linux-user: Fix stale tbs after mmap

If we execute linux-user code that does the following:

  * A = mmap()
  * execute code in A
  * munmap(A)
  * B = mmap(), but mmap returns the same address as A
  * execute code in B

we end up executing a stale cached tb that contains translated code
from A, while we want new code from B.

This patch adds a TB flush for mmap'ed regions, before we return them,
avoiding the whole issue. It also adds a flush for munmap, so that we
don't execute stale TBs instead of getting a segfault.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Riku Voipio <riku.voipio@linaro.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 7125d1cd4..d9468fea9 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -573,6 +573,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
     page_dump(stdout);
     printf("\n");
 #endif
+    tb_invalidate_phys_range(start, start + len, 0);
     mmap_unlock();
     return start;
 fail:
@@ -675,8 +676,10 @@ int target_munmap(abi_ulong start, abi_ulong len)
         }
     }
 
-    if (ret == 0)
+    if (ret == 0) {
         page_set_flags(start, start + len, 0);
+        tb_invalidate_phys_range(start, start + len, 0);
+    }
     mmap_unlock();
     return ret;
 }
@@ -754,6 +757,7 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
         page_set_flags(old_addr, old_addr + old_size, 0);
         page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID);
     }
+    tb_invalidate_phys_range(new_addr, new_addr + new_size, 0);
     mmap_unlock();
     return new_addr;
 }