From 7db15418d390cf878d7c77ae08a4ad39f1534bc5 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Tue, 22 Aug 2023 16:27:49 +0200 Subject: [PATCH] nios2: fix flush_dcache_page() for usage from irq context 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. Link: https://lkml.kernel.org/r/ZOTF5WWURQNH9+iw@p100 Signed-off-by: Helge Deller Cc: Dinh Nguyen Signed-off-by: Andrew Morton --- 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 7c48c5213fb7..348cea097792 100644 --- a/arch/nios2/include/asm/cacheflush.h +++ b/arch/nios2/include/asm/cacheflush.h @@ -52,5 +52,9 @@ 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 28b805f465a8..0ee9c5f02e08 100644 --- a/arch/nios2/mm/cacheflush.c +++ b/arch/nios2/mm/cacheflush.c @@ -75,12 +75,13 @@ static void flush_aliases(struct address_space *mapping, struct folio *folio) { struct mm_struct *mm = current->active_mm; struct vm_area_struct *vma; + unsigned long flags; pgoff_t pgoff; unsigned long nr = folio_nr_pages(folio); pgoff = folio->index; - flush_dcache_mmap_lock(mapping); + flush_dcache_mmap_lock_irqsave(mapping, flags); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff + nr - 1) { unsigned long start; @@ -92,7 +93,7 @@ static void flush_aliases(struct address_space *mapping, struct folio *folio) start = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); flush_cache_range(vma, start, start + nr * PAGE_SIZE); } - flush_dcache_mmap_unlock(mapping); + flush_dcache_mmap_unlock_irqrestore(mapping, flags); } void flush_cache_all(void)