This is a note to let you know that I've just added the patch titled
openrisc: Fix pagewalk usage in arch_dma_{clear, set}_uncached
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:
openrisc-fix-pagewalk-usage-in-arch_dma_-clear-set-_.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.
commit 89e6f0e2c56eb4a9460a921e5f3e9a0b3c506427
Author: Jann Horn <jannh@xxxxxxxxxx>
Date: Thu Oct 6 20:33:01 2022 +0200
openrisc: Fix pagewalk usage in arch_dma_{clear, set}_uncached
[ Upstream commit 28148a17c988b614534f457da86893f83664ad43 ]
Since commit 8782fb61cc848 ("mm: pagewalk: Fix race between unmap and page
walker"), walk_page_range() on kernel ranges won't work anymore,
walk_page_range_novma() must be used instead.
Note: I don't have an openrisc development setup, so this is completely
untested.
Fixes: 8782fb61cc848 ("mm: pagewalk: Fix race between unmap and page walker")
Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
Signed-off-by: Stafford Horne <shorne@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c
index a82b2caaa560d..b3edbb33b621d 100644
--- a/arch/openrisc/kernel/dma.c
+++ b/arch/openrisc/kernel/dma.c
@@ -74,10 +74,10 @@ void *arch_dma_set_uncached(void *cpu_addr, size_t size)
* We need to iterate through the pages, clearing the dcache for
* them and setting the cache-inhibit bit.
*/
- mmap_read_lock(&init_mm);
- error = walk_page_range(&init_mm, va, va + size, &set_nocache_walk_ops,
- NULL);
- mmap_read_unlock(&init_mm);
+ mmap_write_lock(&init_mm);
+ error = walk_page_range_novma(&init_mm, va, va + size,
+ &set_nocache_walk_ops, NULL, NULL);
+ mmap_write_unlock(&init_mm);
if (error)
return ERR_PTR(error);
@@ -88,11 +88,11 @@ void arch_dma_clear_uncached(void *cpu_addr, size_t size)
{
unsigned long va = (unsigned long)cpu_addr;
- mmap_read_lock(&init_mm);
+ mmap_write_lock(&init_mm);
/* walk_page_range shouldn't be able to fail here */
- WARN_ON(walk_page_range(&init_mm, va, va + size,
- &clear_nocache_walk_ops, NULL));
- mmap_read_unlock(&init_mm);
+ WARN_ON(walk_page_range_novma(&init_mm, va, va + size,
+ &clear_nocache_walk_ops, NULL, NULL));
+ mmap_write_unlock(&init_mm);
}
void arch_sync_dma_for_device(phys_addr_t addr, size_t size,
