This is a note to let you know that I've just added the patch titled
parisc: Fix flush_dcache_page() for usage from irq context
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
parisc-fix-flush_dcache_page-for-usage-from-irq-context.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 61e150fb310729c98227a5edf6e4a3619edc3702 Mon Sep 17 00:00:00 2001
From: Helge Deller <deller@xxxxxx>
Date: Wed, 24 May 2023 17:07:07 +0200
Subject: parisc: Fix flush_dcache_page() for usage from irq context
From: Helge Deller <deller@xxxxxx>
commit 61e150fb310729c98227a5edf6e4a3619edc3702 upstream.
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
Cc: stable@xxxxxxxxxx # 5.18+
Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/parisc/include/asm/cacheflush.h | 5 +++++
arch/parisc/kernel/cache.c | 5 +++--
2 files changed, 8 insertions(+), 2 deletions(-)
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -53,6 +53,11 @@ extern void flush_dcache_page(struct pag
#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)); \
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -324,6 +324,7 @@ void flush_dcache_page(struct page *page
struct vm_area_struct *mpnt;
unsigned long offset;
unsigned long addr, old_addr = 0;
+ unsigned long flags;
pgoff_t pgoff;
if (mapping && !mapping_mapped(mapping)) {
@@ -343,7 +344,7 @@ void flush_dcache_page(struct page *page
* declared as MAP_PRIVATE or MAP_SHARED), so we only need
* to flush one address here for them all to become coherent */
- 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;
@@ -366,7 +367,7 @@ void flush_dcache_page(struct page *page
old_addr = addr;
}
}
- flush_dcache_mmap_unlock(mapping);
+ flush_dcache_mmap_unlock_irqrestore(mapping, flags);
}
EXPORT_SYMBOL(flush_dcache_page);
Patches currently in stable-queue which might be from deller@xxxxxx are
queue-5.15/parisc-allow-to-reboot-machine-after-system-halt.patch
queue-5.15/parisc-handle-kgdb-breakpoints-only-in-kernel-context.patch
queue-5.15/parisc-fix-flush_dcache_page-for-usage-from-irq-context.patch
