 +103,7 @@
#define TCPC_POWER_STATUS_SINKING_VBUS BIT(0)
#define TCPC_FAULT_STATUS 0x1f
+#define TCPC_FAULT_STATUS_ALL_REG_RST_TO_DEFAULT BIT(7)
#define TCPC_ALERT_EXTENDED 0x21