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

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git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4255 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
balrog 2008-04-26 12:17:34 +00:00
parent 662caa6f91
commit 7ab240ad4b
2 changed files with 17 additions and 7 deletions
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13
linux-user/mmap.c
View file

@ -259,13 +259,24 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
host_start += offset - host_offset; host_start += offset - host_offset;
start = h2g(host_start); start = h2g(host_start);
} else { } else {
int flg;
target_ulong addr;
if (start & ~TARGET_PAGE_MASK) { if (start & ~TARGET_PAGE_MASK) {
errno = EINVAL; errno = EINVAL;
return -1; return -1;
} }
end = start + len; end = start + len;
real_end = HOST_PAGE_ALIGN(end); 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 /* worst case: we cannot map the file because the offset is not
aligned, so we read it */ aligned, so we read it */
if (!(flags & MAP_ANONYMOUS) && if (!(flags & MAP_ANONYMOUS) &&

11
linux-user/syscall.c
View file

@ -420,7 +420,7 @@ abi_long do_brk(abi_ulong new_brk)
if (!new_brk) if (!new_brk)
return target_brk; return target_brk;
if (new_brk < target_original_brk) if (new_brk < target_original_brk)
return -TARGET_ENOMEM; return target_brk;
brk_page = HOST_PAGE_ALIGN(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, mapped_addr = get_errno(target_mmap(brk_page, new_alloc_size,
PROT_READ|PROT_WRITE, PROT_READ|PROT_WRITE,
MAP_ANON|MAP_FIXED|MAP_PRIVATE, 0, 0)); MAP_ANON|MAP_FIXED|MAP_PRIVATE, 0, 0));
if (is_error(mapped_addr)) {
return mapped_addr; if (!is_error(mapped_addr))
} else {
target_brk = new_brk; target_brk = new_brk;
return target_brk;
} return target_brk;
} }
static inline abi_long copy_from_user_fdset(fd_set *fds, static inline abi_long copy_from_user_fdset(fd_set *fds,