Will do, thanks! On Thu, 26 Jul 2018 at 19:12, Laurent Vivier <laur...@vivier.eu> wrote:
> Le 26/07/2018 à 19:58, Alex Bennée a écrit : > > > > Laurent Vivier <laur...@vivier.eu> writes: > > > >> Le 26/07/2018 à 15:29, Alex Bennée a écrit: > >>> I've slightly re-organised the check to more closely match the > >>> sequence that the kernel uses in do_mmap(). > >>> > >>> Signed-off-by: Alex Bennée <alex.ben...@linaro.org> > >>> Cc: umarcor <1783...@bugs.launchpad.net> > >>> --- > >>> linux-user/mmap.c | 14 +++++++++++--- > >>> 1 file changed, 11 insertions(+), 3 deletions(-) > >>> > >>> diff --git a/linux-user/mmap.c b/linux-user/mmap.c > >>> index d0c50e4888..3ef69fa2d0 100644 > >>> --- a/linux-user/mmap.c > >>> +++ b/linux-user/mmap.c > >>> @@ -391,14 +391,22 @@ abi_long target_mmap(abi_ulong start, abi_ulong > len, int prot, > >>> } > >>> #endif > >>> > >>> - if (offset & ~TARGET_PAGE_MASK) { > >>> + if (!len) { > >>> errno = EINVAL; > >>> goto fail; > >>> } > >>> > >>> len = TARGET_PAGE_ALIGN(len); > >>> - if (len == 0) > >>> - goto the_end; > >>> + if (!len) { > >>> + errno = EINVAL; > >>> + goto fail; > >>> + } > >> > >> Why do you check twice len? > >> TARGET_PAGE_ALIGN() rounds up the value, so if it was not 0, it cannot > >> be now. > > > > I was trying to follow the kernel style but I realise TARGET_PAGE_ALIGN > > might be a different test compared to the kernel's PAGE_ALIGN(len) for > > overflows: > ... > > /* Careful about overflows.. */ > > len = PAGE_ALIGN(len); > > if (!len) > > return -ENOMEM; > > > > > OK, so keep it but you should use ENOMEM, not EINVAL (and add a comment :) > ) > > Thanks, > Laurent > -- Alex Bennée KVM/QEMU Hacker for Linaro