* [PATCH 0/3] Fix flush_dcache_page() for usage from irq context on ARM, NIOS2 and PARISC
@ 2023-05-24 15:26 Helge Deller
2023-05-24 15:26 ` [PATCH 1/3] arm: Fix flush_dcache_page() for usage from irq context Helge Deller
` (2 more replies)
0 siblings, 3 replies; 9+ messages in thread
From: Helge Deller @ 2023-05-24 15:26 UTC (permalink / raw)
To: linux, dinguyen, linux-kernel, linux-parisc; +Cc: Helge Deller
ARM, NIOS2 and PARISC unintentionally re-enable IRQs in
flush_dcache_page() when called from irq context.
This series fixes it and should go to stable series to at
least kernel 6.1.
Helge
Helge Deller (3):
arm: Fix flush_dcache_page() for usage from irq context
nios2: Fix flush_dcache_page() for usage from irq context
parisc: Fix flush_dcache_page() for usage from irq context
arch/arm/include/asm/cacheflush.h | 4 ++++
arch/arm/mm/flush.c | 5 +++--
arch/nios2/include/asm/cacheflush.h | 4 ++++
arch/nios2/mm/cacheflush.c | 5 +++--
arch/parisc/include/asm/cacheflush.h | 4 ++++
arch/parisc/kernel/cache.c | 5 +++--
6 files changed, 21 insertions(+), 6 deletions(-)
--
2.38.1
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH 1/3] arm: Fix flush_dcache_page() for usage from irq context
2023-05-24 15:26 [PATCH 0/3] Fix flush_dcache_page() for usage from irq context on ARM, NIOS2 and PARISC Helge Deller
@ 2023-05-24 15:26 ` Helge Deller
2023-05-24 20:00 ` Arnd Bergmann
2023-05-24 15:26 ` [PATCH 2/3] nios2: " Helge Deller
2023-05-24 15:26 ` [PATCH 3/3] parisc: " Helge Deller
2 siblings, 1 reply; 9+ messages in thread
From: Helge Deller @ 2023-05-24 15:26 UTC (permalink / raw)
To: linux, dinguyen, linux-kernel, linux-parisc
Cc: Helge Deller, Arnd Bergmann, linux-arm-kernel
Since at least kernel 6.1, flush_dcache_page() is called with IRQs
disabled, e.g. from aio_complete().
But the current implementation for flush_dcache_page() on ARM
unintentionally re-enables IRQs, which may lead to deadlocks.
Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore()
for the flush_dcache_mmap_*lock() macros instead.
Cc: Russell King (Oracle) <linux@armlinux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Helge Deller <deller@gmx.de>
---
arch/arm/include/asm/cacheflush.h | 4 ++++
arch/arm/mm/flush.c | 5 +++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index a094f964c869..5b8a1ef0dc50 100644
--- a/arch/arm/include/asm/cacheflush.h
+++ b/arch/arm/include/asm/cacheflush.h
@@ -315,6 +315,10 @@ static inline void flush_anon_page(struct vm_area_struct *vma,
#define flush_dcache_mmap_lock(mapping) xa_lock_irq(&mapping->i_pages)
#define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&mapping->i_pages)
+#define flush_dcache_mmap_lock_irqsave(mapping, flags) \
+ xa_lock_irqsave(&mapping->i_pages, flags)
+#define flush_dcache_mmap_unlock_irqrestore(mapping, flags) \
+ xa_unlock_irqrestore(&mapping->i_pages, flags)
/*
* We don't appear to need to do anything here. In fact, if we did, we'd
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 7ff9feea13a6..d57ec9165520 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -238,6 +238,7 @@ static void __flush_dcache_aliases(struct address_space *mapping, struct page *p
{
struct mm_struct *mm = current->active_mm;
struct vm_area_struct *mpnt;
+ unsigned long flags;
pgoff_t pgoff;
/*
@@ -248,7 +249,7 @@ static void __flush_dcache_aliases(struct address_space *mapping, struct page *p
*/
pgoff = page->index;
- flush_dcache_mmap_lock(mapping);
+ flush_dcache_mmap_lock_irqsave(mapping, flags);
vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
unsigned long offset;
@@ -262,7 +263,7 @@ static void __flush_dcache_aliases(struct address_space *mapping, struct page *p
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page));
}
- flush_dcache_mmap_unlock(mapping);
+ flush_dcache_mmap_unlock_irqrestore(mapping, flags);
}
#if __LINUX_ARM_ARCH__ >= 6
--
2.38.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH 2/3] nios2: Fix flush_dcache_page() for usage from irq context
2023-05-24 15:26 [PATCH 0/3] Fix flush_dcache_page() for usage from irq context on ARM, NIOS2 and PARISC Helge Deller
2023-05-24 15:26 ` [PATCH 1/3] arm: Fix flush_dcache_page() for usage from irq context Helge Deller
@ 2023-05-24 15:26 ` Helge Deller
2023-06-13 22:39 ` Dinh Nguyen
2023-05-24 15:26 ` [PATCH 3/3] parisc: " Helge Deller
2 siblings, 1 reply; 9+ messages in thread
From: Helge Deller @ 2023-05-24 15:26 UTC (permalink / raw)
To: linux, dinguyen, linux-kernel, linux-parisc; +Cc: Helge Deller
Since at least kernel 6.1, flush_dcache_page() is called with IRQs
disabled, e.g. from aio_complete().
But the current implementation for flush_dcache_page() on NIOS2
unintentionally re-enables IRQs, which may lead to deadlocks.
Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore()
for the flush_dcache_mmap_*lock() macros instead.
Cc: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Helge Deller <deller@gmx.de>
---
arch/nios2/include/asm/cacheflush.h | 4 ++++
arch/nios2/mm/cacheflush.c | 5 +++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/nios2/include/asm/cacheflush.h b/arch/nios2/include/asm/cacheflush.h
index d0b71dd71287..a37242662809 100644
--- a/arch/nios2/include/asm/cacheflush.h
+++ b/arch/nios2/include/asm/cacheflush.h
@@ -48,5 +48,9 @@ extern void invalidate_dcache_range(unsigned long start, unsigned long end);
#define flush_dcache_mmap_lock(mapping) xa_lock_irq(&mapping->i_pages)
#define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&mapping->i_pages)
+#define flush_dcache_mmap_lock_irqsave(mapping, flags) \
+ xa_lock_irqsave(&mapping->i_pages, flags)
+#define flush_dcache_mmap_unlock_irqrestore(mapping, flags) \
+ xa_unlock_irqrestore(&mapping->i_pages, flags)
#endif /* _ASM_NIOS2_CACHEFLUSH_H */
diff --git a/arch/nios2/mm/cacheflush.c b/arch/nios2/mm/cacheflush.c
index 6aa9257c3ede..35f3b599187f 100644
--- a/arch/nios2/mm/cacheflush.c
+++ b/arch/nios2/mm/cacheflush.c
@@ -75,11 +75,12 @@ static void flush_aliases(struct address_space *mapping, struct page *page)
{
struct mm_struct *mm = current->active_mm;
struct vm_area_struct *mpnt;
+ unsigned long flags;
pgoff_t pgoff;
pgoff = page->index;
- flush_dcache_mmap_lock(mapping);
+ flush_dcache_mmap_lock_irqsave(mapping, flags);
vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
unsigned long offset;
@@ -92,7 +93,7 @@ static void flush_aliases(struct address_space *mapping, struct page *page)
flush_cache_page(mpnt, mpnt->vm_start + offset,
page_to_pfn(page));
}
- flush_dcache_mmap_unlock(mapping);
+ flush_dcache_mmap_unlock_irqrestore(mapping, flags);
}
void flush_cache_all(void)
--
2.38.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH 3/3] parisc: Fix flush_dcache_page() for usage from irq context
2023-05-24 15:26 [PATCH 0/3] Fix flush_dcache_page() for usage from irq context on ARM, NIOS2 and PARISC Helge Deller
2023-05-24 15:26 ` [PATCH 1/3] arm: Fix flush_dcache_page() for usage from irq context Helge Deller
2023-05-24 15:26 ` [PATCH 2/3] nios2: " Helge Deller
@ 2023-05-24 15:26 ` Helge Deller
2 siblings, 0 replies; 9+ messages in thread
From: Helge Deller @ 2023-05-24 15:26 UTC (permalink / raw)
To: linux, dinguyen, linux-kernel, linux-parisc; +Cc: Helge Deller
Since at least kernel 6.1, flush_dcache_page() is called with IRQs
disabled, e.g. from aio_complete().
But the current implementation for flush_dcache_page() on parisc
unintentionally re-enables IRQs, which may lead to deadlocks.
Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore()
for the flush_dcache_mmap_*lock() macros instead.
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
---
arch/parisc/include/asm/cacheflush.h | 4 ++++
arch/parisc/kernel/cache.c | 5 +++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index 0bdee6724132..c8b6928cee1e 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -48,6 +48,10 @@ void flush_dcache_page(struct page *page);
#define flush_dcache_mmap_lock(mapping) xa_lock_irq(&mapping->i_pages)
#define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&mapping->i_pages)
+#define flush_dcache_mmap_lock_irqsave(mapping, flags) \
+ xa_lock_irqsave(&mapping->i_pages, flags)
+#define flush_dcache_mmap_unlock_irqrestore(mapping, flags) \
+ xa_unlock_irqrestore(&mapping->i_pages, flags)
#define flush_icache_page(vma,page) do { \
flush_kernel_dcache_page_addr(page_address(page)); \
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 1d3b8bc8a623..ca4a302d4365 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -399,6 +399,7 @@ void flush_dcache_page(struct page *page)
unsigned long offset;
unsigned long addr, old_addr = 0;
unsigned long count = 0;
+ unsigned long flags;
pgoff_t pgoff;
if (mapping && !mapping_mapped(mapping)) {
@@ -420,7 +421,7 @@ void flush_dcache_page(struct page *page)
* to flush one address here for them all to become coherent
* on machines that support equivalent aliasing
*/
- flush_dcache_mmap_lock(mapping);
+ flush_dcache_mmap_lock_irqsave(mapping, flags);
vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
addr = mpnt->vm_start + offset;
@@ -460,7 +461,7 @@ void flush_dcache_page(struct page *page)
}
WARN_ON(++count == 4096);
}
- flush_dcache_mmap_unlock(mapping);
+ flush_dcache_mmap_unlock_irqrestore(mapping, flags);
}
EXPORT_SYMBOL(flush_dcache_page);
--
2.38.1
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH 1/3] arm: Fix flush_dcache_page() for usage from irq context
2023-05-24 15:26 ` [PATCH 1/3] arm: Fix flush_dcache_page() for usage from irq context Helge Deller
@ 2023-05-24 20:00 ` Arnd Bergmann
2023-05-24 20:56 ` Helge Deller
2023-07-20 6:53 ` Helge Deller
0 siblings, 2 replies; 9+ messages in thread
From: Arnd Bergmann @ 2023-05-24 20:00 UTC (permalink / raw)
To: Helge Deller, Russell King, Dinh Nguyen, linux-kernel, linux-parisc
Cc: linux-arm-kernel
On Wed, May 24, 2023, at 17:26, Helge Deller wrote:
> Since at least kernel 6.1, flush_dcache_page() is called with IRQs
> disabled, e.g. from aio_complete().
>
> But the current implementation for flush_dcache_page() on ARM
> unintentionally re-enables IRQs, which may lead to deadlocks.
>
> Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore()
> for the flush_dcache_mmap_*lock() macros instead.
>
> Cc: Russell King (Oracle) <linux@armlinux.org.uk>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: linux-arm-kernel@lists.infradead.org
> Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
From what I can tell, the behavior in aio_complete has been
there for over 10 years, since 21b40200cfe96 ("aio: use
flush_dcache_page()"). Others may have done the same already
back then.
I also see you sent patches for nios2 and parisc, but not
for csky, which appears to need the same thing.
Arnd
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 1/3] arm: Fix flush_dcache_page() for usage from irq context
2023-05-24 20:00 ` Arnd Bergmann
@ 2023-05-24 20:56 ` Helge Deller
2023-07-20 6:53 ` Helge Deller
1 sibling, 0 replies; 9+ messages in thread
From: Helge Deller @ 2023-05-24 20:56 UTC (permalink / raw)
To: Arnd Bergmann, Russell King, Dinh Nguyen, linux-kernel, linux-parisc
Cc: linux-arm-kernel
On 5/24/23 22:00, Arnd Bergmann wrote:
> On Wed, May 24, 2023, at 17:26, Helge Deller wrote:
>> Since at least kernel 6.1, flush_dcache_page() is called with IRQs
>> disabled, e.g. from aio_complete().
>>
>> But the current implementation for flush_dcache_page() on ARM
>> unintentionally re-enables IRQs, which may lead to deadlocks.
>>
>> Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore()
>> for the flush_dcache_mmap_*lock() macros instead.
>>
>> Cc: Russell King (Oracle) <linux@armlinux.org.uk>
>> Cc: Arnd Bergmann <arnd@arndb.de>
>> Cc: linux-arm-kernel@lists.infradead.org
>> Signed-off-by: Helge Deller <deller@gmx.de>
>
> Cc: stable@vger.kernel.org
> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Thanks!
I assume it's picked up in the arm git tree then.
> From what I can tell, the behavior in aio_complete has been
> there for over 10 years, since 21b40200cfe96 ("aio: use
> flush_dcache_page()").
Oh, then those arches are broken since then.
> Others may have done the same already back then.
>
> I also see you sent patches for nios2 and parisc, but not
> for csky, which appears to need the same thing.
csky doesn't use flush_dcache_mmap_lock() inside it's
flush_dcache_page() function, so I think it's not affected.
Helge
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 2/3] nios2: Fix flush_dcache_page() for usage from irq context
2023-05-24 15:26 ` [PATCH 2/3] nios2: " Helge Deller
@ 2023-06-13 22:39 ` Dinh Nguyen
2023-06-19 10:10 ` Helge Deller
0 siblings, 1 reply; 9+ messages in thread
From: Dinh Nguyen @ 2023-06-13 22:39 UTC (permalink / raw)
To: Helge Deller, linux, linux-kernel, linux-parisc
Hi Helge,
Thanks for the patch. Does it need a Fixes tag?
Dinh
On 5/24/23 10:26, Helge Deller wrote:
> Since at least kernel 6.1, flush_dcache_page() is called with IRQs
> disabled, e.g. from aio_complete().
>
> But the current implementation for flush_dcache_page() on NIOS2
> unintentionally re-enables IRQs, which may lead to deadlocks.
>
> Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore()
> for the flush_dcache_mmap_*lock() macros instead.
>
> Cc: Dinh Nguyen <dinguyen@kernel.org>
> Signed-off-by: Helge Deller <deller@gmx.de>
> ---
> arch/nios2/include/asm/cacheflush.h | 4 ++++
> arch/nios2/mm/cacheflush.c | 5 +++--
> 2 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/arch/nios2/include/asm/cacheflush.h b/arch/nios2/include/asm/cacheflush.h
> index d0b71dd71287..a37242662809 100644
> --- a/arch/nios2/include/asm/cacheflush.h
> +++ b/arch/nios2/include/asm/cacheflush.h
> @@ -48,5 +48,9 @@ extern void invalidate_dcache_range(unsigned long start, unsigned long end);
>
> #define flush_dcache_mmap_lock(mapping) xa_lock_irq(&mapping->i_pages)
> #define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&mapping->i_pages)
> +#define flush_dcache_mmap_lock_irqsave(mapping, flags) \
> + xa_lock_irqsave(&mapping->i_pages, flags)
> +#define flush_dcache_mmap_unlock_irqrestore(mapping, flags) \
> + xa_unlock_irqrestore(&mapping->i_pages, flags)
>
> #endif /* _ASM_NIOS2_CACHEFLUSH_H */
> diff --git a/arch/nios2/mm/cacheflush.c b/arch/nios2/mm/cacheflush.c
> index 6aa9257c3ede..35f3b599187f 100644
> --- a/arch/nios2/mm/cacheflush.c
> +++ b/arch/nios2/mm/cacheflush.c
> @@ -75,11 +75,12 @@ static void flush_aliases(struct address_space *mapping, struct page *page)
> {
> struct mm_struct *mm = current->active_mm;
> struct vm_area_struct *mpnt;
> + unsigned long flags;
> pgoff_t pgoff;
>
> pgoff = page->index;
>
> - flush_dcache_mmap_lock(mapping);
> + flush_dcache_mmap_lock_irqsave(mapping, flags);
> vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
> unsigned long offset;
>
> @@ -92,7 +93,7 @@ static void flush_aliases(struct address_space *mapping, struct page *page)
> flush_cache_page(mpnt, mpnt->vm_start + offset,
> page_to_pfn(page));
> }
> - flush_dcache_mmap_unlock(mapping);
> + flush_dcache_mmap_unlock_irqrestore(mapping, flags);
> }
>
> void flush_cache_all(void)
> --
> 2.38.1
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 2/3] nios2: Fix flush_dcache_page() for usage from irq context
2023-06-13 22:39 ` Dinh Nguyen
@ 2023-06-19 10:10 ` Helge Deller
0 siblings, 0 replies; 9+ messages in thread
From: Helge Deller @ 2023-06-19 10:10 UTC (permalink / raw)
To: Dinh Nguyen, linux, linux-kernel, linux-parisc
Hi Dinh,
On 6/14/23 00:39, Dinh Nguyen wrote:
> Thanks for the patch. Does it need a Fixes tag?
I did not add a fixes tag for the parisc or arm version.
The code was originally correct, but later patches then suddenly started
using cache flushes from irq context (e.g. 21b40200cfe96 ("aio: use
flush_dcache_page()")) which then triggers the bug.
So, it's hard to say that it fixes one specific commit.
I suggest you backport it as far as possible.
Helge
> Dinh
>
> On 5/24/23 10:26, Helge Deller wrote:
>> Since at least kernel 6.1, flush_dcache_page() is called with IRQs
>> disabled, e.g. from aio_complete().
>>
>> But the current implementation for flush_dcache_page() on NIOS2
>> unintentionally re-enables IRQs, which may lead to deadlocks.
>>
>> Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore()
>> for the flush_dcache_mmap_*lock() macros instead.
>>
>> Cc: Dinh Nguyen <dinguyen@kernel.org>
>> Signed-off-by: Helge Deller <deller@gmx.de>
>> ---
>> arch/nios2/include/asm/cacheflush.h | 4 ++++
>> arch/nios2/mm/cacheflush.c | 5 +++--
>> 2 files changed, 7 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/nios2/include/asm/cacheflush.h b/arch/nios2/include/asm/cacheflush.h
>> index d0b71dd71287..a37242662809 100644
>> --- a/arch/nios2/include/asm/cacheflush.h
>> +++ b/arch/nios2/include/asm/cacheflush.h
>> @@ -48,5 +48,9 @@ extern void invalidate_dcache_range(unsigned long start, unsigned long end);
>>
>> #define flush_dcache_mmap_lock(mapping) xa_lock_irq(&mapping->i_pages)
>> #define flush_dcache_mmap_unlock(mapping) xa_unlock_irq(&mapping->i_pages)
>> +#define flush_dcache_mmap_lock_irqsave(mapping, flags) \
>> + xa_lock_irqsave(&mapping->i_pages, flags)
>> +#define flush_dcache_mmap_unlock_irqrestore(mapping, flags) \
>> + xa_unlock_irqrestore(&mapping->i_pages, flags)
>>
>> #endif /* _ASM_NIOS2_CACHEFLUSH_H */
>> diff --git a/arch/nios2/mm/cacheflush.c b/arch/nios2/mm/cacheflush.c
>> index 6aa9257c3ede..35f3b599187f 100644
>> --- a/arch/nios2/mm/cacheflush.c
>> +++ b/arch/nios2/mm/cacheflush.c
>> @@ -75,11 +75,12 @@ static void flush_aliases(struct address_space *mapping, struct page *page)
>> {
>> struct mm_struct *mm = current->active_mm;
>> struct vm_area_struct *mpnt;
>> + unsigned long flags;
>> pgoff_t pgoff;
>>
>> pgoff = page->index;
>>
>> - flush_dcache_mmap_lock(mapping);
>> + flush_dcache_mmap_lock_irqsave(mapping, flags);
>> vma_interval_tree_foreach(mpnt, &mapping->i_mmap, pgoff, pgoff) {
>> unsigned long offset;
>>
>> @@ -92,7 +93,7 @@ static void flush_aliases(struct address_space *mapping, struct page *page)
>> flush_cache_page(mpnt, mpnt->vm_start + offset,
>> page_to_pfn(page));
>> }
>> - flush_dcache_mmap_unlock(mapping);
>> + flush_dcache_mmap_unlock_irqrestore(mapping, flags);
>> }
>>
>> void flush_cache_all(void)
>> --
>> 2.38.1
>>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH 1/3] arm: Fix flush_dcache_page() for usage from irq context
2023-05-24 20:00 ` Arnd Bergmann
2023-05-24 20:56 ` Helge Deller
@ 2023-07-20 6:53 ` Helge Deller
1 sibling, 0 replies; 9+ messages in thread
From: Helge Deller @ 2023-07-20 6:53 UTC (permalink / raw)
To: Arnd Bergmann, Russell King, Dinh Nguyen, linux-kernel, linux-parisc
Cc: linux-arm-kernel
On 5/24/23 22:00, Arnd Bergmann wrote:
> On Wed, May 24, 2023, at 17:26, Helge Deller wrote:
>> Since at least kernel 6.1, flush_dcache_page() is called with IRQs
>> disabled, e.g. from aio_complete().
>>
>> But the current implementation for flush_dcache_page() on ARM
>> unintentionally re-enables IRQs, which may lead to deadlocks.
>>
>> Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore()
>> for the flush_dcache_mmap_*lock() macros instead.
>>
>> Cc: Russell King (Oracle) <linux@armlinux.org.uk>
>> Cc: Arnd Bergmann <arnd@arndb.de>
>> Cc: linux-arm-kernel@lists.infradead.org
>> Signed-off-by: Helge Deller <deller@gmx.de>
>
> Cc: stable@vger.kernel.org
> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
>
> From what I can tell, the behavior in aio_complete has been
> there for over 10 years, since 21b40200cfe96 ("aio: use
> flush_dcache_page()"). Others may have done the same already
> back then.
gentle ping...
I think this patch hasn't been picked up yet for arm.
Helge
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2023-07-20 6:53 UTC | newest]
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2023-05-24 15:26 [PATCH 0/3] Fix flush_dcache_page() for usage from irq context on ARM, NIOS2 and PARISC Helge Deller
2023-05-24 15:26 ` [PATCH 1/3] arm: Fix flush_dcache_page() for usage from irq context Helge Deller
2023-05-24 20:00 ` Arnd Bergmann
2023-05-24 20:56 ` Helge Deller
2023-07-20 6:53 ` Helge Deller
2023-05-24 15:26 ` [PATCH 2/3] nios2: " Helge Deller
2023-06-13 22:39 ` Dinh Nguyen
2023-06-19 10:10 ` Helge Deller
2023-05-24 15:26 ` [PATCH 3/3] parisc: " Helge Deller
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