[PULL 05/15] accel/tcg: Pass last not end to page_reset_target_data

Richard Henderson posted 15 patches 2 years ago
Maintainers: Richard Henderson <richard.henderson@linaro.org>, Paolo Bonzini <pbonzini@redhat.com>, Riku Voipio <riku.voipio@iki.fi>, Warner Losh <imp@bsdimp.com>, Kyle Evans <kevans@freebsd.org>, "Alex Bennée" <alex.bennee@linaro.org>, Thomas Huth <thuth@redhat.com>, Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Yanan Wang <wangyanan55@huawei.com>, Laurent Vivier <laurent@vivier.eu>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, "Daniel P. Berrangé" <berrange@redhat.com>, Peter Xu <peterx@redhat.com>, David Hildenbrand <david@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Ilya Leoshkevich <iii@linux.ibm.com>
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[PULL 05/15] accel/tcg: Pass last not end to page_reset_target_data
Posted by Richard Henderson 2 years ago
Pass the address of the last byte to be changed, rather than
the first address past the last byte.  This avoids overflow
when the last page of the address space is involved.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/exec/cpu-all.h |  2 +-
 accel/tcg/user-exec.c  | 11 +++++------
 linux-user/mmap.c      |  2 +-
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index a2662b1e83..64cb62dc54 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -277,7 +277,7 @@ int walk_memory_regions(void *, walk_memory_regions_fn);
 
 int page_get_flags(target_ulong address);
 void page_set_flags(target_ulong start, target_ulong last, int flags);
-void page_reset_target_data(target_ulong start, target_ulong end);
+void page_reset_target_data(target_ulong start, target_ulong last);
 int page_check_range(target_ulong start, target_ulong len, int flags);
 
 /**
diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
index 035f8096b2..20b6fc2f6e 100644
--- a/accel/tcg/user-exec.c
+++ b/accel/tcg/user-exec.c
@@ -508,7 +508,7 @@ void page_set_flags(target_ulong start, target_ulong last, int flags)
     }
 
     if (!flags || reset) {
-        page_reset_target_data(start, last + 1);
+        page_reset_target_data(start, last);
         inval_tb |= pageflags_unset(start, last);
     }
     if (flags) {
@@ -814,15 +814,14 @@ typedef struct TargetPageDataNode {
 
 static IntervalTreeRoot targetdata_root;
 
-void page_reset_target_data(target_ulong start, target_ulong end)
+void page_reset_target_data(target_ulong start, target_ulong last)
 {
     IntervalTreeNode *n, *next;
-    target_ulong last;
 
     assert_memory_lock();
 
-    start = start & TARGET_PAGE_MASK;
-    last = TARGET_PAGE_ALIGN(end) - 1;
+    start &= TARGET_PAGE_MASK;
+    last |= ~TARGET_PAGE_MASK;
 
     for (n = interval_tree_iter_first(&targetdata_root, start, last),
          next = n ? interval_tree_iter_next(n, start, last) : NULL;
@@ -885,7 +884,7 @@ void *page_get_target_data(target_ulong address)
     return t->data[(page - region) >> TARGET_PAGE_BITS];
 }
 #else
-void page_reset_target_data(target_ulong start, target_ulong end) { }
+void page_reset_target_data(target_ulong start, target_ulong last) { }
 #endif /* TARGET_PAGE_DATA_SIZE */
 
 /* The softmmu versions of these helpers are in cputlb.c.  */
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index 1d07ff5d2c..995146f60d 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -946,7 +946,7 @@ abi_long target_madvise(abi_ulong start, abi_ulong len_in, int advice)
         if (can_passthrough_madvise(start, end)) {
             ret = get_errno(madvise(g2h_untagged(start), len, advice));
             if ((advice == MADV_DONTNEED) && (ret == 0)) {
-                page_reset_target_data(start, start + len);
+                page_reset_target_data(start, start + len - 1);
             }
         }
     }
-- 
2.34.1