Messages in this thread | | | Subject | Re: [PATCHv4 0/5] Fix compatible mmap() return pointer over 4Gb | From | Dmitry Safonov <> | Date | Mon, 6 Feb 2017 19:46:55 +0300 |
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On 01/30/2017 03:04 PM, Dmitry Safonov wrote: > Changes since v3: > - fixed usage of 64-bit random mask for 32-bit mm->mmap_compat_base, > during introducing mmap_compat{_legacy,}_base > > Changes since v2: > - don't distinguish native and compat tasks by TIF_ADDR32, > introduced mmap_compat{_legacy,}_base which allows to treat them > the same > - fixed kbuild errors > > 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.
Gentle ping. Any thought on this?
> > [1]: https://marc.info/?l=linux-kernel&m=148311451525315 > [2]: https://marc.info/?l=linux-kernel&m=148415888707662 > > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: Andy Lutomirski <luto@kernel.org> > Cc: Borislav Petkov <bp@suse.de> > Cc: x86@kernel.org > Cc: linux-mm@kvack.org > > Dmitry Safonov (5): > x86/mm: split arch_mmap_rnd() on compat/native versions > x86/mm: introduce mmap{,_legacy}_base > x86/mm: fix 32-bit mmap() for 64-bit ELF > x86/mm: check in_compat_syscall() instead TIF_ADDR32 for > mmap(MAP_32BIT) > selftests/x86: add test to check compat mmap() return addr > > arch/Kconfig | 7 + > arch/x86/Kconfig | 1 + > arch/x86/include/asm/elf.h | 4 +- > arch/x86/include/asm/processor.h | 3 +- > arch/x86/kernel/sys_x86_64.c | 32 +++- > arch/x86/mm/mmap.c | 89 +++++++---- > include/linux/mm_types.h | 5 + > tools/testing/selftests/x86/Makefile | 2 +- > tools/testing/selftests/x86/test_compat_mmap.c | 208 +++++++++++++++++++++++++ > 9 files changed, 311 insertions(+), 40 deletions(-) > create mode 100644 tools/testing/selftests/x86/test_compat_mmap.c >
-- Dmitry
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