* [PATCH v3] kasan: Don't call find_vm_area() in RT kernel
@ 2025-02-17 4:21 Waiman Long
2025-02-17 15:43 ` Sebastian Andrzej Siewior
2025-02-17 16:28 ` Andrey Konovalov
0 siblings, 2 replies; 6+ messages in thread
From: Waiman Long @ 2025-02-17 4:21 UTC (permalink / raw)
To: Andrey Ryabinin, Alexander Potapenko, Andrey Konovalov,
Dmitry Vyukov, Vincenzo Frascino, Andrew Morton,
Sebastian Andrzej Siewior, Clark Williams, Steven Rostedt
Cc: kasan-dev, linux-mm, linux-kernel, linux-rt-devel, Nico Pache,
Waiman Long
The following bug report appeared with a test run in a RT debug kernel.
[ 3359.353842] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
[ 3359.353848] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 140605, name: kunit_try_catch
[ 3359.353853] preempt_count: 1, expected: 0
:
[ 3359.353933] Call trace:
:
[ 3359.353955] rt_spin_lock+0x70/0x140
[ 3359.353959] find_vmap_area+0x84/0x168
[ 3359.353963] find_vm_area+0x1c/0x50
[ 3359.353966] print_address_description.constprop.0+0x2a0/0x320
[ 3359.353972] print_report+0x108/0x1f8
[ 3359.353976] kasan_report+0x90/0xc8
[ 3359.353980] __asan_load1+0x60/0x70
Commit e30a0361b851 ("kasan: make report_lock a raw spinlock")
changes report_lock to a raw_spinlock_t to avoid a similar RT problem.
The print_address_description() function is called with report_lock
acquired and interrupt disabled. However, the find_vm_area() function
still needs to acquire a spinlock_t which becomes a sleeping lock in
the RT kernel. IOW, we can't call find_vm_area() in a RT kernel and
changing report_lock to a raw_spinlock_t is not enough to completely
solve this RT kernel problem.
Fix this bug report by skipping the find_vm_area() call in this case
and just print out the address as is.
For !RT kernel, follow the example set in commit 0cce06ba859a
("debugobjects,locking: Annotate debug_object_fill_pool() wait type
violation") and use DEFINE_WAIT_OVERRIDE_MAP() to avoid a spinlock_t
inside raw_spinlock_t warning.
Fixes: e30a0361b851 ("kasan: make report_lock a raw spinlock")
Signed-off-by: Waiman Long <longman@redhat.com>
---
mm/kasan/report.c | 43 ++++++++++++++++++++++++++++++-------------
1 file changed, 30 insertions(+), 13 deletions(-)
[v3] Rename helper to print_vmalloc_info_set_page.
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 3fe77a360f1c..7c8c2e173aa4 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -370,6 +370,34 @@ static inline bool init_task_stack_addr(const void *addr)
sizeof(init_thread_union.stack));
}
+/*
+ * RT kernel cannot call find_vm_area() in atomic context. For !RT kernel,
+ * prevent spinlock_t inside raw_spinlock_t warning by raising wait-type
+ * to WAIT_SLEEP.
+ */
+static inline void print_vmalloc_info_set_page(void *addr, struct page **ppage)
+{
+ if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
+ static DEFINE_WAIT_OVERRIDE_MAP(vmalloc_map, LD_WAIT_SLEEP);
+ struct vm_struct *va;
+
+ lock_map_acquire_try(&vmalloc_map);
+ va = find_vm_area(addr);
+ if (va) {
+ pr_err("The buggy address belongs to the virtual mapping at\n"
+ " [%px, %px) created by:\n"
+ " %pS\n",
+ va->addr, va->addr + va->size, va->caller);
+ pr_err("\n");
+
+ *ppage = vmalloc_to_page(addr);
+ }
+ lock_map_release(&vmalloc_map);
+ return;
+ }
+ pr_err("The buggy address %px belongs to a vmalloc virtual mapping\n", addr);
+}
+
static void print_address_description(void *addr, u8 tag,
struct kasan_report_info *info)
{
@@ -398,19 +426,8 @@ static void print_address_description(void *addr, u8 tag,
pr_err("\n");
}
- if (is_vmalloc_addr(addr)) {
- struct vm_struct *va = find_vm_area(addr);
-
- if (va) {
- pr_err("The buggy address belongs to the virtual mapping at\n"
- " [%px, %px) created by:\n"
- " %pS\n",
- va->addr, va->addr + va->size, va->caller);
- pr_err("\n");
-
- page = vmalloc_to_page(addr);
- }
- }
+ if (is_vmalloc_addr(addr))
+ print_vmalloc_info_set_page(addr, &page);
if (page) {
pr_err("The buggy address belongs to the physical page:\n");
--
2.48.1
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v3] kasan: Don't call find_vm_area() in RT kernel
2025-02-17 4:21 [PATCH v3] kasan: Don't call find_vm_area() in RT kernel Waiman Long
@ 2025-02-17 15:43 ` Sebastian Andrzej Siewior
2025-02-17 16:29 ` Andrey Konovalov
2025-02-17 16:28 ` Andrey Konovalov
1 sibling, 1 reply; 6+ messages in thread
From: Sebastian Andrzej Siewior @ 2025-02-17 15:43 UTC (permalink / raw)
To: Waiman Long
Cc: Andrey Ryabinin, Alexander Potapenko, Andrey Konovalov,
Dmitry Vyukov, Vincenzo Frascino, Andrew Morton, Clark Williams,
Steven Rostedt, kasan-dev, linux-mm, linux-kernel,
linux-rt-devel, Nico Pache
On 2025-02-16 23:21:08 [-0500], Waiman Long wrote:
I would skip the first part. The backtrace is not really helpful here.
> The following bug report appeared with a test run in a RT debug kernel.
>
> [ 3359.353842] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
> [ 3359.353848] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 140605, name: kunit_try_catch
> [ 3359.353853] preempt_count: 1, expected: 0
> :
> [ 3359.353933] Call trace:
> :
> [ 3359.353955] rt_spin_lock+0x70/0x140
> [ 3359.353959] find_vmap_area+0x84/0x168
> [ 3359.353963] find_vm_area+0x1c/0x50
> [ 3359.353966] print_address_description.constprop.0+0x2a0/0x320
> [ 3359.353972] print_report+0x108/0x1f8
> [ 3359.353976] kasan_report+0x90/0xc8
> [ 3359.353980] __asan_load1+0x60/0x70
>
> Commit e30a0361b851 ("kasan: make report_lock a raw spinlock")
> changes report_lock to a raw_spinlock_t to avoid a similar RT problem.
s/to avoid.*//. This has nothing to do with the problem at hand.
> The print_address_description() function is called with report_lock
> acquired and interrupt disabled. However, the find_vm_area() function
> still needs to acquire a spinlock_t which becomes a sleeping lock in
> the RT kernel. IOW, we can't call find_vm_area() in a RT kernel and
> changing report_lock to a raw_spinlock_t is not enough to completely
> solve this RT kernel problem.
This function is always invoked under the report_lock which is a
raw_spinlock_t. The context under this lock is always atomic even on
PREEMPT_RT. find_vm_area() acquires vmap_node::busy.lock which is a
spinlock_t, becoming a sleeping lock on PREEMPT_RT and must not be
acquired in atomic context.
> Fix this bug report by skipping the find_vm_area() call in this case
> and just print out the address as is.
Please use PREEMPT_RT instead of RT.
Don't invoke find_vm_area() on PREEMPT_RT and just print the address.
Non-PREEMPT_RT builds remain unchanged. Add a DEFINE_WAIT_OVERRIDE_MAP()
is to tell lockdep that this lock nesting allowed because the PREEMPT_RT
part (which is invalid) has been taken care of.
> For !RT kernel, follow the example set in commit 0cce06ba859a
> ("debugobjects,locking: Annotate debug_object_fill_pool() wait type
> violation") and use DEFINE_WAIT_OVERRIDE_MAP() to avoid a spinlock_t
> inside raw_spinlock_t warning.
> Fixes: e30a0361b851 ("kasan: make report_lock a raw spinlock")
> Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
> mm/kasan/report.c | 43 ++++++++++++++++++++++++++++++-------------
> 1 file changed, 30 insertions(+), 13 deletions(-)
>
> [v3] Rename helper to print_vmalloc_info_set_page.
>
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index 3fe77a360f1c..7c8c2e173aa4 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -370,6 +370,34 @@ static inline bool init_task_stack_addr(const void *addr)
> sizeof(init_thread_union.stack));
> }
>
> +/*
> + * RT kernel cannot call find_vm_area() in atomic context. For !RT kernel,
> + * prevent spinlock_t inside raw_spinlock_t warning by raising wait-type
> + * to WAIT_SLEEP.
> + */
Do we need this comment? I lacks context of why it is atomic. And we
have it in the commit description.
> +static inline void print_vmalloc_info_set_page(void *addr, struct page **ppage)
> +{
> + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
> + static DEFINE_WAIT_OVERRIDE_MAP(vmalloc_map, LD_WAIT_SLEEP);
> + struct vm_struct *va;
> +
> + lock_map_acquire_try(&vmalloc_map);
> + va = find_vm_area(addr);
> + if (va) {
> + pr_err("The buggy address belongs to the virtual mapping at\n"
> + " [%px, %px) created by:\n"
> + " %pS\n",
> + va->addr, va->addr + va->size, va->caller);
> + pr_err("\n");
> +
> + *ppage = vmalloc_to_page(addr);
> + }
> + lock_map_release(&vmalloc_map);
> + return;
> + }
> + pr_err("The buggy address %px belongs to a vmalloc virtual mapping\n", addr);
> +}
> +
> static void print_address_description(void *addr, u8 tag,
> struct kasan_report_info *info)
> {
Sebastian
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v3] kasan: Don't call find_vm_area() in RT kernel
2025-02-17 15:43 ` Sebastian Andrzej Siewior
@ 2025-02-17 16:29 ` Andrey Konovalov
0 siblings, 0 replies; 6+ messages in thread
From: Andrey Konovalov @ 2025-02-17 16:29 UTC (permalink / raw)
To: Sebastian Andrzej Siewior
Cc: Waiman Long, Andrey Ryabinin, Alexander Potapenko, Dmitry Vyukov,
Vincenzo Frascino, Andrew Morton, Clark Williams, Steven Rostedt,
kasan-dev, linux-mm, linux-kernel, linux-rt-devel, Nico Pache
On Mon, Feb 17, 2025 at 4:43 PM Sebastian Andrzej Siewior
<bigeasy@linutronix.de> wrote:
>
> > --- a/mm/kasan/report.c
> > +++ b/mm/kasan/report.c
> > @@ -370,6 +370,34 @@ static inline bool init_task_stack_addr(const void *addr)
> > sizeof(init_thread_union.stack));
> > }
> >
> > +/*
> > + * RT kernel cannot call find_vm_area() in atomic context. For !RT kernel,
> > + * prevent spinlock_t inside raw_spinlock_t warning by raising wait-type
> > + * to WAIT_SLEEP.
> > + */
>
> Do we need this comment? I lacks context of why it is atomic. And we
> have it in the commit description.
I would prefer to have this in the comment, but with a full
explanation of why this needs to be done.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v3] kasan: Don't call find_vm_area() in RT kernel
2025-02-17 4:21 [PATCH v3] kasan: Don't call find_vm_area() in RT kernel Waiman Long
2025-02-17 15:43 ` Sebastian Andrzej Siewior
@ 2025-02-17 16:28 ` Andrey Konovalov
2025-02-17 17:56 ` Waiman Long
1 sibling, 1 reply; 6+ messages in thread
From: Andrey Konovalov @ 2025-02-17 16:28 UTC (permalink / raw)
To: Waiman Long
Cc: Andrey Ryabinin, Alexander Potapenko, Dmitry Vyukov,
Vincenzo Frascino, Andrew Morton, Sebastian Andrzej Siewior,
Clark Williams, Steven Rostedt, kasan-dev, linux-mm,
linux-kernel, linux-rt-devel, Nico Pache
On Mon, Feb 17, 2025 at 5:21 AM Waiman Long <longman@redhat.com> wrote:
>
> The following bug report appeared with a test run in a RT debug kernel.
>
> [ 3359.353842] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
> [ 3359.353848] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 140605, name: kunit_try_catch
> [ 3359.353853] preempt_count: 1, expected: 0
> :
> [ 3359.353933] Call trace:
> :
> [ 3359.353955] rt_spin_lock+0x70/0x140
> [ 3359.353959] find_vmap_area+0x84/0x168
> [ 3359.353963] find_vm_area+0x1c/0x50
> [ 3359.353966] print_address_description.constprop.0+0x2a0/0x320
> [ 3359.353972] print_report+0x108/0x1f8
> [ 3359.353976] kasan_report+0x90/0xc8
> [ 3359.353980] __asan_load1+0x60/0x70
>
> Commit e30a0361b851 ("kasan: make report_lock a raw spinlock")
> changes report_lock to a raw_spinlock_t to avoid a similar RT problem.
> The print_address_description() function is called with report_lock
> acquired and interrupt disabled. However, the find_vm_area() function
> still needs to acquire a spinlock_t which becomes a sleeping lock in
> the RT kernel. IOW, we can't call find_vm_area() in a RT kernel and
> changing report_lock to a raw_spinlock_t is not enough to completely
> solve this RT kernel problem.
>
> Fix this bug report by skipping the find_vm_area() call in this case
> and just print out the address as is.
>
> For !RT kernel, follow the example set in commit 0cce06ba859a
> ("debugobjects,locking: Annotate debug_object_fill_pool() wait type
> violation") and use DEFINE_WAIT_OVERRIDE_MAP() to avoid a spinlock_t
> inside raw_spinlock_t warning.
>
> Fixes: e30a0361b851 ("kasan: make report_lock a raw spinlock")
> Signed-off-by: Waiman Long <longman@redhat.com>
> ---
> mm/kasan/report.c | 43 ++++++++++++++++++++++++++++++-------------
> 1 file changed, 30 insertions(+), 13 deletions(-)
>
> [v3] Rename helper to print_vmalloc_info_set_page.
>
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index 3fe77a360f1c..7c8c2e173aa4 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -370,6 +370,34 @@ static inline bool init_task_stack_addr(const void *addr)
> sizeof(init_thread_union.stack));
> }
>
> +/*
> + * RT kernel cannot call find_vm_area() in atomic context. For !RT kernel,
> + * prevent spinlock_t inside raw_spinlock_t warning by raising wait-type
> + * to WAIT_SLEEP.
Quoting your response from the other thread:
> Lockdep currently issues warnings for taking spinlock_t inside
> raw_spinlock_t because it is not allowed in RT. Test coverage of RT
> kernels is likely less than !RT kernel and so less bug of this kind will
> be caught. By making !RT doing the same check, we increase coverage.
> However, we do allow override in the !RT case, but it has to be done on
> a case-by-case basis.
Got it.
So let's put this exactly this explanation in the comment, otherwise
it's unclear why we need something special for the !RT case.
> + */
> +static inline void print_vmalloc_info_set_page(void *addr, struct page **ppage)
> +{
> + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
> + static DEFINE_WAIT_OVERRIDE_MAP(vmalloc_map, LD_WAIT_SLEEP);
> + struct vm_struct *va;
> +
> + lock_map_acquire_try(&vmalloc_map);
> + va = find_vm_area(addr);
> + if (va) {
> + pr_err("The buggy address belongs to the virtual mapping at\n"
> + " [%px, %px) created by:\n"
> + " %pS\n",
> + va->addr, va->addr + va->size, va->caller);
> + pr_err("\n");
> +
> + *ppage = vmalloc_to_page(addr);
Looking at the code again, I actually like the Andrey Ryabinin's
suggestion from the v1 thread: add a separate function that contains
an annotated call of find_vm_area(). And keep vmalloc_to_page()
outside of it, just as done in the upstream version now.
> + }
> + lock_map_release(&vmalloc_map);
> + return;
> + }
> + pr_err("The buggy address %px belongs to a vmalloc virtual mapping\n", addr);
> +}
> +
> static void print_address_description(void *addr, u8 tag,
> struct kasan_report_info *info)
> {
> @@ -398,19 +426,8 @@ static void print_address_description(void *addr, u8 tag,
> pr_err("\n");
> }
>
> - if (is_vmalloc_addr(addr)) {
> - struct vm_struct *va = find_vm_area(addr);
> -
> - if (va) {
> - pr_err("The buggy address belongs to the virtual mapping at\n"
> - " [%px, %px) created by:\n"
> - " %pS\n",
> - va->addr, va->addr + va->size, va->caller);
> - pr_err("\n");
> -
> - page = vmalloc_to_page(addr);
> - }
> - }
> + if (is_vmalloc_addr(addr))
> + print_vmalloc_info_set_page(addr, &page);
>
> if (page) {
> pr_err("The buggy address belongs to the physical page:\n");
> --
> 2.48.1
>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v3] kasan: Don't call find_vm_area() in RT kernel
2025-02-17 16:28 ` Andrey Konovalov
@ 2025-02-17 17:56 ` Waiman Long
2025-02-17 18:59 ` Andrey Konovalov
0 siblings, 1 reply; 6+ messages in thread
From: Waiman Long @ 2025-02-17 17:56 UTC (permalink / raw)
To: Andrey Konovalov
Cc: Andrey Ryabinin, Alexander Potapenko, Dmitry Vyukov,
Vincenzo Frascino, Andrew Morton, Sebastian Andrzej Siewior,
Clark Williams, Steven Rostedt, kasan-dev, linux-mm,
linux-kernel, linux-rt-devel, Nico Pache
On 2/17/25 11:28 AM, Andrey Konovalov wrote:
> On Mon, Feb 17, 2025 at 5:21 AM Waiman Long <longman@redhat.com> wrote:
>> The following bug report appeared with a test run in a RT debug kernel.
>>
>> [ 3359.353842] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
>> [ 3359.353848] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 140605, name: kunit_try_catch
>> [ 3359.353853] preempt_count: 1, expected: 0
>> :
>> [ 3359.353933] Call trace:
>> :
>> [ 3359.353955] rt_spin_lock+0x70/0x140
>> [ 3359.353959] find_vmap_area+0x84/0x168
>> [ 3359.353963] find_vm_area+0x1c/0x50
>> [ 3359.353966] print_address_description.constprop.0+0x2a0/0x320
>> [ 3359.353972] print_report+0x108/0x1f8
>> [ 3359.353976] kasan_report+0x90/0xc8
>> [ 3359.353980] __asan_load1+0x60/0x70
>>
>> Commit e30a0361b851 ("kasan: make report_lock a raw spinlock")
>> changes report_lock to a raw_spinlock_t to avoid a similar RT problem.
>> The print_address_description() function is called with report_lock
>> acquired and interrupt disabled. However, the find_vm_area() function
>> still needs to acquire a spinlock_t which becomes a sleeping lock in
>> the RT kernel. IOW, we can't call find_vm_area() in a RT kernel and
>> changing report_lock to a raw_spinlock_t is not enough to completely
>> solve this RT kernel problem.
>>
>> Fix this bug report by skipping the find_vm_area() call in this case
>> and just print out the address as is.
>>
>> For !RT kernel, follow the example set in commit 0cce06ba859a
>> ("debugobjects,locking: Annotate debug_object_fill_pool() wait type
>> violation") and use DEFINE_WAIT_OVERRIDE_MAP() to avoid a spinlock_t
>> inside raw_spinlock_t warning.
>>
>> Fixes: e30a0361b851 ("kasan: make report_lock a raw spinlock")
>> Signed-off-by: Waiman Long <longman@redhat.com>
>> ---
>> mm/kasan/report.c | 43 ++++++++++++++++++++++++++++++-------------
>> 1 file changed, 30 insertions(+), 13 deletions(-)
>>
>> [v3] Rename helper to print_vmalloc_info_set_page.
>>
>> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
>> index 3fe77a360f1c..7c8c2e173aa4 100644
>> --- a/mm/kasan/report.c
>> +++ b/mm/kasan/report.c
>> @@ -370,6 +370,34 @@ static inline bool init_task_stack_addr(const void *addr)
>> sizeof(init_thread_union.stack));
>> }
>>
>> +/*
>> + * RT kernel cannot call find_vm_area() in atomic context. For !RT kernel,
>> + * prevent spinlock_t inside raw_spinlock_t warning by raising wait-type
>> + * to WAIT_SLEEP.
> Quoting your response from the other thread:
>
>> Lockdep currently issues warnings for taking spinlock_t inside
>> raw_spinlock_t because it is not allowed in RT. Test coverage of RT
>> kernels is likely less than !RT kernel and so less bug of this kind will
>> be caught. By making !RT doing the same check, we increase coverage.
>> However, we do allow override in the !RT case, but it has to be done on
>> a case-by-case basis.
> Got it.
>
> So let's put this exactly this explanation in the comment, otherwise
> it's unclear why we need something special for the !RT case.
Sure. Will do that.
>> + */
>> +static inline void print_vmalloc_info_set_page(void *addr, struct page **ppage)
>> +{
>> + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
>> + static DEFINE_WAIT_OVERRIDE_MAP(vmalloc_map, LD_WAIT_SLEEP);
>> + struct vm_struct *va;
>> +
>> + lock_map_acquire_try(&vmalloc_map);
>> + va = find_vm_area(addr);
>> + if (va) {
>> + pr_err("The buggy address belongs to the virtual mapping at\n"
>> + " [%px, %px) created by:\n"
>> + " %pS\n",
>> + va->addr, va->addr + va->size, va->caller);
>> + pr_err("\n");
>> +
>> + *ppage = vmalloc_to_page(addr);
> Looking at the code again, I actually like the Andrey Ryabinin's
> suggestion from the v1 thread: add a separate function that contains
> an annotated call of find_vm_area(). And keep vmalloc_to_page()
> outside of it, just as done in the upstream version now.
I can make the change if it is what you want.
Cheers,
Longman
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v3] kasan: Don't call find_vm_area() in RT kernel
2025-02-17 17:56 ` Waiman Long
@ 2025-02-17 18:59 ` Andrey Konovalov
0 siblings, 0 replies; 6+ messages in thread
From: Andrey Konovalov @ 2025-02-17 18:59 UTC (permalink / raw)
To: Waiman Long
Cc: Andrey Ryabinin, Alexander Potapenko, Dmitry Vyukov,
Vincenzo Frascino, Andrew Morton, Sebastian Andrzej Siewior,
Clark Williams, Steven Rostedt, kasan-dev, linux-mm,
linux-kernel, linux-rt-devel, Nico Pache
On Mon, Feb 17, 2025 at 6:56 PM Waiman Long <llong@redhat.com> wrote:
>
> >> + */
> >> +static inline void print_vmalloc_info_set_page(void *addr, struct page **ppage)
> >> +{
> >> + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) {
> >> + static DEFINE_WAIT_OVERRIDE_MAP(vmalloc_map, LD_WAIT_SLEEP);
> >> + struct vm_struct *va;
> >> +
> >> + lock_map_acquire_try(&vmalloc_map);
> >> + va = find_vm_area(addr);
> >> + if (va) {
> >> + pr_err("The buggy address belongs to the virtual mapping at\n"
> >> + " [%px, %px) created by:\n"
> >> + " %pS\n",
> >> + va->addr, va->addr + va->size, va->caller);
> >> + pr_err("\n");
> >> +
> >> + *ppage = vmalloc_to_page(addr);
> > Looking at the code again, I actually like the Andrey Ryabinin's
> > suggestion from the v1 thread: add a separate function that contains
> > an annotated call of find_vm_area(). And keep vmalloc_to_page()
> > outside of it, just as done in the upstream version now.
>
> I can make the change if it is what you want.
Yes, please, I think splitting out the call that requires an
annotation into a separate function makes sense.
^ permalink raw reply [flat|nested] 6+ messages in thread
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2025-02-17 4:21 [PATCH v3] kasan: Don't call find_vm_area() in RT kernel Waiman Long
2025-02-17 15:43 ` Sebastian Andrzej Siewior
2025-02-17 16:29 ` Andrey Konovalov
2025-02-17 16:28 ` Andrey Konovalov
2025-02-17 17:56 ` Waiman Long
2025-02-17 18:59 ` Andrey Konovalov
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