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parisc: Fix flush_dcache_page() for usage from irq context

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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
Cc: stable@kernel.org # 5.18+
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Helge Deller 2023-05-24 17:07:07 +02:00
parent 6888ff04e3
commit 61e150fb31
2 changed files with 7 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
arch/parisc/include/asm/cacheflush.h
View File

@ -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)); \

5
arch/parisc/kernel/cache.c
View File

@ -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);