I've slightly re-organised the check to more closely match the
sequence that the kernel uses in do_mmap(). We check for both the zero
case (EINVAL) and the overflow length case (ENOMEM).
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
Cc: umarcor <1783...@bugs.launchpad.net>
---
v2
- add comment on overflow
---
linux-user/mmap.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index d0c50e4888..41e0983ce8 100644
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -391,14 +391,23 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int
prot,
}
#endif
- if (offset & ~TARGET_PAGE_MASK) {
+ if (!len) {
errno = EINVAL;
goto fail;
}
+ /* Also check for overflows... */
len = TARGET_PAGE_ALIGN(len);
- if (len == 0)
- goto the_end;
+ if (!len) {
+ errno = ENOMEM;
+ goto fail;
+ }
+
+ if (offset & ~TARGET_PAGE_MASK) {
+ errno = EINVAL;
+ goto fail;
+ }
+
real_start = start & qemu_host_page_mask;
host_offset = offset & qemu_host_page_mask;
--
2.17.1
--
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https://bugs.launchpad.net/bugs/1783362
Title:
qemu-user: mmap should return failure (MAP_FAILED, -1) instead of
success (NULL, 0) when len==0
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