On May 6, 2019 12:20:12 AM PDT, Ingo Molnar <mi...@kernel.org> wrote: >Linus, > >Please pull the latest core-objtool-for-linus git tree from: > >git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git >core-objtool-for-linus > ># HEAD: 29da93fea3ea39ab9b12270cc6be1b70ef201c9e mm/uaccess: Use >'unsigned long' to placate UBSAN warnings on older GCC versions > >This is a series from Peter Zijlstra that adds x86 build-time uaccess >validation of SMAP to objtool, which will detect and warn about the >following uaccess API usage bugs and weirdnesses: > > call to %s() with UACCESS enabled > return with UACCESS enabled > return with UACCESS disabled from a UACCESS-safe function > recursive UACCESS enable > redundant UACCESS disable > UACCESS-safe disables UACCESS > >As it turns out not leaking uaccess permissions outside the intended >uaccess functionality is hard when the interfaces are complex and when >such bugs are mostly dormant. > >As a bonus we now also check the DF flag. We had at least one >high-profile bug in that area in the early days of Linux, and the >checking is fairly simple. The checks performed and warnings emitted >are: > > call to %s() with DF set > return with DF set > return with modified stack frame > recursive STD > redundant CLD > >It's all x86-only for now, but later on this can also be used for PAN >on >ARM and objtool is fairly cross-platform in principle. > >While all warnings emitted by this new checking facility that got >reported to us were fixed, there might be GCC version dependent >warnings >that were not reported yet - which we'll address, should they trigger. > >The warnings are non-fatal build warnings. > > Thanks, > > Ingo > >------------------> >Josh Poimboeuf (1): > tracing: Improve "if" macro code generation > >Peter Zijlstra (26): > sched/x86: Save [ER]FLAGS on context switch > x86/ia32: Fix ia32_restore_sigcontext() AC leak > i915, uaccess: Fix redundant CLAC > x86/uaccess: Move copy_user_handle_tail() into asm > x86/uaccess: Fix up the fixup > x86/nospec, objtool: Introduce ANNOTATE_IGNORE_ALTERNATIVE > x86/uaccess, xen: Suppress SMAP warnings > x86/uaccess: Always inline user_access_begin() > x86/uaccess, signal: Fix AC=1 bloat > x86/uaccess: Introduce user_access_{save,restore}() > x86/smap: Ditch __stringify() > x86/uaccess, kasan: Fix KASAN vs SMAP > x86/uaccess, ubsan: Fix UBSAN vs. SMAP > x86/uaccess, ftrace: Fix ftrace_likely_update() vs. SMAP > x86/uaccess, kcov: Disable stack protector > objtool: Set insn->func for alternatives > objtool: Handle function aliases > objtool: Rewrite add_ignores() > objtool: Add --backtrace support > objtool: Rewrite alt->skip_orig > objtool: Fix sibling call detection > objtool: Add UACCESS validation > objtool: Add Direction Flag validation > sched/x86_64: Don't save flags on context switch >x86/uaccess: Dont leak the AC flag into __put_user() argument >evaluation >mm/uaccess: Use 'unsigned long' to placate UBSAN warnings on older GCC >versions > > > arch/x86/entry/entry_32.S | 2 + > arch/x86/ia32/ia32_signal.c | 29 ++- > arch/x86/include/asm/alternative-asm.h | 11 + > arch/x86/include/asm/alternative.h | 10 + > arch/x86/include/asm/asm.h | 24 -- > arch/x86/include/asm/nospec-branch.h | 28 +- > arch/x86/include/asm/smap.h | 37 ++- > arch/x86/include/asm/switch_to.h | 1 + > arch/x86/include/asm/uaccess.h | 12 +- > arch/x86/include/asm/uaccess_64.h | 3 - > arch/x86/include/asm/xen/hypercall.h | 24 +- > arch/x86/kernel/process_32.c | 7 + > arch/x86/kernel/process_64.c | 1 + > arch/x86/kernel/signal.c | 29 ++- > arch/x86/lib/copy_user_64.S | 48 ++++ > arch/x86/lib/memcpy_64.S | 3 +- > arch/x86/lib/usercopy_64.c | 20 -- > drivers/gpu/drm/i915/i915_gem_execbuffer.c | 6 +- > include/linux/compiler.h | 2 +- > include/linux/uaccess.h | 2 + > kernel/Makefile | 1 + > kernel/trace/trace_branch.c | 4 + > lib/Makefile | 1 + > lib/strncpy_from_user.c | 5 +- > lib/strnlen_user.c | 4 +- > lib/ubsan.c | 4 + > mm/kasan/Makefile | 3 + > mm/kasan/common.c | 10 + > mm/kasan/report.c | 3 +- > scripts/Makefile.build | 3 + > tools/objtool/arch.h | 8 +- > tools/objtool/arch/x86/decode.c | 21 +- > tools/objtool/builtin-check.c | 4 +- > tools/objtool/builtin.h | 2 +- >tools/objtool/check.c | 400 >++++++++++++++++++++++------- > tools/objtool/check.h | 4 +- > tools/objtool/elf.c | 15 +- > tools/objtool/elf.h | 3 +- > tools/objtool/special.c | 18 ++ > tools/objtool/special.h | 1 + > tools/objtool/warn.h | 8 + > 41 files changed, 602 insertions(+), 219 deletions(-)
Superb work. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.