Kirill, can you take a careful look at this series? I bet you're going to run into this stuff too. On Mon, Jan 16, 2017 at 4:33 AM, Dmitry Safonov <dsafonov@xxxxxxxxxxxxx> wrote: > Changes since v1: > - Recalculate mmap_base instead of using max possible virtual address > for compat/native syscall. That will make policy for allocation the > same in 32-bit binaries and in 32-bit syscalls in 64-bit binaries. > I need this because sys_mmap() in restored 32-bit process shouldn't > hit the stack area. > - Fixed mmap() with MAP_32BIT flag in the same usecases > - used in_compat_syscall() helper rather TS_COMPAT check (Andy noticed) > - introduced find_top() helper as suggested by Andy to simplify code > - fixed test error-handeling: it checked the result of sys_mmap() with > MMAP_FAILED, which is not correct, as it calls raw syscall - now > checks return value to be aligned to PAGE_SIZE. > > Description from v1 [2]: > > A fix for bug in mmap() that I referenced in [1]. > Also selftest for it. > > I would like to mark the fix as for stable v4.9 kernel if it'll > be accepted, as I try to support compatible 32-bit C/R > after v4.9 and working compatible mmap() is really wanted there. > > [1]: https://marc.info/?l=linux-kernel&m=148311451525315 > [2]: https://marc.info/?l=linux-kernel&m=148415888707662 > > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> > Cc: Andy Lutomirski <luto@xxxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxx> > Cc: x86@xxxxxxxxxx > Cc: linux-mm@xxxxxxxxx > > Dmitry Safonov (5): > x86/mm: split arch_mmap_rnd() on compat/native versions > x86/mm: introduce mmap_{,legacy}_base > x86/mm: fix native mmap() in compat bins and vice-versa > x86/mm: for MAP_32BIT check in_compat_syscall() instead TIF_ADDR32 > selftests/x86: add test to check compat mmap() return addr > > arch/x86/include/asm/elf.h | 14 +- > arch/x86/include/asm/processor.h | 2 +- > arch/x86/kernel/sys_x86_64.c | 48 +++++- > arch/x86/mm/hugetlbpage.c | 2 +- > arch/x86/mm/mmap.c | 56 ++++--- > tools/testing/selftests/x86/Makefile | 2 +- > tools/testing/selftests/x86/test_compat_mmap.c | 208 +++++++++++++++++++++++++ > 7 files changed, 301 insertions(+), 31 deletions(-) > create mode 100644 tools/testing/selftests/x86/test_compat_mmap.c > > -- > 2.11.0 > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>