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@xxxxxxxxxxxxxxx
Signed-off-by: Helge Deller <deller@xxxxxx>
---
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
