diff options
| -rw-r--r-- | linux-user/syscall.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 6bdf4e6ab4..ae08c9e538 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -797,6 +797,15 @@ abi_long do_brk(abi_ulong new_brk) MAP_ANON|MAP_PRIVATE, 0, 0)); if (mapped_addr == brk_page) { + /* Heap contents are initialized to zero, as for anonymous + * mapped pages. Technically the new pages are already + * initialized to zero since they *are* anonymous mapped + * pages, however we have to take care with the contents that + * come from the remaining part of the previous page: it may + * contains garbage data due to a previous heap usage (grown + * then shrunken). */ + memset(g2h(target_brk), 0, brk_page - target_brk); + target_brk = new_brk; brk_page = HOST_PAGE_ALIGN(target_brk); DEBUGF_BRK("%#010x (mapped_addr == brk_page)\n", target_brk); |