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| author | John David Anglin <dave.anglin@bell.net> | 2022-06-18 15:14:34 +0000 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2022-06-26 12:23:15 +0200 |
| commit | e9ed22e6e5010997a2f922eef61ca797d0a2a246 (patch) | |
| tree | 0d7e7676ffe3f53fc08a57dbf7950613946b9b0f | |
| parent | d16c5c7c925658ea94689dfe4469441f7fd59f00 (diff) | |
| download | lwn-e9ed22e6e5010997a2f922eef61ca797d0a2a246.tar.gz lwn-e9ed22e6e5010997a2f922eef61ca797d0a2a246.zip | |
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 <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.18+
| -rw-r--r-- | arch/parisc/kernel/cache.c | 5 |
1 files changed, 4 insertions, 1 deletions
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; } |