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authorRichard Henderson <richard.henderson@linaro.org>2023-03-06 01:51:09 +0300
committerRichard Henderson <richard.henderson@linaro.org>2023-03-28 15:23:10 -0700
commit49840a4a098149067789255bca6894645f411036 (patch)
tree0b5cd9d9f8ef1770890352e9a58bc1e39aa89c6c /linux-user/syscall.c
parent2f7828b5729337c61e6c58466d0d78af079db42d (diff)
downloadfocaccia-qemu-49840a4a098149067789255bca6894645f411036.tar.gz
focaccia-qemu-49840a4a098149067789255bca6894645f411036.zip
accel/tcg: Pass last not end to page_set_flags
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.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1528
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'linux-user/syscall.c')
-rw-r--r--linux-user/syscall.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 27871641f4..69f740ff98 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -4595,7 +4595,7 @@ static inline abi_ulong do_shmat(CPUArchState *cpu_env,
     }
     raddr=h2g((unsigned long)host_raddr);
 
-    page_set_flags(raddr, raddr + shm_info.shm_segsz,
+    page_set_flags(raddr, raddr + shm_info.shm_segsz - 1,
                    PAGE_VALID | PAGE_RESET | PAGE_READ |
                    (shmflg & SHM_RDONLY ? 0 : PAGE_WRITE));
 
@@ -4625,7 +4625,7 @@ static inline abi_long do_shmdt(abi_ulong shmaddr)
     for (i = 0; i < N_SHM_REGIONS; ++i) {
         if (shm_regions[i].in_use && shm_regions[i].start == shmaddr) {
             shm_regions[i].in_use = false;
-            page_set_flags(shmaddr, shmaddr + shm_regions[i].size, 0);
+            page_set_flags(shmaddr, shmaddr + shm_regions[i].size - 1, 0);
             break;
         }
     }