From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
commit 950b879b7f0251317d26bae0687e72592d607532 upstream.
In commit 588a513d3425 ("arm64: Fix race condition on PG_dcache_clean
in __sync_icache_dcache()"), we found RISC-V has the same issue as the
previous arm64. The previous implementation didn't guarantee the correct
sequence of operations, which means flush_icache_all() hasn't been
called when the PG_dcache_clean was set. That would cause a risk of page
synchronization.
Fixes: 08f051eda33b ("RISC-V: Flush I$ when making a dirty page executable")
Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxx>
Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230127035306.1819561-1-guoren@xxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/riscv/mm/cacheflush.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/arch/riscv/mm/cacheflush.c
+++ b/arch/riscv/mm/cacheflush.c
@@ -71,6 +71,8 @@ void flush_icache_pte(pte_t pte)
{
struct page *page = pte_page(pte);
- if (!test_and_set_bit(PG_dcache_clean, &page->flags))
+ if (!test_bit(PG_dcache_clean, &page->flags)) {
flush_icache_all();
+ set_bit(PG_dcache_clean, &page->flags);
+ }
}
