From e9ed22e6e5010997a2f922eef61ca797d0a2a246 Mon Sep 17 00:00:00 2001 From: John David Anglin Date: Sat, 18 Jun 2022 15:14:34 +0000 Subject: parisc: Fix flush_anon_page on PA8800/PA8900 Anonymous pages are allocated with the shared mappings colouring, SHM_COLOUR. Since the alias boundary on machines with PA8800 and PA8900 processors is unknown, flush_user_cache_page() might not flush all mappings of a shared anonymous page. Flushing the whole data cache flushes all mappings. This won't fix all coherency issues with shared mappings but it seems to work well in practice. I haven't seen any random memory faults in almost a month on a rp3440 running as a debian buildd machine. There is a small preformance hit. Signed-off-by: John David Anglin Signed-off-by: Helge Deller Cc: stable@vger.kernel.org # v5.18+ --- arch/parisc/kernel/cache.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch/parisc') diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c index c8a11fcecf4c..a9bc578e4c52 100644 --- a/arch/parisc/kernel/cache.c +++ b/arch/parisc/kernel/cache.c @@ -722,7 +722,10 @@ void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned lon return; if (parisc_requires_coherency()) { - flush_user_cache_page(vma, vmaddr); + if (vma->vm_flags & VM_SHARED) + flush_data_cache(); + else + flush_user_cache_page(vma, vmaddr); return; } -- cgit v1.2.3