[PATCH for-8.0 v2 09/12] accel/tcg: Pass last not end to tb_invalidate_phys_range

From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: alex.bennee@linaro.org, philmd@linaro.org
Subject: [PATCH for-8.0 v2 09/12] accel/tcg: Pass last not end to tb_invalidate_phys_range
Date: Mon, 27 Mar 2023 14:18:21 -0700	[thread overview]
Message-ID: <20230327211824.1785547-10-richard.henderson@linaro.org> (raw)
In-Reply-To: <20230327211824.1785547-1-richard.henderson@linaro.org>

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/exec-all.h   |  2 +-
 accel/tcg/tb-maint.c      | 31 ++++++++++++++++---------------
 accel/tcg/translate-all.c |  2 +-
 accel/tcg/user-exec.c     |  2 +-
 softmmu/physmem.c         |  2 +-
 5 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index ad9eb6067b..ecded1f112 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -678,7 +678,7 @@ void tb_invalidate_phys_addr(target_ulong addr);
 void tb_invalidate_phys_addr(AddressSpace *as, hwaddr addr, MemTxAttrs attrs);
 #endif
 void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr);
-void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end);
+void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t last);
 void tb_set_jmp_target(TranslationBlock *tb, int n, uintptr_t addr);
 
 /* GETPC is the true target of the return instruction that we'll execute.  */
diff --git a/accel/tcg/tb-maint.c b/accel/tcg/tb-maint.c
index 74823ba464..cb1f806f00 100644
--- a/accel/tcg/tb-maint.c
+++ b/accel/tcg/tb-maint.c
@@ -991,11 +991,10 @@ TranslationBlock *tb_link_page(TranslationBlock *tb, tb_page_addr_t phys_pc,
  * Called with mmap_lock held for user-mode emulation.
  * NOTE: this function must not be called while a TB is running.
  */
-void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
+void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t last)
 {
     TranslationBlock *tb;
     PageForEachNext n;
-    tb_page_addr_t last = end - 1;
 
     assert_memory_lock();
 
@@ -1011,11 +1010,11 @@ void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
  */
 void tb_invalidate_phys_page(tb_page_addr_t addr)
 {
-    tb_page_addr_t start, end;
+    tb_page_addr_t start, last;
 
     start = addr & TARGET_PAGE_MASK;
-    end = start + TARGET_PAGE_SIZE;
-    tb_invalidate_phys_range(start, end);
+    last = addr | ~TARGET_PAGE_MASK;
+    tb_invalidate_phys_range(start, last);
 }
 
 /*
@@ -1169,28 +1168,30 @@ void tb_invalidate_phys_page(tb_page_addr_t addr)
 
 /*
  * Invalidate all TBs which intersect with the target physical address range
- * [start;end[. NOTE: start and end may refer to *different* physical pages.
+ * [start;last]. NOTE: start and end may refer to *different* physical pages.
  * 'is_cpu_write_access' should be true if called from a real cpu write
  * access: the virtual CPU will exit the current TB if code is modified inside
  * this TB.
  */
-void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
+void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t last)
 {
     struct page_collection *pages;
-    tb_page_addr_t next;
+    tb_page_addr_t index, index_last;
 
-    pages = page_collection_lock(start, end - 1);
-    for (next = (start & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE;
-         start < end;
-         start = next, next += TARGET_PAGE_SIZE) {
-        PageDesc *pd = page_find(start >> TARGET_PAGE_BITS);
-        tb_page_addr_t bound = MIN(next, end);
+    pages = page_collection_lock(start, last);
+
+    index_last = last >> TARGET_PAGE_BITS;
+    for (index = start >> TARGET_PAGE_BITS; index <= index_last; index++) {
+        PageDesc *pd = page_find(index);
+        tb_page_addr_t bound;
 
         if (pd == NULL) {
             continue;
         }
         assert_page_locked(pd);
-        tb_invalidate_phys_page_range__locked(pages, pd, start, bound - 1, 0);
+        bound = (index << TARGET_PAGE_BITS) | ~TARGET_PAGE_MASK;
+        bound = MIN(bound, last);
+        tb_invalidate_phys_page_range__locked(pages, pd, start, bound, 0);
     }
     page_collection_unlock(pages);
 }
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 74deb18bd0..5b13281119 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -572,7 +572,7 @@ void tb_check_watchpoint(CPUState *cpu, uintptr_t retaddr)
         cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
         addr = get_page_addr_code(env, pc);
         if (addr != -1) {
-            tb_invalidate_phys_range(addr, addr + 1);
+            tb_invalidate_phys_range(addr, addr);
         }
     }
 }
diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c
index 20b6fc2f6e..a7e0c3e2f4 100644
--- a/accel/tcg/user-exec.c
+++ b/accel/tcg/user-exec.c
@@ -516,7 +516,7 @@ void page_set_flags(target_ulong start, target_ulong last, int flags)
                                         ~(reset ? 0 : PAGE_STICKY));
     }
     if (inval_tb) {
-        tb_invalidate_phys_range(start, last + 1);
+        tb_invalidate_phys_range(start, last);
     }
 }
 
diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index e35061bba4..0e0182d9f2 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -2527,7 +2527,7 @@ static void invalidate_and_set_dirty(MemoryRegion *mr, hwaddr addr,
     }
     if (dirty_log_mask & (1 << DIRTY_MEMORY_CODE)) {
         assert(tcg_enabled());
-        tb_invalidate_phys_range(addr, addr + length);
+        tb_invalidate_phys_range(addr, addr + length - 1);
         dirty_log_mask &= ~(1 << DIRTY_MEMORY_CODE);
     }
     cpu_physical_memory_set_dirty_range(addr, length, dirty_log_mask);
-- 
2.34.1


