Commit 7ab240ad authored by balrog's avatar balrog

Teach mmap to not overwrite reserved pages and fix brk return value (Richard Purdie).


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4255 c046a42c-6fe2-441c-8c8c-71466251a162
parent 662caa6f
......@@ -259,13 +259,24 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
host_start += offset - host_offset;
start = h2g(host_start);
} else {
int flg;
target_ulong addr;
if (start & ~TARGET_PAGE_MASK) {
errno = EINVAL;
return -1;
}
end = start + len;
real_end = HOST_PAGE_ALIGN(end);
for(addr = real_start; addr < real_end; addr += TARGET_PAGE_SIZE) {
flg = page_get_flags(addr);
if (flg & PAGE_RESERVED) {
errno = ENXIO;
return -1;
}
}
/* worst case: we cannot map the file because the offset is not
aligned, so we read it */
if (!(flags & MAP_ANONYMOUS) &&
......
......@@ -420,7 +420,7 @@ abi_long do_brk(abi_ulong new_brk)
if (!new_brk)
return target_brk;
if (new_brk < target_original_brk)
return -TARGET_ENOMEM;
return target_brk;
brk_page = HOST_PAGE_ALIGN(target_brk);
......@@ -435,12 +435,11 @@ abi_long do_brk(abi_ulong new_brk)
mapped_addr = get_errno(target_mmap(brk_page, new_alloc_size,
PROT_READ|PROT_WRITE,
MAP_ANON|MAP_FIXED|MAP_PRIVATE, 0, 0));
if (is_error(mapped_addr)) {
return mapped_addr;
} else {
if (!is_error(mapped_addr))
target_brk = new_brk;
return target_brk;
}
return target_brk;
}
static inline abi_long copy_from_user_fdset(fd_set *fds,
......
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